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AA-HD95A-TK

December 1987

575 pages

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Document:	VAXmate Technical Reference Manual Volume 2 Feb1987
Order Number:	AA-HD95A-TK
Revision:
Pages:	575
Original Filename:	http://bitsavers.org/pdf/dec/vaxmate/AA-HD95A-TK_VAXmate_Technical_Reference_Manual_Volume_2_Feb1987.pdf

OCR Text

AA-H D95A-TK

Technical
Reference Manual
Volume 2

DECLIT
I~A

CF:OSS
HD~5~~

~D~DD~D

wore

nzate

Technical
Reference Manual
Volume 2

First Printing, February 1987
© Digital Equipment Corporation 1987. All Rights Reserved.
The material in this document is for informational purposes and is subject to change
without notice; it should not be construed as a commitment by Digital Equipment
Corporation. Digital Equipment Corporation assumes no responsibility for any errors
that may appear in this document.
Digital Equipment Corporation assumes no responsibility for the use or reliability of its
software on equipment that is not supplied by Digital.
MS-DOS, MS-WINDOWS, and MS-NET are trademarks of Microsoft Corporation.
Topview is a trademark of International Business Corporation.
Motorola is a registered trademark of Motorola, Inc.
IBM PC AT is a trademark of International Business Machines Corporation.
The following are trademarks of Digital Equipment Corporation.

mamalla

DEC
DECmate
DECnet
DECsystem-10
DECSYSTEM-20
DECUS
DECwriter
DIBOL
EduSystem

Printed in U.S.A.

lAS

MASSBUS
MicroPDP
MicroVAX
MINC-ll
OMNIBUS
OS/8
PDP
PDT
P/OS

Professional
Rainbow
RSTS
RSX
ThinWire
VAX
VAXmate
VMS
VT

Work Processor

Contents

Preface ....

xxxiii

VOLUME 1
Chapter 1 VAXmate Workstation Overview.

1-1

Base System . . . . .
Optional Components . . . . . . . . . . .

1-1
1-3

Chapter 2 VAXmate Microprocessor.

2-1
2-1
2-1
2-1
2-2
2-2

Overview . . . . . . . . . . . . . . . . . . .
Real Address Mode . . . . . . . . . .
Protected Virtual Address Mode. . .
Coprocessor. . . . . . . . . . . . .
Additional Sources of Information . . .
Memory Map . . . . . . . . .
Input/Output Address Map .
Interrupt Vector Map . . . .
Bus Timing and Structure ..
Expansion Box Technical Specifications
Expansion Box Operating Ranges . . .

Chapter 3 Interrupt Controllers
Overview . . . . . . . . . . . . . . .
Additional Source of Information.
Read/Write Control .. . . . . . .

2-3
2-4

2-6
2-9

2-10
2-10

3-1
3-1
3-3

3-3

Contents iii

Initialization Command Words . . .
Initialization Command Word 1
Initialization Command Word 2
Initialization Command Word 3
ICW3 (Master) . . . . . . .
ICW3 (Slave) . . . . . . . .
Initialization Command Word 4
Operation Command Words . . . .
Operation Command Word 1 .
Operation Command Word 2.
Priority Rotation. . . . . . . .
Operation Command Word 3 .
Interrupt Request and In-Service Registers
Interrupt Request Register
In-Service Register
Poll Command . . . . .
Poll Data Register
Interrupt Sequence. . . . .
Programming Example . .
Constant Values and Data Structures.
Initialization Data . . . . . . . . . . . .
Initializing the Peripheral Interrupt Controller
Issuing an End-of-Interrupt Command.
Masking Interrupts . . . . . . . . . . . .

Chapter 4 DMA Controller.
Overview . . . . . . . . . . . .
Additional Source of Information.
Operation ... .
Idle Cycle . . . . . . . . . .
Active Cycle . . . . . . . .
Single Transfer Mode.
Block Transfer Mode .
Demand Transfer Mode
Cascade Mode .
Data Transfers . .
Auto-Initialize .
Priority . . . . .
Address Generation.
iv Contents

3-f

3-,r
3-~

3-!
3-!
3-!

3-I(
3-1:
3-1:
3-1!
3-1:
3-1~

3-1j
3-1j
3-1j
3-1'
3-1'
3-1:

3-2
3-2.
3-2
3-2
3-2
3-2
444-

4444-

4·
4·
4·
4·
4·
4·

4·

Registers . . . . . . . . . . . . . . . . . . .
Base and Current Address Register.
Base and Current Word Register ..
Command Register ..
... . .
Write Single Mask Bit.
Write All Mask Bits.
Mode Register ..
Request Register. . .
Status Register. . . .
Temporary Register.
Programming Example
Constant Values . . .
Data Structures ...
Initializing the DMA Controller.
Opening a DMA Channel . . . . .
Preparing a Channel for Data Transfer .
Disabling a DMA Channel . . . . . . . .

Chapter 5 Real-Time Clock and CMOS RAM.
Overview . . . . . . . . . . . . . . .
Additional Source of Information.
Battery-Backup Considerations ..
Addressing the Real-Time Clock.
Real-Time Clock Registers
Register A.
Register B.
Register C.
Register D
Real-Time Clock Data Registers.
Alarms . . . .
Update Cycle . . . . . . . . .
Interrupts . . . . . . . . . . .
Urdate-Ended Interrupt
Alarm Interrupt . .
Programming Example
Constant Values . .
Data Structures . .
Reading the Registers and RAM.
Writing the Registers and RAM.
Calculating the Checksum . . .
Converting Binary-Coded Data.
Reading the Date. . . . . . . . .

4-7
4-7
4-8
4-9

4-11
4-11
4-12
4-13
4-14
4-14
4-16
4-16
4-17
4-18
4-19
4-20
4-22
6-1
6-1
6-2
6-2
6-2
6-3

5-4
5-6
6-8

5-9
5-10
5-12
5-13
5-14
5-14
5-14
5-15
5-16
5-18
5-20
5-21
5-22
5-23
5-24

Contents v

Reading the Time . ..
. . . . . . . . . .
Displaying the Date ..
... . . . . . . .
Displaying the Time. .
.. . . . . . .
Displaying the Diskette Drive Type. . . . .
Displaying the Hard Disk Type . . . . . . . .
Handling the Clock Interrupts . .
... . . . . . . . . .
Interpreting the RAM Contents .
. . . . . . . . . . . .
Initializing the Real-Time Clock .
... . . . . . . . . .
Restoring the Interrupt Vectors.
Real-Time Clock Example . . . . . . . . . . . . . . . .

Chapter 6 Three-Channel Counter and Speaker . . .
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Additional Source ofInformation. . . . . . . . . . . . . . .
Block Diagram . . . .
. . . . . . . . . . . . . . . . .
Counter Description . . . . . . . . . . . . . . . . . . . . . . . .
Mode Definitions . . . . . . . . . . . . . . . .
Mode 0 (Interrupt on Terminal Count) . . . . . . . . .
Initializing Mode 0 . . . . . . . . . . . . . . . . . .
Mode 0 Cycle. . . . . . . . . . . . . . . . . . . . . .
Mode 1 {Hardware Retriggerable One-Shot) . . . . . .
Initializing Mode 1 . . . . . . . . . . . . . . . . . .
Mode 1 Cycle. . . . . . . . . . . . . . . . . . . . . .
Mode 2 {Rate Generator) . . . . . . . . . . .. . . . . .
Initializing Mode 2 . . .
Mode 2 Cycle . . . . . . .
Mode 3 {Square Wave Mode) ...
Initializing Mode 3 . . . . . .
Mode 3 Cycle . . . . . . . . . .
Mode 4 {Software Triggered Strobe) . . . . . .
Initializing Mode 4 . . . . . . . . . . . . .
Mode 4 Cycle. . . . . . . . . . . . . . . . . . . . . . . .
Mode 5 (Hardware Triggered Strobe) . . . . . . . . . . . .
Initializing Mode 5
. . . . .
Mode 5 Cycle.
Registers. . . . . . . . . . .
. ....
System Register . . . .
. . . . .
Control Word Register
...... .
Counter-Latch Command (Control Word Register) ..
Read-Back Command (Control Word Register) ..
Status Response (Read-back Command) . . . . . . . .
vi Contents

5-2f
5-2(
5-2~

5-2f
5-2~

5-3(
5-3:
5-35-31
5-3f

6-:
6-:
6-:
6-,'

6-:
6-:
6-,
6-·
6-,
6-·
6-·
6-·
6-:
666666-

66666-

6·
66-1
6-1
6-1
6-1

Programming Example
Constant Values . .
Writing a Counter.
Making a Bell Sound .
Counter and Speaker Example.

6-16
6-16
6-18
6-18
6-20

Chapter 7 Video Controller. . . . .

7-1
7-1
7-1
7-2
7-2
7-2
7-3
7-4
7-5
7-6
7-6
7-7
7-8
7-9
7-10
7-10
7-18
7-22
7-23
7-25
7-25
7-25
7-28
7-28
7-29
7-29
7-30
7-30
7-31
7-31
7-32
7-33
7-33
7-34
7-34
7-34

Introduction. . . . . . . . . . . . . .
Industry-Standard Text and Graphics Features.
Enhancements to Industry-Standard Features
Industry-Standard Features Not Available
Extra Features . . . . . . . . .
Block Diagram . . . . . . . . . . . .
Additional Sources of Information .
Video Modes . . . . . . . . . .
Text Modes . . . . . . . . . . . . . .
Character Buffer Format . . . .
Character Position to Memory Location Mapping
Programmable Cursor . . . . . . . . . . . . . . . .
Programmable Character Generator (Font RAM) .
Graphics Mode . . . . . . . . . . . . .
Mapping the Display to Address
Video Look-Up Table . . . . .
Video System Registers . . . .
Special Purpose Register.
CRTC Registers ..
Index Register.
Data Register
Register RO
Register Rl
Register R2
Register R3
Register R4
Register R5
Register R6
Register R7
Register R8
Register R9
Register RIO
Register Rll
Register R12
Register R13

Contents vii

Register R14
Register R15
Register R16
Register R17
Status Register A .
Status Register B . . .
Write Data Register ..
Color Select Register .
Control Register A.
Control Register B. . .
Monitor Interface . . . . .
Monitor Specification Summary.
Programming Example . . . . . . . .

Chapter 8 Keyboard-Interface Controller and Keyboard.
Introduction. . . . . . . . . . . . . . .
Keyboard-Interface Controller . . . . .
Physical Interface to the CPU . . .
Physical Interface to the Keyboard
Logical Interface. . . . . . . . . . . .
Control Functions . . . . . . . . . . .
Keyboard-Interface Controller Diagnostics.
Keyboard-Interface Controller Registers
Data Register. . . .
Command Register
Status Register. . .
Command Register
Read Command Byte .
Write Command Byte.
Self-Test . . . . .
Interface Test . .
Disable Keyboard
Enable Keyboard
Read Port 1.
Read Port 1.
Read Port 2.
Write Port 2
Read Test Inputs .
Write Status Register.
Pulse Output Port. . .
Keyboard-Interface Controller Error Handling.
viii

Contents

7-35
7-35
7-36
7-36
7-37
7-38
7-39
7-39
7-41
7-43
7-44
7-44
7-45
8-1
8-1
8-1
8-1
8-2
8-2
8-3
8-4
8-5
8-5
8-5
8-6
8-9
8-10
8-10
8-12
8-12
8-12
8-12
8-12
8-12
8-13
8-13
8-13
8-13
8-13
8-14

LK250 Keyboard . . . . . . . . . . . . .
Scan Codes . . . . . . . . . . . . . .
LK250 Keyboard Command Codes
Invalid Commands . . . . . . "
. . . . . . . .
Request Keyboard 10. . . . . ..
. . . . . . . .
Enter DIGITAL Extended Scan Code Mode... .
Exit DIGITAL Extended Scan Code Mode ... .
Set Keyboard LED. .
. .... .
Reset Keyboard LED. . . .
. .... .
Set Keyclick Volume . . . .
. . . . . . . . . . . .
Enable Autorepeat. . . . .
. . . . . . . . . . . . . . .
Disable Autorepeat . . .
Keyboard Mode Lock . .
Keyboard Mode Unlock.
Reserved ...
LEOs On/Off .
Echo . . . . . .
Reserved .. .
Set Autorepeat Delay and Rate .
Enable Key Scanning . . . . . . .
Disable Key Scanning and Restore to Defaults . .
Restore To Defaults.
Reserved.
Resend . . . . . . . .
Reset . . . . . . . . .
LK250 Keyboard Responses
Buffer overrun. . .
Self-test success. .
ECHO . . . . . . . .
Release Prefix . . . .
Acknowledge (ACK} .
Self-Test Failure. . .
Resend . . . . . . . .
LK250 Keyboard Error Handling .
U.S. and Foreign Keyboards.
Programming Example . . . . . . . . .

Chapter 9 Serial Communications. .
Overview . . . . . . . . . . . . . . . . . .

8-15
8-15
8-22
8-23
8-23
8-23
8-23
8-23
8-24
8-24
8-24
8-24
8-25
8-25
8-25
8-26
8-26
8-26
8-27
8-28
8-28
8-28
8-29
8-29
8-29
8-30
8-30
8-30
8-30
8-31
8-31
8-31
8-31
8-31
8-31
8-46
9-1
9-1
Contents ix

Additional Sources of Information . . . . . . . . . . . . . . .
Receive Buffer Register/Transmitter Holding Register.
Interrupt Enable Register. . . . .
Interrupt Identification Register.
Line Control Register . .
Modem Control Register
Diagnostic Loopback
Line Status Register. . .
Modem Status Register.
Divisor Latches. . . . . .
Modem Control Programming Exceptions
Special Purpose Register . . . . .
Communications Connector Signals .
Printer Connector Signals.
Modem Connector Signals.
Programming Example.
Program Description .

Chapter 10 Mouse Information.
Introduction. . . . . . . . . . . . .
Communication Requirements . .
Additional Source of Information.
Mouse Commands . . . . . . . . .
Prompt Mode Incremental Stream Mode.
Request Mouse Position. . .
Invoke Self-Test . . . . . . .
Vendor Reserved Function .
Mouse Reports . . . . . . . .
Position Report - Byte 1.
Position Report - Byte 2.
Position Report - Byte 3.
Self-Test Report - Byte 1 .
Self-Test Report - Byte 2 .
Self-Test Report - Byte 3 .
Self-Test Report - Byte 4 .
Serial Interface . . . . . . . . .
Transmit Holding Register and Receive Buffer
Status Register.
Mode Register 1 . .
Mode Register 2 . .
Command Register
Programming Example
x

Contents

9-1
9-3
9-4
9-6

9-7
9-9
9-10
9-11
9-13
9-15
9-17
9-18
9-19
9-20
9-21
9-22
9-23
10-1
10-1
10-2
10-2
10-2
10-3
10-3
10-3
10-3
10-4
10-4
10-5
10-5
10-6
10-€
10-';
10-';
10-t
10-t
10-~

10-l(
10-11
1O-1!

10-1·

Chapter 11 Diskette Drive Controller
Introduction. . . . . . . . . . . . . . .
Diskette Drive Controller Registers .
Control Register . . . .
Main Status Register . . . . .
Data Register. . . . . . . . . .
Data Transfer Rate Register .
Change Register . . . . . . . .
Diskette Drive Controller Internal Registers .
Internal Register - Command. . . . . .
Internal Register - Head/Unit Select .
Internal Register - Status Register 0 .
Internal Register - Status Register 1
Internal Register - Status Register 2
Internal Register - Status Register 3
Internal Register - SRT/HUT
Internal Register - HLT/ND
Internal Register - C.
Internal Register - H.
Internal Register - R.
Internal Register - N
Internal Register - EOT .
Internal Register - GPL.
Internal Register - DTL
Internal Register - SC ..
Internal Register - D. . .
Internal Register - STP .
Internal Register - PCN.
Internal Registers - NCN .
Diskette Drive Controller Programming
Command State
Execution State . . . . . . . . . . . .
Result State . . . . . . . . . . . . . .
Command and Result Register Sets.
Programming Example . . . . . . . . . .

11-1
11-1
11-2
11-3
11-4
11-5
11-6
11-6
11-7
11-7
11-8
11-9
11-10
11-12
11-13
11-14
11-15
11-15
11-15
11-15
11-16
11-16
11-16
11-16
11-16
11-17
11-17
11-17
11-17
11-18
11-18
11-20
11-20
11-20
11-27

Chapter 12 Hard Disk Drive Controller.

12-1
12-1

Introduction. . . . . . . . . . . . . . . . . . .

Contents

Hard Disk Controller Registers. . . .
Data Register. . . . . . . . . . . .
Write Precompensation Register.
Error Register . . . . . .
Sector Count Register. . . . . .
Sector Number Register . . . .
Cylinder Number Low Register
Cylinder Number High Register.
SDH Register . . . . . .
Command Register . .
Restore Command
Seek Command . .
Read Sector Command.
Write Sector Command.
Format Track Command.
Read Verify Command . .
Diagnose Command. . . .
Set Parameters Command.
Status Register. . . . . . .
Alternate Status Register.
Hard Disk Register . .
Digital Input Register.
Programming Example . .

Chapter 13 Network Hardware Interface.
Introduction to the LANCE . . . . . . . . . .
Additional Source of Information. . . . . . . .
Functional Description of the Network Hardware Interface
The Coax Transceiver Interface . . .
The Serial Interface Adapter. . . . .
The Local Area Network Controller.
Programming the LANCE . . . . . . . .
Initialization Block . . . . . . . . . .
Receive and Transmit Descriptor Rings
Data Buffers . . . . . . .
Programming Sequence .
Register Description. . . .
Register Data Port (RDP)
Register Address Port (RAP)
Control And Status Register 0 .
Control And Status Register 1 .
Control And Status Register 2 .
xii Contents

12-1
12-3
12-4
12-5
12-7
12-7
12-8
12-8
12-9
12-10
12-11
12-12
12-13
12-15
12-17
12-19
12-21
12-22
12-23
12-25
12-25
12-26
12-27
13-1
13-1
13-2
13-2
13-2
13-2
13-2
13-3
13-4
13-4
13-4
13-4
13-5
13-6
13-7
13-8
13-13
13-14

Control And Status Register 3. .
NI CSR . . . . . . .
Initialization Block. . .
Mode Field . . . . . . .
Physical Address Field
Logical Address Filter Field
Receive Descriptor Ring Pointer Field
Transmit Descriptor Ring Pointer Field
Buffer Management. . . . . .
Descriptor Rings in Memory. . . . . . .
Receive Descriptor Rings . . . . . . . . .
Receive Message Descriptor 0 (RMDO) .
Receive Message Descriptor 1 (RMD1) .
Receive Message Descriptor 2 (RMD2) .
Receive Message Descriptor 3 (RMD3) .
Transmit Descriptor Ring . . . . . . . . .
Transmit Message Descriptor 0 (TMDO) .
Transmit Message Descriptor 1 (TMD1) .
Transmit Message Descriptor 2 (TMD2) .
Transmit Message Descriptor 3 (TMD3) .
Network Interface External Interconnect
Network Interface System Bus Interconnect.

13-15
13-17
13-18
13-19
13-22
13-22
13-23
13-25
13-27
13-28
13-29
13-29
13-30
13-32
13-33
13-34
13-34
13-35
13-37
13-38
13-40
13-40

Index
VOLUME 2
Chapter 14 System Startup.
Overview . . . . .
Powerup Test . . . . . . . . . .
Initialization . . . . . . . .
Real Mode Versus Virtual Protected Mode .
Extended Self-Test ...
Configuration List .
Soft Reset . . . . . . . .
Hard Reset . . . . . . .
Hardware Jumper Configuration.

Chapter 15 ROM BIOS ..... .
Interrupt 02H: Nonmaskable Interrupt.
Interrupt 05H: Print Screen
Interrupt 08H: Clock Tick.
Interrupt 09H: Keyboard ..

14-1
14-1
14-1
14-9
14-9
14-10
14-11
14-12
14-13
14-14
15-1
15-3
15-4
15-5
15-5
Contents xiii

Interrupt OBH: COM2/ Modem.
. . . . . . . . . . . . . . .
Interrupt OCH: COM1/ Serial . .
. . . . . . . . . . . .
Interrupt OEH: Floppy Disk. . . .
. . . . . . . . . . . . . . .
Interrupt 10H: Video Input/Output . . . . . . . . . . . . . . . . .
Function OOH: Set Video Mode. . . . . . . . . . . . . . . . . .
Function 01H: Set Cursor Type . . . . . . . .
Function 02H: Set Cursor Position . . .
Function 03H: Read Cursor Position ..
Function 04H: Read Light-Pen Position . . . . . . . . .
Function 05H: Set Page Function. . . .
. .... .
Function 06H: Scroll Active Page Up . . . . . . . . . . . .
Function 07H: Scroll Active Page Down . . . . . . . . . . . .
Function 08H: Read Character and Attribute at Cursor
Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Function 09H: Write Character and Attribute at Cursor
Position . . . . . . . . . . . . . . . . . . . . . . . . . . .
Function OAH: Write Character at Cursor Position. . .
Function OBH: Set Color Palette
........ .
Function OCH: Write Pixel . . . . . . . . . . . . . . . . .
Function ODH: Read Pixel . . . . . . . . . . . . . . . . .
Function OEH: Write Character Using Terminal Emulation.
Function OFH: Read Current Video State . . . . . . . . . . .
Function 13H: TTY Write String . . . . . . . . . . . . . . . .
Function DOH: Enable/Disable 256 Character Graphic Font.
Function D1H: Font RAM and Color Map Support ..
Font RAM Functions . . . . . .
. . . . . .
Color Map Functions . . . . . .
Interrupt llH: Read Configuration ..
Interrupt 12H: Return Memory Size ..
Interrupt 13H: Disk Input/Output (I/O) .
Hard Disk Functions . . . . . . . .
Hard Disk Errors . . . . . . . . .
Hard Disk Parameter Tables ...
Function OOH: Initialize Entire Disk Subsystem. . . . . . . .
Function 01H: Return Status Code of Last I/O Request ...
Function 02H: Read One or More Disk Sectors . . . . . .
Function 03H: Write One Or More Disk Sectors . . . .
Function 04H: Verify One or More Disk Sectors . . . . .
Function 05H: Format a Track. . . . . . . . . . . . . . . .
Function 08H: Return Current Drive Parameters . . . . . . .
Function 09H: Initialize Drive Characteristics. . . . .
Function OAH: Read Long . . . . . . . . . . . . . . . . . . . .
xiv Contents

15-6
15-6
15-7
15-8
15-10
15-12
15-13
15-14
15-15
15-16
15-17
15-17
15-19
15-20
15-21
15-22
15-23
15-24
15-25
15-27
15-28
15-30
15-31
15-31
15-32
15-35
15-37
15-38
15-40
15-40
15-41
15-42
15-43
15-44
15-45
15-46
15-47
15-48
15-49
15-50

Function OBH: Write Long. . . . . . . . . .
Function OCH: Seek to Specific Cylinder ..
Function ODH: Hard Disk Reset.
Function 10H: Test Drive Ready. . . . . . .
Function llH: Recalibrate Drive . . . . . . .
Function 14H: Execute Controller Internal Diagnostics
Function 15H: Return Drive Type . . . . . . .
Function DOH: Read Long 256 Byte Sector.
Diskette Functions. . . . . . . .
Diskette Errors . . . . . . . . . . . . . . .
Diskette Parameter Tables. . . . . . . . .
Function OOH: Initialize Diskette Subsystem
Function 01H: Return Status Code of Last I/O Request.
Function 02H: Read One or More Track Sectors .
Function 03H: Write One or More Track Sectors.
Function 04H: Verify One or More Track Sectors.
Function 05H: Format a Track . . . . . . . .
Function 15H: Return Drive Type . . . . . . . . . .
Function 16H: Return Change Line Status . . . . .
Function 17H: Set Drive and Media Type for Format
Interrupt 14H: Asynchronous Communications.
Function OOH: Initialize Asynchronous Port .
Function 01H: Transmit Character.
Buffer Mode Enabled . . . . . .
Function 02H: Receive Character ..
Buffer Mode Enabled . . . . . . .
Function 03H: Return Asynchronous Port Status.
Buffer Mode Enabled . . . . .
Function DOH: Extended Mode .
Buffering Enabled. . .
Notification Enabled ..
Error Codes Returned .
Function DIH: Send Break.
Function D2H: Set Modem Control.
Function D3H: Retry on Timeout Error
Function D4H: Set Baud Rate ...
Interrupt 15H: Cassette Input/Output.
Function 80H: Open Device
Function 81H: Close Device ... .
Function 82H: Termination . . . . .
Function 83H: Set a Wait Interval.
Function 84H: Joystick Support ..

15-51
15-52
15-53
15-54
15-55
15-56
15-57
15-58
15-59
15-59
15-59
15-61
15-62
15-63
15-64
15-65
15-66
15-67
15-68
15-69
15-70
15-72
15-73
15-73
15-74
15-74
15-75
15-76
15-77
15-80
15-81
15-83
15-84
15-85
15-86
15-87
15-88
15-89
15-89
15-90
15-90
15-91
Contents xv

Function 85H: Service System Request Key . . . . . .
Function 86H: Wait (No Return to Usert . . . . . . . .
Function 87H: Move a Block of Memory . . . . . . . .
Function 88H: Return Memory Size Above One Megabyte
Function 89H: Begin Virtual Mode . . . . . . . . . . . . . .
Function 90H: Device Is Busy . . . . . . . . . . . . . . .
Function 91H: Interrupt Completion Handler . . . . . .
Function DOH: Return DIGITAL Configuration Word.
Interrupt 16H: Keyboard Input. . . . . .
. .....
Table of Returned Scan Codes .
. . . . . .
Combination Keys . . . . . . . . . . .
System Reset . . . . . . . . . . .
System Request Key (Sys Reqt .
Extended Self·test. . . . . . . . .
Break . . . . . . . . . . . . . . . .
Pause . . . . . . . . .
Print Screen . . . . . . . . . .
Automatic LED Control. . . . . .
Function OOH: Keyboard Input. .
Function 01H: Keyboard Status.
Function 02H: Keyboard State. .
. . . . . . . .
Function DOH: Key Notification.
. . . . . .
....... .
Key Stroke Notification Enabled
Key Buffering Notification Enabled . . . . . . . . .
Function DIH: Character Count . . . . . . . . . . . . .
Function D2H: Keyboard Buffer. . . . . . . . . . . . .
Function D3H: Extended Codes And Functions ... .
Function D4H: Request Keyboard 10 . . . . . . . . . .
Function D5H: Send to Keyboard . . . . . . . . . . . .
Function D6H: Keyboard Table Pointers . . . . . . . .
Keyboard Translation Table Formats And Usage.
Interrupt 17H: Printer Output . . . . . . . . . . . . . . . . .
Function OOH: Transmit Character . . . . . . . . . . . .
Function 01H: Initialize Printer . . . . . . . . . . . . .
Function 02H: Return Printer Status . . . . . . . . .
Function DOH: Redirect Parallel Printer .. .
Function D1H: Printer Type . . . . . . . . . . . . . . .
Function D2H: Parallel Port Retry . . . . . . . . . . .
Interrupt 18H: Basic. . . . . . . . . . . . . . . . . . . . . . .
Interrupt 19H: Bootstrap . . . . . . . . .
DIGITAL Hard Disk Boot Block . . . . . . . . . . . . .
xvi Contents

15-91
15-92
15-93
15-95
15-96
15-98
15-98
15-99
15-101
15-102
15-107
15-107
15-107
15-108
15-108
15-108
15-108
15-108
15-109
15-109
15-110
15-111
15-112
15-113
15-114
15-115
15-116
15-118
15-119
15-120
15-121
15-123
15-124
15-125
15-126
15-127
15-129
15-131
15-132
15-133
15-134

Interrupt lAH: Time-of-day . . . . . . . .
Function OOH: Read System Clock .
Function 01H: Set System Clock ..
Function 02H: Read Real-Time Clock.
Function 03H: Set Real-Time Clock.
Function 04H: Return RTC Date
Function 05H: Set RTC Date
Function 06H: Set Alarm . . . . .
Function 07H: Cancel Alarm .. .
Function DOH: Return Days-Since-Read Counter.
Interrupt IBH: Keyboard Break .
Interrupt lCH: Timer Tick . . . . . . . . . .
Interrupt IDH: Video Parameters . . . . . .
Interrupt lEH: Diskette Parameter Tables.
Interrupt IFH: Graphics Character Table Pointer.
Interrupt 40H: Revector of Interrupt 13H . . . . .
Interrupt 41H and 46H: Hard Disk Parameter Tables
Interrupt 4AH: RTC Alarm. . . . . . . . .
Interrupt 70H: Real-Time Clock . . . . . . . . . . . . .
Interrupt 71H: Redirect to Interrupt OAH . . . . . . .
Interrupt 72H: Local Area Network Controller (LANCE) .
Interrupt 73H: Serial Printer Port.
Interrupt 74H: Mouse Port.
Interrupt 75H: 80287 Error . . . .
Interrupt 76H: Hard Disk . . . . .
Interrupt 77H: Available (lRQI5)

15-135
15-136
15-136
15-137
15-138
15-138
15-139
15-139
15-140
15-140
15-141
15-141
15-142
15-143
15-145
15-145
15-146
15-148
15-148
15-148
15-149
15-150
15-150
15-151
15-151
15-151

Chapter 16 Programming the VAXmate Under MS-DOS
16-1
16-1
16-2
16-2
16-2
16-3
16-3
16-3
16-5
16.5
16-5
16-5
16-7
16-8

Overview . . . . . . . . . . . . . . . . . . . .
MS-DOS Operating System Versions.
Loading MS-DOS Operating System .. .
MS-DOS Memory Map . . . . . . . . .
MS-DOS Interrupt 21H Digital Specific Functions
Function 30H Get MS-DOS OEM Number
Function 38H Get/Set Country Code.
Loadable MS-DOS Device Drivers.
ANSI.SYS . . . . . . . . .
Installing ANSI.SYS . . .
Cursor Control Functions.
Erase Functions . . . . .
Set Graphics Rendition . .
Contents

xvii

Set Mode Function. . . . . . . . . . . . .
Reset Mode Function . . . . . . . . . . .
Keyboard Key Reassignment Function .
Mouse Driver . . . . . . . . . . .
Detecting the Mouse Driver . . . . . .
Video Support . . . . . . . . . . . . . .
Function OOOOH: Mouse Initialization
Function 0001H: Show Cursor . . . .
Function 0002H: Hide Cursor . . . . .
Function 0003H: Get Mouse Position and Button Status
Function 0004H: Set Mouse Cursor Position ...
Function 0005H: Get Button Press Information . . . . .
Function 0006H: Get Button Release Information . . . .
Function 0007H: Set Minimum and Maximum X-Axis
Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Function 0008H: Set Minimum and Maximum Y-Axis
Position . . . . . . . . . . . . . . . . . . . .
Function 0009H: Define Graphics Cursor . . . .
Function OOOAH: Define Text Cusor . . . . . . .
Function OOOBH: Read Mouse Motion Counters
Function OOOCH: Define Event Handler . . . . .
Function OOODH: Enable Light-Pen Emulation.
Function OOOEH: Disable Light-Pen Emulation.
Function OOOFH: Set Mouse Motion/Pixel Ratio
Function 0010H: Conditional Hide Cursor.
Function 0013H: Set Speed Threshold ...
Function 001CH: Get Driver Version.
Function 0024H: Get Configuration ... .
Function 0025H: Set Configuration . . . . .
Enhanced Graphics Adapter (EGA) Functions
Function FOH: Read EGA Register ... .
Function F1H: Write EGA Register ... .
Function F2H: Read EGA Register Group
Function F3H: Write EGA Register Group
Function F4H: Read EGA Register List.
Function F5H: Write EGA Register List
Function FAH: EGA Functions Installed
MS-DOS Media ID Tables
Disk Parameters .
xviii Contents

16-10
16-11
16-12
16-13
16-14
16-14
16-16
16-17
16-17
16-18
16-19
16-20
16-21
16-22
16-23
16-24
16-26
16-27
16-28
16-30
16-30
16-31
16-31
16-32
16-32
16-33
16-33
16-34
16-35
16-35
16-36
16-36
16-37
16-38
16-38
16-39
16-40

MS-DOS International Support
FONT and GRAFTABL.
FONT.COM. . . . . . . .
GRAFTABL.COM. . . .
Description of Fonts. . .
. . . . . .
How FONT. COM Affects KEYB.COM and SORT.EXE .
Font File Structures. .
Loading Font Files. . .
KEYB . . . . . . . . . . . .
Keyboard Remapping.
Creating Keyboard Map Tables for International Countries.
How Compose Sequences Are Recognized. . . . . . . . .
How Dead Diacritical Keys Are Recognized. . . . . . . .
Format and Use of the Compose Sequence Pointer Table
Format and Use of the Compose Sequence Translation
Table. . . . . . . . . . . . . . . . . . . . . . .
Changing to STDUS.KEY and Back Again
Keyboard Map File Structure
LCOUNTRY . . . . . . . . .
Country File Structure .
Case Conversion Tables.
SORT. . . . . . . . . . . . .
Format for Sorting Order.
Creating Sort Tables for Character Sets. .

Chapter 17 MS-Windows on the VAXmate

16-41
16-41
16-41
16-42
16-42
16-42
16-42
16-45
16-45
16-45
16-47
16-49
16-49
16-49
16-50
16-50
16-50
16-52
16-52
16-54
16-55
16-55
16-55
17-1
17-1
17-1
17-2
17-3
17-4
17-4
17-5
17-5
17-6
17-7
17-7
17-8
17-9
17-10

Introduction. . . . . . . . . . . . . . . . . .
Overview . . . . . . . . . . . . . . . . .
Keyboard Driver for the LK250 Keyboard
Numeric and Edit Keypads. . . . . . .
Keyboard LEOs for the VAXmate LK250 .
VAXmate Compose Handling . . . . . . . .
Reserved Keys Under MS-Windows. . . . .
DIGITAL MS-Windows Keyboard Extensions.
DecSetLockState (lock I .
DecSetKClickVol (voU. . . . . . .
DecSetAutorep (repeatl. . . . . .
DecGetKbdCountry ( I : Result. .
DecSetComposeState (compose_model.
DecSetNumlockMode (numlock_model.
Contents

xix

Windows Keyboard Processing Anomalies . . . .
Repeating Key Allowed to Change Focus. . .
Illogical Set of Keyboard Messages. . . . . .
Key Mappings for VAXmate's LK250. . . . . . .
AnsiToOem,OemToAnsi .
ANSI to OEM Table
OEM to ANSI Table
Mouse . . . . . . . . . . . . .
Communications . . . . . . .
LAT Support Through the Windows Asynchronous Serial
Communications Interface.
OpenComm . . . . .
WriteComm . . . . .
TransmitCommChar
ReadComm. . .
CloseComm . .
SetCommState
GetCommState
EscapeCommFunction .
SetCommBreak . . . .
ClearCommBreak. . .
SetCommEventMask
GetCommEventMask
FlushComm . . . . . .
GetCommError . . . .
Custom LAT Application Interface Under Windows .
OpenLat (lpServiceName, IpNodeName, IpPortName) :
Latid. . . . . . . . . . . .
CloseLat (Latid) : Result . . .
ReadLat (Latid) : Result. . . .
WriteLat (Latid, chI : Result.
GetLatStatus (Latid) : Result
SendLatBreak (Latid) : Result.
InquireLatServices ( ) : LResult
GetLatService (lpServiceName) : Result. .
Display on the VAXmate . . . . .
Standard Applications Support . . . . . . . . .
Keyboard Handling . . . . . . . . . . . . . .
Keyboard Handling Inside an MS-Windows Window.
Keyboard Handling Outside an MS-Windows Window.
ANSI Support Inside an MS-Windows Window . . . . . . .
xx Contents

17-11
17-11
17-12
17-13
17-55
17-55
17-58
17-61
17-61
17-62
17-63
17-63
17-64
17-64
17-64
17-65
17-65
17-65
17-65
17-65
17-65
17-65
17-65
17-66
17-66
17-67
17-68
17-68
17-69
17-69
17-70
17-70
17-71
17-73
17-74
17 -75
17-75
17-78
17-79

17-79
17-82
17-82
17-83
17-83
17-83
17-85

Video Modes Handled Inside an MS-Windows Window.
Interrupt lIh Support
Interrupt 12h Support
Interrupt 15h Support
Unique Icons ..
Printers . . . . . . . . . .
DECWIN.H File Listing.

Chapter 18 VAXmate Network Software.
Introduction. . . . . . . .
Documentation List . . . . . .
Datalink . . . . . . . . . . . . . . .
Common Definition Formats .
Multicast Address Format
Software Capabilities .
Datalink Functions . . . .
Datalink Return Codes . .
Function OOH: Initialization (dll_init) .
Function 01H: Open a Datalink Portal (dll_open) .
Function 02H: Close a Datalink Portal (dll_close).
Function 03H: Enable Multicast Addresses
(dll_enable_ mul) . . . . . . . . . . . . . . . . .
Function 04H: Disable Multicast Addresses
(dll_disable_ mul). . . . . . . . . . . . . . . . .
Function 05H: Transmit (dll_transmit) . . . .
Function 06H: Request Transmit Buffer Function
(dllJequest_ xmit) . . . . . . . . . . . . . . . . . . . .
Function 07H: Deallocate Buffer (dll_deallocate) ..
Function 08H: Read Channel Status (dllJead_chan).
Function 09H: Read the Portal List (dllJead_plist)
Functions OAH: Read the Portal Status
(dllJead _portal) . . . . . . . . . . . . . . . . .
Function OBH: Read the Datalink Counters
(dllJead_count) . . . . . . . . . . . . . .
Function OCH: Network Boot Request
(dll_network_boot) . . . . . . . . . . . . .
Function ODH: Enabling a Channel Function
(ddl_enable_chan) . . . . . . . . . . . . . . . . .
Function OEH: Disabling a Channel (dll_disable_chan) ..
Function 11 H: Read Decparm String Address
(dllJeadecparm) . . . . . . . . . . . . . . . . . . . . . .
Contents

18-1
18-1
18-4
18-5
18-6
18-7
18-8
18-11
18-13
18-16
18-18
18-21
18-22
18-24
18-25
18-27
18-28
18-29
18-31
18-32
18-34
18-38
18-39
18-40
18-41
xxi

Function 12H: Set Decparm String Address
(dll_setdecparm). . . . . . . . . . . . . . . . . .
Function 13H: External Loopback (dll_ext_loopback)
Maintenance Operation Functions. . . . . . . . . . . .
Data Link Interface to the MOP Process. . . . . . . .
Function OFH: Mop Start and Send System ID
(dll_start_mop) . . . . . . . . . . . . . . . .
Function 10 H: Mop Stop (dll_mop_stop) .
Sample Datalink Session .
Local Area Transport . .
LAT Services. . . . .
LAT Command Line
Data Structures . . .
LAT Functions. . . .
Function 03H: LAT Get Status.
Function DOH: Open Session . .
Function DOH: Close LAT Session.
Function 02H Read Data. . . . . . .
Function 01H: Send Data . . . . . .
Function D5H: Get Next LAT Service Name.
Function D6H: LAT Service Table Reset
Function D1H: Send Break Signal
Sample Terminal Program
Session . . . . . . . . . . . . . . . . . . . .
Software Capabilities . . . . . . . . .
MS-Network Session Control Block.
DIGITAL-Specific Session Control Block.
Synchronous Requests . . . . . . . .
Asynchronous Requests. . . . . . . .
Asynchronous Notification Routine.
Network Addressing . . . . . . . . . .
Session Level Services . . . . . . . .
MS-Network Compatible Session Level Services
MS-Network Session Level Return Codes . . . .
Function OOH and Function B800H: Check for Presence
of MS-Network Session . . . . . . . .
Function 35H: Cancel (synchronous) .
Function 32H: Reset (synchronous) ..
Function 33H: Status (synchronous) .
Function B3H: Status (asynchronous)
Function 30H: Add Name (synchronous).
Function BOH: Add Name (asynchronous) .
xxii Contents

18-42
18-43
18-44
18-47
18-47
18-47
18-48
18-56
18-57
18-57
18-60
18-66
18-67
18-68
18-69
18-70
18-71
18-72
18-73
18-74
18-75
18-84
18-86
18-86
18-89
18-90
18-90
18-91
18-91
18-92
18-93
18-94
18-97
18-98
18-99
18-100
18-100
18-103
18-103

Function 31H: Delete Name (synchronous) .
Function B1H: Delete Name (asynchronous)
Function 34H: Name Status (synchronous) .
Function B4H: Name Status (asynchronous)
Function 1OH: Call (synchronous) ..
Function 90H: Call (asynchronous) . .
Function 11H: Listen (synchronous) .
Function 91H: Listen (asynchronous).
Function 12H: Hangup (synchronous)
Function 92H: Hangup (asynchronous) .
Function 14H: Send (synchronous) ...
Function 94H: Send (asynchronous) ..
Function 17H: Send Double (synchronous).
Function 97H: Send Double (asynchronous) .
Function 15H: Receive (synchronous) ... .
Function 95H: Receive (asynchronous) ... .
Function 16H: Receive Any (synchronous) ..
Function 96H: Receive Any (asynchronous) .
Datagram Commands . . . . . . . . . . . . . . .
Function 20H: Send Datagram (synchronous).
Function AOH: Send Datagram (asynchronous) .
Function 21H: Receive Datagram (synchronous)
Function A1H: Receive Datagram (asynchronous)
Function 22H: Send Broadcast (synchronous) ..
Function A2H: Send Broadcast (asynchronous) ..
Function 23H: Receive Broadcast (synchronous) .
Function A3H: Receive Broadcast (asynchronous)
DIGITAL-Specific Session Level Services ...
Function OOH: DIGITAL Function Check
(decfunccheck) . . . . . . . . . . . . . . . . .
Function 01H: Add a Node (decfuncadd) ..
Function 02H: Delete Entry Given the Node Number
(decfuncdelnum) . . . . . . . . . . . . . . . . . . . .
Function 03H: Delete Entry Given Node Name
(decfuncdelname) . . . . . . . . . . . . . . . . . . .
Function 04H: Read Node Entry Given Node Number
(decfuncreadnum) . . . . . . . . . . . . . . . . . . . . . .
Function 05H: Read Node Entry Given Node Name
(decfuncreadnamel. . . . . . . . . . . . . . . . . .
Function 06H: Read Node Entry Given Index
(decfuncreadindex) . . . . . . . . . . . . . . . . . .
Function 07H: Delete All Node Entries (decfuncdelall) ..
Contents

18-104
18-104
18-105
18-105
18-107
18-107
18-109
18-109
18-110
18-110
18-111
18-111
18-112
18-112
18-113
18-113
18-114
18-114
18-115
18-116
18-116
18-117
18-117
18-118
18-118
18-119
18-119
18-120
18-121
18-122
18-123
18-124
18-125
18-126
18-127
18-128
xxiii

Server Message Block ISMBI Protocol . . . . . . . . . . . .
Extended Function DOH: Get Current Date and Time.

Appendix A Support Code for Examples . .
File: SUPPORT.ASM
File: EXAMPLE.H .
File: KYB.H . . . .
File: RB.H . . . . . .
File: VECTORS.C
File: RB.C . . . .
File: DEMO.C .. .

18-129
18-130
A-I
A-I
A-9
A-10
A-ll
A-12
A-16
A-18

Appendix B 80286 Instruction Set

B-1

Appendix C VT220 and VT240 Terminal Emulators.

C-1
C-2
C-2
C-2
C-2
C-2
C-2
C-2
C-3
C-3
C-3
C-3
C-3
C-4
C-4
C-4
C-4
C-4
C-5
C-5
C-5
C-5
C-6

VT220 Emulator and VT220 Terminal Differences
Saving and Restoring Set-Up Selections ..
Video Differences . . . . . . . . . . .
Scrolling . . . . . . . . . . . . . . .
Blinking Characters Remapped . .
No Control Representation Mode.
Font Selection . . . . . . . . . . . .
Communications Differences. . . . . .
LAT Protocol Support INetwork Terminal Services) .
No Split Baud Rate . . .
Session Logging. . . . .
Autotyping Characters .
Keyboard Differences . . .
Keyboard LEDs . . . .
Alternate Characters .
Keyclick . . . . . . . . .
Autorepeat Selection .
Character Sets . . . . . . .
DEC MCS to ISO Latin-1 8-bit Transition
Language Selection . . . . . . . . . . . . . .
Compose Sequences. . . . . . . . . . . . . .
Additional VT220 Emulator Escape Sequences
Assign User-Preference Supplemental Character Set
IDECAUPSS) . . . . . . . . . . . . . . . . . . . . . . . .
Request User-Preference Supplemental Character Set
IDECRQUPSS) . . . . . . . . . . . . . . . . . . . . . . . .
Select User-Preference Supplemental Coded Character
Set ISCS) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
xxiv

Contents

C-6
C-6
C-6

Select DEC Supplemental Coded Character Set (SCS) .
Select ISO Latin-l Supplemental Coded Character Set
(SCS) . . . . . . . . . . . . . . . . .
Primary Device Attribute (DA) . . . . .
Secondary Device Attribute (DA) . . . .
Announcing ANSI Conformance Levels
Printing . . . . . . . .
Printer Options .
Print Terminator
Print Size. . . . .
VT240 Emulator and VT240 Terminal Differences
Saving and Restoring Set-Up Selections. .
Video Differences . . . . . . . . . . . .
Video Modes . . . . . . . . . . . . .
Automatic Video Mode Switching.
Scrolling . . . . . . . . . . . . . . .
No Control Representation Mode.
Underlined Characters. . . . . . .
Line Attributes . . . . . . . . . . .
Double Width Lines for Fast Text Only
Double Height/Double Width Lines for Fast Text Only
Communications Differences. . . . . . . . . . . . . . . . .
LAT Protocol Support (Network Terminal Services) .
Session Logging. . . . .
Autotyping Characters.
Keyboard Differences . . .
Keyboard LEDs . . . . .
Alternate Characters . .
No "Printer to Host" Mode.
Character Sets. . . . . . . .
DEC MCS to ISO Latin-l 8-bit Transition
Compose Sequences. . . . . . . . . . . . . .
Additional VT240 Emulator Escape Sequences
User-Preference Supplemental Character Set
(DECAUPSS) . . . . . . . . . . . . . . . . . . .
Request User-Preference Supplemental Character Set
(DECRQUPSS) . . . . . . . . . . . . . . . . . . . . . . . .
Select User-Preference Supplemental Coded Character
Set (SCS). . . . . . . . . . . . . . . . . . . . . . . . . . . .
Select DEC Supplemental Coded Character Set (SCS) .
Select ISO Latin-l Supplemental Coded Character Set
(SCS) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contents

C-7
C-7
C-8
C-8
C-8
C-9
C-9
C-9
C-9
C-IO
C-IO
C-IO
C-IO
C-IO
C-IO
C-IO
C-ll
C-ll
C-ll
C-ll
C-12
C-12
C-12
C-12
C-12
C-12
C-12
C-12
C-13
C-13
C-13
C-13
C-13
C-14
C-14
C-15
C-15
xxv

Primary Device Attribute (DA) . . . . .
Secondary Device Attribute (DA) ... .
Announcing ANSI Conformance Levels

C-15
C-16
C-16

Bibliography
Index
Tables
Table 2-1 Physical Memory Map . . . . . . . . .
Table 2-2 Input/Output Address Map . . . . . .
Table 2-3 Interrupt Vector Map . . . . . . . . .
Table 2-4 8-Bit Expansion Bus Transfer Times
Table 2-5 Expansion Slot Power Ratings . . . .
Table 3-1 Interrupt Request Lines. . . . . . . .
Table 3-2 Master and Slave I/O Addresses . . .
Table 3-3 Accessing the Interrupt Controller Registers.
Table 4-1 DMA Request Line Assignments . . . . . . . .
Table 4-2 DMA Controller States . . . . . . . . . . . . .
Table 4-3 DMA Controller and Page Register Address Map . .
Table 5-1 Real-Time Clock Address Map.
Table 5-2 Rate Selection Bits. . . . . . . .
Table 5-3 RTC Data Register Ranges . . .
Table 5-4 RTC Automatic Alarm Cycles ..
Table 6-1 Counter Signals. . . . . . . . . .
Table 6-2 Modes Used by the Three Counters.
Table 6-3 8254 and System Register Addresses.
Table 7-1 Available Video Modes . . . . . . . . . .
Table 7-2 Attribute Byte Bit Definitions . . . . .
Table 7-3 Text Mode Display Pages (ROM BIOS) .
Table 7-4 Default VLT Contents . . . . . . . . . . .
Table 7-5 VLT Contents for Video Modes D1H and D2H.
Table 7-6 Video Processor I/O Registers.
Table 7-7 CRTC Internal Registers . . . . . . . .
Table 7-8 CRTC Register Values . . . . . . . . . .
Table 7-9 Color Select Register Bit Assignments
Table 7-10 Color Palettes Selected by CPS and SIC.
Table 7-11 Selecting Video Modes . .
Table 7-12 Monitor Interface Signals
Table 8-1 Port 1 Bit Definitions ...
Table 8-2 Port 2 Bit Definitions . . .
Table 8-3 Keyboard-Interface Controller Commands
Table 8-4 Command Byte Bit Definitions. . . . . . .
xxvi Contents

2-3
2-4
2-7
2-10
2-10
3-2
3-3
3-4
4-2
4-2

4-6
5-3
5-5
5-11
5-12
6-3
6-3
6-8
7-5
7-6
7-8
7-20
7-21
7-22

7-26
7-27
7-40
7-40

7-42
7-44

8-3
8-4
8-~

8-H

Table 8-5 LK250 Scan Codes and Industry-standard
Equivalent Values . . . . . . . . . . . . . . . . . . .
Table 8-6 Scan Codes Translated But Not Used.
Table 8-7 LK250 Keyboard Command Codes.
Table 8-8 LK250 Keyboard Responses ...
Table 9-1 8250 UART Register Addresses
Table 9-2 Interrupt Identification . . . . .
Table 9-3 Baud Rate Table . . . . . . . . .
Table 9-4 Communications Connector Signals .
Table 9-5 Printer Connector Signals. . . . . . .
Table 9-6 Modem Telephone Line Connector Signals .
Table 9-7 Handset Connector Signals . .
Table 10-1 Mouse Command Summary.
Table 10-2 Serial Interface Registers . .
Table 10-3 Baud Rate Table. . . . . . . .
Table 11-1 Diskette Drive Controller Registers
Table 11-2 Diskette Drive Controller Commands
Table 11-3 Register Sets for Read Data Command
Table 11-4 Register Sets for Write Data Command .
Table 11-5 Register Sets for Read Deleted Data Command
Table 11-6 Register Sets for Write Deleted Data Command.
Table 11-7 Register Sets for Read Track Command. .
Table 11-8 Register Sets for Read ID Command. . . .
Table 11-9 Register Sets for Format Track Command
Table 11-10 Register Sets for Scan Equal Command .
Table 11-11 Register Sets for Scan Low or Equal Command.
Table 11-12 Register Sets for Scan High or Equal Command
Table 11-13 Register Sets for Recalibrate Command . .
Table 11-14 Register Sets for Sense Interrupt Status
Command . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 11-15 Register Sets for Specify Command ... .
Table 11-16 Register Sets for Sense Drive Status Command
Table 11-17 Register Sets for Seek Command. . . . . . . .
Table 12-1 Hard Disk Controller Registers . . . . . . . . . .
Table 12-2 Hard Disk Controller Diagnostic Result Codes.
Table 12-3 Memory Image of a Sector Interleave Table ...
Table 12-4 Hard Disk Controller Diagnostic Result Codes.
Table 13-1 Network Interface Registers . . . . . . . . . . . .
Table 13-2 LANCE CSR3 Required Values for the VAXmate
Workstation. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 14-1 VAXmate Powerup and Self-Test Error Codes
Table 14-2 VAXmate Processor Board Jumpers . . . . . .
Contents

8-17
8-21
8-22
8-30
9-2
9-6
9-16
9-19
9-20
9-21
9-21
10-2
10-8
10-11
11-2
11-19
11-21
11-21
11-22
11-22
11-23
11-23
11-24
11-24
11-25
11-25
11-26
11-26
11-26
11-27
11-27
12-2
12-6
12-18
12-21
13-5
13-16
14-8
14-14
xxvii

Table 15-1 ROM BIOS Interrupt Vectors . . . .
Table 15-2 Interrupt 10H: Video 110 Functions
Table 15-3 Video Modes . . . . . . . . . . . . . .
Table 15-4 Mode Dependent Values for Set Cursor Type .
Table 15-5 Default Color Map. . . . . . . . . . . . . . . .
Table 15-6 Color Map for Video Modes DIH and D2H .
Table 15-7 Hard Disk Error Codes. . . . . . . . . . .
Table 15-8 Hard Disk Parameter Table Description.
Table 15-9 Diskette Error Codes. . . . . . . . . . . .
Table 15-10 Diskette Parameter Table Description .
Table 15-11 Communications Control Block (CCB)
Description
Table 15-12 CCB Buffer Structure Description . . . . . . .
Table 15-13 Keyboard Scan Codes Returned by The ROM
BIOS . . . .
Table 15-14 Diskette Parameter Table Description . . .
Table 15-15 Hard Disk Parameter Table Description . .
Table 16-1 Cursor Control Functions . . . . .
Table 16-2 Erase Function . . . . . . . . . . .
Table 16-3 Set Graphics Rendition Function .
Table 16-4 Set Mode Function . . . . . . . . .
Table 16-5 Reset Mode Function. . . . . . . .
Table 16-6 Keyboard Key Reassignment Function.
Table 16-7 Standard Mouse Drive Functions. . . .
Table 16-8 Extended Mouse Driver Functions ...
Table 16-9 Video Sytems and Modes Supported by
MOUSE.SYS . . . . . . . . . . . . . . . . . . . . . . . .
Table 16-10 Extensions to Interrupt 10H EGA Functions.
Table 16-11 EGA Register Groups and Associated Registers
Table 16-12 Hard Disk Types . . . . . . . .
Table 16-13 BIOS Parameter Block Data.
Table 16-14 .FNT File Structure. .
Table 16-15 .GRF File Structure. . . . . .
Table 16-16 Keyboard Tables. . . . . . . .
Table 16-17 Keyboard Map File Structure
Table 16-18 Characters Causing Problems for
COMMAND. COM . . . . . . . . . . . . . . . . . .
Table 16-19 Sort Order for Industry-Standard Character Set
(STD). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 16-20 Sort Order for DIGITAL Multinational Character
Set (MCS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
xxviii

Contents

15-1
15-9
15-10
15-12
15-33
15-34
15-40
15-41
15-59
15-60
15-78
15-80
15-104
15-143
15-147
16-6
16-7
16-8
16-10
16-11
16-12
16-13
16-14
16-15
16-34
16-34
16-39
16-40
16-43
16-15
16-1€
16-5C
16-54
16-5(
16-5~

Table 16-21 Sort Order for International Standards
Organization Character Set (ISO) . . . . . . . . . . .
Table 16-22 Sort Order for French 7-Bit National
Replacement Character Set (FR7) . . . . . . . . . . .
Table 16-23 Sort Order for German 7-Bit National
Replacement Character Set (GR71 . . . . . . . . . . . .
Table 17-1 Keyboard Messages Transmitted by MS-Windows .
Table 17-2 US to ASCII Translation Table. . .
Table 17-3 Danish to ASCII Translation Table.
Table 17-4 Finnish to ASCII Translation Table
Table 17-5 French to ASCII Translation Table.
Table 17-6 French Canadian and Bilingual Canadian to ASCII
Translation Table. . . . . . . . . . . . . . . . . . . .
Table 17-7 German to ASCII Translation Table. .
Table 17-8 Italian to ASCII Translation Table ...
Table 17-9 Norwegian to ASCII Translation Table.
Table 17-10 Spanish to ASCII Translation Table .
Table 17-11 Swedish to ASCII Translation Table .
Table 17-12 Swiss French to ASCII Translation Table .
Table 17-13 Swiss German to ASCII Translation Table.
Table 17-14 Translation of ANSI Set to OEM Set.
Table 17-15 Translation of OEM Set to ANSI Set.
Table 17-16 INT 10H Functions . . . . . . . . . . .
Table 17-17 Supported Video Modes. . . . . . . . .
Table 17-17 Character Sets Supported by Each Printer.
Table 18-1 Interrupt 6D: Datalink Functions . . . . . . . .
Table 18-2 Datalink Return Codes. . . . . . . . . . . . . .
Table 18-3 Recommended Values for Datalink Parameters.
Table 18-4 LAT Call Back Routine . . . . .
Table 18-5 Interrupt 6A: LAT Functions . . . . . .
Table 18-6 Session Control Block Fields. . . . . . .
Table 18-7 DIGITAL Session Control Block Fields
Table 18-8 Interrupt 2A: MS-Network Compatible Services ...
Table 18-9 Interrupt 2A: DIGITAL Specific Session Extensions
Table 18-10 Error Codes Returned by Session .. .
Table 18-11 Session Status Buffer . . . . . . . . . . .
Table C-1 DEC MCS - ASCII Graphics Set (0-71 ..
Table C-2 DEC MCS - Supplemental Graphics Set
Table C-3 ISO Latin-l Character Set (0-7) ... .
Table C-4 ISO Latin-1 Character Set (8-151 ... .
Table C-5 DEC Special Graphics Character Set.
Contents

16-58
16-59
16-60
17-12
17-15
17-21
17-23
17-27
17-30
17-33
17-36
17-39
17-42
17-45
17-48
17-51
17-55
17-58
17-80
17-82
17-84
18-12
18-13
18-17
18-62
18-66
18-87
18-89
18-92
18-92
18-94
18-100
C-18
C-19
C-20
C-21
C-22
xxix

Figures
Figure 1-1 Base Configuration Workstation . . . . . . .
Figure 1-2 Workstation With Installed Expansion Box.
Figure 1-3 Optional 80287 Coprocessor . . . . . . . .
Figure 1-4 Optional Two Megabyte DRAM Module . . .
Figure 1-5 Optional Modem Module . . . . . . . . . . . .
Figure 1-6 Block Diagram of Workstation Components.
Figure 2-1 8-Bit And 16-Bit Bus Connectors.
Figure 3-1 Priority Before Rotation
Figure 3-2 Priority After Rotation . . . . . . .
Figure 3-3 Interrupt Sequence . . . . . . . . .
Figure 6-1 Three Channel Counter/Timer Block Diagram
Figure 7-1 Block Diagram of the VAXmate Video Controller.
Figure 7-2 Character Buffer Format. . . . . . . . . . . . . . .
Figure 7-3 Memory Organization for 320 x 200 4-Color Mode.
Figure 7-4 Pixel to Bit-Field Map for 4-Color Mode . . . . .
Figure 7-5 Memory Organization for 320 x 200 16-Color
Mode ...
Figure 7-6 Pixel to Bit-Field Map for 16-Color Mode . . . .
Figure 7-7 Memory Organization for 640 x 200 2-Color Mode .
Figure 7-8 Pixel to Bit-Field Map for 2-Color (Monochrome)
Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 7-9 Memory Organization for 640 x 200 4-Color Mode .
Figure 7-10 Pixel to Bit-Field Map for 4-Color Mode . . . .
Figure 7-11 Memory Organization for 640 x 400 2-Color
Mode . . . .
Figure 7-12 Pixel to Bit-Field Map for 2-Color Mode . . . .
Figure 7-13 Memory Organization for 640 x 400 4-Color
Mode . . . .
Figure 7-14 Pixel to Bit-Field Map for 4-Color Mode . . . .
Figure 7-15 Memory Organization for 800 x 252 4-Color
Mode . . . .
Figure 7-16 Pixel to Bit-Field Map for 4-Color Mode
Figure 8-1 Keyboard Position Labels. . .
Figure 8-2 U.S.lU.K. Keyboard . . . . .
Figure 8-3 Canadian/English Keyboard .
Figure 8-4 Danish Keyboard . . . . . .
Figure 8-5 Finnish Keyboard . . . . . .
Figure 8-6 French/Canadian Keyboard
Figure 8-7 French Keyboard . . . . . .
Figure 8-8 German/Austrian Keyboard
Figure 8-9 Hebrew Keyboard . . . . . .
xxx

Contents

1-2
1-3
1-4
1-4
1-4
1-5
2-11
3-14
3-14
3-2~

6-2
7-~

7-6
7-11
7-11

7-U
7-U
7-1~
7-1~
7-1~

7-V
7-11
7-11

7-H
7-11

7-1'
7-1'
8-11

8-3:
8-3:
8-38-3
8-3
8-3
8-3
8-3

Figure 8-10 I talian Keyboard . . .
Figure 8-11 Norwegian Keyboard
Figure 8-12 Spanish Keyboard ..
Figure 8-13 Swedish Keyboard . .
Figure 8-14 Swiss/French Keyboard.
Figure 8-15 Swiss/German Keyboard
Figure 10-1 VAXmate Mouse (Part Number VSXXXI
Figure 13-1 Descriptor Rings . . . . . . . . . .
Figure 14-1 Test Sequence - Processor Board
Figure 14-2 Test Sequence - 110 Board . . . .
Figure 14-3 Test Sequence - Options . . . . .
Figure 14-4 Test Sequence - Initialization and Bootstrap.
Figure 14-5 VAXmate Configuration Screen. . . . . . . .
Figure 14-6 VAXmate Processor Board Jumper Configuration
Figure 15-1 LK250 Keyboard Layout . . . . . . .
Figure 16-1 MS-DOS Date and Time Structure.
Figure 17-1 Keyboard Position Labels. . . .
Figure 18-1 VAXmate Network Components ..
Figure 18-2 Multicast Address Format . . . . .
Figure 18-3 Session Interface Implementation.

Contents

8-40
8-41
8-42
8-43
8-44
8-45
10-1
13-28
14-2
14-4
14-5
14-6
14-12
14-14
15-103
16-4
17-14
18-2
18-7
18-85

xxxi

Preface

Audience
This manual provides reference material about the VAXmate workstation. It
covers all programmable components, the firmware, and several MS-DOS related environments. The material and its presentation are directed to experienced programmers or software designers.

Manual Organization
This manual is divided into four parts and appendixes:
• Chapter 1 provides an overview of the VAXmate workstation and optional
equipment.
• Chapters 2 through 13 introduce the VAXmate workstation
programmable hardware devices. Each chapter discusses a single hardware programming task, such as video input/output (110). external interrupt processing, or serial communications and includes the following
information:
A brief device description
A list of additional references
A description of the programmable hardware registers
A programming example
A discussion of the example
The examples are written in the C programming language to reduce the
size of the examples and focus on the task rather than the detail required
by the language.
• Chapter 14 describes the power-up diagnostics and system startup.
• Chapter 15 describes the read-only memory basic input/output system
(ROM BIOS).
• The appendixes contain additional information, including a bibliography of
other useful publications.
Preface

xxxiii

Terminology
The following terms are used throughout this manual and are defined as
follows:
Term

Definition

Industry-standard

The computer industry recognizes two open architectures
as industry standards, the IBM PC AT bus structure and
the Microsoft disk operating system IMS-DOS). Moreover,
supporting MS-DOS requires a defined set of ROM BIOS
services. The term industry-standard refers to compatibility with these architectures.
To avoid confusion and incompatibility, the use of certain
items such as memory space, 110 space, interrupt vectors,
and ROM BIOS parameters or return values must be
clearly defined. These three categories define those items
that do not have a specific use.

Reserved
Available
Unassigned

Reserved

Available

Unassigned

xxxiv Preface

In future hardware or software releases,
DIGITAL may define a specific use for thi~
item. Hardware or software applications
that use this item may not work with
future releases.
Hardware or software applications can use
this item. DIGITAL has defined the specific use of this item as available for
applications.
Hardware or software applications can use
this item. However, there remains some
risk that DIGITAL may define a specific
use for this item.

Federal Communications Commission
Radio Frequency Interference
Class A Computing Devices
This equipment generates, uses, and may emit radio frequency energy. The
equipment has been tested and found to comply with the limits for a Class A
computing device pursuant to Sub-part J of Part 15 of FCC Rules, which are
designed to provide reasonable protection against such radio frequency interference when operated in a commercial environment. Operation of this equipment
in a residential area may cause interference in which case the user at his own
expense may be required to take measures to correct the interference.
If this equipment does cause interference to radio or television reception, which
can be determined by turning the equipment off and on, the user is encouraged
to try to correct the interference by one or more of the following methods:

• re-orient the receiving antenna
• relocate the computer with respect to the receiver
• move the computer away from the receiver
• plug the computer into a different outlet so that computer and receiver
are on different branch circuits.
If necessary, the user should consult the dealer or an experienced radio
and television technician for additional suggestions. The user may find the
booklet, How to Identify and Resolve RadiolI'V Interference Problems,
prepared by the Federal Communications Commission helpful. This booklet is
available from the U.S. Government Printing Office, Washington, DC 20402,
Stock No. 004-000-00398-5.

NOTE
Shielded cables are provided for use with this device. Should any
cables be replaced or added for any reason, these cables should
be the same as, or with higher shielding capabilities, than those
provided by Digital Equipment Corporation.

Preface

xxxv

Chapter 14
System Startup
Overview
During system startup, the ROM firmware on the processor board runs diagnostic tests, initializes the video, memory, disk controller, and firmware data,
Following diagnostic tests and initialization, the firmware tries to load the operating system from the diskette, hard disk, or network.
The ROM diagnostic tests isolate errors to a field-replaceable unit (processor
board, I/O board, keyboard, drives, or DIGITAL options). The diagnostic tests
have two modes, a 30-second powerup test and a 3-minute extended self-test.

Powerup Test
The powerup test automatically performs a brief check of the system hardware.
It performs a processor board test, a keyboard test, an input/output (110) board
test. a brief video check, and an internal I/O interface test. During the video
test, a solid line flashes at the top of the screen. The firmware checks the
presence of a diskette controller, a diskette drive, a hard disk controller, and a
hard disk drive. If found, they are also tested. The last tests performed are
on-board diagnostics for DIGITAL options, such as the modem board. Finally,
the firmware initializes the hardware and firmware data. Figures 14-1 through
14-4 show the powerup test sequence.

System Startup

14 - 1

EXTENDED
SELF-TEST
TRL/AL; TlHONE

SOFT
RESET
CTRL/AL TIDEL

POWER ON

TURN
CPU BOARD

LED ON

HALT
CPU

INITIALIZE
VIDEO SYSTEM
DISPLAY
HORIZONTAL

BAR

LJ 1312

Figure 14-1
14- 2

System Startup

Test Sequence· Processor Board

TURN
CPU BOARD
LED Off

TURN
CPU BOARD
LED ON

TURN
CPU BOARD
LED OfF

LJ-1313

Figure 14-1

Test Sequence· Processor Board ~cont.'
System Startup

14- 3

TURN
lID BOARD

LED ON

TEST
DIGiTAL
VIDEO
DISPLAY
IDEO PATTERN
NO

TURN
lID BOARD
LED OFF

LJ 1314

Figure 14-2 Test Sequence - 1/0 Board

14- 4

System Startup

~N~O____________~

TURN
MODEM
SOARD
LED ON

TURN
MODEM
SOARD
LED OFF

Figure 14-3 Test Sequence - Options
System Startup

14- 5

ERROR
DETECTED
BRIGHTEN ICON
DISPLAY
ERROR NUMBER

INITIALIZE
ALL
HARDIIARE

NOTE' MEMORY IS INITIALIZED
ONLY IN POIIER-UP TEST,
NOT IN EXTENDED
SELF-TEST

DISPLAY
CONFIGURATION
SCREEN

ENABLE
NETIIORK
DATA LINK

Figure 14·4 Test Sequence· Initialization and Bootstrap
14- 6

System Startup

DISABLE
NETIo'ORK
DATA LINK

INITIALIZE
ROM BIOS
AND
DIGITAL
OPTIONS

YES

DISPLAY
DIAGNOSTIC
ERROR
CODE

ENABLE
NETIo'ORK
DATA LINK

READ
BOOT BLOCK
TO START
OPERATING
SYSTEM

LJ-1317

Figure 14-4 Test Sequence - Initialization and Bootstrap (cont.)
System Startup

14- 7

During the powerup test, the firmware diagnostic draws a horizontal bar on the
screen. As tests complete, the firmware gradually shades in this bar. When the
diagnostic detects an error, the filled-in area of the bar changes shade and two
beeps sound. A failure value displays below the middle of the bar and remains
for 5 seconds. When the bar disappears, the error value moves to the middle of
the first line, where it remains until scrolled off the screen. Table 14-1 lists the
error codes.
Table 14-1

VAXmate Powerup and Self-Test Error Codes

Code

FRU

OOH-1FH
20H-3FH
40H-4FH
50H-5FH
60H-6FH
70H-7FH
80H-SFH
90H-9FH
AOH-FFH

CPU Board
110 Board
Diskette Drive A
Option Memory
Keyboard
Hard Disk Controller
Hard Disk
Integral Modem
Reserved

Only a few test failures are severe enough to halt the system. These are in the
basic tests. If a severe failure occurs, the processor board LED stays on, and
two beeps sound.
The tests include:

•
•
•
•

Memory access
Data path validity
Addressing
ROM checksum
Stack and vector area
Refresh request
CMOS shutdown byte

•

•
•

When testing of a field-replaceable unit WRU) completes, the firmware turns
off the LED on the FRU. The FRUs with LEDs include the processor board,
the 110 board, the memory option board (parity errors only), and the modem
option board.
NOTE
Depending on the type of failure, if the video initialization sequence fails, it is possible that the 110 board LED may remain
on.

14- 8

System Startup

The processor board LED and the 110 board LED are visible through the top of
the VAXmate cover. The processor board LED is red color. The 1/0 board LED
is an amber color. The memory board option LED lights up only if the test
detects a parity error.
The powerup test checks only DIGITAL supported hardware. For example, the
test checks the DIGITAL modem option but does not check other vendor
modem boards, unless the vendor adds option ROMs with a powerup test that
conforms to a DIGITAL standard.

Initialization
After the powerup test completes, the firmware diagnostic performs an initialization sequence that consists of sizing the memory, initializing up to 15 Mbytes
of memory, and initializing the hardware. Then, the firmware diagnostic passes
control to the ROM BIOS, which initializes the firmware data, sets up all interrupt vectors, and attempts to load the operating system from the diskette, the
hard disk (if installed), or the network.

Real Mode Versus Virtual Protected Mode
The processor can operate in two modes, real mode and virtual protected mode.
The coding of programs is distinctly different for these two modes. When operating in real mode (the powerup mode), the processor can access only the first
megabyte of physical memory. When operating in virtual protected mode, the
processor can access all 16 Mbytes of the physical address space. The powerup
test checks only the 640K system RAM and the DEC private RAM that reside
in the first megabyte of physical address space.
To prevent parity errors, the memory above the first megabyte, including the
2 Mbytes memory option board. is initialized during power up. The memory
above the first megabyte is tested in the extended self-test mode.

System Startup

14- 9

Extended Self-Test
Holding down the Ctrl and Alt keys, then pressing the Home key on the numeric keypad invokes the extended self-test. A bar goes across the screen and
fills in as each subtest completes. After about 3 minutes (or more, depending
on the options installed), a system configuration list displays on the screen.
In addition to more extensive tests, the extended self-test diagnostic performs
the same series of tests as the powerup test. The extended self-test diagnostic
handles errors in the same manner as the powerup diagnostics. Included in the
extended self-test are tests for protected memory and the 80287 math coprocessor option (if present).

Some video failures do not allow the failure value to be written to the screen. If
the monitor board fails, error reports are not displayed. When the tests complete, the video display may be absent or distorted. If the system has a thirdparty video card installed, the diagnostic bypasses all video tests.
After the video test, the self-test performs extensive internal loopback tests on
the printer, communications, and mouse serial ports. Loopback connectors are
not required. Following the serial port test, the firmware tests the real time
clock.
Then, the firmware tests the diskette controller and drive. A double-sided. highdensity formatted diskette is required for this test. (The test does not write on
the diskette.) The self-test also reads the hard disk (if present) and checks any
other DIGITAL options in the system.
To allow the system to recognize a newly installed option, execute the extended
self-test. When the extended self-test completes, the firmware diplays the
configuration list. If the newly installed option is one of those shown in Figure
14-5, the newly installed option should be displayed in the system configuration
list.
After the self-test completes its subtests, memory is sized and the hardware is
initialized. The firmware updates the CMOS configuration to the new system
configuration and displays the system configuration list on the screen.

14- 10

System Startup

Configuration List
On completion of the self-test, the firmware diagnostic displays the system
configuration list on the screen. The user can check the amount of memory
available, the options installed, the keyboard version, battery backup (if available), the ROM date, and the Ethernet address. See Figure 14-5 for an example of a typical configuration. Because the ROM diagnostics do not include
multinational translation tables, the configuration screen uses numeric values
and option codes. If an option is not present, the position for that option shows
a dashed line.
After checking the configuration list, the user presses any key to continue.
Then the firmware passes control to the ROM BIOS, which initializes the firmware data and tries to load an operating system.
NOTE
If a third-party video board is installed, the configuration list

may not be displayed. Thus, there may be no indication that the
user must press a key to continue.
Configuration list

Explanation (does not appear on screen)

1024 Kb
2048 Kb
1 RX
1 RD
Li
BA500
80287
PC50X-MA
VSXXX-AA
LK25001

Standard memory
Optional memory
Diskette drive
Hard-disk drive option
Lithium battery
Expansion box
Math coprocessor option
Modem option
Mouse
Keyboard version number
ROM and revision date
Ethernet address

27256 MOIDA/YR

08-00-2B-02-78-78

System Startup

14- 11

10204 Kb
1 OX

1 R.
LI
BASOO
90287
PCSOX-J'I1A
VSUX-AA
LK2S0 01
272S6 J'I1Q/DA/YR

08-00-28- 02-78-78

STANDARD MEMORY
OPTIONAL MEMORY
DISKETTE DRIVE
HARD DISK DRIVE OPTION
LITHIUM BATTERY
EXPANSION BOX
MATH COPROCESSOR OPTION
MODEM OPTION
MOUSE
KEYBOARD VERSION NUMBER
ROM AND REVISION DATE
ETHERNET ADDRESS

LJ-103t

Figure 14-5 VAXmate Configuration Screen

Soft Reset
A soft reset, performed by pressing the Ctrl/AltlDel key sequence, goes directly
to the diagnostic initialization procedure. This initializes the hardware, sizes
memory without initializing it, gets the status words, and sets up the CMOS
RAM. Uf the checksum is valid, the CMOS is not changed.) Then, the diagnostic passes control to the ROM BIOS initialization procedure. A soft reset
does not display the configuration screen. The ROM BIOS tries to load the
operating system from a diskette, from the hard disk (if presentt, or from the
network.

14- 12

System Startup

Hard Reset
A hard reset, such as returning from virtual protected mode to real mode,
resets only the processor. The firmware determines the reason for the reset by
reading the shutdown byte, location OFH, in the CMOS RAM. For example:
Shutdown Byte

Meaning

00H-03H

Execute diagnostic tests.

04H

CPU is retuning from CPU with operating system load
request (lNT 19H).

05H

Initialize the interrupt controller and begin execution at
the specified address.
The specified address is contained in two words,
0040:0067H for the instruction pointer and 0040:0069H
for the code segment. These are industry-standard reserved
locations.

09H

CPU is returning from· a block move shutdown (used only
by ROM BIOS INT 15H).

OAH

Begin execution at the specified address. The specified address is contained in two words, 0040:0067H for the
instruction pointer and 0040:0069H for the code segment.
These are industry-standard reserved locations.
The interrupt controller is not initialized.

OBH-FFH

Execute diagnostic tests.

Examples of subprograms that can cause a hard reset are:
•
•
•
•
•
•
•

Memory sizing routine
Memory initialization routine
Reset processor test
Testing memory with physical addresses above 1 Mbyte
MDrive' utility
Move block ROM BIOS call
Third-party software

System Startup

14 - 13

Hardware Jumper Configuration
The processor board has three jumpers to enable testing in one of three modes:
•
•
•

Test hardware including diskette drive (factory configuration)
Test hardware with no diskette drive
Manufacturing mode (no diskette drive or keyboard)

Table 14-2 shows the jumper usage. Figure 14-6 shows the factory
configuration of the jumpers on the processor board. This configuration tests
the system with a diskette drive, a video monitor, and a keyboard.
Table 14-2

VAXmate Processor Board Jumpers

SystemlMode

Factory configuration

IN
IN
IN

OUT

System without diskette drive
Manufacturing mode

DO DO DO
c=Jo
LJ·1319

Figure 14-6 VAXmate Processor Board Jumper Configuration
14- 14

System Startup

Chapter 15
ROM BIOS
This chapter describes the interrupt services provided by the ROM BIOS.
Table 15-1 lists. by hexadecimal value, all ROM BIOS interrupts. Function arguments, register use, and return values are described for each interrupt. Some
functions use the CPU CARRY flag or the CPU ZERO flag as return values.
Throughout this chapter, CF indicates the carry flag, and ZF indicates the zero
flag.
Table 15-1

ROM BIOS Interrupt Vectors

INT

Usage

Description

IndustryStandard

02H

Hardware

Nonmaskable interrupt

Yes

05H

Software

Print screen function

Yes

08H

Hardware

Timer interrupt service

Yes

09H

Hardware

Yes

OBH

Hardware

Keyboard interrupt service
Serial port #2 interrupt service (modem option)

OCH

Hardware

Serial port #1 interrupt service (asynchronous)

Yes

OEH

Hardware

Diskette interrupt service

Yes

10H

Software

Video 1/0

Yes

llH

Software

Return configuration

Yes

12H

Software

Return memory size

Yes

13H

Software

Diskette and Hard Disk 110

Yes

Chapter 15 - ROM BIOS

15 - 1

Table 15-1

ROM BIOS Interrupt Vectors kont.)

INT

Usage

Description

IndustryStandard

I4H

Software

Asynchronous Communications 110

Yes

I5H

Software

Cassette 110 (Multitasking hooks)

Yes

I6H

Software

Keyboard I/O

Yes

I7H

Software

Printer output

Yes

I8H

Software

Invoke network boot/Maintenance Operations
Protocol (MOP)

I9H

Software

Bootstrap

Yes

IAH

Software

Time of day

Yes

IBH

Software

Keyboard BREAK

Yes

ICH

Software

Timer tick vector

Yes

IDH

Pointer

Video parameter table

Yes

IEH

Pointer

Diskette parameter table

Yes

IFH

Pointer

Graphic mode character table (character codes
8OH-FFH)

Yes

40H

Software

Interrupt I3H redirect when hard disk in use

Yes

4IH

Pointer

Parameter table for hard disk 0

Yes

46H

Pointer

Parameter table for hard disk 1

Yes

4AH

Software

Real-time clock alarm

Yes

70H

Hardware

Real-time clock interrupt (IRQ8)

Yes

71H

Hardware

Redirect to interrupt OAH - Old IRQ2 (IRQ9)

Yes

72H

Hardware

Ethernet controller (lRQI0)

73H

Hardware

Serial printer port (IRQll)

74H

Hardware

Mouse port (IRQI2)

75H

Hardware

80287 error (lRQI3)

Yes

76H

Hardware

Hard disk controller (lRQI4)

Yes

77H

Hardware

Available (lRQI5)

Yes

15 - 2

Chapter 15 - ROM BIOS

Interrupt 02H: Nonmaskable Interrupt
Hardware Interrupt - Industry-Standard

Interrupt 02H handles the nonmaskable interrupt (NMI). An NMI is generated
for either of two catastrophic events:
• Memory parity errors
• Input/output UfO) bus parity errors
Interrupt 02H has no arguments, preserves all registers, and returns no values.
To process these inputs to the NMI, the following conditions must exist:
• The nonmaskable interrupt is so named because the 80286 CPU has no
provisions for disabling the NMI. The VAXmate workstation provides for
disconnecting the inputs to the NMI input line using the NMI mask register. The NMI mask register, a write only register, is accessed by writing
bit 7 at 110 address 0070H. When bit 7 is 0, NMI inputs are enabled.
This is the default condition after system startup. The I/O address 0070H
is also used to access the real-time clock. For information about the
real-time clock, see Chapter 5.
• Memory parity checking must be enabled. It is controlled by bit 2 at 110
address 006IH. When bit 2 is 0, memory parity checking is enabled. This
is the default condition after system startup.
Memory errors are confirmed by reading bit 7 of 110 address 0062H.
When bit 7 is set (1), a memory error has occurred. To clear the error
indication (bit 7), disable and reenable memory parity checking.
• I/O bus checking must be enabled. It is controlled by bit 3 at 110 address
006IH. When bit 3 is 0, 110 bus checking is enabled. This is the default
condition after system startup.

110 bus errors are confirmed by reading bit 6 of I/O address 0062H.
When bit 6 is set (1), an 110 bus error has occurred. To clear the error
indication (bit 6), disable and reenable 110 bus checking.

Chapter 15 . ROM BIOS Interrupt 02H

15 - 3

Interrupt 05H: Print Screen
Software Interrupt· Industry·Standard
Interrupt 05H reproduces the ASCII characters, displayed on a video monitor,
by printing them on the LPTl printer. Either program execution (lNT 05H) or
keyboard interaction (pressing the Shift and Prt Sc keys) activates the printer.
Interrupt 05H has no arguments, preserves all registers, and returns no values.
In text mode jsee Interrupt lOH), the character codes are sent to the printer.
In graphic mode (see Interrupt lOH), interrupt 05H interprets the pixel pattern
at each character location in the video display memory. If the interpretation
produces a valid character code, it is sent to the printer.
The ROM BIOS does not support interpretation of the pixel pattern in graphic
mode D2H (see Interrupt lOH).
NOTE
The user can execute the MS·DOS external command
GRAPHICS. This terminate-and-stay-resident program takes
over interrupt 05H. In graphic mode (including mode D2H), it
reproduces pixel graphics at the printer. In text mode, it calls
the ROM BIOS.
If the printer is not using the same character set as the display,

the printer incorrectly reproduces the screen.
The output to LPTl can be redirected to other printers, including a network printer.

15 - 4

Chapter 15 . ROM BIOS Interrupt 05H

Interrupt 08H: Clock Tick
Hardware Interrupt - Industry-Standard with DIGITAL Extensions

Interrupt 08H provides the ROM BIOS with hardware-interrupt services for
the 8254-2 CLOCKI output. CLOCKI interrupts 18.206482 times per second,
which is 1573040 times in a 24 hour period. At each CLOCKI output, interrupt 08H maintains several internal counters. and then provides an application
timing service by executing an INT lCH instruction. Interrupt 08H has no arguments, preserves all registers, and returns no values.
Do not take over interrupt 08H to acquire clock services. Using this interrupt
requires knowledge of the VAXmate workstation hardware, the ROM BIOS,
and the operating system. If an application requires clock services, use the interrupt vector at lCH (see Interrupt lCH). Review functions 35H and 25H of
MS-DOS interrupt 21H for the proper method to get and set interrupt vectors.

Interrupt 09H: Keyboard
Hardware Interrupt - Industry-Standard with DIGITAL Extensions

Interrupt 09H provides the ROM BIOS with hardware-interrupt services for
the keyboard-interface controller. This interrupt service monitors the state of
the keyboard-interface controller, reads scan codes from the keyboard-interface
controller, and maintains the state of the keyboard LEOs. After reading a scan
code, the interrupt service may translate a scan code or a combination of scan
codes. Also. the interrupt service reacts to certain scan code combinations· such
as Ctrl/AltIDel.
Interrupt 09H has no arguments, preserves all registers, and returns no values.
Using this interrupt requires knowledge of the VAXmate hardware. the ROM
BIOS, and the operating system. The keyboard-interface controller is described
in Chapter 8. For information about the ROM BIOS keyboard input service,
see Interrupt 16H.

Chapter 15 - ROM BIOS Interrupts 08H and 09H

15 - 5

Interrupt OBH: COM2 / Modem
Hardware Interrupt - Industry-Standard with DIGITAL Extensions
Interrupt OBH provides the ROM BIOS with hardware-interrupt services for
the optional integral modem or any asynchronous serial communications option
that is configured as COM2. This interrupt service monitors the state of the
serial communications protocol and line status. It also transmits and receives
characters as required.
Interrupt OBH has no arguments, preserves all registers, and returns no
values.
Using this interrupt requires knowledge of the VAXmate hardware, the ROM
BIOS, and the operating system. For information about the 8250A serial communications device, see Chapter 9. For more information about the ROM BIOS
asynchronous communications service, see Interrupt 14H.
The integral modem is an optional device for the VAXmate workstation. For
information about the integral modem, see the Modem User's Guide.

Interrupt OCH: COM! / Serial
Hardware Interrupt - Industry-Standard with DIGITAL Extensions
Interrupt OCH provides the ROM BIOS with hardware-interrupt services for
COM1 asynchronous serial communications port. This interrupt service monitors the state of the serial communications protocol and the line status. It also
transmits and receives characters as required.
Interrupt OCH has no arguments, preserves all registers, and returns no
values.
Using this interrupt requires knowledge of the VAXmate hardware, the ROM
BIOS, and the operating system. For information about the 8250A serial communications device, see Chapter 9. For information about the ROM BIOS
asynchronous communications service, see Interrupt 14H.

15 - 6

Chapter 15 - ROM BIOS Interrupt OBH and OCH

Interrupt OEH: Floppy Disk
Hardware Interrupt - Industry-Standard
Interrupt OEH provides the ROM BIOS with hardware-interrupt services for
the diskette drive controller. This interrupt service provides a operation complete indication from the diskette drive controller.
Interrupt OEH has no arguments, preserves all registers, and returns no
values.
Using this interrupt requires knowledge of the VAXmate hardware, the ROM
BIOS, and the operating system. For information about the diskette drive controller, see Chapter 11. For more information about the ROM BIOS diskette
110 service, see Interrupts 13H, 40H, and lEH.

Chapter 15 - ROM BIOS Interrupt OEH

15 - 7

Interrupt lOH: Video Input/Output
Software Interrupt - Industry-Standard with DIGITAL Extensions
Interrupt 10H provides access to several video management and display functions. These functions support the VAXmate graphic video system, industrystandard color graphic, and monochrome adapters.
NOTE
Although the VAXmate workstation supports color graphics, it
comes with a monochrome graphics monitor. Colors are
displayed as shades of gray or intensity levels.
Use of an industry-standard color graphic adapter or a monochrome adapter requires an external monitor.
When using interrupt 10H functions, the following rules apply:
• In general, there are no validity tests performed on interrupt 10H arguments. Invalid functions or function arguments can destroy data or cause
unpredictable results. The validity of arguments depends on the video
mode in effect at the time.
• The VAXmate graphic video system has a feature that reduces image
burning on the video monitor. When there has been no keyboard input
and no video output for 30 minutes, the video output is disabled.
Execution of any interrupt 10H function or pressing any key on the keyboard enables video output and initializes the screen-blanking counter to
30 minutes. Also, reading or writing the video RAM enables the video
output Ibut not the screen-blanking counter).
• All graphic text operations are based on an 8 x 8 character cell size.
• The video hardware can operate in a graphic mode of 800 x 252 x 4
colors, which emulates DIGITAL terminals. This video mode ID2H), has
the following limited ROM BIOS support:
Function OOH: Set the video mode
Function OFH: Return the video state
Function D1H: Font RAM and color mapping support IColor mapping
only)
These are the only functions supported for video mode D2H. The display
of graphics or graphic text must be accomplished directly by the application. For detailed information on direct programming of the VAXmate
graphic video system, see Chapter 7.
The value in the AH register specifies the desired function. Most functions require additional information in other registers. The function-specific register
usage is defined within the description of each function. Table 15-2 lists the
available functions.
15 - 8

Chapter 15 - ROM BIOS Interrupt 10H

Table 15-2

Interrupt 10H: Video 1/0 Functions

Function

Description

AH = OOH

Set video mode

Yes

AH = OlH

Set cursor type

AH = 02H

Set cursor position

AH = 03H

Read cursor position

AH = 04H

AH = 05H

Read light-pen position
Select display page

AH = 06H

Scroll active page up

AH = 07H

Scroll active page down

AH = 08H

Read character and attribute at current cursor
position

AH = 09H

Write character and attribute at current cursor
position

AH = OAH

Write character at current cursor position

AH = OBH

Set color palette

AH = OCH

Write pixel

AH = ODH

Read pixel

AH = OEH

TTY write character

AH = OFH

Read current video state

Yes

AB = lOB

Reserved

AH = llH

Reserved

AH = l2H

Reserved

AH = l3H

TTY write string

AH = DOH

Enable/disable 256 character graphic fonts

Yes

AH = DlH

Font RAM and color map support

Yes

DIGITAL
Extended

Chapter 15 - ROM BIOS Interrupt 10H

15 - 9

Function OOH: Set Video Mode
Industry-Standard with DIGITAL Extensions
Parameters
AH = OOH
AL = One of the AL values listed in Table 15-3
Returns
Nothing
Table 15-3 list the video modes supported by the ROM BIOS.
Table 15-3

Video Modes

Description

OOH
OlH
02H
03H
04H
05H
06H
07H
DOH
DIH
D2H

40 X 25 monochrome text *
40 X 25 color text *
80 X 25 monochrome text *
80 X 25 color text *
320 X 200 X 4 color graphic
320 X 200 monochrome graphic
640 X 200 monochrome graphic
80 X 25 monochrome (requires monochrome adapter)
640 X 400 X 2 color DIGITAL extended graphics
640 X 400 X 4 color DIGITAL extended graphics
800 X 252 X 4 color DIGITAL extended graphics

* In modes 0 and 2, monochrome means lack of a color burst signal at the
composite video connector of an industry-standard color graphics adapter.
This is the opposite of modes 1 and 3, which do produce a color burst
signal at the composite video connector of an industry-standard color
graphics adapter.
For the VAXmate workstation, there is no difference between modes 0
and 1 or between modes 2 and 3.

15 - 10

Chapter 15 - ROM BIOS Interrupt 10H

This function selects the video mode. Selecting a video mode configures the
video controller and clears the display.
Video mode 07H is only valid when an industry-standard monochrome adapter
is installed in an expansion slot. An industry-standard monochrome or color
graphics adapter installed in an expansion slot is recognized by the ROM BIOS
during the power-up sequence. On finding an industry-standard monochrome or
color graphic adapter, the ROM BIOS disables the VAXmate graphic video
system with the following consequences:
• If an industry-standard monochrome adapter is installed, video mode 07H

becomes the only valid video mode. Attempts to use any other mode are
forced to video mode 07H.
•

If an industry-standard color graphic adapter is installed, video modes

07H, DOH, DIH, and D2H are not valid modes.
Changing between an industry-standard mode and a DIGITAL extended mode
resets the color map to values appropriate for the mode. See function DIH.
Changing from one industry-standard mode to another industry-standard mode
does not affect the color map. Also, changing from one DIGITAL extended
mode to another DIGITAL extended mode does not affect the color map.
For detailed information on direct programming of the VAXmate graphic video
system, see Chapter 7.

Chapter 15 - ROM BIOS Interrupt 10H

15 - 11

Function OlH: Set Cursor Type
Industry-Standard

Parameters
AH = 01H
CH = The cursor start scan line
CL = The cursor end scan line
Returns
Nothing
Table 15-4 lists the allowed values for each of the ROM BIOS supported video
modes.
Table 15-4

Mode-Dependent Values for Set Cursor Type

Modes

Reg

Range

CH
CL

00H-07H
OOH-07H

CH
CL

OOH-ODH
OOH-ODH

OOH, 01H, 02H. 03H

07H

05H, 06H, DOH, DIH,
D2H
CH
CL

Comments
Text mode
Cursor start scan line
Cursor end scan line
Monochrome text
Cursor start scan line
Cursor end scan line
No cursor in graphic modes
Ignored
Ignored

This function selects, within the character cell, the size and placement of the
cursor. When this function executes, it checks the current video mode. If the
current video mode is one of the graphic modes, the initialization sequence is
ignored.
The VAXmate graphic video system character cell height is 16 scan lines, but
the allowable arguments are limited to the range 0-7. To maintain compatibility. the start value is multiplied by two, and the end value is multiplied by two
and incremented.
A start or end value greater than 7 (13 for the monochrome adapter) disables
the cursor. Also, an end value that is less than the start value disables the
cursor. That is, the cursor becomes invisible. Although the cursor is invisible.
subsequent commands that change the cursor position continue to be effective.
15 - 12

Chapter 15 - ROM BIOS Interrupt 10H

Function 02H: Set Cursor Position
Industry-Standard
Parameters
AH = 02H
o H = The row position
DL = The column position
BH = The page number
Returns
Nothing
This function sets the logical cursor position for any display page. Because the
ROM BIOS maintains a logical cursor position for each display page. it is
possible to change the cursor position for a display page that is not active.
When the display page becomes active. the cursor is moved to the new position. If the indicated display page is the active page. the cursor is moved to the
new position.
The unit of measurement is one character cell.
Graphic modes have the following limitations:
• The display page must be page zero.
• No cursor is displayed, but the cursor position is maintained.
• This function is not supported for graphic mode D2H.

Chapter 15 - ROM BIOS Interrupt 10H

15 - 13

Function 03H: Read Cursor Position
Industry-Standard
Parameters
AH = 03H
BH = The page number
Returns
CH = The cursor start scan line
CL = The cursor end scan line
DH = The row position
DL = The column position
This function returns the cursor position of the indicated display page and the
current cursor type. It does not support video mode D2H.

15 - 14

Chapter 15 - ROM BIOS Interrupt 10H

Function 04H: Read Light-Pen Position
Industry-Standard
Parameters
AH = 04H
Returns
AH = OOH

No input or the switch is not closed

AH = 01H

The light pen read
BX = The pixel column 10-319 or 0-6391
CH = The pixel scan line (0-1991
DH = The row character position
DL = The column character position

This function returns the position of the light pen.
To read a light-pen position successfully, the following conditions must exist:
• A video adapter that supports light pens must be installed.
• The read switch on the light pen must be closed.
• The light pen must have detected an input signal.
NOTE
The VAXmate graphic video system does not support light pens.
When the VAXmate graphic video system is in use, the returned AH register contains zero.

Chapter 15 - ROM BIOS Interrupt 10H

15 - 15

Function 05H: Set Page Function
Industry-Standard

Parameters
AH = 05H

AL = The page number
Returns
Nothing
This function selects the active display page. The page is displayed and the
cursor is positioned according to the cursor position for that page.
Valid page numbers depend on the video mode in effect.
Mode

Range

OOH
01H
02H
03H
04H
05H
06H
07H
DOH
D1H
D2H

OOH through 07H
OOH through 07H
OOH through 03H
OOH through 03H

15- 16

Chapter 15 - ROM BIOS Interrupt 10H

Function call ignored
Function call ignored
Function call ignored
Function call ignored
Function call ignored
Function call ignored
Function call ignored

Function 06H: Scroll Active Page Up
Function 07H: Scroll Active Page Down
Parameters
AH = 06H

AH = 07H

Scroll Up
AL = The number of rows (0 means blank the window I
BH = The attribute byte
CH = The row of upper-left corner of scroll window
CL = The column of upper-left corner of scroll window
D H = The row of lower-right corner of scroll window
DL = The column of lower-right corner of scroll window
Scroll Down
AL = The number of rows (0 means blank the windowl
BH = The attribute byte
CH = The row of upper-left corner of scroll window
CL = The column of upper-left corner of scroll window
DH = The row of lower-right corner of scroll window
DL = The column of lower-right corner of scroll window

Returns
Nothing
These functions scroll data within a window on the screen. They work in text
and graphic modes, but do not support video mode D2H.
For these functions, the AL, CH, CL, DH, and DL register values always refer
to character positions. In graphic modes, the graphic data within a character
cell area is treated as a single unit. The AL, CH, and DH registers contain
character row values in the range 0 through 24. The CL and DL registers contain character column values in the range 0 through 39 or 0 through 79.
The scroll area is a window or rectangular area defined by two diagonal points.
The two points are defined by the contents of the CX and DX registers. The
CX register (CH and CL) defines the upper-left corner of the window. The DX
register (DH and DL) defines the lower-right corner of the window.
The scroll up operation moves the rows one at a time so that row CH + 1
moves to row CH, row CH + 2 moves to row CH + 1, and so on. The scroll
down operation moves the rows one at a time so that row DH - 1 moves to row
DH, row DH - 2 moves to row DH - 1, and so on. When the last row is vacated, it is blanked. This process repeats until the specified number of rows are
scrolled. If the specified number of rows is greater than or equal to the vertical
size of the window, the entire window is cleared. Also, if the AL register equals
0, the entire window is cleared.
Chapter 15 - ROM BIOS Interrupt 10H

15 - 17

The contents of the CL and DL registers determine the horizontal position and
width of the scrolled area. For example, if the CL register contains 20 and the
DL register contains 40, only those columns and the data between them is
scrolled.
When using this function, the key difference between text and graphic modes
is the way the attribute byte is applied. In text modes, a space character is
written to the data byte and the contents of the BH register are written to the
attribute byte. In graphic modes, the contents of the BH register are written
as graphic data one byte at a time. Thus, if the current graphic mode requires
two bits of information for each pixel, the BH register must contain data for
four pixels.
Only the active display page can be scrolled. Data scrolled out of the window is
lost. It does not go into the adjacent page.
The cursor position remains the same after scrolling as it was before scrolling.
This function is not supported for video mode D2H.

15 - 18

Chapter 15 - ROM BIOS Interrupt 10H

Function 08H: Read Character and Attribute at Cursor
Position
Industry-Standard

Parameters
AH = 08H
BH = The page number (text modes onlyl
Returns
AL = The character
AH = The attribute (text modes onlyl
In text modes, this function returns the character and attribute at the cursor
location of the specified display page. A page other than the active display page
can be specified. The cursor location, character, and attribute are extracted
from the indicated display page data.
In graphic modes, there is only one page, so the page selection is ignored.
Because there is no attribute byte, only the character value is returned. This is
accomplished similarly to the interrupt 05H interpretation of graphic text. The
ROM BIOS attempts to interpret the pixel pattern in the character cell at the
current cursor location. The pixel pattern is matched with the bit patterns of
the characters used for graphic text. Interrupt 1FH (OOOO:007CHl contains a
pointer to the graphic text character set used in the comparison. If no match is
found, the function returns a character value of O.
Normally. interrupt IFH points to a table containing 128 entries in the range
80H-FFH. However, interrupt lOH function DOH provides an extended mode
where interrupt 1FH points to a table containing 256 entries in the range OOHFFH.
This function is not supported for video mode D2H.

Chapter 15 - ROM BIOS Interrupt 10H

15 - 19

Function 09H: Write Character and Attribute at Cursor
Position
Industry-Standard

Parameters
AH = 09H
AL = The character
BH = The page number (text modes only)
BL = The attribute byte (text modes) or color (graphic modes)
If bit 7 is set (1), exclusive OR the current contents with the contents
of BL and store the result. Normally, the contents of BL are stored.

CX = Number of times to write character and attribute
Returns
Nothing
This function writes a character and attribute at the current cursor position.
The current cursor position is extracted from the page data of the page specified in register BH. The position of the cursor is not updated. That is, the
cursor remains as it was when the function was called. Register CX specifies
the number of times to repeat the operation. Each repetition advances the posi·
tion one character location. A line wrap occurs at the end of a line. Counts thai
exceed the page size continue into the adjacent display page (if one exists).
In graphic modes, the character code in AL is an index into a table of graphic
characters. If 256 character mode is not enabled, and the character code is less
than 80H, the information is retrieved from the ROM. If 256 character mode i:
not enabled, and the character code is 80H or greater, the information is
retrieved from the table pointed to by interrupt vector 1FH. If 256 character
mode is enabled, interrupt vector 1FH points to the beginning of the entire 25j
character table. For each pixel that is on in the pattern, the color selection in
register BL is shifted into position and written to display memory. The numbel
of bits used from register BL is mode dependent. For example, a 4-color mode
uses the two least significant bits, and a 2-color mode uses the least significanl
bit. If bit 7 of the BL register is set to 1, each display memory field is exclusive aRed with the color field in register BL, and the result is written to
display memory.
This function is not supported for video mode D2H.
15 - 20

Chapter 15 - ROM BIOS Interrupt lOU

Function OAR: Write Character at Cursor Position
Industry-Standard

Parameters

AH
AL
BH
BL

=
=
=
=

OAH
The character
The page number (text modes only)
The color (graphic modes only)
If bit 7 is set (1), exclusive OR the current contents with the contents
of BL and store the result. Normally the contents of BL are stored.

CX = Number of times to write character
Returns
Nothing
This function writes a character at the current cursor position. It is similar to
function 09H except that in text modes, a new attribute is not written. The
current cursor position is extracted from the page data of the page as specified
in register BH. The position of the cursor is not updated. That is, the cursor
remains as it was when the function was called. Register CX specifies the
number of times to repeat the operation. Each repetition advances the position
one character location. A line wrap occurs at the end of a line. Counts that
exceed the page size continue into the adjacent display page (if one exists).
In graphic modes, the character code in AL is an index into a table of graphic
characters. If 256 character mode is not enabled, and the character code is less
than SOH, the information is retrieved from the ROM. If 256 character mode is
not enabled, and the character code is SOH or greater, the information is
retrieved from the table pointed to by interrupt vector 1FH. If 256 character
mode is enabled. interrupt vector 1FH points to the beginning of the entire 256
character table. For each pixel that is on in the pattern, the color selection in
register BL is shifted into position and written to display memory. The number
of bits used from register BL is mode dependent. For example, a 4-color mode
uses the two least significant bits. If bit 7 of the BL register is set to 1, the
current bits of the specified pixel field are exclusive ORed with the appropriate
BL bits, and the results are written to the specified pixel field. Otherwise, the
appropriate BL bits replace the current bits of the specified pixel field.
This function is not supported for video mode D2H.
Chapter 15 - ROM BIOS Interrupt 10H

15 - 21

Function OBH: Set Color Palette
Industry-Standard

Parameters
AH = OBH
BH = OOH

BL bits 4-0 control the background color and the palette intensity bit
BH = OlH
BL bit 0 selects the color palette
BL = The background color or palette, depending on contents of BH

Returns
Nothing
This function is not supported for video mode D2H.
If register BH equals 0, this function controls the palette intensity bit and,
depending· on the current video mode, sets the background or border color. If
current video mode is OlH or 03H, it sets the border color Ithe VAXmate
border color is always black.) Otherwise, it sets the background color.
In either case, bits 4-0 of the BL register are interpreted as follows:

BL Bit

Description
Intensity control of the palette colors

m Intensity control of the color

3
2

IR) Red contribution to the color
(G) Green contribution to the color
(B) Blue contribution to the color

NOTE
The VAXmate graphic video system does not control the border
color. The border color is always black.
If register BH equals one, this function selects the color palette for graphic
video mode 04 H.

Pixel Field Value

Palette 0 Selected

Palette 1 Selected

OlH
02H
03H

Green
Red
Yellow

Cyan
Magenta
White

15 - 22

Chapter 15 - ROM BIOS Interrupt 10H

Function OCH: Write Pixel
Industry-Standard
Parameters
AH = oeH
AL = The color value
If bit 7 is set (11. exclusive OR the current contents with the contents
of AL and store the result_ Normally the contents of AL are stored.

ex = The pixel column number
ox = The pixel row number

Returns
Nothing
This function sets a pixel field, specified by registers ex and OX, to the color
specified in register AL. This function is ignored in text modes.
The bits used from register AL depend on the current graphic mode:
Graphic mode

Bits used

Number of colors

04H
05H
06H
DOH
01H

7 and 1-0
7 and 0
7 and 0
7 and 0
7 and 1-0

4
Monochrome
Monochrome
Monochrome
4

If bit 7 of the AL register is set to 1. the current bits of the specified pixel
field are exclusive ORed with the appropriate AL bits, and the results are written to the specified pixel field. Otherwise, the appropriate AL bits replace the
current bits of the specified pixel field.

This function is not supported for video mode 02H.

Chapter 15 - ROM BIOS Interrupt 10H

15 - 23

Function ODH: Read Pixel
Industry-Standard

Parameters
AH = OOH
ex = The pixel column number

DX = The pixel row number
Returns
AL = The color value of the pixel
This function returns the color of the pixel field specified by registers ex and

ox.

The valid bits returned in the AL register depend on the current graphic mode.
Graphic mode

Bits used

Number of colors

04H
05H
06H
DOH
01H

1-0
0
0
0
1-0

4
Monochrome
Monochrome
Monochrome
4

This function is not supported for video mode 02H.

15 - 24

Chapter 15 - ROM BIOS Interrupt 10H

Function OEH: Write Character Using Terminal
Emulation
Industry-Standard

Parameters
AH = OEH
AL = The character
BL = The foreground color (graphic mode onlyl
Returns
Nothing
This function is sometimes known as Write TTY. It operates in text and
graphics modes and accesses only the active display page.
Prior to any other operations, the character in AL is tested for one of four
values:
•

If the character is a carriage return (ODHI, the cursor is moved to the
start of the current line.

•

If the character is backspace (OS HI, the cursor is moved backward one
character position. If the cursor is at the beginning of the line, the character is ignored.

•

If the character is a line feed (OAHI, the cursor is moved to the same
column position on the next line. If the cursor is on the last line, the
screen is scrolled up one line. In this case, the cursor remains in the same
location.

•

If the character is a bell character (07HI, a bell sound (beep I is issued

from the speaker.
For all other values, the character is written to the current cursor position and
the cursor is advanced to the next position in the line. If the cursor was at the
last position on the line, it is positioned at the first location on the next line. If
the cursor was at the last position on the last line, the screen is scrolled up one
line, and the cursor is positioned at the start of an empty line.
In graphic modes, the character code in AL is an index into a table of graphic
characters. If 256 character mode is not enabled, and the character code is less
than SOH, the information is retrieved from the ROM. If 256 character mode is
not enabled, and the character code is SOH or greater, the information is
retrieved from the table pointed to by interrupt vector IFH. If 256 character
mode is enabled, interrupt vector IFH points to the beginning of the entire 256
Chapter 15 - ROM BIOS Interrupt 10H

15 - 25

character table. For each pixel that is on in the pattern, the color selection in
register BL is shifted into position and written to display memory. The number
of bits used from register BL is mode dependent. For example, a 4-color mode
uses the two least significant bits. If bit 7 of the BL register is set to 1, the
current bits of the specified pixel field are exclusive ORed with the appropriate
BL bits, and the results are written to the specified pixel field. Otherwise, the
appropriate BL bits replace the current bits of the specified pixel field.
This function is not supported for video mode D2H.

15 - 26

Chapter 15 - ROM BIOS Interrupt 10H

Function OFH: Read Current Video State
Industry-Standard
Parameters
AH = OFH
Returns
AL = The current video mode
AH = The number of columns
BH = The current page
This function returns the current state of the video system. In text and graphic
modes, the value in the AH register is the width of the screen in character
cells. The mode value returned in the AL register is defined as follows:
AL

Description

OOH
OIH
02H
03H
04H
05H
06H
07H
DOH
DJ H
D2H

40 x 25 monochrome text
40 x 25 color text
80 x 25 monochrome text
80 x 25 color text
320 x 200 x 4 color graphic
320 x 200 monochrome graphic
640 x 200 monochrome graphic
80 x 25 monochrome (requires monochrome adapter)
640 x 400 x 2 color DIGITAL extended graphics
640 x 400 x 4 color DIGITAL extended graphics
800 x 252 x 4 color DIGITAL extended graphics

Chapter 15 - ROM BIOS Interrupt 10H

15 - 27

Function 13H: TTY Write String
Industry-Standard
Parameters
AH = 13H
AL = OOH

The string pointed to by ES:BP is a set of contiguous character
codes. The register BL contains the attribute that is applied as
each character is written to the display page. The CX register
specifies the number of characters to write. After the last character is written, the cursor is restored to the position it had
before this function was executed.

AL = 01H

This subfunction is similar to AL = 0 except that the cursor is
positioned after the last character in the string.

AL = 02H

The string pointed to by ES:BP is a set of contiguous byte
pairs. Each byte pair contains a character code and an attribute.
The first byte of the string is the character; the second is the
attribute. The BL register is ignored. The CX register specifies
the number of characters to write, not the length of the string.
After the last character is written, the cursor is restored to the
position it had before this function was executed.

AL = 03H

This subfunction is similar to AL = 2 except that the cursor is
positioned after the last character in the string.

BH = Display the page to write
BL = The attribute (AL = 0 or AL = 1)
CX = The number of characters to write
DH = The row position of the first character
DL = The column position of the first character
ES:BP = The pointer to the start of the string to write
Returns
Nothing
This function writes a string of characters to the specified display page. It operates in text and graphics modes.
15 - 28

Chapter 15 - ROM BIOS Interrupt 10H

Prior to writing each character, it is tested for one of four values:
NOTE
Even though another page is designated in register BH, the following operations occur on the current display page.
•

If the character is a carriage return (OOHl, the cursor is moved to the
start of the current line.

• If the character is backspace (08HI, the cursor is moved backward one
character position. If the cursor is at the beginning of the line, the char-

acter is ignored.
•

• If the character is a bell character (07H), a bell sound (beep) is issued

from the speaker.
For all other values, the character is written to the current cursor position. and
the cursor is advanced to the next position in the line. If the cursor was at the
last position on the line. it is positioned at the first location on the next line. If
the cursor was at the last position on the last line. the screen is scrolled up one
line, and the cursor is positioned at the start of an empty line.
In graphic modes. the character code in AL is an index into a table of graphic
characters. If 256 character mode is not enabled. and the character code is less
than 80H. the information is retrieved from the ROM. If 256 character mode is
not enabled. and the character code is 80H or greater, the information is
retrieved from the table pointed to by interrupt vector IFH. If 256 character
mode is enabled. interrupt vector IFH points to the beginning of the entire 256
character table. For each pixel that is on in the pattern, the color selection is
shifted into position and written to display memory. The number of bits used is
mode dependent. For example. a 4-color mode uses the two least significant
bits. If bit 7 of the color selection is set to 1, the current bits of the specified
pixel field are exclusive ORed with the color selection bits, and the results are
written to the specified pixel field. Otherwise, the appropriate BL bits replace
the current bits of the specified pixel field.
This function is not supported for video mode 02H.

Chapter 15 - ROM BIOS Interrupt 10H

15 - 29

Function DOH: Enable/Disable 256 Character Graphic
Font
DIGITAL Extension
Parameters
AH = DOH
AL = OOH

Interrupt IFH IOOOO:007CH) points to 128 graphic mode
characters in the range 80H through FFH.

AL = 0IH-FFH

Interrupt IFH (0000:007CH) points to 256 graphic mode
characters in the range OOH through FFH.

Returns
Nothing
Function DOH extends user-defined font tables. On power-up, the ROM BIOS
accesses the ROM for character codes OOH through 7FH. The character codes
80H through FFH are accessed through interrupt IFH (0000:007CH).
This function is not supported for video mode 02H.

15 - 30

Chapter 15 - ROM BIOS Interrupt 10H

Function DIH: Font RAM and Color Map Support
DIGITAL Extension
This function provides access to the extended hardware capabilities of the
VAXmate graphic video system. Using this function, the font RAM or the color
map can be read, written, or restored to the default condition.

Font RAM Functions
Parameters

=
AL
=
ex
=
DL
=
ES:BX =

DH
DH
DH

=
=

DIH
OOH

The font RAM functions

The number of character descriptions to transfer jOOOlH to
0100H)
The first character to transfer (OOH to FFH)
The pointer to the data buffer (at least CX * 16 bytes in size)

OOH
01H
02H

Restore the defaults mS:BX is ignored)
Copy the data at ES:BX to the font RAM
Copy the font RAM to the buffer at ES:BX

Returns
Nothing
In text modes only, the font RAM acts as a character generator ROM. This
subfunction can restore the font RAM to default conditions. It can also read or
write one or more sequential character descriptions in the font RAM.
This function is not available in graphic modes.
Each character description contains 16 bytes of data. Each byte of data represents a scan line in the character cell. The first byte of the character description is the top scan line (scan line 0) in the character cell. Within each byte,
the most significant bit is the leftmost pixel. The character descriptions are
arranged in order of increasing character code value. Reading 256 character
descriptions from the font RAM requires a 4096 byte buffer.

Chapter 15 - ROM BIOS Interrupt 10H

15 - 31

Color Map Functions
Parameters

DIH

01H

CX
=
DL
=
ES:BX =
DH
DH
DH

=
=

The color map functions

The number of entries to transfer (OIH to 10H)
The map address of the entry to transfer (OOH to OFH)
The pointer to the data buffer (at least CX words in size)
OOH
01H
02H

Restore the defaults (ES:BX is ignored)
Copy the data at ES:BX to the color map
Copy the color map to the buffer at ES:BX

Returns
Nothing
This subfunction can read or write one or more sequential values in the color
map. Any of the 16 IROB inputs can be mapped to any of the 16 outputs. The
default condition is gray-scale outputs at power-up. The color map is a synonym
for the video look-up table (VLT). For more information on the VLT, see
Chapter 7.
The color map is arranged as 16 words of IROB output data. Only the least
significant 4 bits of data are output. When the video controller accesses video
memory, the attributes or graphic data are used as an offset into the color
map. The contents of that location in the color map are sent to the video
output circuit. To calculate the offset accessed by any IROB value, use the following bit values:

Bit value

o
1
2
3

Attribute
I (Intensity)
B (Blue)

o (Oreen)
R IRed)

Thus, an attribute of intensified red (lROB = COH) accesses location 09H of
the 16 locations in the color map.
15 - 32

Chapter 15 - ROM BIOS Interrupt 10H

On power-up or system reset and when changing from a DIGITAL extended
4-color video mode 101H or D2HI to an industry-standard video mode, the color
map is initialized to the values in Table 15-5. The color map defined in Table
15-5 supports video modes OOH, 01H, 02H, 03H, 04H, 05H, 06H and DOH.
When changing from any of these modes to video mode DIH or D2H, the color
map is initialized to the values defined in Table 15-6.

Table 15-5

Default Color Map

Offset
RGB I

Contents
R G B I

0
0
0
0
0
0
0
0
1
1

1
1
1
1
1
1

0
0
0
0
1

1
1
1
0
0
0
0
1
1
1
1

0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1

0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1

0
0
0
0
0
0
0
1
1
1
1
1
1
1
0
1

o 0 0
o 0 1
1
1
0
0
1
1
o 0
o 0
0 1
0 1
1 0
1 0
1 1
1 1

0
0
1
1
1
1

0
1
0
1
0
0
0
1
0
1
0
1
1
1

Color

Intensity

Black
Gray
Blue
Light blue
Green
Light green
Cyan
White
Red
Light red
Magenta
Light magenta
Brown
Yellow
Light cyan
Intense white

0
1
2
3
4
5
6
14
8
9

10
11
12
13
7

Chapter 15 - ROM BIOS Interrupt 10H

15 - 33

Table 15-6 Color Map for Video Modes DIH and D2H
Offset
R G B I

Contents
R G B I

Color

Intensity

0 0
0 1
1 0
1 1
0 0
0 1
1 0
1 1
0 0
0 1
1 0
1 1
0 0
0 1
1 0
1 1

o0 0 0
1 000
o1 o0
o 1 1 1

Black
Red
Green
Light cyan

0
4
8

0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1

0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1

15 - 34

Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used

Chapter 15 - ROM BIOS Interrupt 10H

Interrupt IlH: Read Configuration
Software Interrupt - Industry-Standard
Parameters
None
Returns
AX = Configuration data
15-14

This two bit field equals the number of parallel printer ports in
the system.
00 = Zero parallel printer ports
01 = One parallel printer port
10 = Two parallel printer ports
11 = Three parallel printer ports

Unused

Game adapter

o = Game adapter not installed
1 = Game adapter installed

11-9

This three-bit field equals the number of asynchronous serial
ports in the system. The VAXmate workstation has an integral
serial port (COMl) and reserves COM2 for the optional integral modem. The serial printer port is not included in this
count. The maximum number supported is four.
000 = There are zero serial ports
001 = There is one serial port
010 = There are two serial ports
011 = There are three serial ports
100 = There are four serial ports

Unused

7-6

This two-bit field equals the number of diskette drives in the
system minus one. This field is only valid when bit 0 equals 1.
00 = 1 diskette drive
01 = 2 diskette drives
10 = 3 diskette drives
11 = 4 diskette drives

Chapter 15 - ROM BIOS Interrupt llH

15 - 35

Returns Unterrupt llH: Read Configuration - cont.t
5-4

Initial video mode (see Interrupt 10H)
00 = Unused
01 = 40 X 25 {Color Graphics Adaptert
10 = 80 X 25 {Color Graphics Adapted
11 = 80 X 25 {Monochrome Adaptert

3-2

Unused

80287

o = 80287 not installed
1 = 80287 installed

Diskette drive

o = No diskette drives installed {bits 7-6 are invalidt

1 = At least 1 diskette drive installed (bits 7-6 are valid)

This function returns the system configuration information. If the expansion
box and battery are present and the CMOS RAM has not lost power, the
configuration data is extracted from the CMOS RAM. Otherwise, the
configuration data is extracted from the power-up initialization data.
Additional configuration data is available through function DOH of interrupt
15H. This configuration data is specific to the VAXmate workstation.

15 - 36

Chapter 15 - ROM BIOS Interrupt llH

Interrupt 12H: Return Memory Size
Software Interrupt - Industry-Standard

Parameters
None
Returns
AX = Memory size measured in 1 K blocks
This interrupt returns the memory size as the number of contiguous lK 00241
memory blocks. Only the low address memory (OOOO:OOOOH to OOOB:FFFFHl is
measured by this function. The VAXmate workstation always returns 640.

Chapter 15 - ROM BIOS Interrupt 12H

15 - 37

Interrupt 13H: Disk Input/Output (I/O)
Software Interrupt - Industry-Standard with DIGITAL Extensions
This interrupt provides a generalized disk I/O service for diskettes and hard
disks. If a hard disk is not installed, interrupt 13H points to the diskette functions. If a hard disk is installed, interrupt 13H points to the hard disk functions, and interrupt 40H points to the diskette functions.
Bit 7 of the drive number distinguishes diskette and hard disk function
requests. If bit 7 is set (1), the request is for a hard disk function. Thus, hard
disks are assigned drive numbers equal to or greater than SOH. When a hard
disk is installed, interrupt 13H compares the drive number to SOH. Requests
with drive numbers less than 80H are revectored to interrupt 40H.
This revectoring information is provided only for clarity. Always use interrupt
13H for both diskette and hard disk functions.
NOTE
Most operating systems intercept and sometimes modify interrupt 13H requests. When developing or testing software, this
fact is important. For example, several interrupt 13H functions
warn against exceeding a physical page boundary during disk
I/O. By translating a single I/O request into many small sized
110 requests, some operating systems eliminate page boundary
problems.

15 - 38

Chapter 15 - ROM BIOS Interrupt 138

The following is a list of the interrupt 13H hard disk functions:
Function
Number

Description

DIGITAL
Extended

OOH
01H
02H
03H
04H
05H
08H
09H
OAH
OBH
OCH
ODH
10H
llH
14H
15H
DOH

Initialize Entire Disk Subsystem
Return Status Code Of Last 1/0 Request
Read One Or More Disk Sectors
Write One Or More Disk Sectors
Verify One Or More Disk Sectors
Format A Track
Return Current Drive Parameters
Initialize Drive Characteristics
Read Long
Write Long
Seek To Specific Cylinder
Hard Disk Reset
Test Drive Ready
Recalibrate Drive
Execute Controller Internal Diagnostics
Return Drive Type
Read Long 256 Byte Sector

No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
Yes

The following is a list of the interrupt 13H diskette functions:
Function
Number

Description

DIGITAL
Extended

OOH
01H
02H
03H
04H
05H
15H
16H
17H

Initialize Diskette Subsystem
Return Status Code Of Last 110 Request
Read One Or More Track Sectors
Write One Or More Track Sectors
Verify One Or More Track Sectors
Format Track
Return Drive Type
Return Change Line Status
Set Drive And Media Type For Format

No
No
No
No
No
No
No
No
No

Chapter 15 - ROM BIOS Interrupt 13U

15 - 39

Hard Disk Functions
The value in the AH register indicates the desired hard disk function. All hard
disk functions require a drive number in the DL register. Because hard disk
drive numbers start at 80H, hard disk 0 is 80H, and hard disk 1 is 81H.
Functions requiring a cylinder number expect a 10-bit value in the range of

o to 1023. The low-order eight bits of the cylinder number are passed in the
CH register. The two high-order bits of the cylinder number are passed in the
two high-order bits of the CL register. At times, bits 4-0 of the the CL register
contain a sector number. Some functions require a cylinder and sector number.
Except for the flags register, all registers not mentioned in the function
description are preserved.

Hard Disk Errors
If CF is set (1), an error occurred, and the AH register contains the error code.

Table 15-7 lists the hard disk error codes.
Table 15-7

Hard Disk Error Codes

Error
Code

Description

FFH
EOH
CCH
BBH

Sense operation failed (not implemented)
Status error (error register = 0)
Write fault on selected drive
Undefined error occurred
Drive not ready
Hardware failed to respond
Seek operation failed
Disk controller failed
ECC corrected data error

AAH

80H
40H
20H
llH

The ECC algorithm corrected a recoverable error. The data is probably valid, however the calling program must make that decision.
OBH
OAH
09H
07H
05H
04H
02H
01H

ECC for data incorrect
Bad track flag detected (not implemented)
Bad sector flag detected
Data extends too far (past 64K page boundary)
Drive parameter activity failed
Reset failed
Sector not found
Address mark not found
Illegal I/O request (bad command)

15- 40

Chapter 15 - ROM BIOS Interrupt 13H

lOH

Hard Disk Parameter Tables
A hard disk parameter table defines the physical characteristics of a hard disk.
The values in the table are used by the hard disk driver to initialize the hard
disk controller. Table 15-8 describes the contents of a hard disk parameter
table.
Table 15-8

Hard Disk Parameter Table Description

Offset

Size

Description

OOH
02H
03H
05H
07H
08H

1 Word
1 Byte
1 Word
1 Word
1 Byte
1 Byte

Maximum number of cylinders on hard disk drive
Maximum number of heads on hard disk drive
Not used
Cylinder number to start using write precompensation
Not used
Control byte sent to controller
If bit 7 or bit 6 is set (1), disable retries
If bit 3 is set (11, the hard disk has more than eight heads

09H
OCH
OEH
OFH

3 Bytes
1 Word
1 Byte
1 Byte

Not used
Landing zone
Number of sectors per track
Reserved for future use

The hard disk parameter tables are located in DIGITAL private RAM. During
the power-up sequence. the disk type is extracted from CMOS RAM. If the
disk type is unknown. the table contains all zeros. If the disk type is one of the
14 industry-standard types. the table is initialized from the hard disk data in
the ROM BIOS. If the disk type is the DIGITAL extended type OFH, the
ROM BIOS expects the boot block to contain the parameters. The ROM BIOS
initializes the table with data extracted from the boot block. (As part of its
initialization process, the FDISK utility writes the parameters in the boot
block.)
The interrupt vectors for interrupt 41H and 46H point to the hard disk parameter tables for hard disk 0 and hard disk 1. respectively. If hard disk 1 does
not exist, the interrupt vector for interrupt 46H is reserved and undefined.

Chapter 15 - ROM BIOS Interrupt 13H

15 - 41

Function OOH: Initialize Entire Disk Subsystem
Industry-Standard
Parameters
AH = OOH
DL = The drive number (80H or 81Hl

Returns
CF = 0
CF = 1

Indicates a successful operation
Indicates an error condition
AH = The error code

This function resets the diskette and hard disk controllers to their initial
power-up state. The hard disk controller is initialized to the values in the hard
disk parameter tables. Because all drives are marked as reset, the next drive
specific I/O request recalibrates that drive.
To initialize only the hard disk controller, use hard disk function ODH. To initialize only the diskette controller, use diskette function OOH.

15 - 42

Chapter 15 - ROM BIOS Interrupt 13H

Function OlH: Return Status Code of Last 1/0 Request
Industry-Standard
Parameters
AH = 01H
DL = The drive number (80H or 81H)
Returns
AH = 0
AL = The error code of the previous operation
This function returns, in the AL register, the error code of the last function
call. If AL returns a 0, no previous error condition existed. Because calls to
this function do not generate error conditions, successive calls return O.
The AH register always returns O.
For the hard disk error codes, see Table 15-7.

Chapter 15 - ROM BIOS Interrupt 13H

15 - 43

Function 02H: Read One or More Disk Sectors
Industry-Standard
Parameters
AH = 02H
AL = The number of sectors to read
CH = The cylinder number (lower 8 bits)
CL = The starting sector number (and bits 9-8 of cylinder)
DH = The head number
DL = The drive number (80H or 81H)
ES:BX = The buffer address
Returns
CF = 0
CF = 1

Indicates a successful operation
Indicates an error condition
AH = The error code

This function reads the indicated number of sectors and stores the data starting at the buffer address in ES:BX. Attempts to store data past a physical
page boundary return an error. This can occur when the data size exceeds
10000H or when the BX offset plus the data size exceed 10000H.
To calculate the required buffer size, multiply the contents of the AL register
by 512.

15 - 44

Chapter 15 - ROM BIOS Interrupt 13H

Function 03H: Write One Or More Disk Sectors
Industry-Standard
Parameters
AH = 03H
AL = The number of sectors to write
CH = The cylinder number (lower 8 bits)
CL = The starting sector number (and bits 9-8 of cylinder)
DH = The head number
DL = The drive number (80H or 8IH)
ES:BX = The buffer address

Returns
CF = 0
CF = 1

Indicates a successful operation
Indicates an error condition
AH = The error code

This function writes the indicated number of sectors of data starting at the
buffer address in ES:BX. Attempts to read data past a physical page boundary
return an error. This can occur when the data size exceeds IOOOOH or when
the BX offset plus the data size exceed 10000H.
To calculate the number of sectors in a buffer. divide the buffer size by 512. If
the division produces a remainder, increment the sector count.

Chapter 15 - ROM BIOS Interrupt 13H

15 - 45

Function 04H: Verify One or More Disk Sectors
Industry-Standard
Parameters
AH = 04H
AL = The number of sectors to verify
CH = The cylinder number (lower 8 bits)
CL = The starting sector number (and bits 9-8 of cylinder)
DH = The head number
DL = The drive number (80H or 81H)
Returns
CF = 0
CF = 1

Indicates a successful operation
Indicates an error condition
AH = The error code

This function verifies the indicated number of sectors. The data is not compared against data in memory. It is only verified for internal consistency. Thus,
the verify command only checks for Error Correction Code (ECC) errors.

15 - 46

Chapter 15 - ROM BIOS Interrupt 13H

Function 05H: Format a Track
Industry-Standard
Parameters
AH = 05H
AL = The number of sectors per track
CH = The cylinder number Hower 8 bits)
CL = Bits 9-8 of cylinder number
DH = The head number
DL = The drive number (80H or 81H)
ES:BX = The sector interleave table address
Returns
CF = 0
CF = 1

Indicates a successful operation
Indicates an error condition
AH = The error code

This function formats the indicated track. It formats only the sectors described
in the sector interleave table. The data field of the formatted sectors is initialized to zeros. Before formatting the track, the ROM BIOS initializes the
controller to the values found in the hard disk parameter table.
ES: BX points to the sector interleave table, which contains an entry for each
sector on the track. A table entry requires two bytes of data. Therefore, the
expected buffer size is two times the number of sectors per track. The following list describes a single table entry:
Offset

Name

Description

OOH

The sector status

00 H = good sector
80H = bad sector

01H

The sector number

A sector number in the range of 1 to 17

Chapter 15 - ROM BIOS Interrupt 13R

15 - 47

Function 08H: Return Current Drive Parameters
Industry-Standard

Parameters
AH = 08H
DL = The drive number (80H or 81Hl
Returns
CF = 0

CF = 1

Indicates a successful operation
DL = The number of consecutive acknowledging drives
DH =

The maximum usable head number for the requested drive

CH =

Lower 8 bits of the maximum usable cylinder number for
the requested drive

CL =

The maximum usable sector number for the requested drive
and two high bits of the cylinder number

Indicates an error condition
AH = The error code

This function returns the number of consecutive, acknowledging, hard disk
drives. For example, if the DL register contains 02H, hard disks 0 (80HI and 1
(81HI are present and respond to the controller.
If the function returns with CF set (11, only the AH register is valid and con-

tains the error code.
The data returned in the DH, CH, and CL registers is only meaningful for the
drive specified by the calling parameter in the DL register.
NOTE
If an invalid drive type has been specified for the selected drive

or the selected drive is unformatted, this function can return invalid data. For the selected drive, check the parameter table. If
the parameter table contains all zeros, the returned data is invalid. The interrupt vector at interrupt 4lH points to the drive 0
parameter table. The interrupt vector at 46H points to the drive
1 parameter table.

15 - 48

Chapter 15 - ROM BIOS Interrupt 13H

Function 09H: Initialize Drive Characteristics
I ndltstry-Standard
Parameters
AH = 09H
DL = The drive number (80H or 81H)
Returns
CF = 0
CF = 1

Indicates a successful operation
Indicates an error condition
AH = The error code

This function initializes the hard disk controller to the values in the appropriate
hard disk parameter table. For drive 80H, the parameter table pointed to by
interrupt 41H is used. For drive 81H, the parameter table pointed to by interrupt 46H is used.

Chapter 15 - ROM BIOS Interrupt 13H

15 - 49

Function OAH: Read Long
Industry-Standard

Parameters
AH = OAH
AL = The number of sectors to read
CH = The cylinder number (lower 8 bits)
CL = The starting sector number (and bits 9-8 of cylinder)
DH = The head number
DL = The drive number (80H or 8lH)
ES:BX = The buffer address
Returns
CF = 0
CF = 1

Indicates a successful operation
Indicates an error condition
AH = The error code

This function is similar to function 02H, except that each sector of data is
terminated by a 4-byte ECC field. This function reads the indicated number of
sectors and stores the data starting at the buffer address in ES:BX. Attempts
to store data past a physical page boundary return an error. This can occur
when the data size exceeds lOOOOH or when the BX offset plus the data size
exceed lOOOOH.
To calculate the required buffer size, multiply the contents of the AL register
by 516. If the division produces a remainder, increment the sector count.

15 - 50

Chapter 15 - ROM BIOS Interrupt 13H

Function OBH: Write Long
Industry-Standard
Parameters
AH = OBH
AL = The number of sectors to write
CH = The cylinder number (lower 8 bitsl
CL = The starting sector number (and bits 9-8 of cylinderl
DH = The head number
DL = The drive number (80H or 81HI
ES:BX = The buffer address
Returns
CF = 0
CF = 1

Indicates a successful operation
Indicates an error condition
AH = The error code

This function is similar to function 03H, except that each sector of data is
terminated by a 4-byte ECC field. This function writes the indicated number of
sectors of data starting at the buffer address in ES:BX. Attempts to read data
past a physical page boundary return an error. This can occur when the data
size exceeds lOOOOH or when the BX offset plus the data size exceed lOOOOH.
To calculate the number of sectors in a buffer, divide the buffer size by 516.

Chapter 15 - ROM BIOS Interrupt 13H

15 - 51

Function OCH: Seek to Specific Cylinder
Industry-Standard

Parameters
AH = OCH
CH = The cylinder number (lower 8 bits)

CL = Bits 9-8 of cylinder number
DH = The head number
DL = The drive number {80H or 81H}
Returns

CF = 0
CF = 1

Indicates a successful operation
Indicates an error condition
AH = The error code

This function positions the head of the selected drive. Illegal cylinder numbers
produce an error, but no head movement occurs.
Before each invocation of this function, the target drive must be tested to determine if the drive is ready to accept another 1/0 command {see Interrupt
13U, Function 10H).

15 - 52

Chapter 15 - ROM BIOS Interrupt l3B

Function ODH: Hard Disk Reset
Industry-Standard
Parameters
AH = ODH
DL = The drive number 180H or 81H)

Returns
CF = 0
CF = 1

Indicates a successful operation
Indicates an error condition
AH = The error code

This function resets the hard disk controller to its initial power-up state. The
hard disk controller is initialized to the values in the hard disk parameter
tables. The diskette controller is not affected. Only the hard disk controller is
reset.

Chapter 15 - ROM BIOS Interrupt 13H

15 - 53

Function lOH: Test Drive Ready
Industry-Standard
Parameters
AH = 10H
DL = The drive number (80H or 81H)
Returns
CF = 0
CF = 1

Indicates a successful operation
Indicates an error condition
AH = The error code

If this function does not return an error code, the hard disk is ready to accept
110 requests. For the hard disk error codes, see Table 15-7.

15 - 54

Chapter 15 - ROM BIOS Interrupt 13H

Function IlH: Recalibrate Drive
Industry-Standard

Parameters
AH = llH
DL = The drive number (80H or 8lH)
Returns
CF = 0
CF = 1

Indicates a successful operation
Indicates an error condition
AH = The error code

This function moves the head of the selected hard disk to the home position
(cylinder zero).

Chapter 15 - ROM BIOS Interrupt 13H

15 - 55

Function 14H: Execute Controller Internal Diagnostics
Indu.stry-Standard
Parameters
AH = 14H
DL = The drive number (80H or 81H)

Returns
CF = 0
CF = 1

Indicates a successful operation
Indicates an error condition
AH = The error code

This function performs a diagnostic test of the hard disk controller card circuitry. Any errors are reflected in the returned error code.
During testing, this function destroys the initialization state of the controller.
On completion, the controller state is undefined. Use one of the hard disk functions (OOH, 09H, or ODH) to initialize the controller to a normal mode
of operation.

15 - 56

Chapter 15 - ROM BIOS Interrupt 13H

Function 15H: Return Drive Type
Industry-Standard
Parameters
AH = 15H
OL = The drive number (80H or 81H)
Returns
CF = 0

Indicates a successful operation
AH = OOH The drive is not present
AH = 03 H The hard disk is present
CX = The number of 512 byte sectors (high-order
16-bits)

ox =

CF = 1

The number of 512 byte sectors (low-order
16-bits
Indicates an error condition
AH = The error code

This function returns the drive type of the indicated hard disk. If the returned
AH register contains 03H, the CX and OX register pair contains the number
of 512 byte sectors on the disk. The CX register is the high word of the pair.

Chapter 15 - ROM BIOS Interrupt 138

15 - 57

Function DOH: Read Long 256 Byte Sector
DIGITAL Extension
Parameters
AH = DOH
AL = The number of sectors to read
CH = The cylinder number (lower 8 bitsl
CL = The starting sector number (and bits 9-8 of cylinder)
DH = The head number
DL = The drive number (80H or 81H)
ES:BX = The buffer address
Returns
CF = 0
CF = 1

Indicates a successful operation
Indicates an error condition
AH = The error code

This function is similar to function OAH, except that the sector size is 256
bytes instead of 512. Each sector of data is terminated by a 4-byte ECC field.
This function reads the indicated number of sectors and stores the data starting at the buffer address in ES:BX. Attempts to store data past a physical
page boundary return an error. This can occur when the data size exceeds
10000H or when the BX offset plus the data size exceed 10000H.
To calculate the required buffer size, multiply 260 by the contents of the AL
register.

15 - 58

Chapter 15 - ROM BIOS Interrupt 13H

Diskette Functions
The value in the AH register indicates the desired diskette function. All
diskette functions require a drive number in the DL register. The diskette drive
numbers are OOH and 01H.
With the exception of the flags register, all registers not mentioned in the
function description are preserved.

Diskette Errors
If CF is set (1), an error occurred, and the AH register contains the error code.

Table 15-9 lists the diskette error codes.
Table 15-9

Diskette Error Codes

Error
Code

Description

AOH
80H
40H
20H
10H
09H
08H
06H
04H
03H
02H
01H

Combination of 80H and 20H error codes
Hardware failed to respond
Seek operation failed
Disk controller failed
eRe incorrect for data
Direct Memory Access (DMA) overflowed 64K page boundary
DMA controller failed to respond
Disk change line true
Sector not found
Diskette write protected
Sector address mark not found
Illegal 110 request (bad command)

Diskette Parameter Tables
A diskette parameter table defines the physical characteristics of a diskette.
The values in the table are used by the diskette driver to initialize the diskette
controller. Table 15-10 describes the contents of a diskette parameter table.
Each parameter in Table 15-10 is one byte long.

Chapter 15 - ROM BIOS Interrupt 13H

15 - 59

Table 11)-10

Diskette Parameter Table Description

Offset

Bits

Description

OOH

7-4

Step rate
Each increase in the value of bits 7-4 decreases the step
rate by 1 ms, so that zero equals 16 ms, one equals 15
ms, two equals 14 ms, and so on.

3-0

Head unload time
Each increase in the value of bits 3-0 increases the head
unload time by 16 ms, so that zero equals 16 ms, one
equals 32 ms, two equals 48 ms, and so on.

01H

7-1

Head load time
Each increase in the value of bits 7-1 increases the head
load time by 2 ms. so that zero equals 2 ms, one equals 4
ms, two equals 6 ms, and so on.

Direct Memory Access (DMA) selection

o = Do not use DMA mode
1 = Use DMA mode

02H

7-0

Clock ticks until the motor is turned off

03H

7-0

Sector size
Each increase in value doubles the sector size, so that
zero equals 128 bytes, one equals 256 bytes, two equals
512 bytes and so on. The default value is two (512 bytes).

04H

7-0

Sectors per track (8, 9, 10, or 15)

05H

7-0

Sector gap length (IBH)

06H

7-0

Data length (FFH)

07H

7-0

Format gap length (54H)

08H

7-0

Format fill byte (F6H)

09H

7-0

Head settle time in milliseconds
If this value is less than 17 ms, the ROM BIOS uses 17

ms.
OAH

7-0

Motor start-up time in .125 second increments

The interrupt vector for interrupt lEH points to the diskette parameter table.
If a diskette drive does not exist, the interrupt vector for interrupt 1EH is
reserved and undefined.
15 - 60

Chapter 15 - ROM BIOS Interrupt 13H

Function OOH: Initialize Diskette Subsystem
Industry-Standard

Parameters
AH = OOH
DL = The drive number (OOH or OlH)
Returns
CF = 0
CF = 1

Indicates a successful operation
Indicates an error condition
AH = The error code

This function resets the diskette controller to its initial power-up state. the
diskette controller is initialized to the values in the diskette parameter table.
Because the diskette drive is marked as reset, the next diskette 1/0 request
recalibrates that drive.
After hard disk function OOH resets the hard disk controller, it calls this function to reset the diskette controller.

Chapter 15 - ROM BIOS Interrupt 13H

15 - 61

Function OIH: Return Status Code of Last 1/0 Request
Industry-Standard

Parameters
AH = 01H
DL = The drive number (OOH or 01H)
Returns
AH = 0
AL = The error code of the previous operation
This function returns, in the AL register, the error code of the last function
call. If AL returns a 0, no previous error condition existed. Because calls to
this function do not generate error conditions, successive calls return O.
The AH register always returns O.
For the diskette error codes, see Table 15-9.

15 - 62

Chapter 15 - ROM BIOS Interrupt 13H

Function 02H: Read One or More Track Sectors
I ndu.stry-Standard

Parameters
AH = 02H
AL = The number of sectors to read
CH = The track number
CL = The starting sector number
DH = The head number
DL = The drive number (OOH or 01H)
ES:BX = The buffer address
Returns
AL = OOH
CF = 0 Indicates a successful operation
CF = 1 Indicates an error condition
AH = The error code
This function reads the indicated number of sectors and stores the data starting at the buffer address in ES:BX. Requests to read more sectors than remain
on the track return an error. Attempts to store data past a physical page
boundary return an error. This can occur when the BX offset plus the data size
exceed 10000H.
To calculate the required buffer size, multiply the contents of the AL register
by 512.
The AL register always returns OOH.

Chapter 15 - ROM BIOS Interrupt 13H

15 - 63

Function 03H: Write One or More Track Sectors
I ndllstry-Standard

Parameters
AH = 03H
AL = The number of sectors to write
CH = The track number
CL = The starting sector number
DH = The head number
DL = The drive number (OOH or 01H)
ES:BX = The buffer address
Returns
AL = OOH
CF = 0 Indicates a successful operation
CF = 1 Indicates an error condition
AH = The error code
This function writes the indicated number of sectors starting at the buffer address in ES:BX. Requests to write more sectors than remain on the track
return an error. Attempts to read data past a physical page boundary return an
error. This can occur when the data size exceeds 10000H or when the BX
offset plus the data size exceed 10000H.
To calculate the number of sectors in a buffer, divide the buffer size by 512. If
the division produces a remainder, increment the sector count.

15 - 64

Chapter 15 - ROM BIOS Interrupt 13H

Function 04H: Verify One or More Track Sectors
Industry-Standard

Parameters
AH = 04H
AL = The number of sectors to verify
CH = The track number
CL = The starting sector number
DH = The head number
DL = The drive number (OOH or OlH}
ES:BX = The buffer address
Returns
AL = OOH
CF = 0 Indicates a successful operation
CF = 1 Indicates an error condition
AH = The error code
This function verifies the indicated number of sectors. The data is not compared against data in memory. It is only verified for internal consistency. Thus,
the verify command only checks for Cyclical Redundancy Check (CRC) errors.
Requests to verify more sectors than remain on the track return errors.

Chapter 15 - ROM BIOS Interrupt 13H

15 - 65

Function 05H: Format a Track
Industry-Standard
Parameters
AH = 05H
AL = The number of sectors to format
CH = The track number
DH = The head number
DL = The drive number (OOH or 01Hl
ES:BX = The track identification table address
Returns
CF = 0
CF = 1

Indicates a successful operation
Indicates an error condition
AH = The error code

This function formats the indicated track. It formats only the sectors described
in the track identification table. The data field of the formatted sectors is initialized to the diskette parameter table value, sector fill. Before formatting the
track, the ROM BIOS initializes the diskette controller to the values found in
the diskette parameter table.
ES:BX points to the track identification table. which contains an entry for each
sector on the track. A table entry requires four bytes of data. Therefore. the
expected buffer size is four times the number of sectors per track. The following list describes a single table entry.
Offset

Name

OOH

Track

01H

Head

0 = the back side of diskette
1 = the label side of diskette

02H

Sector number

1 to 8 for 48 TPI
1 to 9 for 48 TPI
1 to 15 for 96 TPI (high capacity)

03H

Sector size

Each increase in value doubles the sector size. so
that 0 equals 128 bytes. 1 equals 256 bytes, 2
equals 512 bytes, and so on. The default value is
two (512 bytes).

15 - 66

Chapter 15 - ROM BIOS Interrupt 13H

Description
0 to 39 for 48 tracks per inch (TPI)

o to 79 for 96 TPI

Function 15H: Return Drive Type
Industry-Standard
Parameters
AH = 15H
DL = The drive number fOOH or Oim
Returns
CF = 0

Indicates a successful operation
AH = OOH
The drive is not present
AH = 02H
An RX33 drive with status change line

CF = I

An error condition
AH = The error code

This function returns the drive type of the indicated diskette drive.

Chapter 15 - ROM BIOS Interrupt 13H

15 - 67

Function I6H: Return Change Line Status
Industry-Standard
Parameters
AH = 16H
DL = The drive number (OOH or 01H)

Returns
CF = 0
CF = 1

AH = OOH
AH = 06H

The media has not changed
The media could have changed

This function returns, for the indicated drive, the state of the diskette change
line. A changed status indicates that the media may have been changed since
the last 110 request to that drive. The change flag is set only after the media is
changed and the drive door is closed. If the door is open or no media is
present, a timeout error occurs.

15 - 68

Chapter 15 - ROM BIOS Interrupt 13H

Function 17H: Set Drive and Media Type for Format
Industry-Standard with DIGITAL Extensions
Parameters
AH = 17H
AL = 02H

There is 48 tracks per inch (TPI, media in the RX33 drive

AL = 03H

There is 96 TPI high-capacity media in the RX33 drive

AL = 04H

There is 96 TPI low-capacity media in the RX33 drive (DIGITAL extension,

DL = The drive number (OOH or 01H1
Returns
CF = 0
CF = 1

Indicates a successful operation
Indicates an error condition
AH = The error code

This function sets the diskette media and the drive type. It is called before
function 05H to override an existing diskette format or to define the format for
a blank diskette.

Chapter 15 - ROM BIOS Interrupt 13H

15 - 69

Interrupt 14H: Asynchronous
Communications
Software Interrupt - Industry-Standard with DIGITAL Extensions
This interrupt provides an industry-standard software interface to the
asynchronous communications ports. It also supports extended functionality:
•
•
•
•
•
•
•
•
•
•

Buffered transmit
Buffered receive
Receive notification
Flow control
Line signal notification
Modem signal control
Modem change notification
Break conditions
Error handling (timeout or continuous loop)
Additional baud rates

In accordance with industry-standard practice, the ROM BIOS code supports
four serial ports, and the ROM BIOS data area maintains four base addresses.
However, due to the limited number of interrupt controller inputs, some portions of extended function DOH are limited to ports OOH and 01H.
During power-up, the ROM BIOS looks for serial ports at 110 addresses 03F8H
and 02F8H. The serial port at 03F8H is the integral serial port and is assigned
to port OOH. If a serial port is found at 110 address 02F8H, it is assigned to
port 01H. Normally, this is the optional integral modem.
The serial printer port is treated as a special case. It is assigned to serial port
FFH and can be accessed like other serial ports. This information is provided
for consistency only. Use interrupt 17H. the parallel printer output, for normal
printer output. The ROM BIOS redirects parallel port OOH to serial port FFH.

15 - 70

Chapter 15 - ROM BIOS Interrupt 14H

The following is a list of the available functions:
AH

Description

Digital Extended

OOH
OlH
02H
03H
DOH
DIH
D2H
D3H
D4H

Initialize the asynchronous port
Send a character
Receive a character
Return asynchronous port status
Extended mode
Break control
Modem control
Retry On Timeout Error
Baud rate select

No
No
No
No
Yes
Yes
Yes
Yes
Yes

All registers not specified in the function register usage are preserved.

Chapter 15 - ROM BIOS Interrupt 14"

15 - 71

Function OOH: Initialize Asynchronous Port
Industry-Standard

Parameters
AH = OOH
AL = Initialization byte

Bits 7-5

Baud rate
000 = 110
001 = 150
010 = 300
011 = 600
100 = 1200
101
2400
110 = 4800
111 = 9600

Bits 4-3

Parity
00 = None
01 = Odd
10 = None
11 = Even

Bit 2

Stop bits
0=1

1 =2

Bits 1-0

Data bits
00 = 5
01 = 6
10 = 7
11 = 8

OX = The port number (OOH to 03H and FFH)
Returns
AH = The data status as defined in function 03H

This function initializes the specified port. The value returned in the AL register is interpreted the same as the value returned by function 03 H.

15 - 72

Chapter 15 - ROM BIOS Interrupt 14H

Function OlH: Transmit Character
Indllstry-Stalldard

Parameters
AH = 01H
AL = Character to transmit
DX = The port number (OOH to 03H and FFH)
Returns
AH = Data status as defined in function 03H
This function attempts to transmit a character to the specified port.
Unless modem signal bypass is set (see Interrupt 14H, Function D2H), the following modem signals are required to complete a transmission:
VAXmate Workstation
to External Device

External Device
to VAX mate Workstation

Data Terminal Ready (DTR)
Request To Send (RTS)

Data Set Ready (DSR)
Clear To Send (CTS)

Buffer Mode Enabled
If buffered mode is enabled. continuous retry is disabled, and bit 7 is set in the

returned AH register, then the transmit buffer was full and the character was
not placed in the buffer.
The XON/XOFF characters defined in the communications control block (see
Interrupt 14H, Function DOH) are transmitted independently and before all
other characters in the buffer.
For more information on buffered mode, see function DOH.

Chapter 15 - ROM BIOS Interrupt 14H

15 - 73

Function 02H: Receive Character
Industry-Standard
Parameters
AH = 02H
DX = The port number {OOH to 03H and FFHI
Returns
AL = Received character
AH = Data status as defined in function 03H
The function attempts to receive data from the specified port. Unless modem
signal bypass is set {see Interrupt 14H, Function D2Hl, the following modem
signals are required to complete a transmission.
VAXmate Workstation

External Device

Data Terminal Ready (DTRI

Data Set Ready (DSRI

Buffer Mode Enabled
If bit 7 is set in the returned AH register, the receive buffer is empty.
If bit 1 is set in the returned AH register. the receive buffer overflowed. The
character stored in the buffer is the overflow character, as specified in the communications control block (CCBI.

For more information on buffered mode, see function DOH.

15 - 74

Chapter 15 - ROM BIOS Interrupt 14H

Function 03H: Return Asynchronous Port Status
Industry-Standard
Parameters
AH = 03H

DX = The port number (OOH to 03H and FFHI
Returns
AH = The data status (set bits indicate condition I

Bit 7 -

Timeout error

Bit 6 -

8250 transmit shift register empty (all data has been
transmittedl

Bit 5 -

8250 transmit holding register empty (ready to accept
another character for transmission I

Bit 4 -

Break detect

Bit 3 -

Framing error

Bit 2 -

Parity error

Bit 1 -

Overrun error

Bit 0 -

8250 receive buffer full (received character available I

AL = The modem status (set bits indicate condition)
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 -

Carrier detect
Ring indicate
Data set ready
Clear to send
Delta carrier detect *
Ring trailing edge
Delta data set ready *
Delta clear to send *

If a delta bit is set. it indicates that between that last status request and

this status request, the state of the indicated input has changed.

This function retrieves the current data and modem status of the specified
port.
Chapter 15 - ROM BIOS Interrupt 14H

15 - 75

Buffer Mode Enabled
If the receive buffer is empty. the status returned is the current data and

modem status. Otherwise, the data status reflects the status of the next character to be extracted from the buffer, and the modem status is the current
modem status.
For more information on buffered mode, see function DOH.

15 - 76

Chapter 15 - ROM BIOS Interrupt 14H

Function DOH: Extended Mode
DIGITAL Extension
Parameters
AH = DOH
AL = FFH
AL = OOH

Enable function
Disable function

DX = The port number fOOH to 01H and FFH)
ES:BX = The address of CCB (ignored when AL = OOH)

Returns
AL = OOH
AL = OIH
AL = 02H
AL
03H

Indicates a successful operation
Indicates a nonexistent device
Indicates that the first four CCB entries are 0 (enable only)
Indicates that the buffer size is less than 4 (enable only)

This function is an extension to the industry-standard asynchronous communications functions. The following features are available:
•
•
•
•

Notification on data status interrupt
Notification on modem status interrupt
Flow control
Buffered communications
Notification on receive interrupt (requires receive buffering)
Notification on transmit interrupt frequires transmit buffering)

ES:BX points to the communication control block (CCB), which specifies the
desired environment. Each port is allowed only one CCB. The CCB is assigned
to the port indicated in the DX register. The communications control block is
defined in Table 15-11.
While a CCB is enabled. the first four entries cannot be modified. Within
reason, the remaining entries in the CCB and buffer structures can be modified
dynamically.
The CCB and the CCB-buffer structure must reside in the same memory
segment.
Chapter 15 - ROM BIOS Interrupt 148

15 - 77

Table 15-11

Communications Control Block ICCB) Description

Offset

Name

Size

Description

OOH

Line Vector

Double
word

This is the address Isegment:offset) of the
received-data status interrupt service routine. This interrupt occurs on an overrun,
parity, framing, or break error condition. A
value of OOOO:OOOOH disables this notification. While the CCB is enabled, this value
must not be changed.

04H

Modem
Vector

Double
word

This is the address (segment:offsetl of the
modem status interrupt service routine. This
interrupt occurs whenever clear-to-send,
data-set-ready, ring-indicator, or receivedline-signal-detector changes state. A value of
OOOO:OOOOH disables this notification. While
the CCB is enabled, this value must not be
changed.

08H

Rxbuff

Word

This is the offset of the receive-buffer structure. Table 15-12 describes the receive-buffer
structures. A value of OOOOH disables receive buffering for the indicated port. While
the CCB is enabled, this value must not be
changed.

OAH

Txbuff

Word

This is the offset of the transmit-buffer
structure. Table 15-12 describes the
transmit-buffer structures. A value of OOOOH
disables transmit buffering for the indicated
port. While the CCB is enabled, this value
must not be changed.

OCH

Xflag

Byte

This byte selects the XON/XOFF flow control option. It can be changed at any time
without restriction. A value of FFH enables
flow control. A value of OOH disables flow
control. Flow control is only available when
the buffered mode is active. Flow control
should be disabled for 8-bit binary data
transfers.

ODH

Status

Byte

This byte contains the current flow control
state. If the high order nibble equals OOH,
transmissions are disabled. If the high order
nibble equals FOH, transmissions are
enabled. The low-order nibble contains internal state information and must be
preserved.

15- 78

Chapter 15 - ROM BIOS Interrupt 14H

Table 15-11

Communications Control Block (CCB) Description (cont.)

Offset

Name

Size

Description

OEH

Overflow

Byte

This byte contains the character code that
represents an overflow condition. Under an
overflow (buffer full) condition. this value is
written over the last character in the buffer.
Because a new overflow character can be
written over an old overflow character, this
value should not be changed while the CCB
is enabled.

OFH

Xonchr

Byte

This byte contains the character code used
for XON in the flow control operation.
Because the external device must cooperate
in the change, this value should not be
changed while the CCB is enabled.

10H

Xoffchr

Byte

This byte contains the character code used
for XOFF in the flow control operation.
Because the external device must cooperate
ion the change, this value should not be
changed while the CCB is enabled.

llH

Xonpt

Word

This value defines the number of characters
left in the receive buffer when XON is sent
(low-water mark). This value should be
changed only when the receive buffer is
empty. However. it can be changed any time
if synchronization of flow control is
protected.

13H

Xoffpt

Word

This value defines the number of characters
in the receive buffer when XOFF is sent
(high water mark). This value should be
changed only when the receive buffer is
empty. However, it can be changed any time
if synchronization of flow control is
protected.

15H

CntlMask

Byte

If the value of this byte is nonzero, the received characters are ANDed with it. The
AND operation takes place before the character is tested as a flow control character.
This value can be changed at any time.

Chapter 15 - ROM BIOS Interrupt 14H

15 - 79

Each CCB can have two buffer structures associated with it, one for receive
and one for transmit. The buffer structures contain pointers, counters, and
status information. The maximum size of any buffer is 64 Kbytes. Table 15-12
describes the CCB buffer structure.
Table 15-12

CCB Buffer Structure Description

Offset

Name

Size

Description

OOH

Vector

Double
word

This is the address Isegment: offset) of the receive or transmit interrupt service routine. A
value of OOOO:OOOOH disables this option. It
can be changed at any time.

04H

Head

Double
word

This is a pointer lsegment:offset) to the next
empty position in the buffer. The segment of
the head pointer must be common to the tail,
start, and end pointers.

08H

Tail

Word

This is a pointer (offset only) to the next
available character in the buffer. It assumes
the same segment as the head pointer.

OAH

Start

Word

This is a pointer (offset only) to the beginning of the buffer. It assumes the same segment as the head pointer.

OCH

End

Word

This is a pointer (offset only) to the end of
the buffer. It assumes the same segment as
the head pointer.

OEH

Count

Word

This is the number of characters in the
buffer.

Buffering Enabled
Receive and transmit buffering is enabled or disabled by the contents of the
CCB receive-buffer/transmit-buffer structure pointers. A nonzero pointer indicates a valid pointer to a structure, and the desire for buffering.
Function DOH does not initialize buffer pointers or counters. It only updates
them. This allows a CCB to be enabled (AL = FFH) or disabled IAL = OOH)
dynamically. Therefore, before a CCB is enabled for the first time, all buffer
pointers must be initialized, and all counters must be zeroed.
The ROM BIOS expects the receive buffer and the transmit buffer to occupy
distinct and separate locations.
When buffering is enabled, functions OOH, 01 H. 02lL and 03H continue to operate in the same manner. However, some operations have minor side-effects
on buffered ports:
15 - 80

Chapter 15 - ROM BIOS Interrupt 14H

• Transmit Buffering Enabled
Function 01H buffers characters until they are transmitted. If continuous
retry is disabled, a timeout error indicates a full buffer instead of a
timeout.
The XON and XOFF characters are handled independently and before
any buffered characters.
• Receive Buffering Enabled
Function 02H extracts characters from a buffer. If continuous retry is
disabled, a timeout error indicates an empty buffer instead of a timeout.
The data status returned by functions OOH, 01H. 02H, and 03H depends
on the state of the receive buffer. If the receive buffer is empty, the returned data status is the current data status. Otherwise, the returned
data status is associated with the next character to be extracted from the
buffer and reflects the status when the character was placed in the buffer.
The modem status is always the current modem status.

Notification Enabled
Due to the limited number of interrupt controller inputs, only ports OOH, 01H,
and FFH can use notification.
When a CCB is enabled (AL = FFHI. the ROM BIOS examines the LineVector
and ModemVector pointers. On finding a nonzero pointer, the ROM BIOS
enables the associated interrupt for the indicated port. The ROM BIOS then
examines the receive-buffer/transmit-buffer structure pointers. On finding a
nonzero buffer structure pointer, it is used to examine the Vector pointer. If it
is nonzero, the associated receive or transmit interrupt is enabled. The interrupts remain enabled until the CCB is disabled (AL = OOHl. The application
must disable the CCB before exiting. Otherwise, the ROM BIOS assumes that
it still owns the CCB and buffer locations. On the next interrupt, it uses them
with undefined results.
All service routines are accessed using far calls. They must return to the ROM
BIOS by a far return.
At the time of the call, CPU interrupts are disabled and the interrupt controller is waiting for an end-of-interrupt instruction. After the notified service routine returns control to the ROM BIOS, the interrupt controller is restored, and .
any additional asynchronous port interrupts are serviced. After all
asynchronous interrupts are serviced, the CPU interrupt state is restored by an
IRET instruction. To maintain a minimum system interrupt latency, keep the
service routine as short as possible. Otherwise, handling high baud rates can
create problems, such as missing a timer interrupt.

Chapter 15 - ROM BIOS Interrupt 14H

15 - 81

The service routines are called as follows:
• Receive Notification Enabled
When the service routine is called, ZF is clear, the current data and
modem status are in the AX register lsee function 03HI, and interrupts
are disabled. The service routine returns ZF to indicate the action the
ROM BIOS should take. If ZF is set Ul, the ROM BIOS ignores the data
and modem status in the AX register. If ZF is clear 10), the ROM BIOS
stores the data and modem status in the AX register.
• Transmit Notification Enabled
When the service routine is called, the AL register contains the current
data status lsame as AH in function 03H), and interrupts are disabled.
This service routine is called when the transmit buffer is empty.
• Received Data Status Notification Enabled
When the service routine is called, the AL register contains the current
data status lsame as AH in function 03R), and interrupts are disabled.
This service routine is called when an overrun, parity, framing, or break
interrupt error condition occurs.
• Modem Status Notification Enabled
When the service routine is called, the AL register contains the current
modem status lsame as AL in function 03H). and interrupts are disabled.
This service routine is called when a clear-to-send lCTS), data-set-ready
(DSR), ring-indicator (RI), or received-line-signal-detector lRLSD) changes
state.

15 - 82

Chapter 15 - ROM BIOS Interrupt 14H

Error Codes Returned
When enabling a CCB IAL = FFH), function DOH can return one of the following status codes in the AL register:
AL

Meaning

OOH

A successful operation

OlH

A nonexistent port was specified in the DX register

02H

No operation was specified Ifirst 4 entries in CCB contain 0)

03H

There was an invalid buffer description. IThe end pointer must be at
least four more than the start pointer.)

When disabling a CCB (AL = OOAl. function DOH can return one of the following status codes in the AL register:
AL

Meaning

OOH
OlH

A successful operation
There was a nonexistent port specified in the DX register

Chapter 15 - ROM BIOS Interrupt 14H

15 - 83

Function D IH: Send Break
DIGITAL Extension
Parameters
AH = DIH
DX = The port number (OOH to 03H and FFH)
AL = FFH
AL = OOH

Set the break condition
Clear the break condition

Returns
AH = The data status as defined in function 03H
AL = The modem status as defined in function 03H

This function sets or clears the break condition. When AL equals FFH, the
transmit data line is forced to the space state (break condition is set). When
AL equals OOH, the transmit data line is returned to the mark state (break
condition is cleared).

15 - 84

Chapter 15 - ROM BIOS Interrupt 14H

Function D2H: Set Modem Control
DIGITAL Extension
Parameters
AH = D2H
DX = The port number IOOH to 03H)
AL = FFH
AL = FOH
AL = OFH
AL = OOH to 07H

Set the modem signal bypass
Clear the modem signal bypass
Read the modem control register
Write modem control register
Bit 0

Data Terminal Ready IDTR)

o = DTR is low at the external connector
1 = DTR is high at the external connector

Bit 1

Request to Send lRTS)

o = RTS is low at the external connector
1 = RTS is high at the external connector

Bit 2

Speed Select ISS)

o = SS is low at the external connector
1 = SS is high at the external connector

Returns
AL = The contents of the modem control register
This function reads or writes the modem control register and sets or clears the
modem signal bypass feature.
The modem signal bypass feature disables or enables ROM BIOS servicing of
modem line state changes. If the modem signal bypass is cleared IAL = FOH),
the ROM BIOS services the modem signals. If the modem signal bypass is set
IAL = FFH), the ROM BIOS does not service the modem signals. When
modem signal bypass is enabled, the modem signals are ignored and the serial
port operates in a data-leads-only mode.
Because it provides a different means of handling modem line state changes,
the modem signal bypass feature is not applicable when buffered communication is enabled. For further information on buffered communication, see function DOH.

Chapter 15 - ROM BIOS Interrupt 14H

15 - 85

Function D3H: Retry on Timeout Error
DIGITAL Extension
Parameters
AH = D3H
AL = 01H

Return the current retry map in AL and CL

AL = OOH, 02H-FFH

Write AL and CL (bits 1-01 to the retry map
CL (bits 1-01 = Port FFH retry map

Returns
AL = The current retry map (return map AL = 01HI
CL = The current retry map for port FFH
This function controls the ROM BIOS support of asynchronous port timeout
errors. Each port is individually controlled by reading the current map and
changing only the desired control bits. If the AL register equals 01H, the current retry map is returned in the AL register. Otherwise, the contents of the
AL register are written to the retry map. Initially, all ports are set to return
timeout errors. The retry map bit assignments are defined as follows.
Reg

Port

Bits

Usage

03H

7-6

00 = return the timeout errors
11= loop on the timeout errors

02H

5-4

00 = return the timeout errors
11= loop on the timeout errors

01H

3-2

00 = return the timeout errors
11 = loop on the timeout errors

OOH

1-0

00 = return the timeout errors
11 = loop on the timeout errors

FFH

7-2

Unused

1-0

00 = return the timeout errors
01 = loop on timeout errors

15 - 86

Chapter 15 - ROM BIOS Interrupt 14H

Function D4H: Set Baud Rate
DIGITAL Extension
Parameters
AH = D4H
DX = The port number (OOH to 03Il)
AL = FFH
AL = OOH-FEH

Return the current baud rate in AL
Any value other than FFH sets the baud rate

Returns
AL =

The current baud rate selection
Bits 7-5
000 =
001 =
010 =
011 =

100 =
101 =
110=
111 =

Bit 4

Bit 3-1
Bit 0

Standard group

Extended group

110
150
300
600
1200
2400
4800
9600

50
75
134.5
1800
2000
3600
7200
19200

Baud rate group select
Select the baud rate from the standard group
1 = Select the baud rate from the extended group

Not Used
Split baud rate

o = The baud rate is not split (Port 0 only)
1 =

The baud rates are split (Port 0 only)

This function sets or reads the baud rate and selects split baud rates.
Compared to function OOH, it provides an expanded set of baud rates.
Excluding the split baud rate selection, this function is compatible with
industry-standard serial port adapters.
Split baud rates are only supported on DIGITAL serial ports that have a split
baud rate capability. When the baud rates are split, the receive baud rate is
fixed at 1200 baud, and the transmit baud rate is set to the currently selected
value. The VAXmate workstation integral COM! port supports split baud rates.

Chapter 15 - ROM BIOS Interrupt 14H

15 - 87

Interrupt 15H: Cassette Input/Output
Software Interrupt - Industry-Standard with DIGITAL Extensions
This function provides support for multitasking and other functions associated
with the 80286 CPU in virtual memory mode. Because there is no cassette
hardware, the original cassette I/O functions respond as errors. An extended
function returns a DIGITAL-specific configuration word in the BX register.
Any AH values not defined in the following list of Interrupt 15H functions
return the error condition AH equals 86H and CF set (1).
AH

Function Name

DIGITAL
Extended

OOH-7FH
80H
81H
82H
83H
84H
85H
86H
87H
88H
89H
90H
91H
DOH

Returns error condition (AH = 86H, CF = 1)
Open Device
Close Device
Termination
Set Wait Interval
Joystick Support (not supported)
Service System Request Key
Wait
Move a Block of Memory
Memory size above 1Mb
Begin Virtual Mode
Device is Busy
Interrupt Completion Handler
Return DIGITAL Configuration Word

No
No
No
No
No
No
No
No
No
No
No
No
No
Yes

15 - 88

Chapter 15 - ROM BIOS Interrupt 15H

Function 80H: Open Device
Industry-Standard
Parameters
AH = 80H
Returns
AH = Undefined
CF = 0
This function is just a hook_ It only returns the indicated values.

Function 81H: Close Device
Iltdltstry-Standard
Parameters
AH = 81H
Returns
AH = Undefined
CF = 0
This function is just a hook. It only returns the indicated values.

Chapter 15 - ROM BIOS Interrupt 15H

15 - 89

Function 82H: Termination
Industry-Standard
Parameters
AH = 82H
Returns
AH = Undefined
CF = 0
This function is just a hook. It only returns the indicated values.

Function BaH: Set aWait Interval
Industry-Standard
Parameters
AH = 83H
CX = High IS-bits (number of microseconds delay time) *
OX = Low IS-bits (number of microseconds delay time) *
ES:BX = The pointer to caller-supplied flag byte

Although this parameter is measured in microseconds. the minimum
resolution is 976 ps. Requested values are rounded up to the next 97S-ps
increment.

Returns
CF = 1
CF = 0

The error condition
Interval timer started (application should monitor bit 7 of the callersupplied flag byte)

This function does not wait until the time interval has elapsed before returning.
It returns to the caller immediately. After the specified time interval has
elapsed, this function sets bit 7 of a caller-supplied flag byte. The time interval
is a 32-bit value measured in microseconds.
If an attempt is made to start a second interval before the first interval is

completed. an error condition is returned (CF = 1). This function is mutually
exclusive of function 8SH.
1/S - 90

Chapter 15 - ROM BIOS Interrupt 15H

Function 84H: Joystick Support
Not Supported
Parameters
AH = 84H
Returns
CF = 1

Indicates an error (always returns CF = 1)

NOTE
This function always returns an error (CF = 1). The VAXmate
workstation does not support joysticks.

Function 85H: Service System Request Key
Industry-Standard
Parameters
AH = 85H
Returns
AH = Undefined
CF = 0
This function is just a hook. It only returns the indicated values.

Chapter 15 - ROM BIOS Interrupt 15H

15 - 91

Function 86H: Wait (No Return to User)
Industry-Standard
Parameters

AH = 86H
CX = High 16-bits Inumber of microseconds delay time) *
DX = Low 16-bits (number of microseconds delay time) *

Although this parameter is measured in microseconds, the minimum
resolution is 976 fJS. Requested values are rounded up to the next 976-fJs
increment.

Returns
CF = 0
CF = 1

Indicates a successful operation
Indicates an error condition

This function waits until the specified interval has elapsed before control is returned. The time interval is a 32-bit value measured in microseconds.
This function is mutually exclusive of function 83H. If attempted while function
83H is active, it returns an error ICF = 1l.

15 - 92

Chapter 15 - ROM BIOS Interrupt 15H

Function 87H: Move a Block of Memory
I ndllstry-Standard
Parameters
AH = 87H
CX = The number of I6-bit words to move l8000H maximum I
ES:SI = The pointer to a table of caller-supplied GDT descriptors
Returns
AH = OOH
AH = 01H
AH = 02H
AH = 03H

Indicates a successful operation
Indicates a RAM parity error lerror cleared I
Indicates an exception interrupt error
Indicates an address line 20 gating failure

This function moves a block of memory to or from the address space above
1 Mbyte. The completion status is returned in the AH register and is also
stored in the real-time clock's CMOS RAM at offset 3CH. Table 15-13
describes the caller-supplied table of descriptors.

Chapter 15 - ROM BIOS Interrupt 15H

15 - 93

Table 15-13 Function 87H Descriptor Table
Offset

Size

Contents

OOH

8 bytes

All 0

08H

8 bytes

GDT Descriptor
These values are loaded into the GDTR with the LGDT
instruction. The ROM BIOS supplies this descriptor. It is
the 24-bit equivalent of the entry-time contents of ES:SI.
Thus, this structure becomes the GDT.

10H

8 bytes

I8H

8 bytes

20H

8 bytes

28H

8 bytes

15 - 94

Chapter 15 - ROM BIOS Interrupt 15H

Data Segment Descriptor
After entering virtual protected mode, these values are
loaded into the DS register. The descriptor is supplied by
the caller. This descriptor points to the source data block.
The data block must begin at offset 0 in this segment.
Extra Segment Descriptor
After entering virtual protected mode, these values are
loaded into the ES register. The descriptor is supplied by
the caner. This descriptor points to the destination of the
data block. The destination must begin at offset 0 in this
segment.
Code Segment Descriptor
This is the code segment descriptor for the ROM BIOS
code. The ROM BIOS supplies this descriptor.
Stack Segment Descriptor
This is the stack segment descriptor for the ROM BIOS
code. This descriptor is filled in by the ROM BIOS. The
ROM BIOS uses the caller stack segment and stack
pointer. The caller is responsible for providing a minimum
of 256 bytes of stack space.

Function 88H: Return Memory Size Above One
Megabyte
Industry-Standard
Parameters
AH = 88H

Returns
AX = Starting from address 100000H, the number of contiguous 1 Kbyte
blocks
This function returns the amount of contiguous memory above 1 Mbyte as determined during powerup.

Chapter 15 - ROM BIOS Interrupt 15H

15 - 95

Function 89H: Begin Virtual Mode
Industry-Standard
Parameters
AH = 89H
BH = The offset of interrupt level 1 in interrupt descriptor table (lRQO-7)
BL = The offset of interrupt level 2 in interrupt descriptor table (lRQ8-15)
ES:SI = The pointer to a table of caller-supplied descriptors
Returns
AH = OOH
AH =.- FFH

Indicates a successful operation
Indicates an address line 20 gating failure

This function provides a method of entering the virtual protected mode of the
80286 CPU. Table 15-14 describes the caller-supplied table of descriptors. The
caller must initialize all required tables. Within those tables are new locations
for all 16 hardware interrupt vectors (15 plus the unused IRQ2). Control is returned to the caller at the instruction following the Interrupt 15H instruction
that invoked this function. At that time, one of two conditions exists as
follows:
•

The CPU is in virtual protected mode, all interrupts are disabled. and
the registers are initialized according to the descriptor tables. The AH
register contains OOH.
The master (Bm and slave (BI.) peripheral interrupt controllers are programmed according to the descriptor tables pointed to by the BH and
BL registers. Both peripheral-interrupt-controller mask registers contain
FFH. That is, all interrupt inputs are disabled. The peripheral interrupt
controllers are initialized to the following states:
Cascade mode is enabled
Slave identification equals 02H
Slave interrupts on IRQ2
Vector interval equals 8
Edge-triggered mode is enabled
8086 mode is enabled
Normal EOI mode is enabled
Nonbuffered and not special-fully-nested modes are established
Interrupt descriptors pointed to by BH and BL are loaded into the
respective ICW2 registers

15 - 96

Chapter 15 - ROM BIOS Interrupt 15H

•

The CPU is in real mode and the registers are unchanged (except AH).
The interrupt structure is the same as it was before the function was
invoked. The AH register contains FFH, which indicates a failure in
gating address line 20. The calling routine must be prepared to recover
from this error condition.

Table 15-14 Function 89H Descriptor Table
Offset

Size

Contents

OOH

8 bytes

All 0

08H

8 bytes

GOT Descriptor
This caller-supplied descriptor is loaded into the GDTR
with a LGDT instruction.

10H

8 bytes

IDT Descriptor
This caller-supplied descriptor is loaded into the IDTR
with a LIDT instruction

18H

8 bytes

Data Segment Descriptor
This caller-supplied descriptor is loaded into the DS
register.

20H

8 bytes

Extra Segment Descriptor
This caller-supplied descriptor is loaded into the ES
register.

28H

8 bytes

Stack Segment Descriptor
This caller-supplied descriptor is loaded into the SS
register.

30H

8 bytes

Code Segment Descriptor
This caller-supplied descriptor is for the code that receives
control at the successful conclusion of this function.

38H

8 bytes

Code Segment Descriptor
This descriptor is supplied by the ROM BIOS and is used
by the ROM BIOS while it operates in virtual protected
mode.

Chapter 15 - ROM BIOS Interrupt 15H

15 - 97

Function 90H: Device· Is Busy
Industry-Standard
Parameters
AH = 90H
Returns
AH = Undefined
CF = 0
This function is just a hook. It only returns the indicated values.

Function 91H: Interrupt Completion Handler
Industry-Standard
Parameters
AH = 91H
Returns
AH = Undefined
CF = 0
This function is just a hook. It only returns the indicated values.

15 - 98

Chapter 15 - ROM BIOS Interrupt 15H

Function DOH: Return DIGITAL Configuration Word
DIGITAL Extension
Parameters
AH = DOH
Returns
AH = 86H
CF = 1
BX = The DIGITAL configuration word
This function returns the DIGITAL-unique hardware configuration information
in the BX register. The BX register has the following bit definitions:
Bit

Description

Unused

Modem option or COM2 present

13-10

Hard disk type
0000 =
There is no hard disk
0001 =
The hard disk is an RD xx type drive
0010-1110 =
Reserved
Unknown
1111 =

7-5

Hard disk controller present
No hard disk controller
Hard disk controller present
1 =

Expansion box
No expansion box (no battery)
Expansion box present (implies battery present)
1 =

Video type
000 =
001 =
010 =
011-111 =

An industry-standard monochrome adapter
An industry-standard color graphic adapter
The VAXmate graphic video system
Reserved

Chapter 15 - ROM BIOS Interrupt 15H

15 - 99

Bit
4

3·2

Description

(DIGITAL Configuration Word· cont.)

LK250 keyboard
LK250 keyboard not present
1 = LK250 keyboard present
Diskette drive type (drive 1)
00 =
Not present
01 = RX31 (48-tpi drive)
10 = RX33 (96-tpi high capacity drive)
11 =
Reserved

1-0

Diskette drive type (drive 0)
00 = Not present
01 =
RX31 (48-tpi drive)
10 = RX33 (96-tpi high capacity drive)
11 =
Reserved

15 - 100

Chapter 15 . ROM BIOS Interrupt 15H

Interrupt I6H: Keyboard Input
Software Interrupt - Industry-Standard with DIGITAL Extensions
This interrupt provides an interface to the LK250 keyboard. In addition to the
industry-standard functions, it provides the following enhanced capabilities:
•
•
•
•
•

Increase the size of the keyboard buffer
Determine the number of characters in the keyboard buffer
Real-time key notification
Custom key mapping
Selective disabling of various key conversion processes

Interrupt I6H supports the following functions:
Function

Description

DIGITAL Extended

OOH
OIH

Keyboard Input
Keyboard Status
Keyboard State
Key Notification
Character Count
Keyboard Buffer
Extended Codes And Functions
Request Keyboard ID
Send To Keyboard
Keyboard Table Pointers

No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes

02H

DOH
DIH

D2H
D3H

D4H
D5H

D6H

Chapter 15 - ROM BIOS Interrupt 16H

15 - 101

Table of Returned Scan Codes
Table 15-15 lists the scan codes returned for various conditions. The columns
are marked as follows:
•

The column marked "Key Pos" refers to the key positions shown in
Figure 15-1.

•

The column marked "D" indicates the scan code when a key is
pressed.

•

The column marked "R" indicates the scan code when a key is
released.

•

The columns marked" A" indicate the ASCII key value.

•

The columns marked "S" indicate the scan code.

The symbol process.

indicates an invalid code that is ignored in the conversion

A *1 after an entry indicates that it is only available when DIGITAL extended
codes are in effect and combination keys are disabled.
A *2 after an entry indicates that it is only available when DIGITAL extended
codes are in effect and NumLock, Insert, and Scrl Lock are disabled.
A *3 after an entry indicates that it is only available when DIGITAL extended
codes are in effect.
A *4 after an entry indicates that it is only available when Compose key pass
through is in effect.

15 - 102

Chapter 15 - ROM BIOS Interrupt 16H

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t7:I

IG9-~GOO [G01[GO~G03]

[G151 - G;~

9'-

....

1816 817 818l

820 821 822
A20
L - _______

A23

A22
---

LJ-1310

Table 15-15 Keyboard Scan Codes Returned by the ROM BIOS
Key Scan
Pos Code
DR

Alt

Lock

Ctrl

Normal

E20
EOl
E02
E03
E04

01 81
02 82
03 83
04 84
06 86

lB 01
31 02
32 03
33 04
34 06

lB 01

00 78
00 79
00 7A
00 7B

E06
E06
E07
E08
E09

06 86
07 87
08 88
09 89
OA 8A

00 7C
00 70
00 7E
00 7F
00 80

35 06
36 07
37 08
38 09
39 OA

El0
Ell
E12
E13
000

OB 8B
OC 8C
00 80
OE 8E
OF 8F

00 81
00 82
00 83

30 OB
20 OC
30 00
08 OE
09 OF

001
002
003
004
006

10 90
11 91
12 92
13 93
14 94

00 10
00 11
00 12
00 13
00 14

61 10
57 11
46 12
62 13
54 14

006
007
008
009
010

16 96
16 96
17 97
18 98
19 99

00 16
00 16
00 17
00 18
00 19

011 lA 9A
012 lB 9B
C13 lC 9C
C99 10 90
COllE 9E

15 - 104

00 lE

Num
Lock
AS

lB 01
31 02
32 03
33 04
34 06

lB 01
31 02
32 03
33 04
34 05

lB 01
21 02
40 03
23 04
24 05

35 06
36 07
37 08
38 09
39 OA

26 06
5E 07
26 08
2A 09
28 OA

30 OB
20 OC
30 00
08 OE
09 OF

29 OB
5F OC
2B 00
08 OE
00 OF

11 10
17 11
05 12
12 13
14 14

71 10
7711
65 12
72 13
74 14

51 10
57 11
45 12
62 13
54 14

59 16
55 16
49 17
4F 18
50 19

19 15
15 16
09 17
OF 18
10 19

79 15
75 16
69 17
6F 18
70 19

59 15
55 16
49 17
4F 18
50 19

5B lA
50 lB
00 lC

lB lA
10 lB
OA lC

5B lA
50 lB
00 lC

6B lA
50 lB
00 lC

7B lA
70 lB
00 lC

41 lE

01 lE

61 lE

41 lE

00 03

lE 07

lF OC
7F OE

Chapter 15 - ROM BIOS Interrupt 16H

Shift

Table 15·15 Keyboard Scan Codes Returned by the ROM BIOS (cont.)
Key Scan
Pos Code
DR

Alt

Lock

Ctrl

Normal

CO2
C03
C04
C05
C06

IF 9F
20 AO
21 Al
22 A2
23 A3

00 IF
00 20
00 21
00 22
00 23

53 IF
44 20
46 21
47 22
48 23

C07
C08
C09
CI0
C11

24 A4
25 A5
26 A6
27 A7
28 A8

00 24
00 25
00 26

4A 24
4B 25
4C 26
3B 27
27 28

BOO
B99
C12
BOI
B02

29 A9
2A AA
2B AB
2C AC
20 AO

00 2C
00 20

5C 2B
5A 2C
58 20

B03
B04
B05
B06
B07

2E AE
2F AF
30 BO
31 Bl
32 B2

00 2E
00 2F
00 30
00 31
00 32

43 2E
56 2F
42 30
4E 31
40 32

B08
B09
BI0
B11
E23

33 B3
34 B4
35 BS
36 B6
37 B7

A99
AOI
COO
G99
GOO

38 B8
39 B9
3A BA
3B BB
3C BC

Num
Lock
AS

13 IF
04 20
06 21
07 22
08 23

73 IF
64 20
66 21
67 22
68 23

53 IF
44 20
46 21
47 22
48 23

OA 24
OB 25
OC 26

6A 24
6B 25
6C 26
3B 27
27 28

4A 24
4B 25
4C 26
3A 27
22 28

60 29

7E 29

lC 2B
lA 2C
18 20

SC 2B
7A 2C
78 20

5C 2B
7A 2C
78 20

7C 2B
5A 2C
58 20

03 2E
16 2F
02 30
OE 31
00 32

63 2E
76 2F
62 30
6E 31
60 32

43 2E
56 2F
42 30
4E 31
40 32

2C 33
2E 34
2F 35

3C 33
3E 34
3F 35

60 29

2C 33
2E 34
2F 35

Shift

2A 37

00 72

2A 37

2A 37 *1

20 39

00 68
00 69

00 3B
00 3C

00 5E
005F

00 3B
00 3C

00 54
00 55

Chapter 15 . ROM BIOS Interrupt 16H

15 - 105

Table 15-15 Keyboard Scan Codes Returned by the ROM BIOS (cont.~
Key Scan
Pos Code
DR

Alt

Lock

Ctrl

Normal
AS

Num
Lock
AS

GOl
G02
G03
G05
G06

30 BO
3E BE
3F BF
40 CO
41 Cl

00 6A
00 6B
00 6C
00 60
00 6E

00 30
00 3E
00 3F
00 40
00 41

G07
G08
G09
E21
E22

42 C2
43 C3
44 C4
45 C5
46 C6

00 6F
00 70
00 71

020
021
D22
D23
C20

00 60
00 61
00 62
00 63
00 64

00 30
00 3E
00 3F
00 40
00 41

00 56
00 57
00 58
00 59
00 5A

00 42
00 43
00 44
00 45 *2
00 46 *2

00 65
00 66
00 67

00 42
00 43
00 44
00 45 *2
00 46 *2

00 42
00 43
00 44

00 5B
00 5C
00 5D
00 45 *2
00 46 *2

47 C7
48 C8
49 C9
4A CA
4B CB

00 47
00 48
00 49
2D 4A
00 4B

00 77

00 47
00 48
00 49
2D 4A
00 4B

37 47
38 48
39 49
2D 4A
34 4B

37 47
38 48
39 49
20 4A
34 4B

C21
C22
C23
B20
B21

4C CC
4D CO
4E CE
4F CF
50 DO

00 4C *3
00 40
2B 4E
00 4F
00 50

35 4C
36 40
2B 4E
31 4F
32 50

B22
A20
A22
G23
E16

51 Dl
52 02
53 03
54 04
55 05

00 51
00 52
00 53
00 98
00 85

00 76

00 51
00 52
00 53
00 98
00 85

33 51
30 52
2E 53
00 98
00 85

33 51
30 52
2E 53
00 A4
00 85

E17
E18
016
D17
D18

56 D6
57 07
58 D8
59 D9
5A DA

00 86
00 87
00 88
00 89
00 8A

00 C3
00 Cl

00 86
00 87
00 88
00 89
00 8A

15 - 106

00 84
00 73

00 74
00 75

00 BO

00 C4
00 C2

Chapter 15 - ROM BIOS Interrupt 16H

Shift

Table 15-15 Keyboard Scan Codes Returned by the ROM BIOS (cont.l

Key Scan
Pos Code
DR

Alt

Lock

Ctrl

Normal
AS

Num
Lock
AS

00 A7

00 BB
00 BC
00 BO
00 BE
00 BF

00 BB
00 BC
00 BO
00 BE
00 9B

Shift

C17
B16
B1B
B17
Gll

5B OB
5C OC
50 00
5E OE
5F OF

00 B3

00 BB
00 BC
00 BO
00 BE
00 BF

G12
G13
G14
G15
G16

60 EO
61 El
62 E2
63 E3
64 E4

00 B4
00 B5
00 B6
00 B7
00 BB

00 90
00 91
00 92
00 93
00 94

00 AB
00 A9
00 AA
00 AB
00 AC

00 90
00 91
00 92
00 93
00 94

00 9C
00 90
00 9E
00 9F
00 AO

G20
G21
G22
EOO
A23

65 E5
66 E6
67 E7
6B EB
69 E9

00 B9
00 BA
00 BB
00 BO *4
00 BE

00 95
00 96
00 97
00 BO *4
00 9A

00 AO
00 AE
00 AF
00 BO *4
OA B2

00 95
00 96
00 97
00 BO *4
00 9A

00 Al
00 A2
00 A3
00 BO *4
00 A6

00 BF
00 CO

Combination Keys
When detected by the ROM BIOS, certain key combinations invoke special
functions. Detection of these key combinations occurs after key stroke notification (see function DOH) and before key buffering notification (see function
DOH). If detected and acted upon (see function D3Hl, these key combinations
are not stored in the keyboard buffer.

System Reset
The ROM BIOS recognizes the key combination CtrlfAltfDel as a system reset.
When detected, interrupt 19H (Bootstrap) is executed.

System Request Key (Sys Req)
The ROM BIOS recognizes the key combination AltfF20 as the system request
key. When detected, interrupt 15H function 85H is executed.
The F20 key is also the Sys Req key, and sends the Sys Req key scan code.
However, the system request function is executed only for the AltfF20 key
combination.
Chapter 15 - ROM BIOS Interrupt 16H

15 - 107

Extended Self-test
The ROM BIOS recognizes the key combination
CtrllAlt/Home as the extended self-test key. When detected, the ROM BIOS
invokes the extended self-test diagnostics.

Break
The ROM BIOS recognizes the key combination CtrllBreak as break. When
detected. the ROM BIOS stores OOH in the keyboard buffer and executes interrupt 1BH.

Pause
The ROM BIOS recognizes the key combination CtrllNumLock as a system
pause. When detected, all non interrupt driven tasks are suspended. The tasks
are resumed by pressing any key except the following:
•
•
•
•
•
•
•
•

NumLock
Left-Shift
Right-Shift
Ctrl
Alt
Lock
System Request IAlt/F20)
Insert

Print Screen
The ROM BIOS recognizes the key combination Shift/Prt Sc as print screen.
When detected, interrupt 05H is executed.

Automatic LED Control
The keyboard state can be changed by some functions and by user interaction.
Therefore, during each keyboard function call, the ROM BIOS checks the keyboard state and updates the state of the LK250 LED indicators. Applications
do not have to maintain the LK250 LED indicators.

15 - 108

Chapter 15 - ROM BIOS Interrupt 16H

Function OOH: Keyboard Input
Industry-Standard

Parameters
AH = OOH

Returns
AH = The scan code
AL = The ASCII key value

This function returns the next available character from the keyboard buffer.
This function does not return until it has a character.

Function OlH: Keyboard Status
Industry-Standard

Parameters
AH = OIH

Returns
ZF = 1
ZF = 0

The keyboard buffer is empty
One or more characters in the keyboard buffer
AH = The scan code (remains in buffer)
AL = The ASCII key value (remains in buffer}

This function returns the status of the keyboard buffer. On return, ZF indicates
the state of the buffer. If ZF is 1, the buffer is empty. If ZF is 0, the buffer
contains one or more characters, and the next available character is returned
(AH = scan code, AL = ASCII key value). The character remains in the keyboard buffer. That is, a subsequent function OOH call extracts the same scan
code and ASCII key value.

Chapter 15 - ROM BIOS Interrupt 16H

15 - 109

Function 02H: Keyboard State
1 ndllstry-Standard

Parameters

AH = 02H
Returns
AL = The state of the modifier keys (set bit indicates the state is true)
Bit 7 - Insert
Bit 6 - Lock
Bit 5 - NumLock
Bit 4 - Scrol Lock
Bit 3 - Alternate
Bit 2 - Control
Bit 1 - Left Shift
Bit 0 - Right Shift

The function returns, in the AL register. the current state of the keyboard. A
set (1) bit indicates that the corresponding state is true.

15 - 110

Chapter 15 . ROM BIOS Interrupt I6H

Function DOH: Key Notification
DIGITAL Extension
Parameters
AH = DOH
AL = OOH

Disable key stroke and keyboard buffer notification

AL = 01H

Disable key stroke notification

AL = 02H

Disable keyboard buffer notification

AL = 81H

Return the pointer to the key stroke service routine in ES:BX

AL = 82H

Return the pointer to the keyboard buffer service routine in
ES:BX

AL = FEH

Enable keyboard buffer notification
ES:BX = The address of the keyboard buffer service routine

AL = FFH

Enable key stroke notification
ES:BX = The address of the key stroke service routine

Returns
ES:BX = OOOO:OOOOH
ES:BX =

There is no active service routine {AL = 81H or
AL = 82HI

The pointer to the active service routine {AL = 81H or
AL = 82HI

This function enables or disables key stroke or key buffering notification.
The service routines must preserve all registers except the AX and must use a
far return to exit.
To determine if key stroke or keyboard buffer notification is in use, execute
function DOH with AL = 81H or AL = 82H respectively. If the service routine
is active, the returned ES:BX pair contains a pointer to the service routine.
Otherwise, the returned ES:BX pair contains OOOO:OOOOH.

Chapter 15 - ROM BIOS Interrupt 16H

15 - 111

Key Stroke Notification Enabled
Key Stroke Service Routine Parameters

AH = The keyboard state as defined in function 02H
AL = The scan code
Keystroke Service Routine Returns
AH = F AH

Keystroke should be ignored

AL = The scan code (original or revised)
AH = The keyboard state (original or revised)
The key stroke service routine is called each time a key is depressed or
released.
On return from the service routine, the ROM BIOS examines the contents of
the AL register. If the AL register contains FAH, the keystroke is ignored.
Otherwise, the scan code in AL and the keyboard state in AH are treated as
though the ROM BIOS had just established their values. Thus, an application
can trap keys or map their values.

15 - 112

Chapter 15 . ROM BIOS Interrupt 16H

Key Buffering Notification Enabled
Key Stroke Service Routine Parameters
AH = The scan code
AL = The ASCII key value
BL = The keyboard state as defined in function 02H
ZF = 0
Keystroke Service Routine Returns
ZF = 1

Keystroke ignored Inothing stored in keyboard buffer)
BL = The keyboard state (original or revised)

ZF = 0

The scan code in AH stored in keyboard buffer
BL = The keyboard state loriginal or revised)
AH = The scan code (original or revised)
AL = The ASCII code (original or revised)

The key buffering service routine is called immediately before the character is
placed in the keyboard buffer.
On return from the service routine. the ROM BIOS internal keyboard state is
updated with the the contents of BL. The ROM BIOS then examines ZF. If ZF
is set (1), the code returned in AX is ignored and is not stored in the keyboard
buffer. If ZF is set (0), the code returned in AX is stored in the keyboard
buffer.

Chapter 15 - ROM BIOS Interrupt 16H

15 - 113

Function DiH: Character Count
DIGITAL Extension
Parameters
AH = DIH
Returns
AX = The number of characters in the keyboard buffer
This function returns the number of characters remaining in the keyboard
buffer. The maximum value that can be returned is the keyboard buffer size
minus one. The default keyboard buffer is 16 characters long. However, the
size of the buffer is not fixed. Function D2H increases or resets the size of the
buffer.

15 - 114

Chapter 15 - ROM BIOS Interrupt 16H

Function D2H: Keyboard Buffer
DIGITAL Extension
Parameters
AH = D2H
AL = OOH
AL = FFH

Restore the keyboard buffer to the default location and size
Establish a new keyboard buffer as defined by ES:BX and CX

CX = The new buffer size
ES:BX = The pointer to start of new buffer
Returns
Nothing
This function installs a new keyboard buffer or restores the default
I6-character keyboard buffer.
When a keyboard buffer contains one entry less than its size, the keyboard
buffer is full. To calculate the CX register value, add one to the desired capacity. For example, when the default I6-character keyboard buffer contains 15
characters, it is full. Each entry in the keyboard buffer requires 2 bytes, 1 for
the scan code and 1 for the ASCII key value. To calculate the physical size of
the buffer, double the value in the CX register.
Parameter values are not checked. Invalid or illogical buffer assignments cause
unpredictable results. For example, do not use a buffer size of zero or a buffer
that wraps around the end of a segment.

Chapter 15 - ROM BIOS Interrupt 16H

15 - 115

Function D3H: Extended Codes And Functions
DIGITAL Extension
Parameters
AH = D3H
AL = OOH

Clear all bits Idefault state)

AL = Nonzero value IOlH-FFH) is inclusive ORed
Bit 7

Return the current bit usage in AL register
This bit does not remain set. To return the current bit usage on
successive calls, bit 7 must be set for each call.

Bit 6

Not Used

Bit 5

Enable Compose key pass through
Although DIGITAL extended codes are disabled, the Compose
key is placed in the keyboard buffer.

Bit 4

LK250 in DIGITAL extended mode
This sends the DIGITAL extended mode command to the
LK250, and ROM BIOS use of extended scan codes is enabled.
Normally, the ten cursor edit pad keys return the scan codes of
their equivalent numeric keypad keys.

Bit 3

Disable Shift/Lock override
When the Lock key is in effect, the Shift key does not unshift
alphabetic keys.

Bit 2

Disable combination keys
This disables detection of the key combinations Shift/Prt Sc,
Ctrl-Break, and Ctrl-NumLock. These key combinations no
longer invoke special functions. They are treated as normal key
sequences. The key combinations Ctrl/AitiDel and Ctrl/Alt/Home
are not affected by this command.

15 - 116

Chapter 15 - ROM BIOS Interrupt 168

Parameters

(Function D3H: Extended Codes and Functions· cont.)

Bit 1

Disable Alt compose

Bit 0

This disables the ability to generate any character (0 to 255) by
holding down the Alt key and typing the decimal value on the
numeric keypad with the keypad number keys. The keypad
number keys are treated as normal keys.
Disable keypad state keys
NumLock, Insert, and Scrl Lock no longer set states. Instead,
they are treated as normal characters. That is, they are
translated according to the translation tables and then stored in
the keyboard buffer.

Returns
AL = OOH
AL = 01H
AL = 02H

Indicates a successful operation
The keyboard is busy (operation failed)
There was no keyboard acknowledge (operation failed)

AL = The current bit usage (AL bit 7 = 1)
This function enables or disables various scan code conversion functions. It can
also return the current bit usage.
Bit flags in the AL register select various options. Successive selections are
ORed together. To clear an individual bit, clear all bits (AL = OOH) and then
select the desired bits.

Chapter 15 . ROM BIOS Interrupt 16H

15 - 117

Function D4H: Request Keyboard ID
DIGITAL Extension
Parameters

AH = D4H
Returns

AL = OOH Indicates a successful operation
BL = The LK250 keyboard's firmware version number
BH = OlH
BH = 02H

Industry-standard mode
DIGITAL extended mode

AL = OlH The keyboard is busy joperation failed)
AL = 02H There was no response (operation failed)
This function returns the LK250 keyboard identification.

15 - 118

Chapter 15 - ROM BIOS Interrupt 16H

Function D5H: Send to Keyboard
DIGITAL Extension
Parameters
AH = D5H
AL = The value to send

Returns
AL = OOH
AL = 01H
AL = 02H

Indicates a successful operation
The keyboard is busy loperation failed I
There was no keyboard acknowledge loperation failed I

This function sends commands or data to the LK250 keyboard. It provides only
the means for sending. It does not regulate what is sent. For details on the
commands or data, see Chapter 8.
This function sends a single byte at a time. Use successive calls for multibyte
commands or data.

Chapter 15 . ROM BIOS Interrupt 16H

15 - 119

Function D6H: Keyboard Table Pointers
DIGITAL Extension
Parameters

AH = D6H
AL = OOH Return the table pointer CL in ES:BX
AL = Non-zero (set table pointer CL to ES:BX)
CL = The table pointer to define or return
OOH =
01H =
02H =
03H =
04H =
05H =
06H =
07H =
08H =
09H =
FFH =

Normal table
Ctrl table
Alt table
Shift table
NumLock table
Lock table
Alt/Ctrl table
Alt/Shift table
Ctrllshift table
Alphabetic table
Set all table pointers to default value (AL = non-zero, ES:BX
is ignored)

ES:BX = The pointer to table
Returns
ES:BX = The pointer to table CL tAL = OOH)
This function provides' control of the pointers to the tables used in the scan
code translation process. The value of any table pointer can be set or returned.
Because the table pointer is a double-word pointer, each table can have a different segment address.
Under default conditions, the Alt/Ctrl and Alt/Shift table pointers point to the
Alt table, and the Ctrl/Shift table pointer points to the Ctrl table.
The translation tables convert a scan code into a pair of codes, a scan code and
an ASCII key value. The table used for any given translation depends on the
keyboard state at the time.
15 - 120

Chapter 15 - ROM BIOS Interrupt 16H

Keyboard Translation Table Formats And Usage
In the following description, the term "keypad keys" refers to the keys 0
through 9, the plus key, the minus key, and the period key located on the
keypad. The alphabetic table determines if a key is an alphabetic character.
Only alphabetic characters are shifted by the Lock key or unshifted by the
combination of Lock and Shift. The rules for table usage and precedence are:
Keys in Effect

Tables Used for
Keypad Keys

Tables Used for
Alphabetic Keys

Tables Used for
All Other Keys

Alt
Alt and Ctrl

Alt
Alt/Ctrl

Alt

Alt/Ctrl

Alt and Shift

Alt/Shift

Ctrl

Ctrl and Shift

Ctrl/Shift
Shift
NumLock
Normal

Ctrl/Shift
Shift
Normal

Ctrl/Shift
Shift
Shift

Shift

Normal

Lock

Normal

Shift
Shift and Lock
Shift and
NumLock
NumLock
Lock
None

NumLock
Lock
Normal

Except for the alphabetic and NumLock tables, the format of the table contents are the same. Each table has 105 entries with an entry being a 2-byte
pair. The first byte (low byte) is the ASCII key value (function OOH returns it
in ALI. The second byte (high byte I is the scan code (function OOH returns it in
AHI. To find the correct entry in a table, subtract one from the scan code,
double the result, and add that to the table pointer.
A table entry FFFFH is interpreted as an invalid key and is ignored. In Table
15-15, invalid keys are shown as - -.
The NumLock table has 13 2-byte keypad entries. They are the keys 0 through
9, the plus key, the minus key, and the period key. To find the correct entry in
a NumLock table, subtract 47H from the scan code, double the result, and add
that to the table pointer.
The alphabetic table is 53 bytes in size. Each byte corresponds to one of the
scan codes 01H (Escl through 35H (forward slash). If an entry has a value of 0,
that key is treated as a nonalphabetic key. The Shift key and the combination
Shift/Lock shifts nonalphabetic keys, but Lock key does not. If an entry has a
value of FFH, that key is treated as an alphabetic key. The Shift or Lock key
Chapter 15 - ROM BIOS Interrupt 16H

15 - 121

shifts alphabetic keys, but the combination Shift/Lock does not. To find the
correct entry in an alphabetic table, subtract one from the scan code and add
the result to the table pointer.

15 - 122

Chapter 15 - ROM BIOS Interrupt 16H

Interrupt 17H: Printer Output
Software Interrupt - Industry-Standard with DIGITAL Extensions
This interrupt provides an industry-standard software interface to the parallel
printer ports. It also supports extended functionality, such as:
• Redirecting any parallel port output to any serial port
• Setting or returning the printer type associated with any port
• Setting or returning the current retry map
In accordance with industry-standard practice, the ROM BIOS code supports
four parallel ports, and the ROM BIOS data area maintains four base addresses. However. due to the limited number of interrupt controller inputs. only
parallel port OOH can be interrupt driven.
Initially, parallel port OOH is redirected to serial port FFH, the integral serial
printer port at 110 address OCAOH. Serial port FFH is interrupt driven through
hardware interrupt vector 73H. The default conditions for the serial printer
port are 4800 baud, 8 data bits, no parity, and I stop bit. It is also set to use
XON/XOFF protocol and receive buffering. For additional information on the
serial printer port, see Interrupt I4H.
Parallel port OOH can be redirected to a physical parallel port.
After redirecting parallel port OOH. the ROM BIOS looks for three physical
parallel ports at 110 addresses 0378H, 03BCH, and 0278H. The first port
found is assigned to logical parallel port OIH. The second port found is
assigned to logical parallel port 02H. The third port found is assigned to logical
parallel port 03H.
The following is a list of the available functions:
AH

Description

Digital Extended

OOH
OIH
02H
DOH
DIH
D2H

Transmit character
Initialize printer port
Return port status
Redirect parallel output
Printer type
Parallel Retry On Timeout

No
No
No
Yes
Yes
Yes

Chapter 15 - ROM BIOS Interrupt 17H

15 - 123

Function OOH: Transmit Character
Industry-Standard
Parameters
AH = OOH
AL = The character to transmit
OX = The port number (OOH to 03H)
Returns
AH = The port status (as specified in function 02H)
This function transmits a character to the specified printer port. It returns current port status in AH. Refer to function 02H for the bit definitions.
If a timeout error is returned, the character was not transmitted.

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Chapter 15 - ROM BIOS Interrupt 17H

Function OlH: Initialize Printer
Industry-Standard
Parameters
AH = 01H
OX = The port number (OOH to 03H)
Returns
AH = The port status (as specified in function 02H)
This function initializes the specified port and associated printer. It returns current port status in AH. Refer to function 02H for the bit definitions.
If specified port is a serial device, it is initialized to 4800 baud. 8 data bits, no

parity. and 1 stop bit.

Chapter 15 - ROM BIOS Interrupt 17H

15 - 125

Function 02H: Return Printer Status
Industry-Standard

Parameters
AH = 02H
DX = The port number {OOH to 03H)
Returns
AH = The port status {set bits indicate condition)
For parallel ports:
Bit 7 . Not busy
Bit 6 . Acknowledge
Bit 5 . Out of paper
Bit 4 . Selected
Bit 3 . 110 Error
Bit 2 . Not Used
Bit 1 . Not Used
Bit 0 . Time Out
For serial ports:
Bit 7 . Not busy, serial transmitter empty or done (or serial timeout)
Bit 6 . Not Used
Bit 5 . Not Used
Bit 4 . Modem signals DSR or CTS
Bit 3 . DSR, CTS, break, framing, parity or overrun error
Bit 2 . Not Used
Bit 1 . Not Used
Bit 0 . Serial timeout
This function returns, in the AH register, the current port and printer status.

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Chapter 15 . ROM BIOS Interrupt 17H

Function DOH: Redirect Parallel Printer
DIGITAL Extension
Parameters
AH = DOH
AL = OOH
AL = FFH

Return the redirection map in DH and DL
Set the redirection map according to DH and DL

DH = Parallel device selection mask
DL = Parallel to serial mapping assignment
Returns
DX = Parallel device selection mask (AL = OOH)
DL = Parallel to serial mapping assignment (AL = OOH)
This function redirects any of the four parallel ports to any of the four serial
ports or the integral serial printer port FFH.
When output is redirected to a serial port, the current operational conditions
associated with that serial port remain in effect. For information regarding
serial port communications protocol and signal requirements, see Interrupt
14H.
The DH and DL registers each have four 2-bit fields. If a 2-bit field in DB is
set to 11 (binary). the corresponding 2-bit field in DL defines the target serial
port. If the 2-bit field in DH is set to 00, the corresponding 2-bit field in DL
has no meaning, and that port is set to its original parallel assignment. To
redirect a port, read the current map, set the desired redirection bits, and set
the new map.
The four 2-bit fields in DH and DL are aligned as follows:
Port

Bits

03H
02H
01H
OOH

7-6
5-4

3-2
1-0

Chapter 15 - ROM BIOS Interrupt 17H

15 - 127

The 2-bit fields in DH are the parallel device selection masks and are defined
as follows:
Value

Description

00
01
10
11

The parallel port was not redirected
The parallel port was redirected to the integral serial printer port
Reserved
The parallel port was redirected as defined in DL

The 2-bit fields in DL are the parallel to serial mapping assignments and are
defined as follows:
Value

Description

00
01
10
11

Assigned to logical serial port 00 H
Assigned to logical serial port 01H
Assigned to logical serial port 02H
Assigned to logical serial port 031-1

15 - 128

Chapter 15 - ROM BIOS Interrupt 17H

Function DIH: Printer Type
DIGITAL Extension
Parameters
AH = D1H

AL
OOH
AL = FFH

Return the printer types in BX, ex, and DL
Set the printer types according to BX, ex, and DL

Returns
BX = Parallel printer types

ex = Serial printer types

DL = Printer type at serial printer port (bits 3-0)
This function sets or returns a code that defines the type of printer attached to
any port. This allows applications to tailor the output according to the defined
printer type.
This function has no effect on how the ROM BIOS handles printers. This function provides a method for applications to maintain and share printer-type
information.
The printer types returned in the BX, ex, and DL registers are in 4-bit fields
and aligned as follows:
Port

Bits

03H
02H

15-12
11-8
7-4

01H
OOH

3-0

Chapter 15 - ROM BIOS Interrupt 17H

15 - 129

The following list defines the printer type assigned to each of the possible
values:
Binary Value

Parallel Type

Serial Type

0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110

Unknown
Industry-standard graphic
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Not used
Not used

Unknown
Industry-standard graphic
LA50
LA75 IDIGITAL model
LA75 (Industry-standard mode)
LN03
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Not used
Not used

15 - 130

Chapter 15 - ROM BIOS Interrupt 17H

Function D2H: Parallel Port Retry
DIGITAL Extension

Parameters
AH = D2H
AL = 01H Return the current retry map in AL
AL = Any value other than 01H is written to the retry map
Returns
AL = The current retry map treturn map AL = 0111)
This function controls the ROM BIOS support of parallel port timeout errors.
Each port is individually controlled by reading the current map and changing
only the desired control bits. If the AL register equals 01H, the current retry
map is returned in the AL register. Otherwise, the contents of the AL register
are written to the retry map. Initially, all ports are set to return timeout
errors. The retry map bit assignments are defined as follows.
Port

Bits

Usage

03H

7-6

00 = Return the timeout errors
11 = Loop on the timeout errors

02H

5-4

00 = Return the timeout errors
11 = Loop on the timeout errors

01H

3-2

00 = Return the timeout errors
11 = Loop on the timeout errors

OOH

1-0

00 = Return the timeout errors
11 = Loop on the timeout errors

Chapter 15 - ROM BIOS Interrupt 17H

15 - 131

Interrupt ISH: Basic
Software Interrupt - DIGITAL Extension

Parameters
None
Returns
Nothing
The interrupt attempts to boot from the network. If that fails, interrupt 19H is
invoked.
NOTE
The VAXmate workstation does not have BASIC in ROM.

15 - 132

Chapter 15 - ROM BIOS Interrupt ISH

Interrupt 19H: Bootstrap
Software Interrupt - DIGITAL Extension
Parameters
None
Returns
Nothing
NOTE
Because this interrupt invokes other interrupts to accomplish
the bootstrap, intercepted interrupts must be restored to their
original values. To know when the intercepted interrupts must
be restored, intercept Interrupt 19H. On intercepting
Interrupt 19H, restore any intercepted interrupts {including
Interrupt 19H) and invoke Interrupt 19H.
Interrupt 19H has the following boot logic:
1.

3.
4.

Reset interrupt lEH to the default diskette table. Set the boot device to
diskette O. Read the first sector from diskette 0 into 0000:7COOH.
The contents of the boot block are examined. If the first word is OOOOH
or the first ten words are all equal, the diskette is not considered bootable. The boot block is not tested for AA55H in the last word.
If the read is successful and the contents are correct, execute a far call to
0000:7COOH.
If the diskette is not present or the diskette is not bootable:

a.
b.

The CMOS RAM at offset OEH is read. If bit 3 is 0, boot the hard
disk.
If there is a hard disk present, read the boot block. If the boot block
is a valid DIGITAL boot block, read the boot flag. Otherwise, if the
boot block is a valid industry-standard boot block, try to boot it.
If the boot flag indicates boot network first or the hard disk is not
present:
(1)
Attempt to boot from network.
(2)
(3)

If that fails and hard disk is present, attempt to boot hard disk.
If that fails, go to the start of the process and try again.

If the flag indicates boot hard disk first or boot block is not a

DIGITAL boot block:
Chapter 15 - ROM BIOS Interrupt 19H

15 - 133

(1)

Attempt to boot from the hard disk.

12)

If that fails, attempt to boot from network.

13)

If that fails, go to the start of the process and try again.

This process loops 22 times. If the system has not booted, it drops into a keyboard loop and waits for the key combination Ctrl/Alt/Del. On receiving that
key combination, the ROM BIOS executes Interrupt 19H and restarts the boot
process.

DIGITAL Hard Disk Boot Block
The hard disk boot sector is located at cylinder 0, head 0, sector 1. It consists
of the following:
Offset

Description

0000H-019FH

The boot code

01AOH

The 16-byte disk parameter table
This table is valid only if the DIGITAL signature contains
ODECH and bit 1 of BOOT FLAGS is set.

0IBOH-OIB9H

Reserved

01BAH

16 flag bits lunused bits are set to 0)
Bit 1 - If set, parameter block is valid.
Bit 0 - If set, attempt boot from network first.

01BCH

The DIGITAL signature
A value of ODECH indicates that the boot block contains
valid DIGITAL data.

01BEH

The 32-word industry-standard partition table

01FEH

The industry-standard boot signature
A value of AA55H indicates a valid boot block.

15 - 134

Chapter 15 - ROM BIOS Interrupt 19H

Interrupt lAH: Time-of-day
Software Interrupt - Industry-Standard with DIGITAL Extensions
The functions in this interrupt read and set the system clock and read or set
the real-time clock.
The system clock frequency is 18.20648 Hz or 1573040 ticks per day.
The industry-standard 24-hour overflow flag is invalid if more than 48 hours
elapse between reads. The ROM BIOS provides a days-since-read counter that
can count up to 255 days between reads.
NOTE
The system clock is read or written in timer ticks (1573040
ticks per day) and is a binary value. The real-time clock is read
or written using time measures like month, hours, minutes, and
seconds. However, the value is in binary coded decimal.
NOTE
Execution of interrupt lAH. functions OOH, OIH or DOH, clears
the 24-hour overflow flag and the days-since-read counter.
The following is a list of the available functions:
AU

Description

Digital Extended

OOH
01H
02H
03H
04H
05H
06H
07H
DOH

Read the system clock
Set the system clock
Read the real-time clock
Set the real-time clock
Return the RTC date
Set the RTC date
Set the alarm
Cancel the alarm
Return the days-since-read counter

No
No
No
No
No
No
No
No
Yes

Chapter 15 - ROM BIOS Interrupt 1AU

15 - 135

Function OOH: Read System Clock
I ndllstry-Standard
Parameters
AH = OOH
Returns
AL = OOH 24-hour overflow has not occurred
AL = 01H 24-hour overflow occurred
CX = High-order 16 bits of elapsed-time
OX = Low-order 16 bits of elapsed-time
This function returns the system elapsed-time. The elapsed-time is a 32-bit
value measured in timer ticks from the last time written. At power-up, the
elapsed-time is set to O.

Function OlH: Set System Clock
Industry-Standard
Parameters
AH = 01H
CX = High-order 16 bits of elapsed-time
OX = Low-order 16 bits of elapsed-time
Returns

Nothing
This function sets the system elapsed-time clock. The elapsed-time is a 32-bit
value measured in timer ticks from the last time written. At power-up, the
elapsed-time is set to O.

15 - 136

Chapter 15 - ROM BIOS Interrupt lAH

Function 02H: Read Real-Time Clock
Industry-Standard
Parameters
AH = 02H

Returns
CH = Hours (BCD)
CL = Minutes (BCD)
DH = Seconds (BCD)
This function returns the time from the real-time clock. The returned values
are in binary coded decimal.
NOTE
If an expansion box is installed, the battery-backed clock main-

tains the current date and time. Otherwise, the time is relative
to the last time it was written since power-up (at power-up, the
time is set to 0).

Chapter 15 - ROM BIOS Interrupt 1AH

15 - 137

Function 03H: Set Real-Time Clock
Industry-Standard
Parameters
AH = 03H
CH = Hours (BCD)
CL = Minutes (BCD)
DH = Seconds (BCD)
DL = The daylight savings flag
o = Do not use daylight savings
1 = Use daylight savings
Returns
Nothing
This function sets the real-time clock. The parameters are in binary coded
decimal.

Function 04H: Return RTC Date
Industry-Standard
Parameters
AH = 04H
Returns
CH = Century (19 or 20 in BCD)
CL = Year (00 to 99 in BCD)
DH = Month (BCD)
DL = Day (BCD)
This function returns the real-time clock date. The parameters are in binary
coded decimal.

15 - 138

Chapter 15 - ROM BIOS Interrupt 1AH

Function 05H: Set RTC Date
Industry·Standard
Parameters
AH = 05H
CH = Century (19 or 20 in BCD)
CL = Year (00 to 99 in BCD)
DH = Month (BCD)
DL = Day (BCD)
Returns
Nothing
This function sets the real·time clock date. The parameters are in binary coded
decimal.

Function 06H: Set Alarm
I ndustry·Standard
Parameters
AH = 06H
CH = Hours (BCD)
CL = Minutes (BCD)
DH = Seconds (BCD)
Returns
CF = 0
CF = 1

No previous alarm
The previous alarm was not canceled, this alarm not set

This function sets the real-time clock alarm. At the specified time of the day,
an alarm interrupt is issued by the real-time clock. The ROM BIOS handles
the alarm interrupt and executes interrupt 4AH. The application should set interrupt vector 4AH to point to the alarm service. The parameters are in binary
coded decimal.

Chapter 15 - ROM BIOS Interrupt 1AH

15 - 139

Function 07H: Cancel Alarm
Industry-Standard
Parameters
AH = 07H
Returns
Nothing
This function cancels the real-time clock alarm.

Function DOH: Return Days-Since-Read Counter
DIGITAL Extension
Parameters
AH = DOH
Returns
AL = The contents of days-since-read counter
ex = High-order 16 bits of elapsed-time
DX = Low-order 16 bits of elapsed-time
This function returns the contents of the days-since-read counter and the
elapsed-time. The days-since-read counter indicates the number of 24-hour periods that have passed since any of Interrupt 1AH functions OOH. 01H, or DOH
was executed. The elapsed-time is a 32-bit value measured in timer ticks.
This function is similar to function OOH, except that AL returns days-since-read
instead of the 24-hour overflow flag. The 24-hour overflow flag indicates only
that 24 hours or more have elapsed.
Executing this function clears the 24-hour overflow flag and the days-since-read
counter.

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Chapter 15 - ROM BIOS Interrupt lAH

Interrupt IBH: Keyboard Break
Software Interrupt - Industry-Standard

Parameters
None
Returns
Nothing
Whenever the key combination CtrllBreak is typed. at the keyboard, the routine
pointed to by this vector is executed by interrupt 09H. Use an IRET instruction to return control to interrupt 09H. The ROM BIOS initializes this vector
to point to a ROM BIOS IRET.

Interrupt lCH: Timer Tick
Software Interrupt - Industry-Standard

Parameters
None
Returns
Nothing
When a system clock interrupt occurs, the ROM BIOS executes Interrupt
lCH. Thus, the routine pointed to by this vector is executed. Use an IRET
instruction to return control to the ROM BIOS. The ROM BIOS initializes this
vector to point to a ROM BIOS IRET. For additional information, see
Interrupt OSH.

Chapter 15 - ROM BIOS Interrupt IBH and lCH

15 - 141

Interrupt IDH: Video Parameters
Pointer - Industry-Standard
This vector points to a table, not executable code.
This vector is not a true interrupt. This table is 16 bytes long and corresponds
directly with the registers RO through R15 of the 6845 video controller. For
additional information on the video controller, see Chapter 7.

15 - 142

Chapter 15 - ROM BIOS Interrupt IBH and lCH

Interrupt lEH: Diskette Parameter Tables
Pointer - Industry-Standard
This vector points to a table, not executable code.
A diskette parameter table defines the physical characteristics of a diskette.
The values in the table are used by the diskette driver to initialize the diskette
controller. Table 15-16 describes the contents of a diskette parameter table.
Each parameter in Table 15-16 is one byte long.
The interrupt vector for interrupt 1EH points to the diskette parameter table.
If a diskette drive does not exist, the interrupt vector for interrupt 1EH is

reserved and undefined.
Table 15-16 Diskette Parameter Table Description
Offset

Bits

Description

OOH

7-4

Step rate
Each increase in the value of bits 7-4 decreases the step
rate by 1 ms, so that zero equals 16 ms, one equals 15
ms, two equals 14 ms, and so on.

3-0

Head unload time
Each increase in the value of bits 3-0 increases the head
unload time by 16 ms, so that zero equals 16 ms, one
equals 32 ms, two equals 48 ms, and so on.

7-1

Head load time
Each increase in the value of bits 7-1 increases the head
load time by 2 ms, so that zero equals 2 ms, one equals 4
ms, two equals 6 ms, and so on.
Direct Memory Access {DMAI selection
o = Do not use DMA
1 = Use DMA mode
Clock ticks until motor is turned off

01H

o
02H

7-0

Chapter 15 - ROM BIOS Interrupt 1EH

15 - 143

Table 15-16 Diskette Parameter Table Description ~cont.}
Offset

Bits

Description

03H

7-0

Sector size
Each increase in value doubles the sector size, so that
zero equals 128 bytes, one equals 256 bytes, two equals
512 bytes, and so on. The default is value is two (512
bytes}.

04H
05H

7-0
7-0

Sectors per track ~8, 9. 10, or 15)
Sector gap length (1BH}

06H
07H

7-0
7-0

Data length (FFH)

08H

7-0

Format fill byte (F6H)

09H

7-0

Head settle time in milliseconds

OAH

7-0

Motor start-up time in .125 second increments

15 - 144

Chapter 15 - ROM BIOS Interrupt lEH

Format gap length (54H)

Interrupt IFH: Graphics Character Table
Pointer
Pointer - Industry-Standard with DIGITAL Extension

This vector points to a table, not executable code. It points to a character table
for generation of character codes BOH through FFH. Interrupt 10H, function
DOH extends the functionality of this pointer. If enabled, this vector points
character table for generation of character codes OOH through FFH.

Interrupt 40H: Revector of Interrupt 13H
Software Interrupt - Industry-Standard

Normally, the diskette 110 is serviced through interrupt 13H. When a hard disk
is installed, the hard disk 110 is serviced through interrupt 13H, and the
diskette I/O service is revectored to Interrupt 40H. This revectoring information is provided only for clarity. Always use Interrupt 13H for both diskette
and hard disk functions.

Chapter 15 - ROM BIOS Interrupt IFH and 40H

15 - 145

Interrupt 4tH and 46H: Hard Disk
Parameter Tables
Pointer - Industry-Standard

This vector points to a table, not executable code.
A hard disk parameter table defines the physical characteristics of a hard disk.
The values in the table are used by the hard disk driver to initialize the hard
disk controller. Table 15-17 describes the contents of a hard disk parameter
table.
The hard disk parameter tables are located in DIGITAL private RAM. During
the power-up sequence, the disk type is extracted from CMOS RAM. If the
disk type is unknown, the table contains all zeros. If the disk type is one of the
14 industry-standard types, the table is initialized from the hard disk data in
the ROM BIOS. If the disk type is the DIGITAL extended type OFH, the
ROM BIOS expects the boot block to contain the parameters. The ROM BIOS
initializes the table with data extracted from the boot block. (As part of its
initialization process, the FDISK utility writes the parameters in the boot
block. I
The interrupt vectors for Interrupt 41H and 46H point to the hard disk parameter tables for hard disk 0 and hard disk 1, respectively. If hard disk 1 does
not exist, the interrupt vector for Interrupt 46H is reserved and undefined.

15 - 146

Chapter 15 . ROM BIOS Interrupt 41H and 46H

Table 15-17 Hard Disk Parameter Table Description
Offset

Size

Description

OOH

1 Word

Maximum number of cylinders on hard disk drive

02H

1 Byte

Maximum number of heads on hard disk drive

03H

1 Word

Not used

05H

1 Word

Cylinder number to start using write
precompensation

07H

1 Byte

Not used

OBH

1 Byte

Control byte sent to controller
If bit 7 or bit 6 is set (1 I, disable retries
If bit 3 is set (11, hard disk has more than eight

heads
09H

3 Bytes

Not used

OCH

1 Word

Landing zone

OEH

1 Byte

Number of sectors per track

OFH

1 Byte

Reserved for future use

Chapter 15 - ROM BIOS Interrupt 41H and 46H

15 - 147

Interrupt 4AH: RTC Alarm
Software - Industry-Standard

When a real-time clock alarm occurs. the ROM BIOS executes Interrupt 4AH.
Thus, the routine pointed to by this vector is executed. Use an IRET instruction to return control to the ROM BIOS. For additional information, see
Interrupt 1AH (functions 06H and 07HI.

Interrupt 70H: Real-Time Clock
Hardware Interrupt - Industry-Standard

Interrupt 70H provides the ROM BIOS with hardware-interrupt services for
the real-time clock. This interrupt monitors the periodic interrupt and the
alarm interrupt.
Using this interrupt requires knowledge of the VAXmate hardware, the ROM
BIOS, and the operating system. For informtion about the real-time clock, see
Chapter 5. For information about the ROM BIOS clock services, see Interrupt
1AH.

Interrupt 71H: Redirect to Interrupt OAH
Hardware Interrupt - Industry-Standard

This interrupt redirects the IRQ9 hardware interrupt to Interrupt OAH, which
is the old IRQ2 hardware interrupt. IRQ9 is an available interrupt input and
Interrupt OAH is an available interrupt vector.

15 - 148

Chapter 15 - ROM BIOS Interrupt 4AH, 70H, and 71H

Interrupt 72H: Local Area Network
Controller (LANCE)
Hardware Interrupt - DIGITAL Extension

Interrupt 72H provides the network software with hardware-interrupt services
for the LANCE. This interrupt service provides an operation complete indication from the LANCE.
Interrupt 72H has no arguments. preserves all registers, and returns no values.
Using this interrupt requires knowledge of the VAXmate hardware, the ROM
BIOS, and the operating system. For more information on the LANCE, see
Chapter 13. For more information about network I/O services, see the
VAXmate Network Technical Reference Manual.

Chapter 15 - ROM BIOS Interrupt 728 and 738

15 - 149

Interrupt 73H: Serial Printer Port
Hardware Interrupt - Industry-Standard
Interrupt 73H provides the ROM BIOS with hardware-interrupt services for
the asynchronous serial printer port. This interrupt service monitors the state
of the serial communications protocol. It also transmits and receives characters
as required.
Interrupt 73H has no arguments, preserves all registers, and returns no values.
Using this interrupt requires knowledge of the VAXmate hardware, the ROM
BIOS, and the operating system. For information on the 8250A serial communications device, see Chapter 9. For information about the ROM BIOS
asynchronous communications service, see Interrupt 14H.

Interrupt 74H: Mouse Port
Hardware Interrupt - DIGITAL Extension
Interrupt 74H provides the mouse driver with hardware interrupt services.
The mouse driver interrupt handler is present only when the mouse driver has
been loaded under MS-DOS.
Using this interrupt requires knowledge of the VAXmate hardware. For information on the mouse, see Chapter 10.

15 - 150

Chapter 15 - ROM BIOS Interrupt 73H and 74H

Interrupt 75H: 80287 Error
Hardware Interrupt - Industry-Standard

Interrupt 75H provides MS-DOS with hardware interrupt services for 80287
math coprocessor errors.

Interrupt 76H: Hard Disk
Hardware Interrupt - Industry-Standard

Interrupt 76H provides the ROM BIOS with hardware-interrupt services for
the hard disk controller. This interrupt service provides a operation complete
indication from the hard disk controller.
Interrupt 76H has no arguments, preserves all registers, and returns no values.
Using this interrupt requires knowledge of the VAXmate hardware, the ROM
BIOS, and the operating system. For information on the hard disk controller
see Chapter 12. For more information about the ROM BIOS hard disk 110
service, see Interrupts 13H, 14H, and 46H.

Interrupt 77H: Available (IRQ15)
Hardware Interrupt - Industry-Standard

Interrupt 77H is available for undefined uses related to IRQ15.

Chapter 15 - ROM BIOS Interrupt 75H, 76H and 77H

15 - 151

Chapter 16
Programming the VAXmate
Under MS-DOS
Overview
Microsoft Disk Operating System (MS-DOS) is the operating system for microcomputers using Intel 8086 and 8088 microprocessors. An operating system, a
program that controls the overall operation of a computer, provides an environment within the computer that enables the user to easily perform operations
such as:
•

Program execution

•

File management

•

Resource management

•

Programming

•

Device handling

The MS-DOS operating system provides functions for commonly-used operations and 110 operations that are hardware independent. Therefore, a user can
write an application program to run under the MS-DOS operating system without a detailed knowledge of the computer hardware. Such a program runs on
any computer that can run the MS-DOS operating system, as long as the computer has the appropriate peripherals. MS-DOS provides all the logical operations necessary for writing to and reading from disk storage devices.

Programming the VAXmate Under MS-DOS

16 - 1

MS· DOS Operating System Versions
The MS-DOS operating system has evolved through a number of versions.
Microsoft's Version 3.10 is the base for DIGITAL's VAXmate Version 3.10.
DIGITAL added many new features, modifications, and utilities to Microsoft's
base version. Some new features are:
•

ANSI, which replaces the normal console device with an ANSI
escape sequence parser.

•

MDRIVE, which enables a user to use RAM as a fast logical disk
drive.

•

FDISK, which manages hard disks.

•

International support in MS·DOS Interrupt 21H Function 38H

•

FONT, which enables a user to load file-based text font sets.

•

GRAFTABL, which enables a user to load file-based graphics font
sets.

•

GRAPHICS, which enables a user to print screen images on
DIGITAL and industry standard printers.

•

KEYB, which enables a user to load file-based keyboard maps.

•

LCOUNTRY, which enables a user to load file-based country data
sets.

•

SORT, which coordinates the sort set with the current font set.

Programs written to run under IBM's DOS Version 3.10 and later will run
under DIGITAL's version of MS-DOS.
Programs written for the Rainbow that use only generic MS-DOS Interrupt
21H calls and do not make ROM calls directly can be run under MS-DOS
Version 3.10 for the VAXmate. An example is the Microsoft C Compiler and
Linker.
MS-DOS Version 3.10 runs only in the real mode of the 80286 processor.

Loading MS·DOS Operating System
MS·DOS Memory Map
Chapter 2 contains an MS-DOS memory map.

16- 2

Programming the VAXmate Under MS-DOS

MS-DOS Interrupt 21H Digital Specific
Functions
Function 30H Get MS·DOS OEM Number
Function 30H returns the OEM serial number in register BH. This number is
I6H for DIGITAL's version of MS-DOS, and OOH for IBM's DOS.

Function 38H Get/Set Country Code
To accommodate the VAXmate's ability to load file-based character fonts and
keyboard maps, MS-DOS saves the current font set and keyboard map in a
text string.
To retrieve the pointer to the data area containing the file name of the current
font file and keyboard map, do an INT 2IH with the following values in the
specified registers:
Parameters
AH =

3SH

AL =
BX =
DS:DX =

OFFH
8000H
points to a double word address that is loaded
with the address of the beginning of the current
country-specific table

Returns
DS:DX =

32-bit pointer to the MS-DOS date and time structure containing the current font file and keyboard map

After retrieving the double word pointer to the date and time structure, information about the current font file and keyboard map can be retrieved, changed
or set.
At offset -IAH of the date and time structure, a I4-byte buffer contains the
name of the current keyboard file. When a new keyboard file is loaded, this
string must be replaced with the complete file name of the newly-loaded keyboard file, padded with zeros.
Programming the VAXmate Under MS-DOS

16 - 3

At offset -34H of the date and time structure, a 14-byte buffer contains the
name of the current text font file. When a new font file is loaded, this string
must be replaced with the complete file name of the newly-loaded font file,
padded with zeros.
Figure 16-1 shows the MS-DOS date and time structure.

Offset Relative to Base
-4EH 1000000000000001 Reserved for future use
-34H ISTDoFNTOOOOOOOI Current font file

-lAB STDUS KEYOOOOO I Current keyboard file
DVORD Pointer

MS-DOS Date &
Time Structure
OFFHI

Figure 16-1 MS-DOS Date and Time Structure

16 - 4

Programming the VAXmate Under MS-DOS

Loadable MS-DOS Device Drivers
ANSI.SYS
ANSI.SYS is an MS-DOS loadable device driver that replaces the standard
console device driver. An ANSI escape sequence is a series of characters (beginning with an escape character or keystroke) that defines the following functions
to the MS-DOS operating system:
•

Cursor control functions

•

Erase functions

•

Set graphics rendition function

•

Set mode function

•

Reset mode function

•

Keyboard key reassignment function

ESC is the one byte ASCII code lBH.
The size of the MS-DOS operating system increases by the size of ANSI.SYS.
For more information about the ANSI X3.64-l979 standard, see Information
Systems-Codes, which is available through the Order Department of the
American National Standards Institute, 1430 Broadway, New York, NY, 10018.

Installing ANSI.SYS
To install the ANSI.SYS device driver, insert the following line in a
CONFIG.SYS file:
DEVICE=ANSI.SYS

Cursor Control Functions
Cursor control functions affect the position of the cursor on the screen. Table
16-1 contains the escape sequences to position the cursor on the screen. The #
indicates a string of decimal digits. For example, ESC [lOA moves the cursor
up 10 rows. Row 1 refers to the first line of the screen; row 2 refers to the
second line of the screen, etc.

Programming the VAXmate Under MS-DOS

16- 5

Table 16-1

Cursor Control Functions

Sequence

Function

ESC [#;#H

This sequence moves the cursor to the specified position. The
first # specifies the row. The second # specifies the column. The
default value is 1. If no parameters are specified, the cursor
moves to the upper left hand corner of the screen. Some error
checking is done. If illegal values are specified, garbage is
displayed on the screen.

ESC [#A

This sequence moves the cursor up one or more rows without
changing the column position. The value of # determines the
number of rows moved. The default value is 1. If the cursor is
already on the top row or reaches the top row during this operation, this sequence is ignored.

ESC [#B

This sequence moves the cursor down one or more rows without
changing the column position. The value of # determines the
number of rows moved. The default value is 1. If the cursor is
already on the bottom row or reaches the bottom row during
this operation, this sequence is ignored.

ESC [#e

This sequence moves the cursor forward one or more columns
without changing the row position. The value of # determines
the number of columns moved. The default value is 1. If the
cursor is already in the right-most column or reaches it during
this operation, this sequence is ignored.

ESC [#0

This sequence moves the cursor back one or more columns without changing the row position. The value of # determines the
number of columns moved. The default value is 1. If the cursor
is already in the left-most column or reaches it during this operation, this sequence is ignored.

ESC [#;#f

This sequence moves the cursor to the position specified by #;#.
The first # specifies the row number. The second # specifies the
column. The default value for both is L If no parameters are
specified, the cursor moves to the upper left hand corner of the
screen.

16 - 6

Programming the VAXmate Under MS-DOS

Table 16-1

Cursor Control Functions (cont.~

Sequence

Function

ESC [#;#R

This sequence reports the current cursor position through the
standard input device. The first # specifies ~he current row. The
second # specifies the current column. This is not a command,
but a "Cursor Position Report." This sequence is received after
issuing the "Device Status Report" command.

ESC [6n

This sequence is the Device Status Report. ANSI.SYS outputs
a "Cursor Position Report" when it receives this escape
sequence.
This sequence saves the current cursor position.

ESC [s
ESC [u

This sequence restores the cursor to the value it had when
ANSI.SYS received the last "Save Cursor Position" escape sequence. ESC [s is the "Save Cursor Position."

Erase Functions
Erase functions erase characters from part or all of the screen. Table 16-2
contains the escape sequences to erase text from the screen.
Table 16-2

Erase Functions

Sequence

Function

ESC [2J

This sequence erases the entire screen. The cursor moves to the
upper left hand corner of the screen.

ESC [K

This sequence erases from the cursor to the end of the line, including the cursor position.

Programming the VAXmate Under MS-DOS

16 - 7

Set Graphics Rendition
The set graphics rendition function invokes the graphics rendition specified by
the parameters. All of the following characters are rendered according to the
parameters until the next set graphics rendition. Table 16-3 contains the
escape sequence and parameters to set graphics rendition.
Table 16-3

Set Graphics Rendition Function

Sequence

Function

ESC [#; ... ;#m

Invokes the graphics rendition specified by the parameters.

16 - 8

Parameter

Meaning

Notes

All attributes off

1
4
5

Bold on

Normal white on black
High intensity

Underscore on

Monochrome adapter only

Reverse video on

Canceled on

Black foreground

31
32
33
34
35

Red foreground

Blink on

Green foreground
Yellow foreground
Blue foreground
Magenta foreground

Programming the VAXmate Under MS-DOS

Table 16-3
Sequence

Set Graphics Rendition Function (cont.)
Function
Parameter

Meaning

36
37
40
41
42
43
44
45
46
47

Cyan foreground

Notes

White foreground
Black background
Red background
Green background
Yellow background
Blue background
Magenta background
Cyan background
White background

Programming the VAXmate Under MS·DOS

16 - 9

Set Mode Function
The set mode function sets screen width and screen display. Table 16-4 contains the escape sequence and parameters to set the mode.
Table 16·4

Set Mode Function

Sequence

Function

ESC [= #h

This sequence invokes the screen width or type specified by the
parameter.

ESC [?#h
The ? and = are interchangeable in this command.
ESC [=h assumes a parameter value of zero.

16 - 10

Parameter

Meaning

40x25 black and white

40x25 color

80x25 black and white

80x25 color

320x200 color

320x200 black and white

640x200 black and white

Wrap at end of line

Programming the VAXmate Under MS· DOS

Reset Mode Function
The reset mode function resets the screen width and screen display. Table 16-5
contains the escape sequence and parameters to reset the mode.
Table 16-5

Reset Mode Function

Sequence

Function

ESC [= #1

This sequence resets the screen width or type specified by the
parameter.

ESC [7#1
The 7 and = are interchangeable in this command.
ESC [= 1 assumes a parameter value of zero.
Parameter

Meaning

40x25 black and white

40x25 color
80x25 black and white

80x25 color

320x200 color

320x200 black and white

640x200 black and white

No wrap at end of line. Type past end of line is
lost.

Programming the VAXmate Under MS-DOS

16 - 11

Keyboard Key Reassignment Function
The keyboard key reassignment function intercepts a key and redefines it.
Table 16-6 contains the escape sequence to redefine the meaning of the intercepted keyboard key.
Table 16-6

Keyboard Key Reassignment Function

Sequence

Function

ESC [#;#; ... #p
ESC ["string"p
ESC [#;"string";#;#;"string"; ... p

16 - 12

The first ASCII code in the sequence
defines which code is being mapped.
The remaining numbers define the sequence of ASCII codes generated when
this key is intercepted. If the first
code in this sequence is 0, the first
and second codes make up an extended ASCII redefinition.

Programming the VAXmate Under MS-DOS

Mouse Driver
With the MS-DOS operating system, DIGITAL provides a mouse driver,
MOUSE.SYS or MOUSE.COM. The mouse driver provides the following
features:
•
•
•

Automatic tracking of motion and button events
Optional, automatic cursor management for text and graphic video
modes
Synchronous and asynchronous handling of mouse related events

The mouse driver provides the standard functions listed in Table 16-7 and the
extended functions listed in Table 16-S. Assuming that the mouse driver is present in memory, executing software interrupt 33H invokes the mouse driver.
The contents of register AX specify the desired function. The mouse functions
are defined later in the chapter.
Table 16-7 Standard Mouse Driver Functions
Function

Description

OOOOH
OOOlH
0002H
0003H
0004H
0005H
0006H
0007H
OOOSH
0009H
OOOAH
OOOBH
OOOCH
OOODH
OOOEH
OOOFH
0010H
0013H

Mouse initialization
Show cursor
Hide cursor
Get mouse position and button status
Set mouse cursor position
Get button press information
Get button release information
Set minimum and maximum X-axis position
Set minimum and maximum Y-axis position
Define graphics cursor
Define text cursor
Read mouse motion counters
Define event handler
Light pen emulation mode on
Light pen emulation mode off
Set mouse motion/pixel ratio
Conditional hide cursor
Set speed threshold

Programming the VAXmate Under MS-DOS

16 - 13

Table 16-8 Extended Mouse Driver Functions
Function

Description

001CH
0024H
0025H
0026H-002BH
004DH
006DH

Get driver version
Get configuration
Set configuration
Reserved
Reserved
Reserved

Detecting the Mouse Driver
To determine if the mouse driver is present in memory, load the interrupt
vector at interrupt 51H, add OOOO:OOI0H to that memory address, and examine the resulting address. If the mouse driver is present, that address and the
following locations should contain the following text string:
DIGITAL/LOGITECH MOUSE DRIVER V Xxx<LF> <CR>
Where X represents the release number and xx represents the sub-release
number. The string is terminated by a linefeed and carriage return.

Video Support
To display a cursor, the mouse driver logic must contain information regarding
the video system and the available modes. Table 16-9 defines the supported
video systems and modes.
To provide the correct cursor at all times, the mouse driver monitors calls to
interrupt 10H (video 110). To monitor interrupt 10H, the mouse driver intercepts interrupt 10H function calls. Therefore, applications that intercept interrupt 10H function calls must invoke the mouse driver through the previous
interrupt vector.
Additionally, the mouse driver guarantees consistency of the screen contents
only if the screen is updated through interrupt 10H. Programs that write
directly to video memory should invoke the mouse driver as follows:
1.

Before writing directly to video memory, invoke function 0002H (hide
cursor) or function OOlOH (conditional hide cursor).

After writing directly to video memory, invoke function OOOlH (show
cursor).

16 - 14

Programming the VAXmate Under MS-DOS

Table 16-9 Video Systems and Modes Supported by MOUSE.SYS
Video Mode

Size

DIGITAL
Video
System

Color
Graphics
Adapter

Enhanced
Graphics
Adapter

Text Imonochrome)

40 X 25
80 X 25

Yes
Yes

Text Icolor)

40 X 25
80 X 25

Yes
Yes

Graphics
Imonochrome)

320 X 200

Yes

640 X 200
640 X 350
640 X 400

Yes
No
Yes

Yes
No
No

Yes
Yes
No

Graphics 14-color)

320 X 200
640 X 400
800 X 252

Yes
Yes
Yes

Yes
No
No

Graphics U6-color)

640 X 350

Yes

Programming the VAXmate Under MS-DOS

16 - 15

Function OOOOH: Mouse Initialization
Industry-Standard

Parameters
AX = OOOOH
Returns
AX = OOOOH
AX = FFFFH

Mouse hardware or driver not installed
Mouse hardware and driver installed

BX = The number of logical buttons Isee function 25HI
This function resets the driver and hides the mouse cursor. The hide-cursor
count is set to -1. To display the mouse cursor, execute a show-cursor command lfunction 0001Hl.
This function also restores the following parameters to the default value:
Parameter
Cursor position
Hide-cursor counter
Graphics cursor
Text cursor
Interrupt call mask
Light pen emulation
Horizontal mouse encode count to
pixel ratio
Vertical mouse encode count to pixel
ratio
Horizontal minimum and maximum
cursor position
Vertical minimum and maximum
cursor position

16 - 16

Default Value
Center of screen

-1 Imouse cursor hidden 1

Arrow
Inverted box
Disabled lequals 01
Enabled
8 to 8
16 to 8

o to 639
o to 199

Programming the VAXmate Under MS-DOS

Function OOOlH: Show Cursor
Industry-Standard

Parameters
AX = OOOlH

Returns
Nothing
The show-cursor function increments a software counter. After incrementing
the counter, the show-cursor function tests the software counter contents. If
the software counter equals 0, the show-cursor function displays the mouse
cursor.

Function 0002H: Hide Cursor
Industry-Standard

Parameters
AX = 0002H

Returns
Nothing
The hide-cursor function disables Ihides) the mouse cursor and decrements a
software counter. For the show-cursor command, the mouse driver displays the
mouse cursor only if the software counter equals O. To redisplay the mouse
cursor, execute a show-cursor command for each hide-cursor command executed
since the mouse cursor was last visible.

Programming the VAXmate Under MS-DOS

16 - 17

Function 0003H: Get Mouse Position and Button Status
Industry-Standard
Parameters
AX = 0003H
Returns
BX =

Button status
Bits 15-3
Bit 2

Always 0
Middle button

o = Button released
1 = Button pressed

Bit 1

Right button

o = Button released
1 = Button pressed

Bit 0

Left button

o = Button released

1 = Button pressed
ex = The horizontal cursor position
DX = . The vertical cursor position

The cursor position is a signed 16-bit positive value. When the cursor position
is outside of the pixel range permitted by the current video mode or at the
limits specified by functions 0007H and 0008H, the mouse cursor is not
displayed. The returned cursor position is always within the pixel range permitted by the current video mode or the limits specified by functions 0007H
and 0008H.

16 - 18

Programming the VAXmate Under MS·DOS

Function 0004H: Set Mouse Cursor Position
I ndu,stry-Standard

Parameters
AX = 0004H
ex = Desired horizontal cursor position
OX = Desired vertical cursor position
Returns
Nothing
The cursor position is a signed I6-bit positive value. Negative cursor position
values can cause unpredictable mouse-cursor behavior. When the cursor position
is outside of the pixel range permitted by the current video mode or at the
limits specified by functions 0007H and OOOBH, the mouse cursor is not
displayed. The values specified in registers ex and OX must be within the
limits specified by functions 0007H and OOOBH.

Programming the VAXmate Under MS-DOS

16 - 19

Function 0005H: Get Button Press Information
Industry-Standard
Parameters
AX =
BX =

0005H

Button

o = Return status of left button
1 = Return status of right button
2 = Return status of middle button

Returns
AX = Button status
Bits 15-3
Bit 2

Always 0
Middle button

o = Button released
1 = Button pressed

Bit 1

Right button

o = Button released
1 = Button pressed

Bit 0

Left button

o = Button released
1 = Button pressed

BX = The number of times the button has been pressed since its status was
checked (in the range 0 - 32767}
ex = The horizontal cursor position the last time the button was pressed
OX = The vertical cursor position the last time the button was pressed
The cursor position is a signed 16-bit positive value. When the cursor position
is outside of the pixel range permitted by the current video mode or at the
limits specified by functions 0007H and OOOSH, the mouse cursor is not
displayed. The returned cursor position is always within the pixel range permitted by the current video mode or the limits specified by functions 0007H
and OOOSH.

16 - 20

Programming the VAXmate Under MS-DOS

Function 0006H: Get Button Release Information
Industry-Standard
Parameters
AX = 0006H
BX = Button
o = Return status of left button
1 = Return status of right button
2 = Return status of middle button
Returns
AX =

Button status
Bits 15-3
Bit 2

Always 0
Middle button

o = Button released
1 = Button pressed

Bit 1

Right button

o = Button released
1 = Button pressed

Bit 0

Left button

o = Button released
1 = Button pressed

BX =

ex =

DX =

The number of times the button has been released since its status was
checked (in the range 0 - 32767)
The horizontal cursor position the last time the button was released
The vertical cursor position the last time the button was released

Programming the VAXmate Under MS-DOS

16 - 21

Function 0007H: Set Minimum and Maximum X-Axis
Position
Industry-Standard
Parameters
AX = 0007H
ex = Minimum horizontal cursor position
OX = Maximum horizontal cursor position
Returns
Nothing
The cursor position is a signed I6-bit positive value. Negative cursor position
values can cause unpredictable mouse-cursor behavior. When the cursor position
is outside of the pixel range permitted by the current video mode or at the
limits specified by functions 0007H and 0008H, the mouse cursor is not
displayed. For functions that return cursor position information, the returned
cursor position is always within the pixel range permitted by the current video
mode or the limits specified by functions 0007H and 0008H.
NOTE
When an application starts running. it is the responsibility of
the application to set the desired horizontal and vertical limits.
If an application changes video modes, it is the responsibility of
the application to set the desired horizontal and vertical limits.
If the cursor is outside the limits defined by registers ex and OX, the cursor
is moved to a position that is at the new limit.

16 - 22

Programming the VAXmate Under MS-DOS

Function OOOBH: Set Minimum and Maximum Y-Axis
Position
Industry-Standard

Parameters
AX = OOOSH

ex = Minimum vertical cursor position

DX = Maximum vertical cursor position

Returns
Nothing
The cursor position is a signed I6-bit positive value_ Negative cursor position
values can cause unpredictable mouse-cursor behavior. When the cursor position
is outside of the pixel range permitted by the current video mode or at the
limits specified by functions 0007H and OOOSH, the mouse cursor is not
displayed. For functions that return cursor position information, the returned
cursor position is always within the pixel range permitted by the current video
mode or the limits specified by functions 0007H and OOOSH.
NOTE
When an application starts running, it is the responsibility of
the application to set the desired horizontal and vertical limits.
If an application changes video modes, it is the responsibility of
the application to set the desired horizontal and vertical limits.
If the cursor is outside the limits defined by registers ex and DX, the cursor
is moved to a position that is at the new limit.

Programming the VAXmate Under MS-DOS

16 - 23

Function 0009H: Define Graphics Cursor
Industry-Standard
Parameters
AX = 0009H
BX = Horizontal focal point of cursor (hot spot)
ex = Vertical focal point of cursor (hot spot)
DX = Pointer to the screen and cursor masks (assumes DS:DX)
Returns
Nothing
The graphics cursor is defined by two arrays of bit masks called the screen
mask and the cursor mask Each array has a fixed size of 16 words. The two
arrays are contigous, with the cursor mask following the screen mask. The following e structure declares storage for a graphics cursor:
typedef struct
{

unsigned int screen_mask[16];
unsigned int cursor_mask[16];
} GRAPHICS_CURSOR;
GRAPHICS_CURSOR gc;

/* ds:dx = &gc */

The screen mask determines which cursor mask bits are background (0 value
screen mask bits) or foreground (1 value screen mask bits). The screen mask is
ANDed with the screen contents.
The cursor mask determines shape/color of the cursor. After the screen mask is
AN.Ded with the screen contents, the cursor mask is XORed with the the
results.
The horizontal and vertical focal points of the cursor are signed 16-bit values in
the range, -16 to 16. The focal point of the default cursor is the upper left
corner of the cursor (the hot spot).

16 - 24

Programming the VAXmate Under MS-DOS

The following list of screen mask and cursor mask bit values define the resulting value of the screen pixel:
Screen Mask Bit

Cursor Mask Bit

Resulting Screen Pixel

o
o

Unchanged
Inverted

Programming the VAXmate Under MS-DOS

16 - 26

Function OOOAH: Define Text Cusor
Industry-Standard

Parameters
AX = OOOAH
BX = Select hardware or software text cursor
o = Software text cursor selected
CX = Screen mask
OX = Cursor mask

Hardware text cursor selected
CX = Start scan line
OX = End scan line

Returns
Nothing
The mouse driver supports two kinds of text cursor, a hardware cursor and a
software cursor. The hardware cursor is the same as the cursor defined in interrupt 10H (video 1101. The software cursor is a character or character attribute that modifies the character cell at the cursor location. The software cursor
is defined by the screen mask and cursor mask in the CX and OX registers
respectively. The format of the two masks is as follows:
Bit
15

Description
Blink

o = Nonblinking character
1 = Blinking character

14-12

Background color
Intensity

o = Medium intensity
1 = High intensity

10-8

Foreground color

7-0

Character code

After the screen mask is ANDed with the screen contents, the cursor mask is
XORed with the results.
16 - 26

Programming the VAXmate Under MS-DOS

Function OOOBH: Read Mouse Motion Counters
Industry-Standard
Parameters
AX = OOOBH
Returns
CX = Horizontal count
DX = Vertical count
This function returns the incremental distance traveled by the mouse since the
last time this function was called. After this function loads the software
counters into registers CX and DX, it clears the software counters.
The unit of measurement for the values in registers ex and DX are mouse
encoder counts and are in the range -32768 to 32767 (overflow is ignored). A
positive horizontal count indicates motion to the right. A positive vertical count
indicates motion towards the bottom of the screen.
The mouse encoder resolution is 200 counts per inch of travel. For additional
information about the mouse, see Chapter 10.

Programming the VAXmate Under MS-DOS

16 - 27

Function OOOCH: Define Event Handler
Industry-Standard
Parameters
AX = OOOCH
CX = OOOOH
Disables mouse event handling
CX = Event mask
Specifies which events invoke the event handler
ES:DX = Address of the event handler
Returns
Nothing
This function enables or disables application handling of specific events. If one
or more bits are set in CX, event handling is enabled. The set bits in CX (call
mask) specify which events invoke the event handler. The CX bits have the
following meaning:
Bit

Event that Invokes the Event Handler

15-7

Not used

Releasing the middle button

Pressing the middle button

Releasing the right button

Pressing the right button

Releasing the left button

Pressing the left button

Change in cursor position

16 - 28

Programming the VAXmate Under MS-DOS

When an enabled event occurs, the mouse driver calls the event handler with
the following parameters:
Register

Contents

Event mask
The event mask has the same bit assignments as the event
mask in CX. However, A set bit in AX indicates that the event
occurred.

Button status tsame as defined in function 0003H)

Horizontal cursor position tsame as defined in function 0003H)

Vertical cursor position tsame as defined in function 0003H)

The returned cursor position is always within the pixel range permitted by the
current video mode or the limits specified by functions 0007H and OOOBH.
To return control to the mouse driver, the event handler must use a far return.

Programming the VAXmate Under MS·DOS

16 - 29

Function OOODH: Enable Light-Pen Emulation
Industry-Standard

Parameters
AX = OOODH
Returns
Nothing
This function enables light-pen emulation. When light-pen emulation is enabled,
calls to the interrupt 10H ~video 110) light-pen functions return the position of
the mouse cursor at the last pen down. Pressing both the left and right mouse
buttons simulates pressing the light pen button. When the left and right mouse
buttons are released, the light pen is off the screen.

Function OOOEH: Disable Light-Pen Emulation
Industry-Standard

Parameters
AX = OOOEH
Returns
Nothing
This function disables light-pen emulation. When light-pen emulation is
disabled, calls to interrupt 10H ~video 1/0) light-pen functions return only information about the light pen.
NOTE
The DIGITAL video system does not support the use of light
pens. To use a light pen, an industry-standard video adapter
that supports light pens must be installed. For additional information about the ROM BIOS light-pen functions, see the
description of interrupt 10H ~video 110) in Chapter 15.

16 - 30

Programming the VAXmate Under MS-DOS

Function OOOFH: Set Mouse Motion/Pixel Ratio
I ndllstry-Standard

Parameters
AX =

OOOFH

ex = The number of encoder counts of horizontal mouse motion to 8 pixels
of horizontal cursor motion (range equals 1 - 32767).
DX = The number of encoder counts of vertical mouse motion to 8 pixels of
vertical cursor motion (range equals 1 - 32767).

Returns
Nothing
This function defines the ratio of mouse motion to cursor motion. The default
ratio (see function OOOOH) is 8 encoder counts for 8 pixels of horizontal motion
and 16 encoder counts for 8 pixels of vertical motion. The default ratio requires
approximately 3.2 inches of mouse motion to move the cursor from border to
border (horizontally or vertically).

Function OOlOH: Conditional Hide Cursor
Industry-Standard

Parameters
AX = 0010H

ex = Left margin (smallest x-axis screen coordinate)

DX = Top margin (smallest y-axis screen coordinate)
SI = Right margin (largest x-axis screen coordinate)
DI = Bottom margin (largest y-axis screen coordinate)
Returns
Nothing

This function defines a rectangular protected region on the screen. If the
mouse cursor enters this region, the mouse cursor is disabled automatically.
Executing function 0001H (show cursor) releases the protected region and
displays the cursor. Before screen updates are performed, call this function or
function 0002H (hide cursor).
Programming the VAXmate Under MS-DOS

16 - 31

Function 0013H: Set Speed Threshold
Industry-Standard

Parameters
AX = 0013H
DX = Speed threshold
Returns
Nothing
This function sets a mouse speed threshold. When the speed of the mouse
motion exceeds the specified threshold, the ratio of cursor motion to mouse
motion is doubled. The speed threshold is measured in encoder counts per
second. Function OOOOH initializes the speed threshold to 64 encoder counts
per second.
For additional information about the mouse, see Chapter 10 Mouse
Information.

Function 001 CH: Get Driver Version
DIGITAL Extension

Parameters
AX = 001CH
Returns
BX = Version code
CX = Release number
This function returns the version code and release number of the mouse driver.
Each register returns two ASCII codes. The BX register returns 'SS' (serial
standard) or 'DE' (DIGITAL). The CX register returns two ASCII digits that
represent the release number. For example, '21' equals release number 2.10.

16 - 32

Programming the VAXmate Under MS-DOS

Function 0024H: Get Configuration
DIGITAL Extension
Parameters
AX = 0024H
ES:DX = Address of the configuration table

Returns
AX = FFFFH

Successful operation (any other value indicates failure)
Number of physical buttons updated
Number of logical buttons updated

If the logical number of buttons equals 2, the mouse driver translates the

middle button as a combination of the left and right buttons. The table pointed
to by ES:DX is 32 bytes long and has the following organization:
Offset

Size

Description

OOOOH
OOOCH
OOOEH
0010H

12 bytes
2 bytes
2 bytes
16 bytes

Reserved
Number of physical buttons
Number of logical buttons
Reserved

Function 0025H: Set Configuration
DIGITAL Extension
Parameters
AX = 0025H
BX = 0004H
CX = The number of logical buttons (2 or 3)

Returns
AX = FFFFH

Successful operation (any other value indicates failure)

If the logical number of buttons equals 2, the mouse driver translates the
middle button as a combination of the left and right buttons.

Programming the VAXmate Under MS-DOS

16 - 33

Enhanced Graphics Adapter (EGA) Functions
When the mouse driver detects an enhanced graphics adapter (EGA), the
mouse driver installs extensions to interrupt 10H (video 110). These extensions
provide the mouse driver and the application with a means of communicating
the current state of the EGA write-only registers. Table 16-10 lists the extensions to the interrupt 10H functions.
Table 16-10 Extensions to Interrupt 10H EGA Functions
Function

Description

FOH
F1H
F2H
F3H
F4H
F5H
FAH

Read EGA Register
Write EGA Register
Read EGA Register Group
Write EGA Register Group
Read EGA Register List
Write EGA Register List
EGA Functions Installed

EGA registers are referred to by a group number and a register number. Table
16-11 lists the group numbers and the registers associated with each group.
Table 16-11 EGA Register Groups and Associated Registers
Group

Port

Description

OOH
08H
10H
18H
20H
28H
30H
38H

00H-18H
00H-04H
OOH-OSH
00H-13H
OOH
OOH
OOH
OOH

03D4H
03C4H
03CEH
03COH
03C2H
03DAH
03CCH
03CAH

CRT controller
Sequencer
Graphics controller
Attribute controller
Output register
Feature control register
Graphics 1 position
Graphics 2 position

16 - 34

Programming the VAXmate Under MS-DOS

Function FOH: Read EGA Register
DIGITAL Extension

Parameters
AH = FOH
BX = Register number
OX = The group number

Returns
BL = The contents of the indicated register

Function FIH: Write EGA Register
DIGITAL Extension

Parameters
AH = FIH
BL = Register number
BH = The value to write
OX = The group number

Returns
Nothing

Programming the VAXmate Under MS-DOS

16 - 35

Function F2H: Read EGA Register Group
DIGITAL Extension
Parameters
AH = F2H
ES:BX = Buffer address
CH = Starting register number
CL = Number of registers
OX = Group number
Returns
Nothing
This function reads the contents of the specified EGA registers. The EGA registers are from the group indicated by register OX. The contents of the EGA
registers are stored in the buffer pointed to by ES:BX. Register CH, an index
into the group, specifies the first register contents read. Register CL specifies
the number of registers to write.
The buffer pointed to by ES:BX is an array of 8-bit values. Register CL specifies the number of entries in the buffer. Each entry in the buffer is the value
to write to the corresponding register.

Function F3H: Write EGA Register Group
DIGITAL Extension
Parameters
AH = F3H
ES:BX = Buffer address
CH = Starting register number
CL = Number of registers
OX = Group number
Returns
Nothing
This function writes the specified EGA registers. The EGA registers are from
the group indicated by register OX. Registers ES:BX point to a buffer that
contains the corresponding values. Register CH, an index into the register
group, specifies the first register written. Register CL specifies the number of
registers to write.
16 - 36

Programming the VAXmate Under MS-DOS

Function F4H: Read EGA Register List
DIGITAL Extension
Parameters
AH = F4H
ES:BX = Address of the register list
ex = Number of entries in the list

Returns
Nothing
This function transfers the contents of the indicated EGA register to the corresponding value byte in the list. The caller must supply the group and register
numbers. Each entry is 4 bytes long and contains the following:
Offset

Size

Description

OOH
02H
03H

Word
Byte
Byte

Group number
Register number
Value

Programming the VAXmate Under MS-DOS

16 - 37

Function F5H: Write EGA Register List
DIGITAL Extension
Parameters
AH = F5H
ES:BX = Address of the register list
ex = Number of entries in the list
Returns
Nothing
This function transfers the value byte of each entry to the indicated EGA register. Each entry is 4 bytes long and contains the following:
Offset

Size

Description

OOH
02H
03H

Word
Byte
Byte

Group number
Register number
Value

Function F AH: EGA Functions Installed.
DIGITAL Extension
Parameters
AH = FAH
BX = OOOOH
Returns
BX = OOOOH
BX = 000IH-FFFFH

16 - 38

EGA functions not installed
EGA functions installed

Programming the VAXmate Under MS-DOS

MS-DOS Media ID Tables
Hard Disk Support Through FDISK
FDISK is the MS-DOS fixed disk management utility. It is responsible for initializing the disk, setting up the partition information, and setting up the boot
information. FDISK loads the tables pointed to by the ROM BIOS Interrupt
41H and Interrupt 46H. FDISK was designed so that any hard disk type can
be loaded at these vector pointers. Table 16-12 contains the hard disk types
predefined within the FDISK program.
Table 16-12

Hard Disk Types

Type

Cylinders Heads

Precomp Control

Landing

Sectors

RD32
RD31
1
2
3
4
5
6
7
8
9
10
11
12
13
14
16
17
18
19
20
21
22
23

820
615
306
615
615
940
940
615
462
733
900
820
855
855
306
733
612
977
977
1024
733
733
733
306

None·
256
128
300
300
512
512
None·
256
None·
None·
None·
None·
None*
128
None·
0
300
None·
512
300
300
300
0

910
669
305
615
615
940
940
615
511
733
901
820
855
855
319
733
663
977
977
1023
732
732
733
336

17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17

6
4
4
4
6
8
6
4
8
5
15
3
5
7
8
7
4
5
7
7
5
7
5
4

0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

• To specify no precompensation, the register contents should be FFFFH.

Programming the VAXmate Under MS-DOS

16 - 39

Disk Parameters
MS-DOS for the VAXmate supports many types of disks. Table 16-13 contains
the BIOS parameter block data for the most frequently used and supported
disk types:
Table 16-13

BIOS Parameter Block Data
A

Bytes/Sector
512
Sector/Cluster
1
Reserved Sector 1
Number of FATs 2
Dir Entries
224
Sectors/disk
2400
F9H
Media byte
Sectors/FAT
7
Sectors/Track
15
Heads/drive
2
Hidden Sectors 0
Tracks/disk
80

512
1
1
2
64
360
FCH
2
9
1
0
40

512
2
1
2
112
720
FDH
2
9
2
0
40

512
1
1
2
64
320
FEH
1
8
1
0
40

512
2
1
2
112
640
FFH
1
8
2
0
40

512
1
20
2
96
800
FAH
3
10
1
0
80

512
4
1
2
512
41667
F8H
41
17
4
17
614

512
1
1
1
48
128
FEH
1
0

Disk A is a 96-TPI high capacity VAXmate workstation diskette. This disk
type is supported by FORMAT, MS-DOS read and write operations, and
DISKCOPY.
Disk B is a 48-TPI, single-sided, 9-sector-per-track diskette. This disk type is
supported by FORMAT, MS-DOS read and write operations, and DISKCOPY.
DISK C is a 48-TPI, double-sided, 9-sector-per-track diskette. This disk type is
supported by FORMAT, MS-DOS read and write operations, and DISKCOPY.
DISK D is a 48-TPI, single-sided, 8-sector-per-track diskette This disk type is
supported by FORMAT, MS-DOS read and write operations, and DISKCOPY.
DISK E is. a 48-TPI, double-sided, 8-sector-per-track diskette. This disk type is
supported by FORMAT, MS-DOS read and write operations, and DISKCOPY.
DISK F is a Rainbow RX50 diskette. This disk type is supported by MS-DOS
read and write operations and DISKCOPY.

16 - 40

Programming the VAXmate Under MS-DOS

DISK G is an RD31 fixed disk that has one 20-Mbyte partition. The sector-tocluster ratio becomes eight sectors to one cluster for any fixed disk type F8H
that has less than 32,681 sectors per image. If disk type F8H has 32,680 or
less sectors per image, it uses a 12-bit FAT. If disk type F8H has 32,681 or
more sectors per image, it uses a 16-bit FAT. This disk type is supported by
FDISK. FORMAT, and MS-DOS read and write operations.
DISK H is a Mdrive disk that is a minimum of 64 Kbytes. Each increment of
64 Kbytes of Mdrive increases the allowable root directory entries by the increment size. For example, a 256 Kbyte Mdrive will have 48 (number of directory
entries for one Mdrive) * 4 (4 * 64 Kbytes = 256 Kbytes) = 192 directory
entries. This disk is supported by MS-DOS read and write operations.

MS-DOS International Support
FONT and GRAFTABL
A font file contains the size and shape description of the characters in a character set. The ability to load new fonts from disk allows the VAXmate workstation to display characters from a character set that is appropriate for the
environment. Because of the VAXmate workstation's advanced video features,
fonts are stored in two types of files, depending on the video mode. Font files
with a .FNT file extension support the text video modes. Font files with a
.GRF file extension support the graphics video modes.
The differences between the two types of font files are the character cell size,
the file size, where they are stored in memory, and the utilities used to load
them.

FONT.COM
FONT. COM is an MS-DOS utility that loads disk-based font files. At boot
time, MS-DOS loads the default font file STD.FNT (stored in the ROM BIOS).
STD.FNT can be replaced at any time with another disk-based font file in the
proper format. FONT.COM searches the current directory, the root directory,
the path, and any appended directories for the file. It is not necessary to reboot
the system after FONT. COM loads a new font file. In text mode, a newlyloaded font file affects data already displayed on the screen.

Programming the VAXmate Under MS-DOS

16 - 41

GRAFTABL.COM
GRAFTABL.COM is a terminate and stay resident program that loads diskbased font files. These fonts can be displayed only when the VAXmate workstation is in a graphics mode. A newly-loaded graphics font file affects data already displayed on the screen. If no font file is specified on the command line,
GRAFTABL.COM attempts to load the font file that corresponds to the current font file for text mode. If the current font file for text mode is a font file
other than STD.FNT, GRAFTABL.COM searches the current directory, the
root directory, the path, and any appended directories for the file. If
GRAFTABL.COM cannot find the corresponding font file for graphics mode, or
the file is not a valid font file, an error message is displayed, and no font file
for graphics mode is loaded.
The ROM BIOS uses the information pointed to by the vector at Interrupt
IFH (7CH). This vector can point to either characters O-FF or 80-FF.
GRAFTABL.COM uses Interrupt 10H, Function DOH to tell the ROM BIOS
how many characters the pointer at Interrupt IFH vector points to. To load
STD.GRF, Interrupt IFH vector points to characters 80 - FF. Otherwise,
Interrupt IFH vector points to characters 0 - FF.

Description of Fonts
Each .FNT character cell is 8x16 and is represented by 16 bytes of data. The
total data representing 256 characters is 4096 (4 KI bytes.
Each .GRF character cell is 8x8 and is represented by 8 bytes of data. The
total data representing 256 characters is 2048 (2 KI bytes.

How FONT. COM Affects KEYB.COM and SORT.EXE
FONT. COM affects how KEYB.COM is used. For example, if KEYB.COM
loads a keyboard map that does not correspond to the current text font, the
keyboard is incorrectly mapped. When a key is pressed, an unexpected character is displayed. This also affects the operation of SORT.EXE, because it sorts
according to the current text font file.

Font File Structures
For proper loading. FONT. COM requires font files to be in the format specified
in Table 16-14. There are no other restrictions for the user when creating a
.FNT file.

16- 42

Programming the VAXmate Under MS-DOS

Table 16-14

.FNT File Structure

Bytes

Contents

Description

0-3

FO$N

File identification label. The first four
bytes must contain the ASCII characters "FO$N".

Total bytes

Total bytes per character. Must be 16.

Column

Number of columns per character.
Must be 8.

Row

Number of rows per one font. Must be
16.

7-8

Total Characters

Total number of characters in a file.
Must be 256.

9-10

Start Character

Starting character location to load
first character description. Must be O.

11-12

End Character

Ending character location to load last
character description. Must be 255.

13-131

Reserved

132-4228

Character description

16 bytes per character * 256 characters = 4096 bytes.

4229-4232

FO$N

File identification label.

Programming the VAXmate Under MS-DOS

16- 43

For proper loading, GRAFTABL.COM requires font files to be in the format
specified in Table 16-15. There are no other restrictions for the user when
creating a .GRF file.
Table 16-16

.GRF File Structure

Bytes

Contents

Description

0-3

FO$N

File identification label. The first four
bytes must contain the ASCII characters "FO$N".

Total bytes

Total bytes per character. Must be 8.

Column

Number of columns per character.
Must be 8.

Row

Number of rows per character. Must
be 8.

7-8

Total Characters

Total number of characters in a file.
Must be 256.

9-10

Start Character

Starting character location to load
first character description. Must be O.

11-12

End Character

Ending character location to load last
character description. Must be 255.

13-131

Reserved

132-2180

Character description

8 bytes per character * 256 characters
= 2048 bytes.

2181-2184

FO$N

File identification label.

16 - 44

Programming the VAXmate Under MS-DOS

Loading Font Files
To load a font file in the same way FONT.COM loads one, do an INT lOH
with the following values in the specified registers:
Parameters
AH =

ODlH
AL =
CX =
DH =
DL =
ES:BX =

Number of characters to be loaded (256)
OlH
First character to be loaded (0)
Address of the character description buffer

Returns
Nothing

KEYB
KEYB.COM is a terminate and stay resident program that loads disk-based
keyboard map files. KEYB.COM can load a keyboard map file any time during
an MS-DOS session, and the system does not have to be rebooted.
KEYB.COM searches the current directory, the root directory, the path, and
any appended directories for the file.

Keyboard Remapping
A keyboard map file contains an ASCII code and a scan code for every keyboard key. When a key is pressed, a scan code is generated. The firmware
checks the current keyboard state, and indexes the correct table. Table 16-16
lists the keyboard tables.

Programming the VAXmate Under MS-DOS

16 - 45

Table 16-16

Keyboard Table

Table

Description

Base Table

Used when a key is pressed and no other key is down
leaps lock is offl.

Ctrl Table

Used when the Ctrl key is held down and another key is
pressed.

Alt Table

Used when the Alt key is held down and another key is
pressed.

Shift Table

Used when the Shift key is held down and another key is
pressed.

NumLock Table

Used when the NumLock key has been activated and another key is pressed. The NumLock table only contains entries for scan codes 71 through 83.

Caps Table

Used when the Caps key has been activated and another
key is pressed.

Alt/Ctrl Table

Used when the Alt and Ctrl keys are held down and another key is pressed.

Alt/Shift Table

Used when the Alt and Shift keys are held down and another key is pressed.

CtrllShift Table

U sed when the Ctrl and Shift keys are held down and another key is pressed.

Alpha ID Table

Indicates whether the scan code U-35H) is an alpha key or
a non alpha key. This is used when the Caps and Shift
keys are held down and another key is pressed.

NOTE
When starting the V AXmate workstation, the Alt/Ctrl and the
Alt/Shift pointers point to the Alt table. The CtrllShift pointer
points to the Ctrl table.
Each entry in the table is a word. The high byte contains a scan code, and the
low byte contains an ASCII value. The ROM BIOS calculates the offset to the
appropriate word in the table. It then sends the ASCII value in the low byte to
the MS-DOS operating system. To make a key send out another value, change
the value in the low byte of the word. The high byte can also be changed.
The table entries are arranged in order of the dependent scan code U through
105) for the keys. For more information on keyboards and keyboard mapping,
see Chapter 8.
16 - 46

Programming the VAXmate Under MS-DOS

The Alpha-ID table is 53 bytes in size. Each byte is associated with the keys 1
through 35H, respectively. If an entry is set to zero, that key is treated as a
non alpha key (Shift does not reverse Lock). If an entry is set to OFFH, that
key is treated as an alpha key (Shift reverses Lock). The table is indexed by
the received scan code. KEYB issues the following interrupt to set the keyboard map file:
Interrupt 16H
Parameters

AH =

D6H
AL =
CL =

1 ; has to be a non-zero number
table to be set
o = Base (normal) table
1 = Ctrl table
2 = Alt table
3 = Shift table
4 = NumLock table
5 = Lock table
6 = Alt/Ctrl table
7 = Alt/Shift table
8 = CtrllShift table
9 = Alpha-ID table

ES:BX must point to the caller-defined/supplied table.

Creating Keyboard Map Tables for International
Countries
To support a new country, a keyboard map file must be created for:
•

Industry standard character set (STD)

•

DIGITAL Multinational character set (MCS)

•

International Standards Organization character set (ISO,

•

New country's 7-bit National Replacement character set (NRC)

These tables differ in that not all characters in the four character sets are located in the same position. For example, "a" grave is located at position 85H
in STD, and at location OEOH in MCS and ISO. When creating new tables,
start with the default character set in the ROM BIOS (see Chapter 9) and
make the necessary changes for the country.
Programming the VAXmate Under MS-DOS

16- 47

When creating the Base table, Shift table, and Caps table, the scan codes
should remain the same for all the keys. The character code should change for
those characters located in a new position on the keyboard. For example, on
the French LK250 keyboard, the "M" character is located where the ";" character is on the US keyboard. Therefore, the table entry for ";" in the US table
contains the character code for "M" in the French table.
The NumLock table should remain unchanged.
The Alt table should resemble the default table in the ROM BIOS. The values
returned for a character should be the same regardless of where the character
is located on the keyboard. For example, the "a" on the French keyboard is
located where the "q" is on the US keyboard, but an Alt/a on the French keyboard still produces the same value as an Alt/a on the US keyboard. Therefore,
the table entry has to change to return the value returned on the US keyboard.
For characters that are not on the US keyboard, the entry in the table should
be set to undefined (OFFFFH) in the table.
The Alt/Shift and Alt/Ctrl tables should be identical to the Alt table. If a keyboard contains characters that are accessed by pressing Alt/Ctrl/key, the value
in the table should be identical to the value that would be placed in the base
table if the character was on the keyboard. For example, on the French keyboard, pressing Alt/Ctrl/$ generates the ")" character, so the entry for "$" in
the Alt/Ctrl table should be IB5Dh, which is the same value in the default set,
base table for the "]" character.
The Ctrl table and the Ctrl/Shift table should be identical. The entries for dependent scan codes above 35H should be identical to the default entries in the
ROM BIOS. The entries for dependent scan codes 1 through 35H should be
the same as in the default table in the ROM BIOS. The entries for Ctrl/2
through Ctrl/8, Ctrl/Backspace, and Ctrl/Return should be:
Ctrl/2

entry: 0300H

Ctrl/3

entry: 041BH

Ctrl/4

entry: 051CH

Ctrll5

entry: 061DH

Ctrl/6

entry: 071EH

Ctrll7

entry: 081FH

Ctrl/8

entry: 097FH

CtrllBackspace

entry: OE7FH

Ctrl/Return

entry: lCOAH

The other table entries for 1 through 35H not specified should be undefined
(value OFFFFH).
16 - 48

Programming the VAXmate Under MS-DOS

How Compose Sequences Are Recognized
For compose sequences to work, every key that is pressed must be captured
before it is sent to the user. Firmware interrupt I6H, Function ODOH,
Subfunction OFEH "Enable Notify Before Buffering" notifies a routine before
the key stroke is placed in the keyboard buffer.
When KEYB.COM runs with a valid keyboard map file, the compose routine is
installed in memory as the notify routine. Whenever a key is pressed, the compose routine checks to determine whether it is part of a compose sequence
~which includes dead diacritical keys).
Before the compose routine is installed, firmware interrupt I6H, Function
ODOH, Subfunction 82H "Return Segment:Offset of any Current Buffer Notify
Routine" is called to get the address of the buffer routine that currently exists
~if any).
If a buffer routine exists, the address of that routine is saved, and the buffer-

notify routine is replaced with the compose routine. After the compose routine
is done and before it does a far return, the compose routine checks the address
it saved. If the Segment:Offset is zero, no routine existed, and the compose
routine does a far return. Otherwise, the compose routine does a far jump to
the buffer-notify routine that existed before the compose routine replaced it.
When that routine does a far exit, it returns to whatever called the compose
routine.

How Dead Diacritical Keys Are Recognized
A scan code of OEFH indicates that a key is a dead diacritical key. When the
scan code is received, the compose routine treats the ASCII code (low byte) as
the first key in the compose sequence. The next key pressed is used as the
second key in the compose sequence.

Format and Use of the Compose Sequence Pointer Table
The compose sequence pointer table contains 96 words. Each word contains a
pointer ~byte offset from the beginning of the file) to its corresponding compose
sequence translation table. The 60H entries refer to ASCII values ~character
codes) 20H through 7FH. For example, the first word contains the pointer to
the translation table for the space character ~ASCII value 20H). If the pointer
is zero, no translation table exists for that ASCII value. A compose sequence is
made up of three keys: the compose key followed by two other keys in the
range 20H through 7FH. The second key in the sequence indexes this table
and obtains the pointer to the translation table. The third key in the sequence
is then checked to determine if it exists in the translation table.

Programming the VAXmate Under MS-DOS

16 - 49

Format and Use of the Compose Sequence Translation
Table
The compose sequence translation table can be a maximum of 1024 words. This
area contains the translation tables for the legal compose sequences. It is
possible to have as many as 96 translation tables (one each for ASCII values
20H through 7FH). The first byte in a translation table contains the number of
entries in the table. The size of the table is 2 * number of entries + 1. The
entries consist of 2 bytes:
•

The first byte is the third character (ASCII value) of the compose
sequence.

•

The second byte is the compose character (ASCII value) to be returned as a result of the compose sequence.

Changing to STDUS.KEY and Back Again
Pressing Ctrl/Alt/F2 replaces the current keyboard map file with the default
keyboard map file STDUS.KEY. Pressing Ctrl/Alt/F3 replaces the current keyboard map file with the last map file loaded into memory. This feature is activated when KEYB.COM is run with an external map file (in other words,
MCSUS.KEY).

Keyboard Map File Structure
KEYB.COM requires keyboard map files to be in a specific format for proper
loading. Table 16-17 shows the keyboard map file structure.
Table 16-17

Keyboard Map File Structure

Bytes

Contents

0-7

File identification string. The first four bytes must contain
"KE$Y" for KEYB.COM to load the file. The next 124 bytes of
the header record are reserved.

This byte is used to enable/disable the additional key codes
associated with the LK250 keyboard. This byte is passed in the
AL register to Interrupt 16H Function D3H.
Bit 0 - Disable keypad state keys. The keypad keys NumLock
and INSERT no longer set the keystate flags in the ROM
BIOS area. They are stored in the keypad buffer as normal
keys according to the table translation process.
Bit 1 - Disable" Alt compose". This disables the generating of
key scan codes using the Alt key and the keypad number keys.
The keypad number keys are treated as normal keys.

16 - 50

Programming the VAXmate Under MS-DOS

Table 16-17
Bytes

Keyboard Map File Structure ~cont.)
Contents
Bit 2 - Disable all combination keys except for Ctrl/Alt/Del and
Ctrl/Alt/Home. This disables all special detection of the key
combinations that invoke special functions and treats them as
normal key sequences. The disabled combinations are Shift/Prt
Sc, CtrllBreak, and Ctrl/NumLock.
Bit 3 - Disables the ability to temporarily override the Lock key
with a Shift key to unshift a key.
Bit 4 - Guarantees that the LK250 keyboard is in DIGITAL
mode. It sends a command to the LK250 keyboard to ensure it
is in DIGITAL mode as well. It enables the use of DIGITAL
extended scan codes sent by the LK250 keyboard. If it is not
enabled, the 10-key keypad keys return scan codes of their
equivalent numeric keypad keys as obtained from the current
"normal" table through the table pointer.
Bit 5 - Enable Compose key pass through. This means that
even though the DIGITAL-extended codes are disabled, the
Compose key is placed in the keyboard buffer.

Reserved; must always equal zero.

10-127

Other header information (not currently used).

128-337

Alt Table (105 keys x 2 bytes/entry = 210 bytes)

338-547

Ctrl Table (105 keys x 2 bytes/entry = 210 bytes)

548-757

Base Table (105 keys x 2 bytes/entry = 210 bytes)

758-783

NumLock Table (13 keys x 2 bytes/entry = 26 bytes)

784-993

Shift Table (105 keys x 2 bytes/entry = 210 bytes)

994-1203

Caps Table (105 keys x 2 bytes/entry = 210 bytes)

1204-1413

Alt/Ctrl Table (105 keys x 2 bytes/entry = 210 bytes)

1414-1623

Alt/Shift Table (105 keys x 2 bytes/entry = 210 bytes)

1624-1833

Ctrl/Shift Table (105 keys x 2 bytes/entry = 210 bytes)

1834-1886

Alpha-ID Table (53 Keys x 1 byte/entry = 53 bytes)

1887

Not used

1888-2079

Compose Sequence Pointer Table (96 words = 192 bytes)

2080-4147

Compose Sequence Translation Table ~maximum of 2048 bytes)
Programming the VAXmate Under MS·DOS

16- 51

LCOUNTRY
LCOUNTRY.EXE is an MS-DOS utility that installs and overlays countryspecific information into the MS-DOS operating system. MS-DOS uses the information when it displays the date, the time, currency symbols, decimal separators, and performs case conversions on file names. The exact usage is
country- and character-set dependent. LCOUNTRY.EXE can be executed
manually by the user, or automatically, if the command is contained in the
AUTOEXEC.BAT file.
When seaching for a file, LCOUNTRY.EXE searches the current directory, the
root directory, the path, and any appended directories.
LCOUNTRY.EXE does not check to ensure that the font, keyboard, and
country-specific data match.
Each LCOUNTRY file must have the .COU file extension.
Each .COU file represents a character set and can contain a multiple number
of countries.

Country File Structure
The .COU file is a module that contains data that must be ORGed at OOH.
There is no executable code in the module. The data overlays the previous data
resident in the MS-DOS operating system.
The module size Inumber of bytes that overlay the resident table I cannot
exceed 700 bytes. This is a combination of both the country-specific data structures and the case conversion tables.
The MS-DOS operating system organizes the data into structures that correlate to the country codes leach ISH bytes longl. The block size is the first byte
of the structure. This byte is always ISH or OFFH, which indicates there are
no more structures. Any other values are considered errors.
The second byte is the country code, which is the same as the international
telephone number prefix for the country.
In the .COU file, the offset value is relative to the beginning of the module,
which is ORGed at OOH. LCOUNTRY.EXE takes these offsets and adjusts
them according to where they are loaded in the MS-DOS operating system.
The next assembly language program section describes the file format.

16- 52

Programming the VAXmate Under MS-DOS

18H

COUNTRY_CODE

Currency_sym

DB '$'
DB 0
DB 0
DB 0
DB 0
DB
DB 0
DB
DB 0
DB '-'
DB 0
DB '.'
DB 0
DB o

Bit_field

Currency_cents
DB
Time_24
DB
Case_Convert_Tab DW

DW
DB
DB

;This is 18H for each data structure except
;for the last, which will contain a OFFH to
;indicate the structures have ended.
;This is the value scanned to see if a hit
;has occurred. This is an industry standard
;US sample.
;O-USA, 1-EUR, 2-JAP
;Currency Symbol

;Thousands separator
;Decimal separator
;Date separator
;Time separator

;Bit values
;Bit 0
0 if currency symbol first
1 if currency symbol last
;Bit 1
0 if No space after currency symbol
1 if space after currency symbol
2
;Number of places after currency decimal point
o
;0 if 12-hour time; 1 if 24-hour time
offset ;Address/Offset of case mapping tables for a
;particular country. If tables of several
;countries are the same, the offset may be the
;same. Every structure, however, must have a
;pointer to the case conversion table.
0
;Offset to case mapping routine
;Data list separator character
0

Programming the VAXmate Under MS-DOS

16- 53

Case Conversion Tables
The case conversion tables contain the lowercase character and its associated
uppercase character. This table is scanned by the MS-DOS operating system; if
a hit occurs, the uppercase character is substituted.
Characters are arranged as pairs in the table, and the number of pairs varies.
The first word of the table is neither a lowercase nor an uppercase pair, but the
length of the table. Do not include this word in the table length calculation.

I:2 I ~I

Table -------r----r--.r----- Offset in country table
Order as seen in memory

NOTE
All references to hexadecimal digits in Table 16-18 and the
SORT tables are taken from the DIGITAL Multinational
Character set. The case conversion table cannot contain an entry
for a lowercase character that replaces the backs lash character
(ASCII 5CH). If this is allowed, COMMAND. COM cannot find
any external commands to execute. If the backslash character is
replaced by an uppercase character, there is no effect on the operation of COMMAND. COM.
Table 16-18 lists the characters that can cause problems for COMMAND.COM
if they are replaced by a lowercase character.
Table 16-18

Characters Causing Problems for COMMAND.COM

Name

ASCII

Character

Asterisk
Slash
Colon
Semicolon
Equal
Question mark
Backslash
Vertical bar

2AH
2FH
3AH
3BH
3DH
3FH
5CH
7CH

16 - 54

=
?
\

Programming the VAXmate Under MS-DOS

SORT
SORT.EXE is an MS-DOS utility that sorts character sets according to a
predefined sorting order. When executed, SORT.EXE checks for the name of
the current text font file. Then, it searches for a file with the same name, but
with the file extension .SRT. If this file is found in the current directory, the
root directory, the path, or any appended directories, SORT.EXE reads it into
memory and uses those values for sorting.

Format for Sorting Order
A sort file is 256 bytes long, one byte for each character in the character set.
The first byte in the sort table is the sort order for ASCII 0, the next byte is
the sort order for ASCII 1, and so on. When sorting, all letters are collated
with ASCII characters A-Z (code 41H through 5AH). Lowercase is translated to
uppercase, and international characters are translated to their English
equivalents.

Creating Sort Tables for Character Sets
When creating a sort table for a character set, try to keep the same order as
the ASCII character set. In other words, the control characters (ASCII 0
through 31) should be first. The control characters should be followed by the
symbols and numbers. The letters should come next. with each letter followed
by its corresponding accented characters Hf any). When more than one accented
character exists for a letter, the order of the accented characters should be the
same as the order in the character set. For example, in DIGITAL MCS "A"
grave precedes "A" acute, and "A" acute precedes "A" circumflex. All three of
these characters follow "A" and precede "B".
All upper and lowercase characters should have equivalent sort orders, if the
sort is to be case insensitive. Otherwise, the lowercase characters should sort
after the uppercase characters.
After all the letters and their accented characters, any leftover characters
should follow in the order they appear in the character set.
The sort orders for Tables 16-19 through 16-23 are read from left to right and
from top to bottom. All values in these tables are hexadecimal values.

Programming the VAXmate Under MS-DOS

16 - 55

Table 16-19 Sort Order for Industry Standard Character Set (STD)

00 01

02 03

04 05

06 07

09 OA OB OC OD OE

01 02 03 04 05 06
10 10 11 12 13 14 15 16
20 20 21 22 23 24 25 26
30 30 31 32 33 34 35 36

07 08 09 OA OB OC
17 18 19 1A 1B 1C
27 28 29 2A 2B 2C
37 38 39 3A 3B 3C

OD
1D
2D
3D

OE OF
lE 1F
2E 2F
3E 3F

40 40
50 50
60 60
70 50

41
51
41
51

42 43 44 45 46
52 53 54 55 56
42 43 44 45 46
52 53 54 55 56

47
57
47
57

48 49 4A 4B
58 59 SA 5B
48 49 4A 4B
58 59 SA 7B

4D
5D
4D
7D

4E
5E
4E
7E

80 43
90 45
AO 41
BO BO

55
41
49
B1

45
41
4F
B2

00 00

41
4F
55
B3

4C
5C
4C
7C

41
4F
4E
B4

41
4F
4E
B5

41
55
A6
B6

43 45 45 45
55 59 4F 55
A7 3F A9 AA
B7 B8 B9 BA

CO CO C1 C2 C3 C4
DO DO D1 D2 D3 D4
EO EO 53 E2 E3 E4
FO FO F1 F2 F3 F4

C5
D5
E5
F5

C6
D6
E6
F6

C7 C8 C9 CA CB CC
D7 D8 D9 DA DB DC
E7 E8 E9 EA EB EC
F7 F8 F9 FA FB FC

16 - 56

Programming the VAXmate Under MS-DOS

4F
SF
4F
7F

49 49 49 41 41
24 24 24 24 24
AB AC 21 22 22
BB BC BD BE BF
CD
DD
ED
FD

CE CF
DE DF
EE EF
FE FF

Table 16-20 Sort Order for Digital Multinational Character Set (MCS)

00 01 02 03 04 05 06 07 08 09 OA OB OC OD OE OF
00 00
10 10
20 20
30 30

01 02
11 12
21 22
31 32

03
13
23
33

05
15
25
35

06
16
26
36

07 08
17 18
27 28
37 38

40 40
50 65
60 7E
70 65

41
66
41
66

48 4A 4B
68 6A 6B
48 4A 4B
68 6A 6B

50
70
50
70

51 52 53 58 59 5A
71 72 73 75 79 7A
51 52 53 58 59 5A
71 72 73 75 B6 87

47
67
47
67

04
14
24
34

09
19
29
39

OA
1A
2A
3A

80 BB BC BD BE BF
90 CD CC CD CE CF
AO DB DC DD DE DF
BO ED EC ED BE EF

CO C1
D1
EO E1
FO F1

C2 C3 C4 C5
D2 D3 D4 D5
E2 E3 E4 E5
F2 F3 F4 F5

CO 42 43
5D
EO 42 43
FO FD 5D

78
63
78
63

49
5E
49
5E

00 FB

44
60
44
60

45
61
45
61

46
62
46
62

76
64
76
64

4C
77
4C
77

4D
6C
4D
6C

4E
6D
4E
6D

OB
1B
2B
3B

OC
1C
2C
3C

OD
1D
2D
3D

OE
1E
2E
3E

OF
1F
2F
3F

5B 5C 5F
7B 7C 7D
5B 5C 5F
88 89 BA
C9
D9
E9
F9

C6
D6
E6
F6

C7 C8
D7 DB
E7 E8
F7 F8

4F
6E
4F
6E

54 55 56
6F 74 FC
54 55 56
6F 74 FE

Programming the VAXmate Under MS·DOS

CA
DA
EA

FA
57
69
57
FF

16- 57

Table 16-21
Set (ISO)

Sort Order for International Standards Organization Character

00 01 02 03 04 05 06 07 08 09 OA OB OC OD OE OF
00 00
10 10
20 20
30 30

01
11
21
31

02
12
22
32

03
13
23
33

04
14
24
34

05
15
25
35

06
16
26
36

07 08
17 18
27 28
37 38

40 40
50 64
60 80
70 64

41
65
41
65

47
66
47
66

48
67
48
67

4A
69
4A
69

4B
6A
4B
6A

50
6F
50
6F

51
70
51
70

80 CO
90 00
AO EO
BO FO

C1
D1
E1
F1

CO 42 43
5D
EO 42 43
FO 79 5D
00 79

16 - 58

OE
1E
2E
3E

OF
1F
2F
3F

5B
7D
5B
BD

5C
7E
5C
BE

5E
7F
5E
BF

C2 C3 C4 C5 C6 C7 C8 C9 CA CB
D2 D3 D4 D5 D6 D7 DB D9 DA DB
E2 E3 E4 E5 E6 E7 EO E9 EA EB
F2 F3 F4 F5 F6 F7 F8 F9 FA FB

CC CD
DC DD
EC ED
FC FD

CE
DE
EE
FE

CF
DF
EF
FF

44
SF
44
SF

54
6E
54
6E

45
60
45
60

46
61
46
61

78
62
78
62

76
63
76
63

49
2A
49
2F

09 OA OB OC OD
19 1A 1B 1C 1D
29 2A 2B 2C 2D
39 3A 3B 3C 3D

52 53 58 59
71 72 75 7B
52 53 58 59
71 72 75 BB

4C 4D 4E 4F
77 6B 6C 6D
4C 4D 4E 4F
77 6B 6C 6D

Programming the VAXmate Under MS-DOS

SA
7C
SA
BC

55 56 57
73 7A 68
55 56 57
73 7A 74

Table 16-22
(FR7)

00 01
00 00
10 10
20 20
30 30

Sort Order for French 7-Bit National Replacement Character Set

04 05

08 09 OA OB

02 03 04 05 06 07 08 09
12 13 14 15 16 17 18 19
21 22 23 24 25 26 27 28 29
31 32 33 34 35 36 37 38 39

40 41 40 42 43 45
50 53 54 55 56 57
60 63 40 42 43 45
70 53 54 55 56 57

00 OE
1C 10 1E
2C 20 2E
3C 30 3E

OF
IF
2F
3F

50
60
50
47

51
61
51
7E

52
62
52
7F

80 8E
90 9E

OA OB
1A 1B
2A 2B
3A 3B

40
5E
40
5E

4F
44
4F
59

4A
5B
4A
5B

4B
5C
4B
5C

4C
50
4C
50

82
92
A2
B2

83 84 85 86 87
93 94 95 96 97
A3 A4 AS A6 A7
B3 B4 B5 B6 B7

88
98
A8
B8

89 8A 8B 8C
99 9A 9B 9C
A9 AA AD AC
B9 BA BB BC

BO BE

8F
9F
AF
BF

C1 C2
01 02
EO EO 53 E2
FO FO F1 F2

C3 C4 C5 C6 C7
03 04 05 06 07
E3 E4 E5 E6 E7
F3 F4 F5 F6 F7

C8 C9 CA CB CC CO CE
DB 09 OA OB DC 00 OE
E8 E9 EA EB EC EO EE
F8 F9 FA FB FC FO FE

CF
OF
EF
FF

80 80 81
90 90 91
AO AO A1
BO BO B1
CO CO

DO DO

46
58
46
58

OC 00 OE

49
5A
49
5A

4E
5F
4E
48

Programming the VAXmate Under MS-DOS

16 - 59

Table 16-23

Sort Order for German 7-Bit National Replacement Character Set

(DE7)

00 01

03 04 05 06 07

00 00
10 10
20 20
30 30

01
21
31

02 03 04 05
12 13 14 15
22 23 24 25
32 33 34 35

40 40
50 52
60 61
70 52

41
53
41
53

43
54
43
54

80 80
90 90
AO AO
BO BO

81 82 83 84
91 92 93 94
A1 A2 A3 A4
B1 B2 B3 B4

CO CO C1
D1
EO EO 53
FO FO F1

00 00

16 - 60

C2
02
E2
F2

44
55
44
55

C3
D3
E3
F3

06
16
26
36

45 46 47
57 58 5A
45 46 47
57 58 5A

OA OB OC OD OE OF

27
37

08 09
18 19
28 29
38 39

OA
1A
2A
3A

OB
1B
2B
3B

OC
1C
2C
3C

OD
1D
2D
3D

48
5B
48
5B

49
5C
49
5C

4B
5E
4B
5E

4C
42
4C
42

40
51
40
51

4E 4F 50
59 5F 60
4E 4F 50
59 56 7F

88 89 8A 8B 8C
98 99 9A 9B 9C
A8 A9 AA AB AC
B8 B9 BA BB BC

8D 8E 8F
9D 9E 9F

85 86 87
95 96 97
AS A6 A7
B5 B6 B7

C5 C6 C7
05 D6 D7
E4 E5 E6 E7
F4 F5 F6 F7

C4
D4

DB
E8
F8

4A
5D
4A
5D

OE
1E
2E
3E

OF
1F
2F
3F

BD BE BF

C9 CA CB CC CD CE CF
D9 DA DB DC DD DE DF
E9 EA EB EC ED EE EF
F9 FA FB FC FD FE FF

Programming the VAXmate Under MS-DOS

Chapter 17
MS-Windows on the V AXmate
Introduction
This chapter defines unique features of the DIGITAL adaptation of MSWindows for execution on the VAXmate. The intended audience is the programmer who writes applications for MS-Windows and wants to use extensions
to the Application Programming Interface which DIGITAL provides. This chapter assumes the reader is familiar with the MS-Windows environment and has
the MS-Windows Software Development Kit. This chapter is an addendum to
the manuals provided with the MS-Windows Software Development Kit. The
following documents are part of that kit:
•
•
•

MS-Windows Software Development Kit Programmer's Reference
MS-Windows Software Development Kit Programmer's Utility Guide
MS-Windows Software Development Kit Programming Guide

Overview
The adaptation, sometimes referred to as the OEM layer of MS-Windows,
consists of the machine-dependent support modules and special device drivers
required to communicate with the machine's particular hardware.
The machine-dependent support modules allow MS-Windows to control the
VAXmate hardware, such as the system's display screen, keyboard, mouse, and
communications resources.

MS-Windows on the VAXmate

17 - 1

The adaptation, or OEM layer, is just one of three components or layers of the
MS-Windows environment. It is the lowest level component, dealing only with
the hardware. Above this layer is the Windows layer which consists of:
•

Kernel - The Kernel provides for tasking, memory management, and
the loading of modules and resources. Tasking is non preemptive
with a prioritized round-robin scheduler.

•

User - User is the windowing manager. It manages windows, provides for orderly painting, and provides the user interface ltiled windows, pop-up windows, dialog boxes, menus, icons, cursors and scroll
bars). It also manages events from the mouse, keyboard and timer.
It is responsible for sending messages to applications.

•

GDI - GDI is the Graphics Device Interface for MS-Windows. It
maintains the graphics device state. It provides regions and clipping, display attributes, display objects and display primitives.

Above the Windows layer is the application layer. Applications must use the
MS-Windows Applications Programming Interface to run in the MS-Windows
environment.
DIGITAL's extensions to the OEM layer include routines that are callable from
MS-Windows applications. These extensions allow applications to use some of
the advanced features of the VAXmate's LK250 keyboard and ethernet
communications.
NOTE
Symbolic constants used in this section of the reference manual
are documented in either the WINDOWS.H include file or the
DECWIN.H file listing included at the end of this chapter.

Keyboard Driver for the LK250 Keyboard
The MS-Windows keyboard driver for the VAXmate's LK250 configures the
keyboard in DIGITAL Extended Scan Code mode. In this mode the keyboard
generates unique scan codes for each key. In general, applications running in
the DIGITAL windows environment behave, in regard to the keyboard, basically the same as they would on an industry-standard machine running MSWindows. This mode also allows for extensions in the keyboard architecture
under MS-Windows so applications can uniquely identify each key on the
keyboard.

17 - 2

MS-Windows on the VAXmate

This section describes the following:
•
•

The behavior of the Numeric and Edit keypads on the LK250.
The behavior of the LEDs on the LK250.

•
•

Compose handling.
Extension to the keyboard device driver for MS-Windows.

•
•

Key mappings for each LK250 country keyboard.
Character mappings between the MS-Windows ANSI and OEM
character sets.

Numeric and Edit Keypads
The normal or default action of the numeric keypad is to execute cursor or
editing functions. The Numlock key toggles the state of the numeric keypad
(and associated LED) between two states which generate two separate sets of
output. For example, if the Numlock key is toggled 'off' (LED oW, striking the
key with the '4' legend on top (left arrow in blue on front) generates a
VK LEFT virtual key message. If the Numlock key is toggled 'on' (LED on)
striking the key generates a VK_ NUMPAD4 virtual key message.
Some VK messages generated by the numeric keypad with Numlock off can be
generated on the edit keypad. For example, the edit/cursor keypad left arrow
key generates a VK LEFT, too. One that cannot be generated is the numeric
keypad's 5 key when Numlock is off. See the TOASCII tables below for further
details.
In addition, if Numlock processing is enabled (see following section on the
DecSetNumlockMode routine), Shift may be used to modify the action of the
numeric keypad. Holding a shift key down while using the numeric keypad temporarily causes the keypad to return the messages associated with the other
state of the Numlock key. For example, if Numlock processing is enabled and
Numlock is on and the '4' key on the keypad is pressed, a VK NUMPAD4
message is returned. If Shift is held down and the '4' is pressed again, a
VK LEFT message is returned. The keys affected by this temporary state
switch. are the 10-digit keys, and the Del key.
NOTE
Holding down Shift and pressing the PF4/*/Prt Sc key produces
a print screen function regardless of whether or not Numlock is
enabled and regardless of the Numlock state.
An application that requires the use of the Numlock key for some purpose of
it's own, (Le., PF2 key for the VT220 emulator) and does not want Numlock
toggling can call the keyboard driver to disable Numlock processing. The
Numlock key will generate a VK OEM PF2 message and NOT a
VK_ OEM_NUMBER message. The numeric keypad's state and LED will be
MS-Windows on the VAXmate

17- 3

unaffected by hitting the Numlock/PF2 key or using a shift key. Using this
extension allows the application to receive unique virtual key codes for the
entire keyboard. This is not the default mode for keyboard processing. Also,
there are certain restrictions when using this mode. See the section on MSWindows Keyboard Extensions for details.

Keyboard LEDs for the VAXmate LK250
Although there are four LEDs on the LK250, only the Caps Lock LED and the
Numlock LED are supported in DIGITAL's MS-Windows adaptation for the
VAXmate. The Scroll Lock has no meaning and is always OFF. The SPECIAL
Undustry-Standard/DIGITAL) LED is always OFF while running applications
designed explicitly for MS-Windows. The LED will be ON when a standard application has the keyboard input focus. While in MS-Windows, the user is prevented from toggling the keyboard in and out of Industry-Standard/DIGITAL
keyboard mode (the Alt/F17 key sequence).

VAXmate Compose Handling
Compose sequences may be handled by the MS-Windows keyboard driver or by
the application. The default is for the MS-Windows keyboard driver to handle
compose. An application using the basic MS-Windows message routines (GetMessage, TranslateMessage and DispatchMessage) will receive "composed"
output as described below.
Pressing either the Compose (compose character) key (EOO) or a dead diacritical
key initiates a compose sequence. If the compose sequence is started with the
Compose key then the next two keys define the character to be composed.
When the application sends the virtual Compose key back to the keyboard
driver for translation (TranslateMessage), the compose sequence is initiated and
the key is returned as a WM KEYDOWN and WM KEYUP message with the
virtual key value of VK OEM COMPOSE. The second key in the sequence
must be translated in order to-continue the compose sequence. It generates a
WM DEADCHAR message with the character value of the dead key. The third
key in the sequence must be translated in order to complete the compose sequence. If the key completes a valid compose sequence, it is translated to the
appropriate ASCII value and passed to the application as a WM CHAR
message. If invalid, it is passed to the application as a WM DEADCHAR with
the character value of the last key pressed. Also, the keyboard bell sounds indicating an invalid compose sequence.
Two-key compose sequences are initiated with a dead diacritical key. When the
application sends it back to the keyboard driver for translation (TranslateMessage), the compose sequence is initiated and the key is returned as a
WM DEADCHAR message with the character value of the dead key. The
second key must be translated in order to complete the compose sequence. If
17 - 4

MS-Windows on the VAXmate

the key completes a valid compose sequence it is translated to the appropriate
ASCII value and passed to the application as a WM CHAR message. If invalid,
it is passed to the application as a WM DEADCHAR with the character value
of the last key pressed. Also, the keyboard bell sounds indicating an invalid
compose sequence.
Compose sequences may be aborted by hitting the BACKSPACE key as long
as the application passes it to the Windows TranslateMessage routine, which
generates a WM DEADCHAR message rather than a WM CHAR message for
the BACKSPACE key when it is used to abort a compose sequence.
The default set of compose sequences supported are those that produce output
in the ISO Latin-l Character Set.
An application wishing to receive output in the DIGITAL Multinational
Character Set instead of ISO Character Set may do so by calling the
DecSetComposeState routine as described in the DIGITAL Windows Keyboard
Extensions section below. This set provides the OE ligature, both upper and
lower case, and the uppercase Y with umlaut, which the ISO Latin-l set does
not. In addition, two compose sequence results are remapped. The lowercase y
with umlaut is remapped from FDh to FFh. The international currency symbol
is remapped from A8h to A4h. Characters in the ISO Latin-l set, which are
not in the DIGITAL Multinational Character Set, are considered invalid in this
mode.
There are certain restrictions when changing the compose mode. See the section on MS-Windows Keyboard Extensions for details.

Reserved Keys Under MS-Windows
Use of F17, F18, F19, and F20 with the Alt key are reserved by DIGITAL.
Application programs under MS-Windows must not employ these four key sequences. When not running MS-Windows, Alt/F17 switches the keyboard between DIGITAL-extended mode and compatible mode. Alt/F20 produces the
SYSREQ function. Alt/F18 and Alt/F19 are undefined but reserved for future
use.

DIGITAL MS-Windows Keyboard Extensions
The DIGITAL adaptation of the keyboard driver provides three routines to
handle keyboard user preference features. The first sets the state of the Shift
key into Caps Lock mode or Shift Lock modes. The second sets the keyclick
volume. The third enables or disables autorepeat. These routines are called by
the Control Panel application to allow user selection of these features. The
user's selections are saved in the WIN.INI file by the control panel. The
MS-Windows keyboard driver reads the WIN.INI file during its keyboard
enable routine and sets the keyboard preference features.
MS-Windows on the VAXmate

17 - 5

These routines may also be called by any other MS-Windows application. If
called, the WIN.INI file should be updated to reflect the current user
preference state. For more information about the WIN .INI file, see the
VAXmate User's Guide.
In addition, the keyboard driver provides three application-callable routines. The
first returns the current nationality of the keyboard. The second selects
DIGITAL Multinational Character Set compose processing or ISO Latin-l
Character Set compose processing. The third selects compatible or extended
Numlock key processing.
The six routines are documented in the following sections.

DecSetLockState (lock)
This routine sets the sense in which the Lock key is interpreted.
Parameters
lock

is an integer value specifying the action where:

o = DEC CAPS LOCK (default)
1 = DEC-SHIFTLOCK

Returns
Nothing
When you type a key with DEC CAPSLOCK selected, the uppercase letter is
used for the alphabetic keys, but the lower character on the numeric/symbolic
keys is used. To clear the lock function momentarily, press the Shift key.
When you type a key with DEC SHIFTLOCK selected, the uppercase letter is
used for the alphabetic keys, and the top character on the numeric/symbol keys
is used.

17 - 6

MS-Windows on the VAXmate

DecSetKClickVol (vol)
This routine sets the volume associated with keyclick.
Parameters
vol

is an integer value specifying the action where:

o = DEC NOSOUND
1 = DEC-SOFT
2 = DEC-INTERMED (default)
3 = DEC-LOUD
Returns
Nothing

DecSetAutorep (repeat)
This routine sets autorepeat on or off.
Parameters
repeat

is an integer value specifying the action where:

o = DEC AUTOREPOFF
1 = DEC=AUTOREPON(default)
Returns
Nothing

MS-Windows 011 the VAXmate

17 - 7

DecGetKbdCountry ( ) : Result
This routine returns the keyboard's nationality.
Parameters
none
Returns
Result

is an integer value identifying the country keyboard. These
values are defined in DECWIN.H.
DEC USA is the U.S. keyboard.
DEC-BRITAIN is the British keyboard.
DEC-FRANCE is the French keyboard.
DEC-WEST GERMAN is the German keyboard.
DEC-ITALYis the Italian keyboard.
DEC-SPAIN is the Spanish keyboard.
DEC-SWEDEN is the Swedish keyboard.
DEC-FINLAND is the Finish keyboard.
DEC-NORWAY is the Norwegian keyboard.
DEC-DENMARK is the Danish keyboard.
DEC-CANADA is the Canadian keyboard.
DEC-SWISS GERMAN is the Swiss German keyboard.
DEC=SWISS=FRENCH is the Swiss French keyboard.

17 - 8

MS-Windows on the VAXmate

DecSetComposeState (compose_mode)
Parameters
compose_mode

is an integer value specifying the action where:

o = DEC ISO COMP (default)
1 = DEC-MULTINAT COMP
Returns
Nothing
IMPORTANT
An application using DecSetComposeState to change from
default handling must call the routine to set the non-default
state whenever it receives the keyboard input focus, and must
reset it to the default when it loses the keyboard input focus. If
it does not, other applications (all of which share the keyboard)
that do not understand the non-default modes will not function
properly.
This routine sets the sense in which the compose sequences are processed and
the mapping of returned values.
By default, the legal set of compose characters are those characters in the ISO
Latin-l Character Set. The character translation is the byte value of the character's position in the ISO Latin-l set.
Optionally, the legal set of compose characters can be set to the DIGITAL
Multinational Character Set. The character translation is the byte value of the
character's position in the DIGITAL Multinational Character Set.

MS-Windows on the VAXmate

17 - 9

DecSetNumlockMode (numlock mode)
Parameters
numlock mode

is an integer value specifying the action where:

o = DEC Numlock (default)
1 = DEC-NONumlock

Returns
Nothing
IMPORTANT
An application using DecSetNumlockMode to change from
default handling must call the routine to set the non-default
state whenever it receives the keyboard input focus, and must
reset it to the default when it loses the keyboard input focus. If
it does not. other applications (all of which share the keyboard)
which do not understand the non-default modes will not function
properly.

This routine sets the sense in which the Numlock key is processed.
If numlock mode is 0 (that is. industry-standard-compatible), the Numlock key

toggles the-state of the numeric keypad and subsequent output. The Numlock
key generates a VK_OEM _NUMBER virtual key code.
The application's .DEF file must contain an import statement for each of the
routines it uses as follows:
IMPORTS
Keyboard. DecSetLockState
Keyboard. DecSetKClickVol
Keyboard. DecSetAutorep
Keyboard. DecGetKbdCountry
Keyboard. DecSetComposeState
Keyboard. DecSetNumlockMode
The application must declare the following for each routine it uses:
extern int FAR PASCAL DecSetLockState (int);
extern int FAR PASCAL DecSetKClickVol (int);
extern int FAR PASCAL DecSetAutorep (int);
extern int FAR PASCAL DecGetKbdCountry 0;
extern int FAR PASCAL DecSetComposeState (int);
extern int FAR PASCAL DecSetNumlockMode (int);

17 - 10

MS-Windows on the VAXmate

When Numlock mode is set to no-Numlock, the current state of Numlock and
Numlock LED are saved and the LED is turned OFF. Toggling the Numlock
key always generates a VK OEM PF2 virtual key code. The state of the numeric keypad is equivalent to Numlock being ON. This mode allows for unique
key identificatiqn between all keys on the numeric and edit keypads of the
LK250 keyboard. When Numlock mode is reset to industry-standard
compatible, the previous state is restored.

Windows Keyboard Processing Anomalies
Applications programmers should be aware of the WINDOWS software anomalies described in the following sections.

Repeating Key Allowed to Change Focus
When two or more copies of the same Windows applications program are
loaded, it is possible to change the input focus of a repeating key. To create
the condition, two or more copies of the applications program must have autorepeat enabled.
Select the first copy by moving the cursor to its window and pressing the left
mouse button, which gives the first copy the input focus. Press and hold down
a key (for example, the 'A'). After the required delay, the window displays multiple instances of the 'A' key. While the key is automatically repeating, move
the mouse cursor to another copy of the application and press the left mouse
button. This gives the second copy the input focus. When the focus shifts to
the second copy, the repeating key follows the input focus, and the second copy
displays the repeating key.
If the program monitors only the translated (WM CHAR or WM SYSCHAR)

messages, the problem is not apparent. However, if the program monitors the
KEYDOWN and KEYUP messages, there are at least two problems as follows:
1.

The first copy of the program does not receive a KEYUP message.

The second copy of the program receives a KEYDOWN message with a
previous state of keydown. The second copy should have received a
KEYDOWN message with a previous state of keyup.

MS-Windows on the VAXmate

17 - 11

Illogical Set of Keyboard Messages
The following keyboard operations produce an illogical set of messages:
•

Ensure that the NumLock LED is on.

•

Press and hold down the left shift key.

•

Press and release the '1' key on the numeric pad.

•

Release the left shift key.

Table 17-1 contains the keyboard messages transmitted by MS-Windows.
Table 17-1

Keyboard Messages Transmitted by MS-Windows

MS-Windows
Message
Type

Scan
Code

Prey
Key
State

Virtual
Key
Name

Comments

WM KEYDOWN
WM-KEYUP
WM-KEYDOWN
WM-KEYDOWN
WM-KEYUP
WM-KEYUP
WM-KEYDOWN
WM-KEYUP

2AH
36H
4FH
36H
36H
4FH
36H
2AH

Up
Down
Up
Up
Down
Down
Up
Down

VK SHIFT
VK-SHIFT
VK-END
VK-SHIFT
VK-SHIFT
VK-END
VK-SHIFT
VK-SHIFT

Left shift
Illogical message (right shift)
Keypad '1'
Illogical message (right shift)
Illogical message (right shfit)
Keypad '1'
Illogical message (right shift)
Left shift

If the right shift key is used instead of the left shift key, the number of
messages are the same. However, the two messages with a scan code of 2AH
are changed to 36H.

The keys on the numeric keypad which exhibit this behavior are zero (0)
through nine (9), minus sign (VK SUBTRACT), plus sign (VK ADD) and
period (.), which can be either VK_PECIMAL or VK_DELETE.

17 - 12

MS-Windows on the VAXmate

Key Mappings for VAXmate's LK250
In Tables 17-2 through 17-13:
Keypos

Refers to the keyboard layout numbering scheme
used in Figure 17-1.

Keycap

Refers to the legend in black landfor blue) on the
LK250 key.
Refers to the keyname associated with that key;
these virtkeys may be in any of the three categories: standard, extended Ipreceded by an asterisk), or OEM specific lusing the convention of
VK_OEM_ KEYNAME).

Virtkey

TOASCII Translation Table

Unshift

Refers to the possible virtual key translations
based on the state of the Shift, Ctrl and Alt
keys. The keyboard driver's TOASCII entry
point is ultimately called when an application
makes the TranslateMessage function call.
Refers to the default translated output for the
unshifted keystroke (TOASCII translation tablel.

Shift

Refers to the default translated output for the
shifted keystroke ITOASCII translation table).

Ctrl

Refers to the default translated output for the
keystroke when pressed with control key held
down ITOASCII translation table).

CtrlfAlt

Refers to the default translated output for the
keystroke when pressed with the Ctrl and Alt
keys held down ITOASCII translation table); this
value is the 'extra' output for this key.

CtrlfAltfShift

Refers to the default translated output for the
keystroke when pressed with the Ctrl and Alt
and left Shift keys held down ITOASCII translation table); this value is the shifted 'extra' output
for this key.

MS-Windows on the VAXmate

17 - 13

I-'

""I
I
I-'
~

~
00

....~

::I

0
~

III

0
::I

...

LED LED LED LED
1
2
3
4

....~
IJQ

0000

=
'"I

IG991GOO IGO-¥9Gro]

1<31-

t:I"

I-'

!3
III

E16 E17 E18

E20 E21 E22 E23

'"I

016 017 018

020 021 022 023

C17

C20 C21 C22 C23

...
ID

1(305 G061 G071 G08I GOg]

(G~lIG~;IC;3R

G16

IG20IG21JG221G231

III

...""........
0

C99

III

0
::I

t:"'"

820 821 822
A20

A23

A22

III

aID

I II

Lj·1310

Table 17-2 US to ASCII Translation Table - Main Key Array
Keypos

Keycap

Virtkey

Unshift

EOO
EOl
E02
E03
E04
EOS
E06
E07
E08
E09
El0
Ell
E12
E13

Compose
1 !
2 CI
3 # UKpound
4 $
5 %
6
7 &:
8 *
9 (

VK_OEM_COMPOSE
'1'
'2'
'3'
'4'

1
2
3
4

'5'

6
7
8
9
0

'6'
' 7'
'8 '
'9'
'0'
VK_OEM_MINUS
VK_OEM_PLUS
VK_BACK

DOO
DOl
D02
D03
D04
DOS
D06

TAB
Q

VK_TAB
'Q'

'W'

E
R
T

'E'
'R'
'T'
'y'

Shift

Ctrl

NUL
ESC
FS
GS
RS
US
DEL

%
&:

*(
)
+

DEL

HT
Q

HT
DCl
ETB
ENQ
DC2
DC4
EM

q
w

17-15

Ctrl/Alt

UK pound

Ctrl/Alt/Shift

Table 17-2 US to ASCII Translation Table - Main Key Array (cont.)
Keypos

Keycap

Virtkey

Unshift

Shift

Ctrl

D07
D08
D09
Dl0
Dll
D12

'U'
'I'

U
I

NAK
HT
SI
DLE
ESC
GS

C99
COO
C01
CO2
C03
C04
COS
C06
C07
C08
C09
Cl0
Cll
C12
C13

'0'

'P'

VK_OEM_4
VICOEM_6

P
[
]

[ {
] }
CTRL
LOCK
A
S
D
F
G
H

VK_CONTROlL
VK_CAPITAlL
'A'
'S'

a
s

A
S

'D'

'F'
'G'
'H'

F
G
H

SOH
DC3
EDT
ACK
BEL
BS

'J'

K
L

'K'
'L'
VK_OEM_l
VK_OEM_7
VK_OEM_S
VK_RETURN

J
K

LF
VT

\ I
RETURN

\
CR

°
{
}

"
CR

17-16

FS
LF

Ctrl/Alt

Ctrl/Alt/Shift

Table 17-2 US to ASCII Translation Table - Main Key Array (cont.)
Keypos

Keycap

Virtkey

B99
BOO
B01
B02
B03
B04
B05
B06
B07
BOS
B09
BI0
Bll

SHIFT

VK_SHIFT
VK_OEM_3

A99
A01-09

Unshift

Shift

'Z'

X
C

Ctrl

'X'

'c'

c
v

b
n
m

B
N
M

/ ?
Shift

'V'
'B'
'N'
'M'
VK_OEM_COMMA
VK_OEM_PERIOD
VK_OEM_2
VK_SHIFT

RS
SUB
CAN
ETX
SYN
STX
SO
CR

<
>
?

Alt
Space bar

VK_MENU
VK_SPACE

blank

NUL

X
C
V
B
N
M
, <
. >

17-17

Ctrl/Alt

Ctrl/Alt/Shift

Table 17-2 US to ASCII Translation Table - Edit Key Array
Keypos

Keycap

Virtkey

E16
E17
E18
016
017
018

FIND
INSERT
REMOVE
SELECT
PREY
NEXT

VK_HOME
VK_INSERT
VK_DELETE
*VK_END
VK_PRIOR
VK_NEXT

C17
816
B17
818

up arrow
left arrow
down arrow
right arrow

VK_UP
VK_LEFT
VK_DOWN
VK_RIGHT

Table 17-2 US to ASCII Translation Table - Keypad Array
Keypos

Keycap

Virtkey

E20
E21
E22
E23

PFI
PF2
PF3
PF4

VK_ESCAPE = VK_OEM_PFl
VK_OEM_NUMBER or in no-Numlock mode VK_OEM_PF2
VK_OEM_SCROLL = VK_OEM_PF3, with CTRL produces VK_CANCEL**
*VK_MULTIPLY = VK_OEM_PF4

NOTES
The VK_OEM_PFI (VK_ESCAPE) key, produces a 27 (ESC) for unshifted
and shifted key presses if translated; VK_MULTIPLY generates a
'*' for translation of the unshifted keypress (shifted VK_MULTIPLY
produces a print screen function).

17-18

** VK_CANCEL, when translated by means of a call to
TranslateMessage, produces output of 03h,

Keypos

Keycap

D20
D21
D22
D23
C20
C21
C22
C23
B20
B21
B22
A20
A22
A23

7
8
9
4
5
6
1
2
3
0
ENTER

Virtkey w/Numlock on
or Numlock disabled

Virtkey w/Numlock off

*VK_NUMPAD7
*VK_NUMPAD8
*VK_NUMPAD9
*VK_SUBTRACT
*VK_NUMPAD4
*VK_NUMPAD5
*VK_NUMPAD6
*VK_ADD
*VK_NUMPAD1
*VK_NUMPAD2
*VK_NUMPAD3
*VK_NUMPADO
*VK_DEClMAL
*VK_EXECUTE

VK_HOME
VK_UP
VK_PRIOR
*VK_SUBTRACT
VK_LEFT
*VK_CLEAR
VK_RIGHT
*VK_ADD
*VK_END
VK_DOWN
VK_NEXT
VK_INSERT
VK_DELETE
*VK_EXECUTE

NOTE
Translation of VK_NUMPADO-9 produces '0' through '9', Similarly,
translation of VK_SUBTRACT produces '-', VK_ADD produces '+',
VK_DEClMAL produces ',', and VK_EXECUTE produces a carriage return
(13 decimal),

17-19

TOP ROV FUNCTION KEYS

Keypos

Keycap

Virtkey

G99
GOO
G01
G02
G03
G05
G06
G07
G08
G09

F1
F2
F3
F4
F5
F6
F7
F8
F9
F1

VK_F1
VK_F2
VK_F3
VK_F4
VK_F5
VK_F6
VK_F7
VK_F8
VK_F9
VK_F10

Gll
G12
G13
G14
G15
G16

Fll
F12
F13
F14

HELP
DO

*VK_Fll
*VK_F12
*VK_F13
*VK_F14
*VK_F15
*VK_F16

G20
G21
G22
G23

F17
F18
F19
F20

VK_OEM_F17
VK_OEM_F18
VK_OEM_F19
VK_OEM_F20

with Alt, produces SYSREQ output

17-20

Table 17-3 Danish to ASCII Translation Table
Keypos

Keycap

Virtkey

EOO
EOl
E02
E03
E04
E05
EOS
E07
EOS
E09
EI0
Ell
E12
E13

Compose

VK_OEM_COMPOSE

000
001
002
003
004
005
DOS
007
DOS

Unshift

'1'

2 " a
3 # section
4 $ currency
5 %
S t
7 / t
S ( *
9 ) (

'2'
'3'
'4'
'5'
'S'
'7'
'S'

o=)
<X

'0'
VK_OEM_PLUS
VK_OEM_3
VK_BACK

2
3
4
5
S
7
S
9
0

+ ? -

'g'

Shift

Ctrl

Ctrl/Alt

Ctrl/Alt/Shift

NUL

#
$

ESC
FS
GS

section
currency

%
t
/
(
)

dead '
BS

dead •
BS

as
US
DEL

(
)

DEL

TAB

VK_TAB

Q
W

'Q'
'W'

q
w

Q
W

HT
DCl
ETB

'E'

ENQ

'a'

'T'

r
t

DC2
DC4

'Y'

'U'

Y
u

NAK

'r'

17-21

Table 17-3 Danish to ASCII Translation Table (cont.)
Keypos

Keycap

Virtkey

Unshift

D09
DI0
D11
D12

'0'
'P'

A ring [ {

VK_OEM_6
VK_OEM_7

a ring
dead "

A ring
dead -

C99
COO
COl
CO2
C03
C04
C05
C06
C07
COB
C09
CI0
Cll
C12
C13

CTRL
LOCK
A
S
D
F

VLCONTROL
VK_CAPITAL,
'A'

A
S

'G'

'H'

a
s
d
f
g
h

J
K

'J'

'K'
'L'
VK_OEM_4
VK_OEM_5
VK_OEM_2
VK_RETURN

J
K

B99
BOO
BOl
B02

SHIFT

" -] }

L
AE

°. slash
' "
* ' RETURN

< > \
Z
X

'S'
'0'

'F'

VK_SHIFT
VK_OEM_l
'Z'
'X'

Shift

Ctrl

SI
DLE

F
G

ae
o slash

>
Z

Ctrl/Alt

Ctrl/Alt/Shift

[
]

{
}

SOH
OC3
EOT
ACK
BEL
BS
LF

VT
FF

° slash
*

17-22

dead

\
SUB
CAN

Table 17-3 Danish to ASCII Translation Table (cont.)
Keypos

Keycap

Virtkey

Unshift

Shift

Ctrl

B03
B04
B05
B06
B07
BOS
B09
Bl0
Bll

C
V
B
N
M
, ; <

'C'

c
v
b
n
m

C
V
B
N
M

ETX
SYN
STX
SO
CR

Shift

'V'
'B'
'N'
'M'
VICOEM_COMMA
VIC OEM_PERIOD
VIC OEM_MINUS
VK_SHIFT

A99
A01-09

Alt
Space bar

VK_MENU
VK_SPACE

: >
/ ?

blank

The remainder of the keyboard layout is the same as the u.S. version.

17-23

NUL

Ctrl/Alt

Ctrl/Alt/Shift

<
>
?

Table 17-4 Finnish to ASCII Translation Table
Keypos

Keycap

Virtkey

EOO
EOl
E02
E03
E04
E05
E06
E07
E08
E09
EI0
E11
E12
E13

Compose
1 ! U umlaut
2 " @
3 UKpound #
4 $ section
5 %degree
6 &: ~
7 ! i
8 ( *
9 ) (

VK_OEM_COMPOSE
'1 '
'2'
'3'
'4'
'5'
'6'
'7'
'8'
'9'

o '" )

'0'

1
2
3
4
5
6
7
8
9
0
+

VK_OEM_PLUS
VK_OEM_3
VK_BACK

dead '
BS

dead •
BS

000
001
002
003
004
005
006
007
008

TAB
Q

VK_TAB
'Q'

HT
q

HT
Q

? '" +

Unshift

Shift

Ctrl

NUL
ESC
FS
GS
RS
US
DEL

UKpound
$
%
i

!
(
)

'W'

E
R
T

'E'
'R'
'T'

e
r
t

E
R
T

'Y'

'U'

'I'

u
i

17-24

Ctrl!Alt

Ctrl!Alt!Shift

u umlaut

U umlaut
@

section
degree
&:

*
(
)

DEL
HT
OCl
ETB
ENQ
OC2
OC4
EM
NAK
HT

Table 17-4 Finnish to ASCII Translation Table (cont.)
Keypos
009
010
011
012

Keycap

Virtkey

Unshift
0

'0'

'P'

A ring [ {

" ~ ] }

VK_OEM_6
VK_OEM_7

C99
COO
COl
CO2
C03
C04
C05
C06
C07
COS
C09
CI0
Cll
C12
C13

CTRL
LOCK
A
S
0
F

VK_CONTROL
VK_CAP I TAL
'A'
'S'
'0'
'F'

'G'

B99
BOO
BOl
B02

SHIFT

Shift

Ctrl

SI
OLE

a ring
dead "

A ring
dead ~

A
S
0
F

'H'

a
s
d
f
g
h

SOH
OC3
EOT
ACK
BEL
BS

'J'

K
L

'K'
'L'
VK_OEM_4
VK_OEM_5
VK_OEM_2
VK_RETURN

k
1

K
L

VT
FF

o umlaut
a umlaut

umlaut
A umlaut

umlaut
A umlaut '
t

* . -

RETURN

< > \

VK_SHIFT
VK_OEM_l

'Z'

'X'

°
*

Ctrl/Alt/Shift

[
]

{
}

dead -

z
x

SUB

CAN

17-25

Ctrl/Alt

Table 17-4 Finnish to ASCII Translation Table (cont.)
Keypos

Keycap

Virtkey

Unshift

Shift

Ctrl

B03
B04
B05
B06
B07
B08
B09
B10
Bll

C
V
B
N
M

c
v
b
n

C
V
B
N
M

ETX
SYN
STX
SO
CR

Shift

'C'
'V'
'B'
'N'
'M'
VILOEM_COMMA
VK_OEM_PERIOD
VK_OEM_MINUS
VK_SHIFT

A99
A01-09

Alt
Space bar

VK_MENU
VK_SPACE

.: >
; <

/ ?

Ctrl/Alt

Ctrl/Alt/Shift

blank

The remainder of the keyboard layout is the same as the U.S. version.

17-26

NUL

Tab~e

Keypos
EOO
EOl
E02
E03
E04
E05
E06
E07
E08
E09
El0
E11
E12
E13
DOO
DOl
D02
D03
D04
D05
D06
D07
DOS

17-5 French to ASCII Translation Table
Unshift

Shift

et:

section
e grave

1
2
3
4
5
6
7

c cedil
a grave
)

9
0
degree

DEL

VK_TAB
'A'

HT
a

HT
A

HT
SOH
SUB
ENQ
DC2
DC4
EM

Keycap

Virtkey

Compose

VK_OEM_COMPOSE
'1'
'2'
'3'
'4'
'5'
'6'
'7'
'8'
'9'
'0'
VK_OEM_4
VK_OEM_MINUS
VK_BACK

TAB
A

et: 1 -

e acute 2 C
" 3 #
' 4 •
( 5
section 6 ~
e grave 7
! 8 {
c cedil 9 }
a grave 0
) degree

e acute

"
(

'Z'

E
R
T

'E'
'R'
'T'

e
r
t

E
R
T

'Y'

U
I

'U'
'I'

u
i

Y
U

17-27

Ctrl

Ctrl/Alt

NUL
ESC
FS
GS
RS
US
DEL

dead

NAK

dead •

{
}

Ctrl/Alt/Shift

Table 17-5 French to ASCII Translation Table (cont.)
Keypos
009
010
011
012
C99
COO
COl
CO2
C03
C04
COS
C06
C01
C08
009
C10
Cll
C12
C13
B99
BOO
BOl
B02

Keycap

Virtkey

Unshift

'0'

$ * ]

'p'
VK_OEM_1
VK_OEM_l

CTRL
LOCK

VK_CONTROL
VK_CAPITAL

P
A

[

P
dead
$

Shift

Ctrl

SI
OLE

P
dead "

d
f
g
h

G
H

OCl
OC3
EOT
ACK
BEL
BS

'L'

j
k
1

K
L

'M'
VK_OEM_S
VK_OEM_6
VK_RETURN

m
u grave
mu
CR

VT
FF
CR

'Q'

S
0
F

'S'
'0'
'F'

S
0
F

G
H

'G'
'H'

'J'

K
L
M
u grave ~
mu UK pound
RETURN

'K'

SHIFT
< > \
W
X

[
]

VICSHIFT
VK_OEM_3
'W'
'X'

Ctrl/Alt

UK pound
CR

17-28

\
ETB
CAN

Ctrl/Alt/Shift

Table 17-5 French to ASCII Translation Table (cont.)
Keypos

Keycap

Virtkey

Unshift

Shift

Ctrl

B03
B04
B05
B06
B07
B08
B09
B10
B11

C
V
B
N

'c'

c
v
b
n

C
V
B
N

ETX
SYN
STX
SOH

Shift

'V'
'B'
'N'
VK_OEM_COMMA
VK_OEM_PERIOD
VK_OEM_2
VK_OEM_PLUS
VICSHIFT

A99
A01-09

Alt
Space bar

VK_MENU
VK_SPACE

/
= +

/
+

blank

The remainder of the keyboard layout is the same as the U.S. version.

17-29

NUL

Ctrl/Alt

Ctrl/Alt/Shift

Table 17-6 French Canadian and Bilingual Canadian to ASCII Translation Table
Keypos

Keycap

Virtkey

EOO
EOl
E02
E03
E04
E05
E06
E07
EOS
E09
EIO
Ell
E12
E13

Compose

VK_OEM_COMPOSE

1 !

'1'

2 " C
3/#
4 $
5 %
6 ? ~

'2 '
'3'
'4'
'5'
'6'
'7'
'S'

000
001
002
003
004
005
006
007
008

7 "
S *
9 (

'g'

Unshift

1
2
3
4
5
6
7
S
9
0

Shift

Ctrl

NUL
ESC
FS
GS
RS
US
DEL

%
?

"*
(
)

'0'
VK_OEM_MINUS
VK_OEM_PLUS
VK_BACK

TAB
Q

VK_TAB
'Q'

'w'

E
R
T

'E'
'R'
'T'

e
r
t

E
R
T

Y
U

'y'

'u'

'I'

u
i

Y
U

= +

DEL

HT
Q

HT
DCl
ETB
ENQ
DC2
DC4
EM

17-30

NAK

Ctrl/Alt

Ctrl/Alt/Shift

(il

Table 17-6 French Canadian and Bilingual Canadian to ASCII Translation Table (cont.)
Keypos
009
010
011
012

Keycap

Virtkey

Unshift

Shift

Ctrl

'0'
'p'

°P

SI
OLE

c Cedi! [ {

VK_OEM_4
VK_OEM_6

# CI ] }

C99
COO
COl
CO2
C03
C04
COS
C06
C07
COB
C09
Cl0
Cll
C12
C13

CTRL
LOCK
A
S
0
F

B99
BOO
BOl
B02

SHIFT

c cedilla C cedilla
#

'F'

a
s
d
f

A
S
0
F

VK_CONTRO
VK_CAPITAL
'A'

's'
'D'

'G'

'H'

' J'

'K'

'L'
VK_OEM_l
VK_OEM_7
VK_OEM_S
VK_RETURN

K
L

VT
FF

\ I
RETURN
< > • -

VK_SHIFT
VK_OEM_3

·Z'

'X'

<
z
x

dead LF

Z
X

17-31

[
]

{
}

I
CR

Ctrl/Alt/Shift

SOH
OC3
EOT
ACK
BEL
BS

dead •
\
CR

Ctrl/Alt

SUB
CAN

Table 17-6 French Canadian and Bilingual Canadian to ASCII Translation Table (cont.)
Keypos

Keycap

Virtkey

Unshift

Shift

Ctrl

B03
B04
B05
B06
B01
BOS
B09
Bl0
BU

C
V
B

c
v
b
n
m

C
V
B
N
M

ETX
SYN
STX
SO
CR

E acute / ?
Shift

'C'
'V'
'B'
'N'
'M'
VK_OEM_COMMA
VK_OEM_PERIOD
VK_OEM_2
VK_SHIFT

e acute

dead
E acute

A99
A01-09

Alt
Space bar

VK_MENU
VK_SPACE

blank

M
' <
>

The remainder of the keyboard layout is the same as the U.S. version.

17-32

NUL

Ctrl/Alt

Ctrl/Alt/Shift

<
>
?

Table 17-7 German to ASCII Translation Table
Keypos

Keycap

Virtkey

EOO
EOl
E02
E03
E04
E06
E06
E07
E08
E09
El0
E11
E12
E13

Compose
1 ! 2 " CI
3 section
4 $
6 %
6 t
7 /
8 ( {
9 ) }

VK_OEM_COMPOSE
'1'

'2'

'3'
'4'
'6'
'6'
'7'
'8'
'9'
'0'
VK_OEM_2
VK_OEM_3
VK_BACK

3
4
6
6
7
8
9
0
sharp
dead '
BS

000
001
D02
D03
D04
006
D06
007
008

TAB
Q

VK_TAB
'Q'

Unshift

Shift

Ctrl

Ctrl/Alt

NUL

section

ESC
FS

dead -

%
t

/
(
)

as
as
US
DEL

or
dead •
BS

DEL

'W'

'E'

'a'

'T'

'Z'

e
r
t
z

DCl
ETB
ENQ
DC2
DC4

SUB

U
I

'U'

NAK

'I'

sharp or

17-33

{
}

Ctrl/Alt/Shift

Table 17-7 German to ASCII Translation Table (cant.)
Keypo8

Keycap

D09
Dl0
Dll
D12

P
U umlaut [

C99
COO
COl
CO2
C03
C04
COS
C06
C07

coa

+ * ]

Virtkey

Un8hift

'0'

'P'
V1COEM_6
VK_OEM_PLUS

Shift

Ctrl

P
U umlaut

SI
DLE

u umlaut
+

A
S
D

[
]

CTRL
LOCK
A
S

VK_CONTROL
VK_CAPITAL
'A'

D
F
G

'D'

a
8
d

'F'
'G'

f
g

F
G

'H'

SOH
DC3
EOT
ACK
BEL
BS

J
K

'J'

'K'
'L'
VK_OEM_S
VK_OEM_4
VK_OEM_7
VK_RETURN

K
L

VT
FF

C09
Cl0
Cll
C12
C13

°A umlaut
umlaut

B99
BOO
BOl
B02

SHIFT

L
#

RETURN

< > \
Y
X

's'

VK_SHIFT
VK_OEM_l
'y'
'X'

o umlaut
a umlaut
#

°A umlaut
umlaut
dead
CR

17-34

Ctrl/Alt

\
EM
CAN

Ctrl/Alt/Shift

Table 17-7 German to ASCII Translation Table (cont.)
Keypos

Keycap

Virtkey

Unshift

Shift

Ctrl

B03
B04
BOS
B06
B07
B08
B09
Bl0
Bll

C
V
B
N
M

'c'

c
v
b

Shift

'V'
'B'
'N'
'M'
VK_OEM_COMMA
VLOEM_PERIOD
VK_OEM_MINUS
VK_SHIFT

A99
A01-09

Alt
Space bar

VK_MENU
VK_SPACE

, ;

C
V
B
N

ETX
SYN
STX
SO
CR

blank

NUL

The remainder of the keyboard layout is the same as the U.S. version.

17-35

Ctrl/Alt

Ctrl/ Alt/Shift

Table 17-8 Italian to ASCII Translation Table
Virtkey

Keypos

Keycap

EOO
EOl
E02
E03
E04
E05
E06
E07
E08
E09
El0
Ell
E12
E13

VK_OEM_COMPOSE
Compose
'1'
1 !
2 " ,
'2'
3 UKpound cCedil '3'
'4'
4 $
'5'
5 't.
'6'
6 Ie
'7'
7 /
8 ( {
'8'
'9'
9 ) }
'0'
o=
VK_OEM_2
' ?
VK_OEM_7
i grave
VK_BACK
<X

000
001
002
003
004
005
006
007
008

TAB
Q

VK_TAB
'Q'

Unshift

1
2
3
4
5
6
7
8
9
0

Shift

Ctrl

NUL
ESC
FS
GS
RS
US
DEL

UKpound
$

't.
Ie

/
(

)

dead •
BS

HT
Q

'W'

q
w

E
R
T

'E'
'R'
'T'

e
r
t

E
R
T

'Y'

'U'
'I'

17-36

dead
dead •
c cedilla
degree

{

}

i grave
BS

Ctrl/Alt

DEL
HT
DCl
ETB
ENQ
DC2
DC4
EM
NAK
HT

Ctrl/Alt/Shift

Table 17-8 Italian to ASCII Translation Table (cont.)
Keypos

Keycap

Virtkey

D09
D10
Dll
D12

°P

'0'

'P'
VK_OEM_6
VK_OEM_PLUS

C99
COO
COl
CO2
C03
C04
C05
C06
C07

CTRL
LOCK
A
S
D
F
G
H

VK_CONTROL
VK_CAPITAL
'A'
'S'
'D'
'F'
'G'
'H'

' J'

coa

'K'
K
'L'
L
VK_OEM_5
o grave CI
VK_OEM_4
a grave #
u grave section VK_OEM_l
VK_RETURN
RETURN

C09
C10
Cll
C12
C13
B99
BOO
BOl
B02

eGrav eAcu [
+

SHIFT
< > \
Z
X

VK_SHIFT
VK_OEM_3
'Z'
'X'

Unshift

Shift

Ctrl

°P

SI
DLE

e grave

e acute

a
s

A
S
D
F
G
H

SOH
DC3
EOT
ACK
BEL
BS

K
L
CI

VT
FF

d
f

g
h
j

k
1

o grave
a grave
u grave
CR

<
z
x

Ctrl/Alt

[
]

section
CR

SUB

CAN

17-37

Ctrl/Alt/Shift

Table 17-8 Italian to ASCII Translation Table (cont.)
Keypos

Keycap

Virtkey

Unshift

Shift

Ctrl

B03
B04
B05
B06
B07
Boa
B09
Bl0
B11

C
V
B
N
M

c
v
b
n
m

C
V
B
N
M

ETX

Shift

'C'
'V'
'B'
'N'
'M'
VK_OEM_COMMA
VK_OEM_PERIOD
VK_OEM_MINUS
VK_SHIFT

A99
A01-09

Alt
Space bar

VK_MENU
VK_SPACE

blank

NUL

, ;

The remainder of the keyboard layout is the same as the U.S. version.

17-38

SYN
STX
SO
CR

Ctrl/Alt

Ctrl/Alt/Shift

Table 17-9 Norwegian to ASCII Translation Table
Keypos

Keycap

Virtkey

EOO
EOl
E02
E03
E04
E05
E06
E07
EOS
E09
EI0
Ell
E12
E13

Compose
1 !
2 II G
3 UKpound #
4 $
5 %
6 &: 7 / &:
S ( *
9 ) (

VK_OEM_COMPOSE
'1'
'2'
'3-'
'4'
'5'
'6'
'7'

DOO
DOl
D02
D03
D04
D05
D06
D07
DOS

's'

'9'
'0'
VK_OEM_PLUS
VK_OEM_3
VK_BACK

o= )
+ ? -

= +

Unshift

1
2
3
4
5
6
7
S
9
0

Shift

Ctrl/Alt

Ctrl/Alt/Shift

NUL

UK pound
$

ESC
FS
GS
RS
US
DEL

%
&:

/
(
)

dead '
BS

TAB

VK_TAB

'Q'

'W'

q
w

'E'
'R'
' T'

e
r
t

E
R
T

R
T

Ctrl

(
)

DEL
HT
DCl
ETB
ENQ

DC2
DC4
EM

'Y'

'U'

NAK

'I'

17-39

Table 17-9 Norwegian to ASCII Translation Table (cont.)
Keypos

Keycap

Virtkey

Unshift

Shift

Ctrl

'0'
'P'

0
P

S1
DLE

A ring [ {

VK_OEM_6
VK_OEM_1

a ring
dead "

A ring
dead •

C99
COO
COl
CO2
C03
C04
C05
C06
C01
COS
C09
CI0
C11
C12
C13

CTRL
LOCK
A
S
0
F

VK_CONTROL
VK_CAPITAL
'A'

A
S
D
F

'G'
'H'
' J'

a
s
d
f
g
h

B99
BOO
BOl
B02

SHIFT

009
010
011
012

" .] }

H
J

K
L

° slash
AE ' "

. * ' -

RETURN

's'
'0'
'F'

'K'
'L'
VK_OEM_5
VK_OEM_4
VK_OEM_2
VK_RETURN

G
H
J

K
L

o slash
ae

o slash
*

dead -

>
Z
X

SUB
CAN

Z
X

'Z'
'X'

z
x

{
}

[
]

VT
FF

VK_SH1FT
VK_OEM_l

Ctrl/Alt/Shift

SOH
OC3
EOT
ACK
BEL
BS

< > \ I

Ctrl/Alt

17-40

Table 17-9 Norwegian to ASCII Translation Table (cont.)
Keypos

Keycap

Virtkey

Unshift

Shift

Ctrl

B03
B04
B05
B06
B07
BOB
B09
Bl0
B11

C
V
B
N
M

'c'

c
v
b
n
m

C
V
B
N
M

ETX
SYN
STX
SO
CR

Shift

'V'
'B'
'N'
'M'
VK_OEM_COMMA
VK_OEM_PERIOD
VK_OEM_MINUS
VK_SHIFT

A99
A01-09

Alt
Space bar

VK_MENU
VK_SPACE

, ; <
: >
/ ?

Ctrl/Alt

Ctrl/Alt/Shift

<
>

blank

The remainder of the keyboard layout is the same as the U.S. version.

17-41

NUL

Table 17-10 Spanish to ASCII Translation Table
Keypos

Keycap

Virtkey

EOO
EOl
E02
E03
E04
E05
E06
E07
E08
E09
EI0
Ell
E12
E13

Compose
1 inverted
2 inverted ? (g
3 # UKpound
4 $ aUndersc
5 % oUndersc
6 /
7 .t
8 *
9 ( {

VK_OEM_COMPOSE
'1 '
'2'

DOO
DOl
D02
D03
D04
D05
D06
D07
D08

'3'

Unshift

Shift

1
2
3
4
5
6
7
8
9

inverted !
inverted ?
#

Ctrl

Ctrl/Alt

NUL
ESC
FS
GS
RS
US
DEL

dead

(
)

'4'
'5'
'6'
'7'
'8'
'9'
'0'
VK_OEM_MINUS
VK_OEM_PLUS
VK_BACK

DEL

TAB
Q

VK_TAB
'Q'

HT
q

HT
Q

HT
DCl
ETB
ENQ
DC2
DC4
EM
NAK
HT

o) }
= +

/
.t

{
}

'W'

E
R
T

'E'
'R'
'T'

e
r
t

E
R
T

'Y'

U
I

'U'
'I'

17-42

UKpound
a underscore
o underscore

Ctrl/Alt/Shift

Table 17-10 Spanish to ASCII Translation Table (cont.)
Keypos
009
DI0
011
D12
C99
COO
COl
CO2
C03
C04
COS
C06
C01
COS
C09
CI0
Cll
C12
C13
B99
BOO
BOI
B02

Keycap

Virtkey

Unshift

'0'
'P'

VK_OEM_4
VK_OEM_3

dead '
dead •

dead "
dead

a
s
d

" [
]

CTRL
LOCK
A

VK_CONTROL
VK_CAPITAL
'A'

's'

D
F

'D'
'F'

'G'

f
g

'H'

'J'

K
L
N tilde

'K'
'L'
VK_OEM_S
VK_OEM_l
VK_OEM_2
VK_RETURN

j
k
1

c cedilla
RETURN
SHIFT
< > \
Z
X

VK_SHIFT
VK_OEM_6
'Z'
'X'

n tilde

Shift

Ctrl

SI
DLE

D
F
G
H
J

K
L
N tilde

c cedilla
CR
CR

z
x

[
]

>
Z
X

17-43

Ctrl/Alt

SOH
DC3
EOT
ACK
BEL
BS
LF

VT
FF

\
SUB
CAN

Ctrl/Alt/Shift

Table 11-10 Spanish to ASCII Translation Table (cont.)
Keypos

Keycap

Virtkey

Unshift

Shift

Ctrl

B03
B04
B05
B06
B07
B08
B09
B10
B11

C
V
B
N
M
, ?.

'C'
'V'
'B'

C
V
B

ETX
SYN
STX
SO
CR

' "
Shift

'M'
VK_OEM_COMMA
VK_OEM_PERIOD
VK_OEM_7
VK_SHIFT

c
v
b
n
m

A99
A01-09

Alt
Space bar

VK_MENU
VK_SPACE

. !

'N'

M
?

"
blank

blank

The remainder of the keyboard layout is the same as the U.S. version.

11-44

NUL

Ctrl/Alt

Ctrl/Alt/Shift

Table 17-11 Swedish to ASCII Translation Table
Keypos

Keycap

Virtkey

EOO
EOl
E02
E03
E04
E05
E06
E07
E08
E09
El0
Ell
E12
E13

Compose
1 ! U umlaut
2 " 0
3 UKpound #
4 $ E acute
5 1. degree
6 l 7 / Ie
8 ( *
9 ) (
0=)

VK_OEM_COMPOSE
'1 '
'2'
'3'
'4'
'5'
'6'
'7'
'8'
'9'
'0'
VK_OEM_PLUS
VK_OEM_3
VK_BACK

DOO
DOl
D02
D03
D04
005
006
D07
D08

TAB
Q

VK_TAB
'Q'

+ ? -

= +

Unshift

1
2
3
4
5
6
7
8
9
0

Shift

Ctrl

NUL
ESC
FS
GS
RS
US
DEL

UKpound
$

1.
Ie

/
(
)

Ctrl/Alt

Ctrl/Alt/Shift

u umlaut

U umlaut
CI

e acute
degree

E acute

*(
)

dead '
BS

HT
Q
W

E
R
T

'W'

q
w

E
R
T

'E'
'R'
'T'

e
r
t

'Y'

'U'

'I'

u
i

17-45

DEL
HT
DCl
ETB
ENQ
DC2
DC4
EM
NAK
HT

Table 17-11 Swedish to ASCII Translation Table (cont.)
Keypos
009
010
011
012

Keycap

Virtkey

Unshift

'0'
'p'

A ring [ {

VK_OEM_6
VK_OEM_7

P
"

]

}

Shift

Ctrl

S1
OLE

a ring
dead "

A ring
dead

A
S
0

C99
COO
COl
CO2
C03
C04
C05
C06
C07
COS
C09
Cl0
Cll
C12
C13

CTRL
LOCK
A
S
0
F

VK_CONTROL
VK_CAP1TAL
'A'

's'

'0'
'F'

'G'

'H'

g
h

B99
BOO
BOl
B02

SHIFT

' J'

F
G
H
J

K
L

'K'
'L'
VK_OEM_4
VK_OEM_5
VK_OEM_2
VK_RETURN

°A umlaut
umlaut

°A umlaut
umlaut
' "
•* '
RETURN

< > \
Z
X

VK_SH1FT
VK_OEM_l
'Z'
'X'

o umlaut
a umlaut

<
z

>
Z

17-46

Ctrl/Alt

Ctrl/Alt/Shift

[
]

{
}

SOH
OC3
EOT
ACK
BEL
BS
LF

VT
FF

dead

\
SUB
CAN

Table 17-11 Swedish to ASCII Translation Table (cont.)
Keypos

Keycap

Virtkey

Unshift

B03
B04
BOS
B06

C
V
B
N

'c'

c
v
b
n
m

BOr

B08
B09
BIO
Bll

, ; <
: >

Shift

'N'
'M'
VK_OEM_COMMA
VK_OEM_PERIOD
VK_OEM_MINUS
VK_SHIFT

A99
AOI-09

Alt
Space bar

VK_MENU
VLSPACE

'V'
'B'

/ ?

blank

Shift

Ctrl

ETX
SYN
STX
SO
CR

B
N
M

blank

The remainder of the keyboard layout is the same as the U.S. version.

17-47

NUL

Ctrl/Alt

Ctrl/ Alt/Shift

<
>
?

Table 17-12 Swiss French to ASCII Translation Table
Keypos

Keycap

Virtkey

Unshift

Shift

EOO
EOl
E02
E03
E04
E05
E06
E07
E08
E09
El0
El1
E12
E13

Compose
1 +
2 " @
3 * #
4 cCedil degree
5 % section
6 &:
7/1
8 (
9 )

1
2
3
4
5
6
7
8
9
0
dead '
dead ~
BS

VK_OEM_COMPOSE
'1'
'2'
'3'
'4'
'5'
'6 '
'7 '
'8'
'9'
'0'
VK_OEM_7
VK_OEM_PLUS
VK_BACK

000
001
002
003
004
005
006
007
008

TAB
Q

VK_TAB
'Q'

o=
' ? •

c cedilla

%
&:

/
(
)
+
?

dead '
BS

NUL
ESC
FS
GS
RS
US
DEL

'W'

'E'

'R'

'T'

'Z'

t
z

HT
DCl
ETB
ENQ
DC2
DC4
SUB

U
I

'U'
'I'

U
I

17-48

Ctrl/Alt

degree
section

dead DEL

q
w

HT
Q

Ctrl

NAK

Ctrl/Alt/Shift

Table 17-12 Swiss French to ASCII Translation Table (cont.)
Keypos
009
010
011
012

Keycap

Virtkey

Unshift

'0'

'P'

eGrav uUmlaut

VK_OEM_5
VK_OEM_6

" ! ]

C99
COO
COl
CO2
C03
C04
C05
C06
C07
COB
C09
CI0
Cll
C12
C13

CTRL
LOCK
A
S
0
F
G

VK_CONTROL
VK_CAPITAL
'A'

H
J

'H'
'J'

K
L
eAcu oUmlaut {
aGra aUmlaut }
$ UKpound
RETURN

'K'
'L'
VK_OEM_l
VK_OEM_2
VK_OEM_4
VK_RETURN

B99
BOO
BOl
B02

SHIFT
< > \

VK_SHIFT
VK_OEM_3

Y
X

'Y'
'X'

's'
'0'
'F'
'G'

Shift

Ctrl

SI
OLE

e grave
dead "

u umlaut

a
s
d

A
S
0
F
G
H

g
h

[
]

SOH
OC3
EDT
ACK
BEL
BS

K
L
o umlaut
a umlaut
UKpound
CR

VT
FF

e acute
a grave
$
CR

Y
x

Y
X

17-49

Ctrl/Alt

{
}

\
EM
CAN

Ctrl/Alt/Shift

Table 17-12 Swiss French to ASC][I Translation Table (cont.)
Keypos

Keycap

Virtkey

Unshift

Shift

Ctrl

B03
B04
B05
B06
B01
B08
B09
Bl0
B11

C
V
B
N

'c'

c
v
b
n
m

C
V
B
N
M

ETX
SYN
STX
SO
CR

Shift

VK_OEM_COMMA
VLOEM_PERIOD
VK_OEM_MINUS
VK_SHIFT

A99
A01-09

Alt
Space bar

VK_MENU
VK_SPACE

blank

NUL

'V'
'B'
'N'
'M'

;

The remainder of the keyboard layout is the same as the U.S. version.

Ctrl/Alt

Ctrl/Alt/Shift

Table 17-13 Swiss German to ASCII Translation Table
Keypos

Keycap

Virtkey

EOO
EOl
E02
E03
E04
E05
E06
E07
E08
E09
EI0
Ell
E12
E13

Compose
1 +
2 " l!I
3 * #
4 cCedil degree
5 %section
6 It
7/1
8 (
9 )

VK_OEM_COMPOSE
'1 '
'2'

'4'
'5'
'6'
'7'
'8'
'9'
'0'
VK_OEM_7
VK_OEM_PLUS
VK_BACK

DOO
DOl
D02
D03
D04
D05
D06
007
D08

TAB

VK_TAB

Q
W

'Q'
'W'

q
w

'E'

'R'

'T'

'Z'

DCl
ETB
ENQ
DC2
DC4
SUB

'U'

NAK

'I'

o=
' ?

'3'

Unshift

Shift

1
2
3
4
5
6
7
8
9
0
dead '
dead
BS

"
*

c cedilla

%
It

/
(
)
+

Ctrl

Ctrl/Alt

NUL
ESC
FS
GS
RS
US
DEL

degree
section

dead •
BS

17-51

dead DEL

Ctrl/Alt/Shift

Table 17-13 Swiss German to ASCII Translation Table (cont.)
Keypos
D09
Dl0
Dll
D12

Keycap

Virtkey

'0'
'P'

uUmlaut eGrav [

VK_OEM_5
VK_OEM_S

" ! ]

VK_CONTROL
VK_CAPITAl.
'A'

Unshift
0

Shift

Ctrl

SI
DLE

p
u umlaut
dead "

a
s
d

A
S
D
F
G
H

e grave

CTRL
LOCK
A
S
D
F
G
H
J

' J'

K
L
oUmlaut eAcu {
aUmlaut aGra }
$ UKpound
RETURN

'K'
'L'
VK_OEM_l
VK_OEM_2
VK_OEMA
VK_RETURN

B99
BOO
BOl
B02

SHIFT

VK_SHIFT
VK_OEM_3

'Y'

>
Y

'X'

< > \
Y

's'
'D'
'F'
'G'
'H'

g
h
j
k
1

o umlaut
a umlaut
$
CR

[
]

C99
COO
COl
CO2
C03
C04
C05
COS
C01
C08
C09
Cl0
Cll
C12
C13

SOH
DC3
EOT
ACK
BEL
BS

K
L
e acute
a grave
UKpound
CR

VT
FF

17-52

Ctrl/Alt

{
}

\
EM
CAN

Ctrl/Alt/Shift

Table 17-13 Swiss German to ASCII Translation Table (cont.)
Keypos

Keycap

Virtkey

Unshift

Shift

Ctrl

B03
B04
B05
B06
B07
B08
B09
BI0
Bll

C
V
B
N

'c'

c
v
b
n
m

C
V
B
N
M

ETX
SYN
STX
SO
CR

A99
AOI-09

blank

NUL

'V'
'B'
'N'

'M'

, ;

Shift

VK_OEM_COMMA
VK_OEM_PERIOD
VK_OEM_MINUS
VK_SHIFT

Alt
Space bar

VK_MENU
VK_SPACE

The remainder of the keyboard layout is the same as the U.S. version.

17-53

Ctrl/Alt

Ctrl/ Al t/Shift

U.K. to ASCII Translation
U.K. keyboard mappings are identical to U.S., except that the VK_3 shifted
output is the U.K. pound sign instead of the hash mark, and the 'extra' value
(Ctrl/Alt/3) is the hash mark instead of the U.K. pound sign.

17-54

AnsiToOem, OemToAnsi
The keyboard driver supports two MS-Windows entry points AnsiToOem and
OemToAnsi. These entry points translate character byte values between the
OEM character set. which on the VAXmate is equivalent to the IBM PC character set, and the ANSI character set, also known as the ISO Latin-I.

ANSI to OEM Table
ANSI characters in the range 20h to 7Eh are the same as those in the OEM
character set. ANSI characters from OOh to 1Fh and from 7Fh to AOh are
non-printable control codes. Therefore, there is no translation from the ANSI
character set to the OEM character set for these characters.
Table 17-14 documents the translation from characters AOh through FFh in the
ANSI set to the OEM set.
Table 17-14

Translation of ANSI Set to OEM Set

ANSI Description
Char

OEM
Char

Description (if different
from ANSI)

AOH
A1H
A2H
A3H
A4H
A5H
A6H
A7H
A8H
A9H
AAH
ABH
ACH
ADH
AEH
AFH

no-break space (NBSP)
inverted exclamation point
cent sign
Pound Sterling sign
currency sign
yen sign
broken bar
section sign
diaeresis
copyright sign
feminine ordinal indicator
left angle quotation mark
logical NOT
hyphen
registered trade mark
macron

20H
ADH
9BH
9CH
OFH
9DH
7CH
15H
22H
63H
A6H
AEH
AAH
2DH
72H
5FH

space

BOH
B1H
B2H
B3H
B4H
B5H

ring above, degree sign
plus-minus sign
2 (superscript)
3 (superscript)
acute accent
Greek small mu, micro sign

F8H
F1H
FDH
33H
27H
E6H

quotation mark
lowercase c

minus sign
lowercase r
low line

digit 3
apostrophe

MS-Windows on the VAXmate

17 - 55

Table 17-14

Translation of ANSI Set to OEM Set ~cont.)

ANSI Description
Char

OEM
Char

B6H
B7H
B8H
B9H
BAH
BBH
BCH
BDH
BEH
BFH

pilcrow sign, paragraph sign
middle dot
cedilla
1 (superscript)
masculine ordinal indicator
right angle quotation mark
1/4
1/2
3/4
inverted question mark

14H
FAH
2CH
3lH
A7H
AFH
ACH
ABH
5FH
A8H

COH
ClI-I
C2H
C3H
C4H
C5H
C6H
C7H
C8H
C9H
CAH
CBH
CCH
CDH
CEH
CFH

A grave uppercase
A acute uppercase
A circumflex uppercase
A tilde uppercase
A diaeresis uppercase
A ring uppercase
AE diphthong uppercase
C cedilla uppercase
E grave uppercase
E acute uppercase
E circumflex uppercase
E diaeresis uppercase
I grave uppercase
I acute uppercase
I circumflex uppercase
I diaeresis uppercase

4lH
4lH
41H
4lH
8EH
8FH
92H
80H
45H
90H
45H
45H
49H
49H
49H
49H

DOH
DlH
D2H
D3H
D4H
D5H
D6H
D7H
D8H
D9H

Icelandic Eth uppercase
N tilde uppercase
o grave uppercase
o acute uppercase
o circumflex uppercase
o tilde uppercase
o diaeresis uppercase
multiplication sign
o with oblique stroke uppercase
U grave uppercase

44H
A5H
4FH
4FH
4FH
4FH
99H
78H
4FH
55H

17 - 56

MS-Windows on the VAXmate

Description (if different
from ANSI)

comma
digit 1

low line
uppercase A
uppercase A
uppercase A
uppercase A

uppercase E
uppercase E
uppercase E
uppercase I
uppercase I
uppercase I
uppercase I
uppercase D
uppercase 0
uppercase 0
uppercase 0
uppercase 0
lowercase x
uppercase 0
uppercase U

Table 17-14

Translation of ANSI Set to OEM Set (cont.)

ANSI Description
Char

OEM
Char

Description (if different
from ANSI)

DAH
DBH
DCH
DOH
OEH
OFH

U acute uppercase
U circumflex uppercase
U diaeresis uppercase
Y acute uppercase
Icelandic Thorn uppercase
German sharp S lowercase

55H
55H
9AH
59H
5FH
E1H

uppercase U
uppercase U

EOH
ElH
E2H
E3H
E4H
E5H
E6H
E7H
E8H
E9H
EAH
EBH
ECH
EOH
EEH
EFH

a grave lowercase
a acute lowercase
a circumflex lowercase
a tilde lowercase
a diaeresis lowercase
a ring lowercase
ae diphthong lowercase
c cedilla lowercase
e grave lowercase
e acute lowercase
e circumflex lowercase
e diaeresis lowercase
i grave lowercase
i acute lowercase
i circumflex lowercase
i diaeresis lowercase

85H
AOH
83H
6lH
84H
86H
9lH
87H
8AH
82H
88H
89H
8DH
AlH
8CH
8BH

FOH Icelandic Eth lowercase
FlH n tilde lowercase
F2H o grave lowercase
F3H o acute lowercase
F4H o circumflex lowercase
F5H o tilde lowercase
F6H o diaeresis lowercase
F7H division sign
F8H o with oblique stroke lowercase
F9H u grave lowercase
FAH u acute lowercase
FBH u circumflex lowercase
FCH u diaeresis lowercase
FDH yacute lowercase
FEH Icelandic Thorn lowercase
FFH y diaeresis lowercase

64H
A4H
95H
A2H
93H
6FH
94H
F6H
6FH
97H
A3H
96H
8lH
79H
5FH
98H

uppercase Y
low line

lowercase a

lowercase d

lowercase 0
lowercase 0

lowercase y
low line

MS-Windows on the VAX mate

17 - 57

OEM to ANSI Table
OEM characters in the range 20h to 7Eh are the same as those in the ANSI
character set. Therefore, there is no translation. OEM characters from OOh to
1 Fh are also not translated. Therefore, they are equivalent to the corresponding
control code in the ANSI set.
Table 17-15 documents the translation from characters 80h through FFh in the
OEM set to the ANSI set.
Table 17-15

Translation of OEM Set to ANSI Set

OEM Description
Char

ANSI
Char

80H
81H
82H
83H
84H
85H
86H
87H
88H
89H
8AH
8BH
8CH
8DH
8EH
8FH

C cedilla uppercase
u diaeresis lowercase
e acute lowercase
a circumflex lowercase
a diaeresis lowercase
a grave lowercase
a ring lowercase
c cedilla lowercase
e circumflex lowercase
e diaeresis lowercase
e grave lowercase
i diaeresis lowercase
i circumflex lowercase
i grave lowercase
A diaeresis uppercase
A ring uppercase

C7H
FCH
E9H
E2H
E4H
EOH
E5H
E7H
EAH
EBH
E8H
EFH
EEH
ECH
C4H
C5H

90H
91H
92H
93H
94H
95H
96H
97H
98H
99H
9AH
9BH
9CH
9DH
9EH
9FH

E acute uppercase
ae diphthong lowercase
AE diphthong uppercase
o circumflex lowercase
o diaeresis lowercase
o grave lowercase
u circumflex lowercase
u grave lowercase
y diaeresis lowercase
o diaeresis uppercase
U diaeresis uppercase
cent
Pound Sterling sign
yen
Peseta sign or point sign Wt)
Function sign (curved f)

C9H
E6H
C6H
F4H
F6H
F2H
FBH
F9H
FFH
D6H
DCH
A2H
A3H
A5H
70H
66H

17 - 58

MS-Windows on the VAXmate

Description (if different
from OEM)

lowercase p
lowercase f

Table 17-15

Translation of OEM Set to ANSI Set (cont.~

OEM Description
Char

ANSI
Char

Description (if different
from OEM~

AOH
AIH
A2H
A3H
A4H
A5H
A6H
A7H
ASH
A9H
AAH
ABH
ACH
ADH
AEH
AFH

a acute lowercase
i acute lowercase
o acute lowercase
u acute lowercase
n tilde lowercase
N tilde uppercase
feminine ordinal indicator
masculine ordinal indicator
inverted question mark
Reverse logical NOT sign
logical NOT sign
1/2
1/4
inverted exclamation point
left angle quotation mark
right angle quotation mark

EIH
EDH
F3H
FAH
FIH
DIH
AAH
BAH
BFH
5FH
ACH
BDH
BCH
AIH
ABH
BBH

BOH
BIH
B2H
B3H
B4H
B5H
B6H
B7H
B8H
B9H
BAH
BBH
BCH
BDH
BEH
BFH

graphic character
graphic character
graphic character
graphic character
graphic character
graphic character
graphic character
graphic character
graphic character
graphic character
graphic character
graphic character
graphic character
graphic character
graphic character
graphic character

20H
20H
20H
7CH
2BH
2BH
2BH
2BH
2BH
2BH
7CH
2BH
2BH
2BH
2BH
2BH

space
space
space
vertical line
plus sign
plus sign
plus sign
plus sign
plus sign
plus sign
vertical line
plus sign
plus sign
plus sign
plus sign
plus sign

COH
CIH
C2H
C3H
C4H

graphic character
graphic character
graphic character
graphic character
graphic character

2BH
2BH
2BH
2BH
2DH

plus sign
plus sign
plus sign
plus sign
minus sign

low line
logical NOT

MS-Windows on the VAXmate

17 - 59

Table 17-15

Translation of OEM Set to ANSI Set (cont.~

OEM Description
Char

ANSI
Char

Description (if different
from OEM~

C5H
C6H
C7H
C8H
C9H
CAH
CBH
CCH
CDH
CEH
CFH

graphic character
graphic character
graphic character
graphic character
graphic character
graphic character
graphic character
graphic character
graphic character
graphic character
graphic character

2BH
2BH
2BH
2BH
2BH
2BH
2BH
2BH
3DH
2BH
2BH

plus sign
plus sign
plus sign
plus sign
plus sign
plus sign
plus sign
plus sign
equal sign
plus sign
plus sign

DOH
DIH
D2H
D3H
D4H
D5H
D6H
D7H
D8H
D9H
DAH
DBH
DCH
DDH
DEH
DFH

2BH
2BH
2BH
2BH
2BH
2BH
2BH
2BH
2BH
2BH
2BH
20H
20H
20H
20H
20H

plus sign
plus sign
plus sign
plus sign
plus sign
plus sign
plus sign
plus sign
plus sign
plus sign
plus sign
space
space
space
space
space

EOH
EIH
E2H
E3H
E4H
E5H
E6H
E7H
E8H
E9H
EAH

Alpha
Beta
Gamma
Pi
sigma uppercase
sigma lowercase
mu lowercase
tau lowercase
phi uppercase
theta uppercase
omega uppercase

5FH
DFH
5FH
B6H
5FH
5FH
B5H
5FH
5FH
5FH
5FH

low line

17 - 60

MS-Windows on the VAXmate

low line
pilcrow sign, paragraph sign
low line
low line
low line
low line
low line
low line

Table 17-15

Translation of OEM Set to ANSI Set (cont.)

OEM Description
Char

ANSI
Char

Description (if different
from OEM)

EBH
ECH
EDH
EEH
EFH

delta lowercase
infinity sign
math empty set or phi lowercase
math own sign
math intersection sign

5FH
5FH
5FH
5FH
5FH

low line
low line
low line
low line
low line

FOH
FIH
F2H
F3H
F4H
F5H
F6H
F7H
F8H
F9H
FAH
FBH
FCH
FDH
FEH
FFH

math equivalence sign
plus-minus sign
greater than or equal sign
less than or equal sign
math integral upper part
math integral lower part
divide sign
math roughly equals sign
degree sign
bold dot
middle dot
square root
n superscript
2 superscript
black box (or diaeresis)
space

5FH
BIH
5FH
5FH
5FH
5FH
F7H
5FH
BOH
B7H
B7H
5FH
6EH
B2H
A8H
20H

low line
low line
low line
low line
low line
low line
middle dot
low line
lowercase n
diaresis

Mouse
The VAXmate uses the DIGITAL 3-button mouse. Movement of the mouse
and/or button transitions on the mouse results in standard MS-Windows
messages.

Communications
Communications on the VAXmate under MS-Windows may take place via an
asynchronous serial communications device, parallel device or over ethernet
with the support of the DIGITAL LAT driver.
Full asynchronous serial and parallel communications device support is provided
as defined in the MS-Windows Software Development Kit Programmer's
Reference Manu.al. In addition, DIGITAL adaptation allows for the LPTx ports
which are redirected to the DIGITAL Serial Printer Port (SPP) to be accessed.
Redirection of an LPTx port to a network device is also allowed. Redirection of
an LPTx port to a COMx port is not allowed.
MS-Windows on the VAXmate

17 - 61

LAT support is an enhancement to DIGITAL's MS-Windows product. Support
is in two forms. First, there is a custom application interface to the DIGITAL
LAT driver. Second, there is a mapping of the MS-Windows RS232
asynchronous serial communications interface to LAT functions.
The Windows LAT support driver supports up to four sessions or circuits. This
is due to the fact that only four LAT Control Blocks ILCBs) are available for
use in the MS-Windows communications driver. Any attempt to open a fifth
session or circuit results in an out-of-memory initialization error return code.

LAT Support Through the Windows Asynchronous
Serial Communications Interface
The RS232 communications functions in the standard Windows adaptation can
optionally be mapped to LAT functions. It has certain restrictions and is under
the user's control. The LAT support driver is transparent to applications which
are aware of the Windows asynchronous communications interface.
In order to provide LAT via the asynchronous serial communications interface,
the asynchronous serial communication devices must be logically mapped to
LAT services. The user of Windows is required to associate the desired LAT
service name with one of the asynchronous serial communication devices,
namely COM1 or COM2. If the communications device is'mapped to a LAT
service, then applications which use the standard asynchronous serial communications routines supplied under Windows will have the calls automatically redirected to the LAT support driver. The user's mapping of asynchronous devices
to LAT services is supported in the Control Panel. The user's selection is saved
in the WIN.INI file. See the section on the Control Panel application in the
VAXmate User's Guide.
Each MS-Windows supplied and defined serial communication routine is
mapped to an appropriate LAT function.
Not all error return codes are 100% meaningful when mapping asynchronous
communications functions to LAT functions. The most meaningful error defined
by Windows was chosen to indicate errors in the LAT support driver.
In the following section, each Windows communications function is followed by
a one sentence description of its purpose. IMore detail may be obtained from
the MS-Windows Programmer's Reference ManuaL) Each description is followed by the routine's functionality when redirected to LAT.

17 - 62

MS-Windows on the VAXmate

OpenComm
This routine handles the opening of a communications device. A LAT session is
opened if:
1.

2.
3.

4.
5.
6.

7.
8.

The LAT driver has been loaded. If not, the OPEN request is handled
by the asynchronous communications driver.
The device ID is 0 or 1. If not, the OPEN request is handled by the
asynchronous communications driver.
The mode of transmission is computer to computer. Therefore, the
FDTRFLOW, FRTSFLOW, FOUTXCTSFLOW, and
FOUTXDSRFLOW flags in the serial communications DCB must be O.
If not, the open call is handled by the serial communications open
routine.
The transmit/receive byte size is valid. If less than 4 or greater than 8,
an illegal byte size (IE _ BYTESIZE) error is returned.
There is an available LCB. If not, the open call is handed off to the
serial communications driver.
A service name is present in the WIN.INI file for the serial communications device being opened. If not, the open call is handed off to the
serial communications open routine.
The LAT service is available. If the LAT service is unavailable, an invalid or unsupported 10 error is returned (IE _ BADID).
The serial communications DCB is copied into the LCB in case the
application performs a GetCommState call.

All subsequent Windows communications functions are handled by the LAT
support routine if a successful open-under-LAT was previously performed.
Otherwise, the call is handled by the asynchronous communications driver.

WriteComm
This Windows routine handles write operations to the communications device.
The following actions are performed:
1.

Check for a LAT session fail or stop. If so, the break-event bit,
EV BREAK, is set in the communications event word. The communications event word can be read by the GetCommEventMask or
SetCommEventMask functions. The communications error code
CE BREAK is also returned indicating the LAT session failure or
stop.
The transmit/receive byte size passed in the serial communications
Device Control Block (DCB) during the OpenComm call is used to
mask unwanted data bits.
The character passed is transmitted. If unable to transmit, a transmit
queue full error ICE TXFULL) is logged and can be retrieved by doing
a GetCommError call.
MS-Windows on the VAXmate

17 - 63

TransmitCommChar
This LAT support routine transmits a character immediately, just as any other
character. Therefore, its functionality is identical to the WriteComm routine.

ReadComm
This routine reads the communications device. The following actions are
performed:
1.

Check for a LAT session fail or stop. If so, no characters are returned
for the read. Rather. the break-event bit, EV BREAK, is set in the
communications event word. Also, the communications error code
CE _BREAK is returned indicating the LAT session failure or stop.

2.
3.

The end of file flag is checked. If set, the EOF character is returned.
A character is read. If a character is available, steps 4-7 are performed,

The transmit/receive byte size passed in the serial communications
Device Control Block (DCB) during the OpenComm call is used to
mask unwanted data bits.
If the strip receive null flag (FNULL) passed in the DCB is set and
the character received is a null, no character is returned to the caller.
If the binary flag (FBI NARY) in the DCB is not set, check for the
EOF character as passed in the DCB (EOFCHAR). If character read is
the EOF, it is returned to the caller and the EOF status flag (FEOF)
is set. The FEOF status flag may be retrieved by doing a
GetCommError call.

5.
6.

The event character (EVTCHAR) passed in the DCB is checked
against the read character. If equal, the event is logged and can be
retrieved by calling SetCommEventMask or GetCommEventMask.

CloseComm
This routine closes the communication device. The following actions are
performed:
1.

The LAT session is unconditionally closed.

Data structures allocated to the session are freed.

17 - 64

MS-Windows on the VAXmate

SetCommState
This routine sets parameters in the serial communications DCB. The following
actions are performed:
1.

The FDTRFLOW, FRTSFLOW, FOUTXCTSFLOW, and
FOUTXDSRFLOW flags in the serial communications DCB must all
be reset to indicate computer-to-computer transmission. If not, the
LAT session is closed and a call is made to the asynchronous communications driver's OPEN routine. Otherwise, steps 2-3 are performed.

The transmit/receive byte size is checked. If less than 4 or greater
than 8, an illegal byte size liE _ BYTESIZE) error is returned.

The serial communications DCB is copied into the LCB.

GetCommState
This routine fills a buffer with the serial communications DCB.

EscapeCommFunction
This LAT support routine performs extended communication functions. It does
nothing except exit with the current device error word.

SetCommBreak
This LAT support routine puts the communications device in a break state. It
performs the following function:
1.

SendCommBreak sends a break to the host and exits with the current
device error word. If the break cannot be sent, the CE TXFULL bit is
set in the communications error word.
-

ClearCommBreak
This LAT support routine clears the communication device's break state. It
does nothing except exit with the current device error word.

SetCommEventMask
This LAT support routine enables and retrieves the event mask. Its
functionality is identical to the asynchronous communications driver.

GetCommEventMask
This LAT support routine returns and clears the event mask. Its functionality
is identical to the asynchronous communications driver.

FlushComm
This LAT support routine flushes characters from the transmit or receive
queue. Its functionality is identical to the asynchronous communications driver.
MS-Windows on the VAXmate

17- 65

GetCommError
This LAT support routine fills a communications status buffer and returns the
communications error word if an error occurred since the last GetCommError.
Its functionality is identical to the asynchronous communications driver. The
only flag which may ever be set in STFLAGS in the status buffer is the EOF
character flag IFEOF). The only communications device error bit which may
ever be set in the communications error word are CETXFULL and
CE BREAK.
The Windows LAT interface ignores RS232 specific parameters which are part
of the LAT Device Control Block data structure (e.g., baud rate, parity, stop
bits, etc.).

Custom LAT Application Interface Under Windows
Applications that are aware of LAT may use custom functions provided under
DIGITAL's adaptation of MS-Windows. These functions are a direct interface
to LAT from the application. Parameters passed and returned are specific to
LAT. The interface does not attempt to emulate the asynchronous communications interface provided under MS-Windows.
There are eight custom application interface functions provided to support the
interface to LAT. They are described in detail below.

17 - 66

MS-Windows on the VAXmate

OpenLat (lpServiceN arne, IpN odeNarne, IpPortN arne) :
Latid
This routine opens a session to a LAT-supported service and assigns a LATID
handle to it. The routine allocates the data structures for the LAT session including space for the receive and transmit queues.
Parameters
IpServiceN arne

Is a long pointer to a null-terminated string that contains
the requested service name. It may be 1-18 characters in
length.

IpNodeName

Is a long pointer to a null-terminated string that contains
the requested node name. This parameter may be NULL
or up to 18 characters in length.

IpPortName

Is a long pointer to a null-terminated string that contains
the requested port name. This parameter may be NULL or
up to 18 characters in length.

Returns
Latid

Is an integer value identifying the opened communication
device. If Latid is negative an initialization error occurred.

IE LATINSTALL

Is returned if the LAT driver was not installed.

IE LATSERVICE

Is returned if the requested service is unavailable.

IE LATMEMORY

Is returned if unable to allocate memory for the LAT
data structures.

IE LATSESSIONS

Is returned if no sessions are available.

IE LATCIRCSESS

Is returned if no sessions are available on the circuit.

IE LATVIRTCIRC

If no more virtual circuit blocks are available.

IE LATBUFFER

Is returned if there is a data buffer specification error
(internal LAT driver error).

MS-Windows on the VAXmate

17 - 67

CloseLat (Latid) : Result
The routine closes the LAT session specified by the Latid and frees all the data
structures associated with the session.
Parameters
is an integer value identifying the LAT session to be closed.

Latid
Returns
Result

is an integer value specifying the result of the routine.
= 0 (CE_LATOKI if the session was closed.
= a negative number if there was an error.

= CE LATID if there is no session associated with Latid.

= CE_ LATSTOP if the LAT circuit failed or was stopped.
ReadLat (Latid) : Result
This routine attempts to read a character from the receive queue for a session
as specified by Latid.
Parameters
Latid is an integer value identifying the LAT session to be read from.
Returns
The low order 8 bits of Result contain the read character.
= a negative value if no character was read or there was an error.
= CE LATID if there is no session associated with Latid.

= CE_LATSTOP if the LAT circuit failed or was stopped.
= CE LATNOCHAR if no character was available.

17 - 68

MS-Windows on the VAXmate

WriteLat (Latid, ch) : Result
This routine writes a character to the transmit queue for the session specified
by Latid.
Parameters
Latid

is an integer value identifying the LAT session to which the
character is queued.

is the 8-bit value of the character to write to the transmit
queue.

Returns
Result

= 0 (CE_LATOK) if the write was successful.

= a negative value if the write was unsuccessful.
= CE LATID if there is no session associated with Latid.

= CE _ LATTXQUE if unable to queue the character.

= CE _ LATSTOP if the LAT circuit failed or was stopped.
GetLatStatus (Latid) : Result
This routine is used to get the status of the LAT session specified by Latid.
Parameters
Latid

is an integer value identifying the LAT session to get status
from.

Returns
Result

is an unsigned integer value whose bits, when set, indicate LAT
status. The bits set can be any combination of the following:
ST LATREC

Receive data is available.

ST_LATTXQUE

Unable to queue transmit data.

ST LATSESINACT Lat session is not active.
ST TXEMPTY
Result

Transmit buffer is empty.

= a negative value if the status call was in error.
= CE LATID if there is no session associated with Latid.

CE _ LATSTOP if the LAT circuit failed or was stopped.
MS-Windows on the VAXmate

17 - 69

SendLatBreak (La tid) : Result
This routine causes the LAT driver to send a break to the host.
Parameters
Latid

is an integer value identifying the LAT session over which the
break is sent.

Returns
Result

= 0 ICE_LATOK) if the break was sent.
= a negative value if the break was not sent.
= CE LATID if there is no session associated with Latid.

= CE_LATSTOP if the LAT circuit failed or was stopped.
= CE LATBRK if unable to transmit the break because a
buffer or transmit credit is not available.

InquireLatServices ( ) : LResult
This routine asks the LAT driver to return the maximum number of service
name entries in its service table. The number of actual service names available
may be less. It also resets the service name counter so that the first
GetLatService call returns the first name in the service table. If the LAT service table has overflowed the caller is informed.
Parameters
None
Returns
LResult

is a long 132) bit integer. The high word of LResult indicates
error return codes. The low word of LResult is the maximum
number of services in the LAT driver's table.

High word

= IE LATINSTALL if the LAT driver is not installed.

= IE LATOVERFLOW if the LAT driver's service table
overflowed.
= zero if no errors are returned.
= IE LATOVERFLOWor O. the low word of LResult is the
maximum number of services in the LAT driver's table.
Otherwise, the low word is undefined.

17 - 70

MS-Windows on the VAXmate

GetLatService (lpServiceNarne) : Result
This routine asks the LAT driver for the next service name in its table. It fills
the buffer passed with the service name. An InquireLatServices call must be
made before the first call to GetLatService.
Parameters
IpServiceN arne

is a long pointer to a character string buffer containing a
null terminated string. This string is the LAT service
name. The actual service name may be up to 16 characters
in length. Therefore, allocate a buffer of at least 17 bytes.

Returns
Result

is the number of service names remaining in the LAT
driver's table.
= 0 indicates the last name in the list is being returned.

= a negative number if there was an error.

= IE LATINSTALL if the LAT driver was not installed.
= IE LATNOSERVNAME if no service name is being returneCf because 11 the InquireLatServices function was not
called, or 21 the end of the service name table was reached
on a previous GetLatService call.
IMPORTANT
Result may be decremented by more than one from a previous
call. This is due to the LAT driver's filtering out of duplicate
service names. Note too that because of this feature zero may
never be returned. Therefore, programs must loop while Result
not equal IE _ LATNOSERVNAME.

If the Windows LAT interface detects a circuit failure or stop ~CE LATSTOPI,

the application's virtual connection to the communication device is-closed. The
Windows LAT interface driver invalidates the applications LAT session ID. It
also automatically deallocates any data structures associated with the LAT
session. The application may make a CloseLat function call, but is not required.

MS-Windows on the VAXmate

17 - 71

The application's .DEF file must contain an import statement for each of the
custom LAT routines it uses as follows (these statements are in DECWIN.H):
IMPORTS
comm.OpenLat
comm.CloseLat
comm.ReadLat
comm.WriteLat
comm.GetLatStatus
comm.SendLatBreak
comm.lnquireLatServices
comm.GetLatService
The application must declare the following for each routine it uses:
extern int FAR PASCAL OpenLat (LPSTR, LPSTR, LPSTR) ;
extern int FAR PASCAL WriteLat (int, char);
extern int FAR PASCAL GetLatStatus (int);
extern int FAR PASCAL ReadLat (int) ;
extern int FAR PASCAL CloseLat (int);
extern int FAR PASCAL SendLatBreak (int);
extern long FAR PASCAL InquireLatServices ();
extern int FAR PASCAL GetLatService (LPSTR);

17 - 72

MS-Windows on the VAXmate

Display on the VAXmate
The VAXmate video controller when running under MS-Windows is configured
to operate in the 640x400 2-color graphics mode. This mode has twice the vertical resolution as the industry-standard color graphics adapter. This mode
allows for smoother looking graphics and the use of a higher quality font.
A custom font is supplied for the display resolution in order to support
DIGITAL's VT220 Terminal Emulator, which runs under MS-Windows. Other
applications may also use this font.
The DIGITAL Terminal Emulation font has an 8x14 and a 6x9 lwidth x
height) character cell for single-high/single-wide characters and a 16x14 and
12x9 character cell for double-wide characters. Fonts are provided for doublewide/double-high top and double-wide/double-high bottom. When combined, character cell sizes of 16x28 and 12x18 are realized. The character cell size selection allows for 24 text lines of display in a full screen window which contains a
caption area and a horizontal scroll bar.
Each font has a unique face name so that they can be enumerated and
distinguished in size. The face names are listed below along with the character
cell description and cell size.
OECTerm

Single-high/single-wide character, cell
size 8x14

OECTerm Small

Single-high/single-wide character, cell
size 6x9

OECTerm Obi-Wide

Single-high/double-wide character, cell
size 16x14

OECTerm Small Obi-Wide

Single-high/double-wide character, cell
size 12x9

OECTerm Obi-Size Upper

Top half of double-high/double-wide
character, cell size 16x14

OECTerm Obi-Size Lower

Bottom half of double-high/double-wide
character, cell size 16x14

OECTerm Small Obi-Size Upper

Top half of double-high/double-wide
character, cell size 12x9

OECTerm Small Obi-Size Lower

Bottom half of double-high/double-wide
character, cell size 12x9

See the OECWIN.H listing for the symbolic constants that should be used by
applications when accessing the character set.
MS-Windows on the VAXmate

17 - 73

There is one character set provided in the font. The character set in the font is
a superset of the ANSI Character Set. It is designated by the character set ID
DECTERM CHARSET in the DECWIN.H file. The ANSI Character Set has
characters in positions 21h-7Eh and Alh-FFh. The DIGITAL Terminal
Emulation fonts character set provides all those characters in the same positions. Included are the newly ISO approved times and divide signs in positions
D7h and F7h, respectively.
Three characters, which are in the DIGITAL Multinational character set but
which are not represented in the ANSI Character Set for Windows, occupy p0sitions 9Dh-9Fh in the DIGITAL Terminal Emulation Font. The three characters are the upper and lower case oe ligature and the lower case y-umlaut.
The reverSe question mark, used to represent communications errors, occupies
position 9Ch.
Characters in positions 60h-7Eh in the DIGITAL Special Graphics Character
Set ~also known as the VT100 line drawing set) occupy positions OOh-IEh in
the DIGITAL Terminal Emulation Font.
NOTE
The ANSI Character Set for Windows is equivalent to the ISO
Latin-l character set.

Standard Applications Support
MS-Windows provides support for standard MS-DOS applications. These applications are not designed to run in the MS-Windows environment. The old applications driver is responsible for managing the invocation and operation of the
standard applications on a per task basis. All system resources are managed so
that the standard application may co-exist within the MS-Windows environment and with other MS-Windows applications.
The old application support module is essentially the same as the support pro·
vided in the standard version with a few exceptions.

•

Keyboard handling

•

ANSI Support

•
•
•

Video modes handled

•

Interrupt 15 Support

•

Memory requirements

•

Unique Icons

17- 74

Interrupt 11 Support
Interrupt 12 Support

MS-Windows on the VAXmate

Keyboard Handling
Keyboard Handling Inside an MS-Windows Window
If the standard application is running within an MS-Windows window, the ap-

plication has access to Interrupt 16h functions. While the old applications
driver is being enabled, the old interrupt vector is read and saved. A new
vector is set for interrupt 16h which points to a routine within the old applications driver. In this manner, Interrupt 16h functions are intercepted by the old
applications driver and filtered appropriately. The following functions are
supported.
Normal Functions
Fetch Next Character Illput From Keyboard

Parameters
AH = 0
Returns
AH = Scan Code
AL = ASCII Character
Test For Character Available

Parameters
AH = 1
Returns
AH = Scan Code
AL = ASCII Character
ZF = 0 Character is available
ZF = 1 No Character is available

MS-Windows on the VAXmate

17 - 75

Return Current Shift Status Flags
Parameters
AH = 2

Returns
Current shift status flags
AL = Contents of Keyboard Status Flag
Extended Functions:

Enter DEC mode
Parameters
AH = D5
AL = AC

Returns
Nothing

Exit DEC Mode
Parameters
AH = D5
AL = AD

Returns
Nothing

17 - 76

MS" Windows on the VAXmate

Enable/Disable Additional Key Codes
Parameters
AH = 03

Enable/disable additional key codes associated with LK250
keyboard.

AL = N

Each bit with enable/disable special functions, all are processed.

Extended functions not supported:

Key Notification
Parameters
AH = 00

Returns
Nothing

Character Count
Parameters
AH = 01

Returns
Nothing

Keyboard Buffer
Parameters
AH = 02

Returns
Nothing

MS-Windows on the VAXmate

17 - 77

Request Keyboard ID

Parameters
AH = .D4

Returns
Nothing
Get/Set Table Pointer

Parameters
AH = D6

Returns
Nothing
If the keyboard is in DIGITAL-extended mode, the numeric keypad returns nu-

meric values at all times. The scan codes returned are compatible with those
returned while outside of MS-Windows when the keyboard is in DIGITALextended mode.
Function D5h. which sends a command byte to the keyboard, is allowed if the
command is to enter or exit DIGITAL-extended mode (ie, ACh or ADh). All
other commands via D5 return to the caller. Function D3h, which sets ROM
BIOS keyboard states, is allowed only for bit 0 (ie, set/reset numpad states).
Functions such as Ctrl/C and CtrllS are supported as they normally are in an
intrinsic MS-DOS environment. Ctrl/P is not supported by the MS-Windows old
applications driver.

Keyboard Handling Outside an MS-Windows Window
While managing a standard application that runs outside of an MS-Windows
window, the old applications driver takes over interrupt vector 9, the keyboard
interrupt. This vector is taken over so key strokes may be monitored for program switch and screen exchange. The key strokes are Alt/Tab or Alt/Enter for
program switch. Alt/Prt Sc is monitored for screen exchange. If these keys are
not pressed, a call is made to the previous interrupt 9 handler.
When a standard application is run, the keyboard is set to industry-standard
mode. When the application is exited, the keyboard is put back into DIGITALunique mode. This is accomplished from routines within the old applications
driver, which are called when there is a change in the keyboard input focus.
17 - 78

MS-Windows on the VAXmate

While the application is running, the user may wish to temporarily suspend the
standard application and return to MS-Windows without terminating the standard application. If the PIF file associated with the standard application allows
for program switching, then the keyboard state is remembered along with the
video state and video memory. Both are restored when the standard application
is reactivated.

ANSI Support Inside an MS-Windows Window
The MS- Windows old applications driver supports most ANSI escape sequences that are supported by ANSLSYS for standard applications that run in
an MS-Windows window. The following is a list of functions which are not
supported:
Cursor Position Report
Set Mode
Keyboard Reassignment
Set Graphics Rendition
Faint on
Italic on
Rapid blink on
Subscript
Superscript

Video Modes Handled Inside an MS-Windows Window
Standard applications running in an MS-Windows window may access certain
ROM BIOS video functions provided by the old applications driver (WINOLDAPI. Table 17-16 contains the Interrupt 10h functions available and indicates
how they can be used.

MS-Windows on the VAXmate

17 - 79

Table 17-16

Interrupt 10H Functions

Function Name

Function N

Windows Response

Set mode

Ignored

Set cursor type

Emulated by WINOLDAP

Set cursor position

Emulated by WINOLDAP

Get cursor position

BH= Active page (ignore this)
DH,DL = Row,col
CH,CL = Cursor mode

Get light pen position

AX = 0 (no light pen)

Set active page

Ignored

Scroll active page up

Emulated by WINOLDAP

Scroll active page down 7

Emulated by WINOLDAP

Get character and attribute at cursor

BH is ignored

AH,AL = attribute,character
Write character and
attribute at cursor

Emulated by WINOLDAP

Write character string
at cursor

Emulated by WINOLDAP

Set color palette

Ignored

Write dot

Ignored

Read dot

Ignored

Write TTY

Emulated by WINOLDAP

Get video state

AL = mode (always 7, monochrome)
AH = MaxCol (80 columns)
BH = Current active display page
(always 0)

Set palette reg EGA

Ignored

Char gen EGA

Ignored

17- 80

MS-Windows on the VAXmate

Table 17-16

Interrupt 10H Functions (cont.)

Function Name

Function /I

Windows Response

Alternate select EGA

Ignored

Write string EGA

All ignored
AL = 0 BL attribute for all characters, string is ex characters and the
cursor is not moved
AL = 1 BL attribute for all characters, string is ex characters and the
cursor is moved
AL = 2 String is ex characters,
attrib pairs and the cursor is not
moved
AL = 3 String is ex characters.
attrib pairs and the cursor is moved

TopView get video
buffer address

Returns a pointer to the buffer
address

TopView update video
buffer

The display is updated

MS-Windows on the VAXmate

17 - 81

Associated with the old applications driver is a screen grabber that captures
text and graphics video. It supports both industry-standard video modes and
DIGITAL-unique video modes. Table 17-17 contains the supported video modes.
Table 17-17

Supported Video Modes

Mode

Description

Mode 0

40x25 Black/White

Mode 1

40x25 Color

Mode 2

80x25 Black/White

Mode 3

80x25 Color

Mode 4

320x200 Color

Mode 5

320x200 Black/White

Mode 6

640x200 Black/White

Mode 7

80x25 IBM monochrome

Mode DOh

640x400 Black/White (DIGITAL-unique)

Mode Dlh

640x400 Color (DIGITAL-unique)

Mode D2h

800x250 Color (DIGITAL-unique)

Interrupt llh Support
This interrupt returns the equipment available on the system to the caller. This
interrupt is managed for applications running in an MS-Windows window.
While the interrupt is not intercepted, the location, 40:10h is read and then
ORed with bits that always indicate the system is running with a 80x25 BW
card. The ORing in effect takes over the interrupt because the Interrupt llh
call reads the location. When the standard application exits, the original state
of 40:10h is restored.

Interrupt 12h Support
Interrupt 12h calls are filtered for standard applications running in an MSWindows window by the old applications driver. This function returns the
memory size to the application. This is performed on a task basis and really
does not indicate total memory, but the .amount of memory available to the
task, that is, the size of applications partition.

17- 82

MS-Windows on the VAXmate

Interrupt 15h Support
Interrupt 15h is revectored to a handler within the old applications driver for
standard applications running in MS-Windows. All functions normally supported by interrupt 15h are passed on to the firmware. Two Topview calls are
emulated in the handler; one tells the caller that Topview is present while the
other indicates it is Topview Version 1. The DIGITAL-extended DOh function
ANDs the value passed back from the real Interrupt 15h call to simulate a
IBM monochrome adapter is present. This maintains consistency with the Get
Mode Interrupt 10h call and the Interrupt lIh equipment check.

Unique Icons
When a standard application is run, the user may want a more visually appealing and descriptive icon associated with the application. For most standard applications, the first three letters of the application name appear in a white box
as the icon. This is a generic icon. However, the user can create an icon (using
ICONEDIT.EXE) and save the icon (of the form AppName.ICO) somewhere on
the path. This icon is associated with the application of the same name. The
icon is seen if the application can switch to/from MS-Windows by pressing the
Alt/Tab keys or if the application is loaded (runs as an icon). If the icon (.ICO
file) is not found on the path, the three letter functionality is used as before.
For the generic icon, small dots appear near the bottom of the box to denote
multiple instances. For unique icons, dots do not appear for multiple instances.

Printers
Full GDI support for the LN03PLUS (with cartridge) and the LA 75 Companion
printers is supplied. The LA75 is supported in both the DIGITAL mode and
STD (industry-standard) mode. Printing from MS-Windows may either be local
or remote over the ethernet.
All the printer drivers support the ISO Latin-1 character set. The LA50. LN03,
LN03PLUS, and LA75DEC use the fallback representations for characters not
in its ROM font.

MS-Windows on the VAXmate

17 - 83

The printer drivers also support all of the character sets native to the printer.
These include various National Replacement Character (NRC) sets and
DIGITAL-unique character sets. Applications may select these character sets
using standard MS-Windows functions passing the constants listed in the
DECWIN.H file listing. Table 17-18 indicates the character sets supported by
each printer.
Table 17-18

Character Set Supported by Each Printer

Character Set

LA50 LN03 LN03PLUSLA75DEC LA75STD

ISO Latin-1
Industry Standard STD
United Kingdom NRC
French NRC
German NRC
Italian NRC
Danish NRC
Norwegian NRC
Spanish NRC
Swedish NRC
Japanese (JIS Roman) NRC
Japanese Katakana Graphic
Finnish NRC
French Canadian NRC
Dutch NRC
Swiss NRC
Portuguese NRC
DIGITAL Multinational
DIGITAL Special (VT100)
DIGITAL Technical
DIGITAL Publishing

X
X
X
X
X
X
X
X
X
X
X
X
X
X

X
X

X
X
X
X
X
X
X
X
X
X
X
X
X
X

X
X
X
X
X
X
X
X
X

X
X
X
X

X
X

X
X
X

X
X

Refer to the DECWIN.H file for constants that define these character sets.

17 - 84

MS-Windows on the VAXmate

DECWIN.H File Listing
A C programming language include file that documents constants and routine
declarations follows. Values of symbolic constants used in earlier sections are
documented in this include file.

/* DECWIN.H
This collection of constants and routine declarations details
information specific to DIGITAL's Adaptation of MS-Windows for
the VAXmate.

Copyright (c) 1986 by
Digital Equipment Corporation, Maynard, Mass.
This software is furnished under a license and may be used and copied
only in accordance with the terms of such license and with the
inclusion of the above copyright notice. This software or any other
copies thereof may not be provided or otherwise made available to any
other person. No title to and ownership of the software is hereby
transferred.
The information in this software is subject to change without notice
and should not be construed as a commitment by Digital Equipment
Corporation.
DIGITAL assumes no responsibility for the use or reliability
software on equipment which is not supplied by DIGITAL.

its

/**************************************************************************

*
*
*

Version 1.01.11
07/21/86
*
DECWIN.H Application layer include file for DIGITAL extensions *
for MS-Windows version 1.01
*

**************************************************************************/

These three routines and the following constants are used to switch
keyboard states according to user preference. They handle the state

MS-Windows on the VAXmate

17- 85

of the LOCK key (caps/shift), keyclick volume, and the autorepeat
on/off state.

*/
extern int FAR PASCAL DecSetLockState();
extern int FAR PASCAL DecSetKClickVol();
extern int FAR PASCAL DecSetAutorep();
#define
#define

DEC_CAPSLOCK
DEC_SHIFTLOCK

0
1

/*
/*

#define
#define
#define
#define

DEC_NOSOUND
DEC_SOFT
DEC_INTERMED
DEC_LOUD

0
1

/* values for keyclick volume */

#define
#define

DEC_AUTOREPOFF
DEC_AUTOREPON

0
1

lock sense - capslock
lock sense - shift

*/
*/

2
3

/* state of autorepeat

/* DecSetComposeState routine allows an application to switch between
ISO mode compose sequences (the default) and DIGITAL Multinational
Compose sequences. An application using this routine to receive
DIGITAL Multinational sequences should call it with the
DEC_MULTINAT_COMP value upon getting the keyboard input focus, and
MUST CALL IT AGAIN with the DEC_ISO_COMP value upon losing keyboard
input focus. If the second call is not made, other applications will
be receiving DIGITAL Multinational sequences when they are expecting
ISO.

extern int FAR PASCAL DecSetComposeState();
#define DEC_ISO_COMP
0
#define DEC_MULTINAT_COMP 1

/* select ISO compose sequences ~
/* select DEC Multinational seqs

/* DecSetNumlockMode routine allows an application to switch between
Numlock interpretation VK_OEM_NUMBER of the PF2 key on the numeric
keypad and a unique interpretation VK_OEM_PF2 of the key. The default
is Numlock enabled. An application desiring this functionality should
call this routine with the DEC_NONumlock value upon getting the
keyboard input focus. The application MUST RE-ENABLE Numlock PROCESS II
upon losing the keyboard input focus. If the second call is not made,
other applications will get unexpected keyboard output.

*/
extern int FAR PASCAL DecSetNumlockMode();
#define DEC_Numlock

17 - 86

MS-Windows on the VAXmate

/* enable Numlock interpretation

#define DEC_NONumlock

/* disable Numlock interpretation

/* Decfonts used for terminal emulation.
The following constants are used to sel~ct a specific font.

The following character set constant is used in selecting any
DECTERM.FON specific font. Each font variation in the set has a unique
face name.

#define DECTERM_CHARSET

/* DIGITAL Standard Terminal Character Set */
#define DECTERM_NORMAL
#define DECTERM_SMALL

"DECTerm"
"DECTerm Small"

/* DIGITAL Double Wide Terminal Character Set */

#define DECTERM_WIDE
#define DECTERM_SMALL_WIDE

"DECTerm Dbl-Wide"
"DECTerm Small Dbl-Wide"

/* DIGITAL Double High Terminal Character Set (Top and Bottom halves) */
#define DECTERM_DBL_TOP
#define DECTERM_DBL_BOTTOM
#define DECTERM_SMALL_DBL_TOP
#define DECTERM_SMALL_DBL_BOTTOM

"DECTerm Dbl-Size Upper"
"DECTerm Dbl-Size Lower"
"DECTerm Small Dbl-Size Upper"
"DECTerm Small Dbl-Size Lower"

DecGetKbdCountry returns the nationality of the current keyboard
specified in the list below. */

extern int FAR PASCAL DecGetKbdCountry();
/* Return codes from DecGetKbdCountry */

#define DEC_USA
#define DEC_BRITAIN
#define DEC]RANCE
#define DEC_WEST_GERMANY
#define DEC_ITALY
#define DEC_SPAIN
#define DEC_SWEDEN
#define DEC]INLAND

2
3
4
5
6
7
8

/* U.S. keyboard */
/* British keyboard */
/* French keyboard */
/* German keyboard */
/* Italian keyboard */
/* Spanish keyboard */
/* Swedish keyboard */
/* Finish keyboard */

MS-Windows on the VAXmote

17- 87

#define DEC_NORWAY
#define DEC_DENMARK
#define DEC_CANADA
#define DEC_SWISS_GERMAN
#define DEC_SWISS_FRENCH

9
10
11

12
13

/* Norwegian keyboard */
/* Danish keyboard */
/* Canadian keyboard */
/* Swiss German keyboard */
/* Swiss French keyboard */

/* Non-standard virtual keys defined in MS-Windows version 1.01 */
#define VK_OEM_NUMBER
#define VK_OEM_SCROLL
#define VK_OEM_1
#define VK_OEM_PLUS
#define VK_OEM_COMMA
#define VK_OEM_MINUS
#define VK_OEM_PERIOD
#define VK_OEM_2
#define VK_OEM_3
#define VK_OEM_4
#define VK_OEM_5
#define VK_OEM_6
#define VK_OEM_7
#define VK_OEM_8

Ox90
Ox91
OxBA
OxBB
OxBC
OxBD
OxBE
OxBF
OxCO
Ox DB
OxDC
OxDD
OxDE
OxDF

/* Numlock
/* ScrollLock
/* '., , for US
/* '+' any country
, ,
/* , any country
, ,
/* - any country
, ,
any country
/*
/* '/1' for US
,-,
for US
/*
/* ' [{, for US
/* '\1 ' for US
/* 'D' for US
for US
/* '
Not
assigned
/*

.".

*/
*/
*/
*/
*/
*/
*/
*/
*/
*/
*/
*/
*/
*/

/* DIGITAL defined virtual keys */
#define VK_OEM_PF1
VK_ESCAPE
#define VK_OEM_PF2
OxE2
#define VK_OEM_PF3
VK_OEM_SCROLL
#define VK_OEM_PF4
VK_MULTIPLY
#define VLOEM]17
#define VK_OEM_F18
#define VLOEM_F19
#define VK_OEM_F20

OxE3
OxE4
OxES
OxE6

#define VK_OEM_COMPOSE

Ox92

The following definitions are for the Windows LAT interface. */

Windows LAT interface functions */

extern int
extern int
extern int
extern int
extern int

17 - 88

FAR PASCAL OpenLat (LPSTR, LPSTR, LPSTR) ;
FAR PASCAL WriteLat (int, char);
FAR PASCAL GetLatStatus (int) ;
FAR PASCAL ReadLat (int);
FAR PASCAL CloseLat (int);

MS-Windows on the VAXmate

extern int FAR PASCAL SendLatBreak (int);
extern long FAR PASCAL InquireLatServices ();
extern int FAR PASCAL GetLatService (LPSTR);

/* LAT initialization error and service table error return codes */
#define IE_LATINSTALL
#define IE_LATSERVICE
#define IE_LATVIRTCIRC

-1
-2

#define IE_LATSESSIONS
#define IE_LATMEMORY

-4
-5

#define IE_LATBUFFER
#define IE_LATCIRCSESS

-6
-7

-3

/* Lat driver not installed */
/* Service not in table or name error */
/* No more virtual circuit blocks
available */
/* No more sessions available */
/* All SCBs allocated, no memory
available */
/* Data buffer specification error */
/* No more sessions available on this
circuit */
/* No service name returned, have not

#define IE_LATNOSERVNAME -8
called the LAT service table reset
function or have reached the end of the
table */
#define IE LATOVERFLOW -9
/* LAT service table overflow */

/* LAT function return codes
All error codes are negative 16 bit integers */
#define CE_LATOK
#define CE_LATID
#define CE_LATTXQUE

0
-1
-2

#define CE_LATNOCHAR

-3

#define CE_LATSTOP

-4

/* General function success return value */
/* Invalid LAT session ID */
/* Unable to queue character for
transmission */
/* No character available on a read
request */
/* LAT circuit failed or stopped */

#define CE_LATBRK

-5

/* Unable to send break to host */

/* LAT status word bit definitions */
#define ST_LATREC
#define ST_LATTXQUE
#define ST_LATSESINACT
#define ST_TXEMPTY

OxOOO1
OxOOO2
OxOOO4
OxOO20

/* Receive data is available. */
/* Unable to queue transmit data. */
/* Lat session is not active. */
/* Transmit buffer is empty. */

/* The following constants define new character set definitions for
DIGITAL's MS-Windows printer drivers.
The terms GL and GR are used below.

Character sets in GL fall in the

MS-Windows on the VAXmate

17- 89

range of 20h to 7Fh.
FFh.

Character sets in GR fall in the range of AOh

*/
#define UK_NRC
#define FRENCH_NRC
#define GERMAN_NRC
#define ITALiAN_NRC
#define DANISH_NRC
#define NORWEGIAN_NRC
#define SPANISH_NRC
#define SWEDISH_NRC
#define JIS_ROMAN_NRC
#define KATAKANA_NRC

224
226
226
227
228
229
230
231
232
233

/* United Kingdom NRC in GL */
/* French NRC in GL */
/* German NRC in GL */
/* Italian NRC in GL */
/* Danish NRC in GL */
/* Norwegian NRC in GL */
/* Spanish NRC in GL */
/* Swedish NRC in GL */
/* Japanese (JIS Roman) NRC in GL */
/* Japanese Katakana Graphic Char Set

#define FINNISH_NRC
#define FR_CANADIAN_NRC
#define DUTCH_NRC
#define SWISS_NRC
#define PORTUGUESE_NRC
#define DEC_MCS

234
236
236
237
238
240

/* Finnish NRC in GL */
/* French Canadian NRC in GL */
/* Dutch NRC in GL */
/* Swiss NRC in GL */
/* Portuguese NRC in GL */
/* ASCII in GL. DIGITAL Multinational

#define DEC_SPC_GRAPHICS

241

/* DIGITAL Special (VT100) Graphics in

#define DEC_TECHNICAL
#define DEC_PUBLISHING

242
243

/* DIGITAL Technical Character Set */
/* DIGITAL Publishing Character Set */

*/
*/

17 - 90

MS-Windows on the VAXmate

Chapter 18
VAXmate Network Software
Introduction
The VAXmate network software allows VAXmate workstations to be nodes in a
DIGITAL local area network. The software provides users and applications with
a Microsoft MS-Network compatible environment and a DIGITAL DECnet
compatible environment.
This chapter describes the VAXmate-specific programmer interfaces into the
network environment. It also discusses the relationship among the various components that implement the network interfaces. Some of the described interfaces are not recommended for use by application software. Their description is
provided only for completeness.
The discussion of the network software is restricted to the VAXmate client
node. VAXmate client nodes are those VAXmate workstations that sit on a
user's desk and utilize the services of VAXNMS servers and VAXmate servers.
This chapter assumes the reader is familiar with the Microsoft MS-Network
Vl.O implementation and has documentation on that implementation. To learn
more about Ethernet and the DIGITAL Network Architecture, refer to the
documentation list at the end of this introduction.

18- 1

Figure 18-1 shows the basic components that comprise the VAXmate client
network system.

Application Programs

I
MS-Network
Session level

I
DECnet-DOS

Session level

Local Area
Transport

I
Data Link

I
Hardware
Figure 18-1

VAXmate Network Components

Each item in Figure 18-1 is discussed in the following section.
Hardware
The center of the VAXmate Thin Wire Ethernet network hardware is the
DIGITAL Local Area Network Controller integrated circuit; referred to as the
LANCE chip. This chip and its support circuits connect the VAXmate workstation to the ThinWire Ethernet local area network. The LANCE chip internal
registers are described in this manual.
VAXmate workstations contain different versions of network hardware, which
behave differently on large networks that have high levels of traffic. The network hardware that is different requires special treatment by software. Digital
Equipment Corporation recommends that you not attempt to directly program
the hardware interface. It is recommended that applications use the MSNetwork session level interface, DECnet-DOS session level interface, and the
Data Link interface to access the network.
For more information about the VAXmate network hardware, see chapter 13.

18 - 2

Introduction

Datalink
The Datalink is implemented in VAXmate ROM code. The datalink interface,
which is used by all upper levels of the VAXmate network, provides a hardware
independent interface for accessing the network. The Datalink is the lowest
supported interface through which applications access the Thin Wire network
and it is capable of managing multiple network streams. Applications can
access the datalink concurrently with the DECnet-DOS and MS-Network
sessions.
The VAXmate ROM code also contains a subset of the DECnet Maintenance
Operation Protocol IMOPI. This protocol allows the booting of a VAXmate
workstation from a host machine located on the network and provides loopback
functions to support network trouble shooting.
Local Area Transport
The Local Area Transport (LATllets the VT220 and VT240 terminal emulators
and MS-Windows serial communication applications to access VAXNMS
systems using the ThinWire Ethernet network. The LAT module implements
the DIGITAL proprietary LAT protocol for Ethernet networks. With this protocol, applications that normally used serial communication lines into VAXNMS
hosts can be written to use the Thin Wire Ethernet.
For many VAXNMS communications applications the LAT interface eliminates
the need for a serial line or a modem between the VAXmate workstation and
its host.
DECnet-DOS Session Level
DECnet-DOS is the center of the RAM resident network software. Application
programs can directly access all DECnet-DOS services. In particular,
transparent task-to-task communications can be implemented between applications running on different network nodes.
For a full description of DECnet-DOS, its application visible interfaces, and its
supporting utilities, refer to DECnet-DOS Programmer Reference Manual and
DECnet-DOS User Guide.
MS-Network Session
The MS-Network Session is a DIGITAL-developed emulation of the Microsoft
MS-Network session level interface. The MS-Network session level interface is
lets application programs created to run with Microsoft MS-Network execute.
The emulation uses the DECnet.-DOS programming interface to access the network. The MS-Network protocol is treated as an application level protocol in
the DECnet environment.
The MS-DOS REDIRECTOR interfaces to the MS-Network Session Level
emulator for network file access and network printing.
Introduction

18 - 3

Documentation List
For further reading on DECnet-DOS refer to:
•

DECnet·DOS Programmers Reference Manual

•

DECnet·DOS Users Guide

For further information on Microsoft MS-Network software or the Session
Level interface refer to:
•

ServerlRedirector File Sharing Protocol (Microsoft Corporation), which
describes in detail the Server Message Block protocol that is used by
the Redirector for accessing remote file and print services.

•

Microsoft Network Session Layer Interface (Microsoft Corporation),
which describes the interface between the session and higher layers of
the Microsoft Network.

•

MS-Network Version 1.0 documentation

For Further information on the DIGITAL Network Architecture refer to the
following Digital DECnet publications:
•

DNA General Description

•

DNA Session Control Functional Specification

•

DNA Routing Functional Specification

•

DNA Maintenance Operations Functional Specification

•

DNA Network Management Functional Specification

•

DNA Data Access Protocol WAP) Functional Specification

•

The Ethernet, A Local Area Network, Datalink Layer and Physical
Layer Specification

18 - 4

Introduction

Datalink
The datalink layer is that portion of the DNA architecture that lies between
the routing layer and the physical network hardware. The purpose of the
datalink is to provide a hardware independent set of services for use by higher
levels of network software and special application programs. Software that
directly accesses the datalink interface is called a client of the datalink. In the
VAXmate DECnet implementation, the routing layer is a client of the datalink.
The Local Area Transport software also is a client of the datalink. Multiple
clients can access the data link services simultaneously.
The VAXmate workstation implementation of the datalink has two modules:
•

The datal ink module, which provides the client interfaces described in
this chapter. This datalink layer is independent of the underlying
Ethernet hardware used to implement the actual physical network.

•

The port driver module, which provides an unsupported interface to the
underlying hardware. The port driver is specific to the Ethernet hardware implementation.

The VAXmate datalink, in combination with the port driver. provides a complete program interface for accessing the Thin Wire Ethernet.
The datalink is independant of the operating system service. No operating
system services are accessed from within the datalink. Most of the VAXmate
data link code is resident in the same system ROM as the ROM BIOS and the
self-test diagnostic code. A small portion of the VAXmate datalink is implemented by the DLL.EXE program. which is a terminate and stay resident
module that runs as part of the VAXmate workstation network startup procedure. It initializes the data link and allocates RAM resident variable and buffer
storage.
An application interacts with the datalink through a portal. A portal is comprised of the state variables and data structures shared by a specific application
and the datalink for the reception or transmission of information over the network. Applications open and close portals as a part of their interaction with the
datalink.

Datalink

18- 5

The data link layer is responsible for multiplexing messages received from the
ThinWire Ethernet to the correct program client of the datalink. The multiplexing is done first by address and then by protocol type. The protocol type field
is the last 2 bytes of the Ethernet datalink header in non-802.3 compatible
mode. IEEE 802.3 compatible mode is treated as a protocol type.
The type of multiplexing is determined on a per portal basis and is specified
when the portal is opened.
If a portal is opened in IEEE 802.3 compatible mode. the multiplexing is done
based on the address. Only one 802.3 compatible portal can be enabled at a
time. The length field must be less than or equal to the maximum Ethernet
length of 1518(decimal).

Future versions of the VAXmate datalink may implement extensions to the
802.3 mode described in this chapter. Applications that use the 802.3 mode
described here may not work in future network environments.
All non-802.3 protocols are identified by protocol type values that are larger
than the maximum Ethernet packet length of 1518(decimal).
For the VAXmate workstation in the DIGITAL Ethernet environment, the multiplexing is done on both address and protocol type. The protocol type value
must be larger than the maximum Ethernet packet length of 1518(decimal).
In either case. the address is the station ID for the VAXmate workstation, or
the multicast address of one of the portals enabled for reception of multicast
messages.

Common Definition Formats
Throughout this chapter, C language constructs are used to describe the data
structures associated with accessing the services of the datalink.
The following terminology applies to the structures:
•

int is an unsigned 16 bit integer value.

•

uchar is an unsigned 8 bit value.

•

farptr is a double word pointer.

18 - 6

Datalink

Datalink Communication Block
Client software must define a Datalink Communication Block IDCBI as part of
the datalink interface definition.
The following C programming language structure describes the DCB. For many
datalink accesses, actual use of fields described here may not conform with expected meaning of the field names.
struct dcb
{

int portal_id;
/* The portal 1D for this request */
uchar source_address[6];
/* The source address */
uchar destination_address[6]; /* The destination address */
farptr *bh;
/* double word pointer to the buffer header */
int bl;
/* Buffer length */
int operation;
/* Used by each function differently */
uchar pad;
/* Pad flag used on open */
uchar mode;
/* Mode flag used on open */
farptr *line_state();
/* pointer to line state change routine */
farptr *rcv_callback();
/* pointer to received data routine */
farptr *xmit_callback();
/* pointer to transmitted data routine */
char max_outstanding;
/* Number of outstanding transmits/receives */
uchar ptype[2];
/* Protocol type */
int buffers_lost;
/* Number of buffers lost */
};

Multicast Address Format
Figure 18-2 describes the format of an Ethernet multicast address. A multicast
address is six bytes long. The Xs in the diagram represent address-specific bits.
Byte 0

Byte 1

Byte 2

Byte 3

Byte 4

Byte 5

17161514131211101765432101765432101765432101765432101765432101
1---------------1--------1--------1--------1--------1--------1
Ixlxlxlxlxlxlxl 1 1xxxxxxxx 1xxxxxxxx Ixxxxxxxx 1xxxxxxxx Ix xxxxxxxi
1______ ---______ 1________ 1________ 1________ 1________ 1-_______ 1

Figure 18-2 Multicast Address Format
The special case Broadcast Address is specified by a multicast address, where
all address bits equal 1.

Datalink

18 - 7

Byte 0, Bit 0 distinguishes a multicast address from a physical address.
Byte 0 <0>

= 1
= 0

This is a multicast address.
This is a physical address.

For example, 08 is a physical address, and 09 is a multicast address.

Software Capabilities
The datalink layer is that portion of the ISO/DNA architecture that is responsible for the multiplexing of messages from the Ethernet port driver to clients
of the datalink. This multiplexing is done on the destination address and protocol type fields of the Ethernet message.
User Call-Back Routines
The datalink invokes call-back routines that are specified in the DCB.
Call-back routines are required application-specific subroutines that are
dispatched to by the datalink. The routine is invoked by a FAR CALL. Within
the call-back routine, the client should not attempt to use any MS-DOS facilities and the client should not enable or disable interrupts. The call-back routine
must end with a FAR RETURN. The data link ensures that a call-back routine
is not called again until the previous call is complete with aFAR RETURN.
The routines are called by the datalink when an event occurs that indicates a
change in the Ethernet hardware. The event can be either an error, a receive
buffer filled, a transmit buffer sent, or a line state change. The datalink callback routines are described in the next sections.
Each call-back routine involves a data structure called the the User Call Back
block {UCB). The address of the UCB is passed to the client in the ES:BX
register.
The following C structure describes the UCB.
structure ucb
{

int
portal_id;
/* Portal 10 from the request */
uchar destination[6];
/* Destination address from the buffer header */
uchar source[6];
/* Source address from the buffer header */
farptr *buffer;
/* Pointer to the client buffer being returned */
int
bl;
/* NULL or byte length of received message */
uchar buffer_status; /* COMPLETE or ERROR */
uchar buffer_reason; /* Completion error reason or LINE_STATE_CHANGE */
};

18 - 8

Datalink

The UCB fields are further described below:
•

ucb.portaI _id is the portal ID of the request that led to this call-back.

•

ucb.destination corresponds to the first 6 bytes of the Ethernet frame
and to the destination field of the Ethernet packet.

•

ucb.source is the second 6 bytes of the Ethernet frame and corresponds
to the Ethernet address of the originating node.

•

ucb.bI is the count of client data bytes actually in the buffer on a receive request completion. Field ucb.bI has no meaning on a transmitted
message completion.

•

ucb.buffer is the address of the data portion of the transmit or receive
buffer that is being returned to the client.

•

ucb.buffer status indicates the status of the buffer and can be one of
the followmg values:
COMPLETE - Value = 1 - The request was completed.
ERROR - Value = 3 - The request encountered an error and could
not be completed.

•

ucb.buffer reason is a further explanation of the buffer status field and
attempts fo tell the upper layers why the operation was aborted.
For a transmit complete call-back routine with an ERROR status,
ucb.buffer reason is a byte of bit flags with the following meaning. Bit
set means-true.
765
1

Reserved

ILCAR 1 LCOL

EXC

2
1

BUF

UNDER 1

1 ___ 1 ___ 1 ___ 1 _____ 1 ______ 1 _____ 1 _____ 1 _______ 1

Bit 7-5:
Bit 4:
Bit 3:
Bit 2:
Bit 1:
Bit 0:

Reserved for future use.
The LCAR flag means the hardware lost the carrier signal
during the transmission.
The LCOL flag means the hardware detected a collision
which was after the slot time during the transmission.
The EXC flag means that too many collisions occurred
during the transmission. The hardware could not transmit
the packet and aborted the transmission.
The BUF flag means the hardware could not access the
bus during the transmission.
The UNDER flag means the hardware experienced an underflow error during the transmission of the packet.

For a line state change call-back, field ucb.buffer Jeason means:
LINE STATE CHANGED - Value = 3 - The line state is changed
from ON to some other state and therefore all connections are
aborted.
Datalink

18 - 9

The receive call-back routine UeB does not return ERROR status. All receive
errors are handled within the Ethernet hardware and data link layer.

18 - 10

Datalink

Line State Change Call-Back Routine
The line-state-change call back routine specified in the DCB is used to notify
the client of a state change on the Ethernet channel. Notification consists of
executing the call-back routine pointed at by the line state field of the DCB
structure. If this field contains a zero value, the dataTInk does not notify the
client application of a line state change.
When the datalink calls the line-state-change call-back routine, the ES:BX register pair points at the UCB. See the section "User Call Back Routines" for
more information on line-state-change call-backs.
Within the line-state-change call back routine, the client should not use any
MS-DOS facilities or enable or disable interrupts. The call-back routine must
end with a FAR RETURN. The datalink ensures that a call-back routine is not
called again until the previous call is completed with a FAR RETURN.
Receive
There is not an explicit receive function. Opening a datalink portal automatically sets the interface up for receiving information. The receive call-back routine is the mechanism by which the client is notified of a message received on
its behalf. Notification consists of executing the call-back routine pointed at by
the rcv callback field of the DCB structure.
When the receive call-back routine is called by the datalink, the ES:BX register
pair points at the UCB. See the section "User call-back Routines" for more
information on receive call-backs.
Within the receive call-back routine, the client should not attempt to use any
MS-DOS facilities or enable or disable interrupts. The receive call-back routine
must end with a FAR RETURN. The datalink ensures that a call-back routine
is not called again until the previous call is completed with a FAR RETURN.
The client should deallocate its receive buffers before exiting.
NOTE
If datalink clients do not return (dll deallocate) all

datalink transmit and receive buffers before exiting, the
datalink runs out of buffers and does not function
properly. This leads to serious network problems.
Transmit
The transmit function DLL TRANSMIT is discussed in the section "Datalink
Functions" in this chapter.

Datalink Functions
Client programs request services from the datalink through Interrupt 6DH.
After initialization, each time the datalink is accessed, the client program must
Datalink

18- 11

pass the address of the DCB in the form of a far pointer in registers ES:BX.
The client program must specify the function code in the AH register. Upon
return from a datalink request, the AX register contains the status of the
request.
Table 18-1 describes the function codes passed in register AH to call the datalink routines.
Table 18-1

Interrupt 60: Datalink Functions

Function

Value in
Register AH

Description

DLL INIT
DLL-OPEN
DLL-CLOSE
DLL-ENABLE MUL
DLL-DISABLE- MUL
DLL-TRANSMIT
DLL=REQUEST_ XMIT

OOH
01H
02H
03H
04H
05H
06H

DLL DEALLOCATE
DLL-READ CHAN
DLL-READ-PLIST
DLL-READ-PORTAL

07H
08H
09H
OAH

DLL READ COUNT
DLL-NETWORK BOOT

OBH
OCH

DLL ENABLE CHAN
DLL-DISABLE CHAN
DLL-START MOP

OOH
OEH
OFH

DLL STOP MOP

10H

DLL READECPARM

llH

DLL SETDECPARM

12H

DLL EXT LOOPBACK

13H

Initialize datalink and port driver
Open a data link portal
Close a datalink portal
Enable a multicast address
Disable a multicast address
Transmit an Ethernet message
Request a transmit buffer for an
Ethernet message
Deallocate buffer
Read the channel status
Read the datalink portal list
Read information about a datalink
portal
Read and/or clear counters
Request to boot from a network
server
Enable the Ethernet channel
Disable the Ethernet channel
Start MOP/Send a System ID
message
Stop MOP (documented in MOP
section)
Read the address of the
DECPARM string
Set the address of the DECPARM
string
Loopback a message through the
Ethernet hardware

18 - 12

Datalink

Datalink Return Codes
The datalink always returns with status from a client request for a service. The
status is returned in the AX register. The return value overwrites the function
code that was in AH. Table 18-2 describes the return code values returned to
the client software.
Table 18-2

Datalink Return Codes

Symbol Name

Value in
Register
AX

Description

SUCCESS

OOH

Successful completion.

INITIALIZATION FAILURE

01H

The hardware failed to
initialize.

CHANNEL NOT OFF

02H

The channel state was not off.
Set it off to execute this
function.

STATE OFF

03H

The channel state is off. Set it
on to execute this function.

ADDRESS NOT SET

04H

The address of the Ethernet
hardware is not set. Set it
before starting the port.

NO HARDWARE

05H

Reading from the Ethernet
hardware meaning that there is
none available, indicating a
hardware malfunction if there
is hardware.

BUFFER- TOO- SMALL

06H

On read counters, the buffer
that holds the counters is too
small to fit all the counter
values.

NONE AVAILABLE

07H

There are no more buffers
available.

NO RESOURCES

08H

There are no more resources
available for this request.

PROMISCUOUS
RECEIVER ACTIVE

09H

A promiscuous receiver is currently active, therefore the requested function is illegal.

Datalink

18 - 13

Table 18-2 Datalink Return Codes (cont.)
Symbol Name

Va]ue in
Register
AX

Description

NON EXCLUSIVE

OAH

UNRECOGNIZED PORTAL

OBH

Client attempted to enable promiscuous mode, but a promiscuous mode receiver is
already active, or another
portal has enabled a protocol or
multicast. Client attempted to
enable 802.3 compatible mode,
but another portal is currently
in 802.3 compatible mode.
The portal ID returned was not
recognized.

PROTOCQL_TYPE_IN_USE

OCH

The protocol type the client attempted to enable is in use for
another datalink portal.

NOT MULTICAST

ODH

The multicast address supplied
to enable multicast is not a
valid multicast address.

OUTSTANDING CALLS

OEH

Outstanding transmit or re~
ceive calls are pending, therefore the client may not close
the datalink portal.

NO- RECEIVE- BAD

OFH

The client specified reception of
bad frames to the datalink
layer and the hardware does
not support the function.

NONE OUTSTANDING

10H

There are no receive buffers to
be aborted.

NO EVENTS

llH

There are no events in the
event queue to be read.

STATE BROKEN

12H

The port driver could not initialize the port hardware.

18 - 14

Datalink

Table 18-2

Datalink Return Codes lcont.~

Symbol Name

Value in
Register
AX

Description

QUOTA_EXCEEDED

13H

The user buffer quota is exceeded. No more buffers can be
allocated to this portal.

ALREADY INITED

14H

The datalink layer is already
initialized. This is an INIT failure error, but the datalink is
still usable if the state is ON.

LB FAILURE

15H

The hardware failed to loopback data, indicating an
Ethernet hardware failure.

Datalink

18 - 15

Function OOH: Initialization (dll init)
Datalink intialization is automatically done when the DLL.EXE module is
loaded as a part of the network start up procedure. Under most circumstances,
an application should not attempt to initialize the datalink. This service is documented here for completeness. You should excercise caution if you decide to
replace DLL.EXE and initialize the datalink yourself. DIGITAL does not support the datalink interface if it is initialized by the application. Future versions
of the VAXmate workstation and the network software may require different
initialization parameters than those described here.
The datalink initialization function is invoked once at startup time to initialize
the datalink and port driver modules. Parameters to the initialization call are
the port driver and datalink buffer pool blocks. the maximum number of portals allowed, the maximum number of multicasts allowed, and the maximum
number of receive buffers allowed to be queued for a single portal.
Parameters

AH =
ES:BX =
CH =
CL =
DI =
DH =

OOH
Port driver buffer pool
Number of Port driver buffers
Number of transmit and receive rings as power of 2
Maximum number of open portals
Maximum number of multicasts allowed per portal

Returns
AX =

OOOOH
OOOlH
0014H

SUCCESS
INITIALIZATION FAILURE
ALREADY INITE-D

Use the following formulas to calculate the amount of buffer space required for
the port driver and datalink.

Where:
dlLsize

(MAX_OLL_PORTALS*(SIZE PLIST» +
(MAX_OLL_PORTALS*(SIZE OLL_POB» +
(MAX_OLL_PORTALS*MAX_MULTICAST*SIZE OF MULTICAST)
MAX_OLL_PORTALS
= 01
SIZE PLIST
= 5
SIZE OLL_POB
= 24
MAX_MULTICAST
= OH
SIZE OF MULTICAST = 6

18 - 16

Datalink

Recommended value is 8
Size of internal data structure
Size of internal data structure
Recommended value is 8
Ethernet constant

«MAX_ETHER_PACK + (SIZE BHEAD»*TOTAL_BUFFERS)+
(2~NUM_BUFFER_RINGS/2 * SIZE RECEIVE) +
(2~NUM_BUFFER_RINGS/2 * SIZE TRANSMIT) + JUSTIFY
MAX_ETHER_PACK
SIZE BHEAD

SIZE RECEIVE
SIZE TRANSMIT
JUSTIFY

= 8

1518
9

= 8

1514 byte of data + 4 bytes CRC
Size of internal data structure
Recommended value is 5
Size of hardware receive buffer ring
Size of hardware transmit buffer ring
Number of bytes for LANCE buffer alignment

Table 18-3 describes the recommended values for the datalink parameters.
Table 18-3

Recommended Values for Datalink Parameters

Symbol Name

Value

Meaning

MAX PROTOCOLS

The maximum number of protocol types that may be enabled at
one time

MAX MULTICAST

The maximum number of multicast addresses that may be
enabled at one time

MIN Ethernet PACKET

The minimum Ethernet packet
size including the datalink header
and checksum (60 data+4 CRC
bytes)

MAX Ethernet PACKET

1518

The maximum Ethernet packet
size including datalink header
and checksum (1514 data+4
bytes CRC)

MAX PORTALS

The maximum number of
datalink portals allowed to be
opened at any time

Datalink

18 - 17

Function OlH: Open a Datalink Portal (dll open)
The open function opens a portal so the client can transmit and receive frames
from the Ethernet port driver. This routine, which is called with a DCB, expects the 'pad' flag to be set to PAD if padding is to be used and NO PAD if
it is not.
If the mode flag is PROMISCUOUS _MODE, no other portals are allowed to

open.
Parameters

AH =
ES:BX =

OlH
far pointer to DCB
dcb.pad =

PAD or NO PAD.

dcb.mode =

802 COMPATABLE or Ethernet or
PROMISCUOUS MODE.
Protocol type to enable if not
promiscuous.
Address of line state change routine
or O.
Address of receive call-back routine .

dcb.ptype =
dcb.line state =
deb. rev callback =
dcb.xmit callback =
deb. max_outstanding =

Address of transmit call-back routine.
Maximum number of outstanding
buffers.

Returns

AX =

18 - 18

OOOOH 0003H 0008H 0009H OOOCH OOOAH -

Datalink

SUCCESS with deb. portal id as the portal ID
STATE OFF
NO RESOURCES
PROMISCUOUS RECEIVER ACTIVE
PROTOCOL TYPE IN USENON EXCLUSIVE- -

The DCB fields and return values are described in the following section:
•

•

deb.pad indicates whether frames are to be padded out to minimum
Ethernet frame size or not.
NOPAD

value = 0

Do not pad messages out to minimum Ethernet length.

PAD

value = 1

Pad the Ethernet messages on
this portal out to minimum length
if they are less then the Ethernet
minimum size. Padding must be
agreed upon by both sides or else
the remote side does not know to
de-pad the packet.

deb.mode indicates the mode in which the portal is to be opened.
Certain events and routines act differently in IEEE 802.3 compatible
mode than they do in Ethernet compatible mode. The major difference
is that in IEEE 802.3 compatible mode. the protocol-type field is set to
the actual amount of user data in the frame. The header and CRC bytes
are not included in this byte count. Protocol-type multiplexing cannot
occur because there is no protocol-type field.
802 COMPATABLE - value = 0 - Open a datalink portal in 802.3
compatible mode.
Ethernet - value = 1 - Open a datalink portal in Ethernet
compatible mode.
PROMISCUOUS MODE - value 2 - Open a datalink portal in promiscuous mode. -

•

deb.ptype indicates the protocol type to enable on this portal.

•

deb.linestate indicates the address of the line-state-change routine. If
the client does not want to be notified of line-state changes, the client
should specify a 0 for this double word routine pointer.

•

deb.rcv callback indicates the address of the routine the datalink calls
when a-buffer comes in for the client. A valid address must be specified.

•

deb.xmit callback indicates the address of the routine the datalink calls
when a Duffer that this portal has queued for transmission either aborts
due to an error, or is successfully transmitted.

•

dcb.max outstanding indicates the portals quota for the number of buffers, including transmit and receive buffers, that can be outstanding at
anyone time. If the client specifies a quota of zero, a default quota of
one receive and one transmit buffer is given. If the client specifies a
quota larger than the number of buffers allocated on the dll init call
and no other datalink clients exist, the number of buffers used in
dll init are allocated to the caller. This means the client can effectively
use all of the datalink buffer space. If other data link clients already
exist and the caller asks for more buffers than are available. the caller
is given the buffers that remain.
Datalink

18- 19

•

SUCCESS indicates that a portal is open and therefore dcb.portal id is
set to a valid portal ID.
-

•

NO RESOURCES indicates that there were not enough resources to
open another portal.
STATE OFF indicates that the channel is currently off or broken, and
therefore no opens are .allowed.

•
•

PROMISCUOUS RECEIVER ACTIVE indicates that there is a promiscuous receiver-active and tnerefore no other portals may be opened
at this time.

•

PROTOCOL TYPE IN USE indicates that the protocol type you tried
to enable was already in-use by another portal.

•

NON_EXCLUSIVE indicates on of the following:
You tried to enable promiscuous mode with a promiscuous receiver
active.
You tried to enable another 802.3 compatible portal when there was
already an 802.3 mode compatible portal enabled.

18 - 20

Datalink

Function 02H: Close a Datalink Portal (dll close)
The close function closes an open Ethernet portal and releases all of its resources. A portal cannot be closed unless all outstanding transmit and receive
requests are completed.
Parameters
AH =
ES:BX =

02H
far pointer to DCB
dcb.portal_id =

Portal ID from open

OOOOH OOOBH OOOEH -

SUCCESS
UNRECOGNIZED PORTAL
OUTSTANDING CALLS

Returns
AX =

The DCB field and return values are described below:
•

dcb.portal_id is the portal ID from the open call that you want to close.

•

SUCCESS indicates that the portal is successfully closed. Any references to this portal return the UNRECOGNIZED _PORTAL error.

•

UNRECOGNIZED PORTAL indicates that the portal ID is not a valid
open datalink portalID.

•

OUTSTANDING CALLS indicates that the portal could not be closed
because there are-incomplete transmit or receive requests on this portal.

Datalink

18 - 21

Function 03H: Enable Multicast Addresses (dll enable mul)
The enable multicast request is made to enable reception of frames addressed
to a specific group address (a multicast address) for this portal.
Parameters
AH =
ES:BX =

03H
far pointer to DCB
dcb.portal_id =
dcb.source address =

The portal ID from the open
call
multicast address to be enabled

Returns
AX =

OOOOH OOODH 0008H OOOBH 0009H
0003H -

SUCCESS
NOT MULTICAST
NO RESOURCES
UN-RECOGNIZED PORTAL
PROMISCUOUS RECEIVER ACTIVE
STATE OFF

The DCB fields and the return values are described below:
•

deb. portal id is a valid datalink portal ID on which this multicast address is to be multiplexed.

•

deb.souree address is the multicast address to start receiving messages
for.
NOTE
If you specify the broadcast address, FF-FF-FF-FF-FF-FFH, no
error is returned. This address is not displayed as part of the
Read Portal Status function. However, the Broadcast Address is
always enabled for this portal.

•

SUCCESS indicates that the multicast address is enabled for this
portal.

•

NOT MULTICAST indicates that the address specified in the source
address was not a valid multicast address.

•

NO RESOURCES indicates that there are currently not enough resources to filter another multicast address for this portal.

•

UNRECOGNIZED PORTAL indicates that the portal ID specified in
the DCB was not a-valid open datalink portal.

18 - 22

Datalink

•

PROMISCUOUS RECEIVER ACTIVE indicates that there is currently
a promiscuous receiver, and, therefore, no protocol types or multicast
addresses are enabled.

•

STATE OFF indicates that the channel state was set to BROKEN or
OFF. Tne channel state must be ON to filter multicast addresses.

Datalink

18 - 23

Function 04H: Disable Multicast Addresses (dll disable mul)
The disable multicast function request indicates that a client no longer wants
to receive frames for the specified multicast address through this portal.
Parameters
AH =
ES:BX =

04H
far pointer to DCB
deb. portal id =
deb. source address =

Portal ID from open call
Multicast address to be disabled

Returns
AX =

OOOOH OOOBH -

SUCCESS
UNRECOGNIZED PORTAL

The DCB fiel~s and the return values are described below:
•

deb.portal_id is a valid portalID returned by the open function on
which the multicast address is to be disabled.

•

deb.souree address is the multicast address to be disabled.

•

SUCCESS indicates that the multicast address is no longer multiplexed
for this portal.

•

UNRECOGNIZED PORTAL indicates that the portal id did not correspond to a valid open datalink portal.

18 - 24

Datalink

Function 05H: Transmit (dll transmit)
The transmit function queues a frame for transmission. The client is notified at
the call back address when the transmission is completed. Notification consists
of executing the call-back routine pointed at by the xmit callback field of the
DCB structure. When the transmit call-back routine is cailed by the datalink,
the ES:BX register pair points at the UCB block. See the section "User callback Routines" for more information on transmit call-back routines.
Within the transmit call-back routine, the client should not attempt to use any
MS-DOS facilities or enable or disable interrupts. The transmit call-back routine must end with a FAR RETURN. The datalink ensures that a call-back
routine is not called again until the previous call has completed with a FAR
RETURN.
No abort transmit function is provided because transmission always succeeds or
fails within a short period of time.
NOTE
If datalink clients do not return (dll deallocate I all datalink

transmit and receive buffers before exiting, the datalink runs
out of buffers and does not function properly. This leads to
serious network problems.
A client application can supply its own buffer for transmission or request a
buffer from the datalink using the Request Transmit Buffer function. Client
supplied buffers do not have to be deallocated to the data link before exiting.
Parameters
AH =
ES:BX =

05H
far pointer to DCB

dcb.portal_id =

The portal ID from the open call

deb. destination address =

Address of remote node

dcb.ptype =

Protocol type or NULL

dcb.bh =

Pointer to the buffer to be sent

dcb.bI =

The buffer length excluding the
datalink header

Datalink

18 - 25

Returns

AX=

OOOOH 0008H OOOBH 0003H -

ES:BX =

Far pointer to User call-back Block.
See the section "User call-back Routines" for further
information.

SUCCESS
NO RESOURCES
UNltECOGNIZED PORTAL
STATE OFF
-

The DCB fields and the return values are described below:
•

deb.portal_id is the portal ID returned by the open call.

•

deb.destination address is the 6 byte address to which this transmission
is to be sent. This address can be a physical address, a multicast address, or the broadcast address.

•

deb.ptype is the protocol type field in Ethernet compatible mode. It is
ignored in the IEEE 802.3 compatible mode. In IEEE 802.3 mode the
type field is used for the frame length.

•

deb.bh is the pointer to a buffer to be transmitted.

•

deb.bl is the length of the client data in the buffer. The length does not
include the datalink header length.

•

SUCCESS indicates that the buffer is successfully queued for
transmission. The client is notified at the transmit complete call back
routine supplied as part of the calling sequence.

•

NO RESOURCES indicates that there are currently not enough resources to queue the buffer for transmission.

•

UNRECOGNIZED PORTAL indicates that the portal id supplied is not
a valid open dataliri'k portal.
STATE OFF indicates that the Ethernet channel on which this portal
has been opened is currently not turned on.

•

18 - 26

Datalink

Function 06H: Request Transmit Buffer Function
(dll request xmit)
Therequest transmit buffer function allocates a data link transmit buffer. Once
a buffer is allocated, the client owns the buffer until it returns the buffer via
the deallocate buffer function. The client should return all allocated buffers to
the datalink before exiting.
NOTE
If datalink clients do not return (dll deallocate) all datalink

transmit and receive buffers before exiting, the datalink runs
out of buffers and does not function properly. This leads to
serious network problems.
A client application can supply its own buffer for transmission. The client does
not need to request a transmit buffer from the datalink layer. Client supplied
buffers do not have to be deallocated to the datalink before exiting.
Parameters
AH =
ES:BX =

06H
far pointer to DCB
dcb.portal_id =

The portal 10 from the open call

Returns
AX =

OOOOH 0008H OOOBH 0003H -

dcb.bh =

The address of the buffer into which a client can place a
message

SUCCESS
NO RESOURCES
UN-RECOGNIZED PORTAL
STATE OFF
-

The DCB fields and the return values are described below:
•

dcb.portal_id is the portal 10 to which the buffer is to be allocated.

•

dcb.bh is the address of the buffer in which the data is to be placed
when transmitting a frame.

•

SUCCESS indicates that a buffer address is returned to the user.

•

NO RESOURCES indicates that there are currently not enough resources to process this request.

•

UNRECOGNIZED PORTAL indicates that the portal 10 provided is
not a valid datalink-portal 10.

•

STATE_OFF indicates that the channel is currently not turned on.
Datalink

18 - 27

Function 07H: Deallocate Buffer (dll deallocate)
The deallocate buffer request is made to return a data buffer to the datalink
layer. The buffers returned are transmit buffers and receive buffers.
NOTE
If data link clients do not return (dll deallocate) all buffers before

exiting, the datalink runs out of buffers and does not function
properly. This leads to serious network problems.
Parameters
AH =
ES:BX =

07H
far pointer to DCB
deb. portal id =
dcb.bh =-

Portal ID returned by open
Address of buffer to free up

Returns
AX=

OOOOH OOOBH -

SUCCESS
UNRECOGNIZED PORTAL

The DCB fields and the return values are described below:
•

deb. portal id is the portal ID on which receive and transmit buffers are
to be returned.

•

dcb.bh is the address of the data buffer the client wants to return to
the datalink buffer pool. The buffer should be one that was previously
given to the client as part of a receive call-back sequence or the requesttransmit buffer (dllJequest _ xmit) call.

•

SUCCESS indicates that the function completed successfully and all
buffers are returned.

•

UNRECOGNIZED PORTAL indicates that the portal ID supplied was
not a valid open datalink portal.

18 - 28

Datalink

Function 08H: Read Channel Status (dII read chan)
The read channel function is the network managementinterface to read information about a specified channel from the port driver. A channel corresponds
to a physical Ethernet port. This is equivalent to a hardware controller. The
VAXmate workstation has only one hardware Ethernet port.
Parameters
AH =
ES:BX =

08H
far pointer to DCB

Returns
AX =

OOOOH -

SUCCESS with:

dcb.source address =

Physical address

dcb.destination address =

Hardware address

dcb.operation =

STATE(ON ,OFF,INIT,BROKEN)

dcb.mode =

Reserved

dcb.pad =

Hardware interrupt vector
number

dcb.max_outstanding =

MOP Status

The DCB fields and the return values are described below:
•

SUCCESS indicates that the function completed successfully, and the
following locations in the DCB have been set.
deb.souree address is set to the current physical channel address
which is tile address the channel is currently using.
deb.destination address is set to the hardware address associated
with the channel. This mayor may not be the same as the physical
address.
deb.operation is set to the current state of the datalink and can be
one of the following:
State

Value

Meaning

OFF
ON
INIT
BROKEN

0
1
2
3

The datalink state is now off.
The datalink state is now on.
The port hardware is initializing.
The datalink failed to initialize.
Datalink

18 - 29

deb. mode is reserved.
deb. pad is the interrupt vector which the Ethernet hardware is
using to get its interrupts.
deb.max outstanding is a mask which indicates the current status
of the Maintenance Operations Protocol module, MOP. It has the
following form:

MOP STATUS MASK
7

543

Reserved

CONSOLE

LOOPBACK

1
1
1
1
1 ___ 1 ___ 1 ___ 1 ___ 1 ___ 1 ___ 1 _________ 1 __________ 1

LOOPBACK indicates that the LOOPBACK server is enabled when
a ONE is in this field.
CONSOLE indicates that the remote console is enabled when a one
in this bit.

18- 30

Datalink

Function 09H: Read the Portal List (dll read plist)
This is the network management function usedto obtain a list of open portal
IDs. It returns them in the buffer specified as its argument. If there is not
enough space in the buffer, a partial list is returned, along with an error.
Parameters

AH =
ES:BX =

09H
far pointer to DCB
dcb.bh =

Buffer to receive portal ID list

dcb.bl =

Buffer length in 16 bit words

Returns
AX =

SUCCESS
0006H - BUFFER TOO SMALL
Number of portals returned on SUCCESS
Current datalink state
OOOOH -

deb.bl =
deb. operation =

The DCB fields and the return values are described below:
•

deb.bh is the address of the buffer to receive portal IDs. Each portal ID
occupies one word in the buffer.

•

deb.bI is the number of words held by the buffer. Note that this is not
the number of bytes. It is actually the number of portal IDs that can be
placed into the buffer.

•

deb.operation is set to the current state of the datalink and can be one
of the following:
State

Value

Meaning

OFF
ON
INIT
BROKEN

The data link state is now off.
The datalink state is now on.
The port hardware is initializing.
The datalink failed to initialize.

1
2
3

•

deb.operation is the current datalink state.

•

SUCCESS indicates that the function was successfully completed and
the buffer now has the list of portal IDs.

•

BUFFER TOO SMALL indicates that there were more portal IDs than
the buffer-Iengtli argument allowed for. An incomplete list is returned.

Datalink

18 - 31

Functions OAH: Read the Portal Status (dll read portal)
The read portal function reads portal data base information for a given portal.
Parameters
AH =
ES:BX =

OAH
far pointer to DCB
dcb.portal_id =

Portal ID from open call

dcb.bh =

Address of portal status buffer

dcb.bl =

Size of portal status buffer

Returns
AX =
dcb.bl =

OOOOH - SUCCESS
OOOBH - UNRECOGNIZED PORTAL
0006H - BUFFER TOO SMALL
number of multicast addresses

The DCB fields and the retllrn values are described below:
•

deb.portal_id is th~ portal id whose data base you want to read from.

•

dcb.bh is a pointer to the portal status buffer. When the function call
returns, this bqff"r has all the information about the portal. The format
of the read portal information buffer is outlined below.

•

deb.bl is the length of the buffer in which the portal status is to be
returned. If there is not enough space in the buffer, a partial list is
returned along with the BUFFER_TOO_SMALL error.

•

SUCCESS indicates that the routine has read the data base successfully
and the information is returned.

•

UNRECOGNIZED PORTAL indicates that the portal ID was not
recognized by the clatalink layer as being that of a valid portal.

•

BUFFER TOO SMALL indicates that the buffer was too small so only
a partial lIst was returned.

18 - 32

Datalink

The format of the buffer that the dllJead _portal function returns to the caller
is:
struct

portal_status

{

int
uchar
uchar

lost_buffers;
enabled_protocol_type[2] ;
enabled_multicasts[MAXMULTICAST] [6] ;

};

Where:
lost buffers

Is a two-byte count of the client buffers that are lost.

enabled _protocol_type

Is a two-byte description of enabled protocol type for
this portal.

enabled multicasts

Is a return list of enabled multicast addresses. The
size of the list is always MAXMULTICAST multiplied
by 6 bytes per multicast address. The enabled multicast addresses appear first in the list. The rest of the
entries are all zero.

Datalink

18 - 33

Function OBH: Read the Datalink Counters (dll read count)
The read counters function reads the system counters and optionally clears
them all.
Parameters
AH =
ES:BX =

OBH
far pointer to DCB
deb. operation =
dcb.bh =

[CLEAR! NULL]
Address of the buffer to hold the
datalink counters

Returns
AX =

OOOOH -

SUCCESS { never returns error I

The DCB fields and the return values are described below:
•

•
•

deb.operation tells the datalink layer that after the counters are read,
all the counters should either be cleared {CLEAR=11 or not cleared
{NULL=OI.
deb.bh points to a buffer which is to hold the datalink counters.
SUCCESS indicates that the specified counters were read and placed
into the client supplied buffer.

The data link layer maintains several counters for diagnosing network related
problems. The datalink counters structure is listed below:
struct datalink_counters
{

int
long
long
long
long
long
long
long
long
long
uint
uint
uint
u:int

18- 34

seconds_since_zeroed;
bytes_received;
bytes_transmitted;
frames_received;
frames_sent;
multicast_bytes_received;
multicast_frames_received;
blocks_sent_initially_deffered;
blocks_sent_single_collision;
blocks_sent_multiple_collisions;
send_failures;
send_failure_mask;
receive_failures;
receive_failure_mask;

Datalink

uint
uint
uint
uint
uint

unrecognized_frame_destination;
data_overrun;
system_buffer_unavailable;
user_buffer_unavailable;
collision_detect_check_failed;

};

The datalink counters fields are described below:
•

seconds_since_zeroed (16 bitsl counter is reserved for future use.

•

bytes received (32 bitsl counter indicates the total number of bytes receivea by the port hardware successfully.

•

bytes transmitted (32 bitsl counter indicates the total number of bytes
transmitted by the port hardware excluding the data link header bytes.
It does not include bytes caused by datalink layer retransmission of
messages.

•

frames received (32 bitsl counter indicates the number of frames received oy the datalink.

•

frames sent (32 bitsl counter indicates the number of frames
transmitted by the datalink.

•

multicast bytes received (32 bitsl counter counts the number of frames
received that were addressed to multicast addresses.

•

multicast frames received (32 bits) counter counts the number of
frames received from multicast addresses.

•

blocks sent initially deferred (32 bitsl counter is the total number of
times that aframe was deferred on its first attempt. This counter is
maintained by the port driver. This counter is not available for all
hardware.

•

blocks sent single collision (32 bitsl counter is the total number of
times that frame-was successfully sent on the second attempt after
its first collision. this counter is maintained by the port driver.

•

blocks sent multiple collisions (32 bitsl counter is the total number of
times frame was transmitted successfully after experiencing multiple
collisions on the Ethernet. This counter is maintained by the port
driver. This counter is not available for all hardware.

•

send failures (16 bits) counter is the total number of times a transmit
failed to occur. The reason for the failure is specified by the
send failure mask field.

•

send failure mask (16 bits) is a bit mask that determines what types of
errors occurred that causes the transmit failure counter to increment.

Datalink

18 - 35

Bit

Reason

Description

15-6

Reserved for furture use
Remote failure to defer A collision was detected after
the slot time for the Ethernet
wire.
4
Frame too long
The frame to be transmitted
was to long to fit into the maximum length Ethernet message.
Open Circuit
There is a short or open circuit
3
on the Ethernet wire.
Short Circuit
There is a short or open circuit
2
on the Ethernet wire.
1
Carrier check failed
The hardware could not detect
the Carrier on the line, so no
transmission was made.
o
Excessive collisions
A node experienced more than
the allowed number of collisions
and aborted the transmission.
receive failures U 6 bits) counter indicates the total number of frames
receivea with some form of data error. The reason for the failure is
specified in the Receive Failure Mask field.
receive failure mask (16 bits) is a bit mask which contains the reason(s)
that the receive failure counter has been incremented.
Bit
Reason
Description
5

•
•

15-3

The length of the receive data was
greater than the maximum
Ethernet message size.
1
Framing error
Both an odd number of bits was
received and a eRC error occured.
o
Block Check (CRC) A CRC error was detected in the
Error
receive data.
unrecognized frame destination (16 bits) counter indicates the total
number of times a frame was discarded because there was no portal
with the protocol type (non-802 compatible mode) or multicast address
enabled. This includes frames received for the physical address, broadcast address, or a multicast address.
data overrun (16 bits) counter is the total number of times the hardware-lost a frame because it could not keep up with the data rate. This
counter is maintained by the port driver. This counter is not available
for all hardware.
system buffer unavailable {I6 bits) counter is the total number of times
a frame was ruscarded because the datalink had insufficient internal
buffers to receive a message from the hardware. This counter is maintained by the port driver.
2

•

18 - 36

Reserved for
future use
Frame too long

Datalink

•

user buffer unavailable (16 bitsl counter is the total number of times a
frame was aiscarded because a client application buffer was not available to store the message.

•

collision detect check failed (16 bits I indicates the approximate number
of times-that cOllision -detect was not sensed after a transmission. This
counter is maintained by the port driver.

Datalink

18- 37

Function OCH: Network Boot Request (dll network boot)
This function is called to request a remote boot ofthis node from another node
on the network. It does not return unless the boot request fails to find a suitable boot server to boot the node. If the boot request succeeds, the datalink
state is left ON and the Maintenance Operation Protocol, MOP, portal ID is
opened and enabled. If the boot request fails, the datalink and port driver are
left in the OFF state and need to be initialized.
Further information on network booting is presented in the MOP section of
this chapter.
Parameters
AH =
ES:BX =

OCH
Far pointer to DCB

Returns
AX =

18 - 38

OOOOH -

Datalink

SUCCESS ( never returns error I

Function ODH: Enabling a Channel Function (ddl enable chan)
The enable channel function is called by the network management software to
turn on an Ethernet channel, as well as set the station ID used by the
Ethernet hardware.
Parameters
AH =
ES:BX =

ODH
far pointer to DCB
dcb.source address = address to set

Returns
AX =

OOOOH 0004H OOODH -

SUCCESS
ADDRESS NOT SET
NOT MULTICAST

The return fields are described below:
•

SUCCESS indicates that the channel is now enabled. A channel that
has been enabled is not necessarily usable. The caller can determine the
actual state of the channel by issuing the read_channel function.

•

ADDRESS NOT SET indicates that the physical address for the channel is not set yet;-and therefore the channel cannot be enabled.

•

NOT MULTICAST indicates that the address that you attempted to
enable as your station ID was a multicast address, and it should be a
physical address. If this error occurs, and an address was previously set,
the previous address is still recognized as the station ID.

Datalink

18 - 39

Function OEH: Disabling a Channel (dll disable chan)
The disable channel function is invoked to put the channel into the OFF state.
Parameters
AH =
ES:BX =

OEH

Far pointer to DCB

Returns

AX=

OOOOH -

SUCCESS tnever returns error)

The return field is SUCCESS, which indicates that the channel is disabled.

18 - 40

Datalink

Function IlH: Read Decparm String Address (dll readecparm)
This function is invoked to read the current DECPARM string address for the
datalink. The address is a pointer to the null terminated ASCII string that
describes the MS-DOS path to the DECnet data files. This path is where
DECnet-DOS looks for its data files.
Parameters
AH =
ES:BX =

llH
Far pointer to DCB

Returns
AX =

OOOOH -

SUCCESS I never returns error)

dcb.bh =

Address of DECPARM string

Datalink

18 - 41

Function 12H: Set Decparm String Address (dll setdecparm)
This function is invoked to set the DECPARM string address for the datalink.
This address points at null terminated ASCII string that describes the MSDOS path to the DECnet-DOS data files. This. path is where the DECnet
driver looks for its data files.
NOTE
If a client application modifies the DECPARM string address
while DECnet-DOS is loaded in the VAXmate workstation, the
network may fail.
Parameters
AH =
ES:BX =

12H
Far pointer to DCB
DCB.BH =

Address of DECPARM string

Returns
AX =

18 - 42

OOOOH -

Datalink

SUCCESS ( never returns error )

Function 13H: External Loopback (dll ext loopback)
This function invokes an external loopback test for diagnostic purposes. The.
function requires no arguments. If the hardware successfully loops the message,
the SUCCESS return is given. If the message is not looped or the function is
not supported, the LB FAILURE return is given. Loopback testing can be accomplished using a Loopback Terminator.
Parameters
AH =
ES:BX =

13H
far pointer to DCB

Returns
AX =

OOOOH
0002H
0015H

SUCCESS
CHANNEL NOT OFF
LB FAILURE

Datalillk

18 - 43

Maintenance Operation Functions
The VAXmate workstation implements a subset of the DIGITAL Network
Architecture Maintenance Operations capability, which is referred to as the
Maintenance Operations Protocol (MOP).
MOP services are used by network management software to assist in network
configuration determination and network problem diagnosis. The VAXmate
MOP implementation also provides for loading a system image from another
node on the Ethernet. This is provided to facilitate loading operating systems
or standalone applications from a host node.
The MOP functions implemented in the VAXmate workstation are:
•
•
•
•

Loop Services
Console Server Identify Self
Remote Read Counters
Network Boot Request

These functions are described in the following sections:
Loop Services
Loop services allow a remote node to loop a message through the client node.
The Loop Server functions are provided to allow the VAXmate workstation to
respond to MOP Loop Test requests from another system on the Ethernet.
These requests can be serviced at any time. The only requirement is that the
MOP process not be stopped. Servicing a MOP Loop Test request will not
affect the operation of other network software on the VAXmate workstation.
For further information on loop services refer to Digital Network Architecture
Maintenance Operations Functional Specification.
Console Server Identify Self
The Console Server Identify Self periodically sends the system identification
Il1essage and sends the system identification message to a requesting system.
This function is not visible to application software and is provided to allow this
VAXmate workstation to respond to MOP Request ID messages from another
system on the Ethernet. This request can be serviced at any time. The only
requirement is that the MOP process not be stopped. Servicing a MOP
Request ID message will not affect the operation of other network software on
the VAXmate workstation.
The VAXmate system periodically transmits an unsolicited system ID message
to the MOP multicast address. The message is transmitted at approximately 9
minute intervals. The messages are not transmitted if a portal is active in promiscuous mode.
18 - 44

Datalink

The VAXmate system ID message conforms to the Digital Network
Architecture MOP system ID message. The VAXmate workstation specific
fields are the Comm field with a value of 25(decimal), and the System
Processor Type field with a value of 7.
For further information on System ID message refer to Digital Network
Architecture Maintenance Operations Functional Specification.
Remote Read Counters
Remote Read Counters send Ethernet Data Link counters to the requesting
system. This function is provided to allow this VAXmate workstation to
respond to the MOP Request Counters message from another system on the
Ethernet. This request can be serviced at any time. The only requirement is
that the MOP process not be stopped. Servicing a MOP Request Counters
message will not affect the operation of other network software executing in
the VAXmate workstation.
The Counters are counts of events maintained by the Data Link. For further
information on Data Link counters refer to Digital Network Architecture
Maintenance Operations Functional Specification.
Network Boot Request
Network Boot Request requests a remote boot of this node. as part of the
VAXmate boot procedure. The default VAXmate boot sequence is the following:
1.

Attempt to boot from the floppy drive.

Attempt to boot from the optional Hard Disk.

Attempt to boot from the network.

Repeat the sequence.

A VAXmate network boot can only be initiated by powering on the system or
by a system reset (such as pressing Ctrl/Alt/Del). Another system on the
Ethernet cannot force a remote boot or a system reset of a VAXmate
workstation.
A successful network boot procedure is as follows.
1.

Send a MOP Request Program Load multicast message. Multicast address AB-OO-OO-O 1-00-00.

Nodes on the Ethernet that can perform program loads check their network databases against the Ethernet address of the requesting node. If
the address and an associated Load File specifier is found in the data
base, the load request can be serviced.
Datalink

18 - 45

The nodes that can service the request then volunteer to load the
VAXmate workstation. They volunteer by sending a MOP Assistance
Volunteer message to the Ethernet address of the VAXmate system.
3.

The VAXmate workstation sends a directed MOP Request Program
Load message to the physical Ethernet address of the first system it
receives an Assistance Volunteer message from.

The VAXmate system image is now transferred into the workstation.

For VAXNMS systems, target node Ethernet addresses and associated load
files are specified using the Network Control Program, NCP.
For further information on Remote Boot procedures refer to Digital Network
Architecture Maintenance Operations Functional Specification and VAXNMS
DECnet manuals covering network management topics.
NOTE
Currently VAXNMS systems require that the system image to
be loaded into a remote node be in a file format compatible with
RSX/ll-S down line load able images.

18 - 46

Datalink

Data Link Interface to the MOP Process
The Data Link interface supports two MOP functions.

Function OFH: Mop Start and Send System ID (dll start mop)
This function is called to send a MOP system 10 message. The first-time the
routine is called, it will also start the MOP Loopback server if it is not already
running. This function returns no errors.
Parameters
AH =
ES:BX =

OFH
far pointer to DCB

Returns
AX =

OOOOH -

SUCCESS I never returns error}

Function 10H: Mop Stop (dll mop stop)
This function is called to halt the operation of MOP and disable all protocol
and multicast message processing associated with the MOP process.
MOP STOP must be performed to enable promiscuous mode or take over any
of the MOP functions.
The MOP software continues to transmit periodic system 10 messages if the
MOP Remote Console Protocol Type is not being used by a client application
portal. The Digital Network Architecture requires a system 10 message
transmission every 10 minutes or less. If the client application uses the MOP
Remote Console Protocol Type and MOP is stopped, the application must implement periodic system 10 message function.
Parameters
AH =
ES:BX =

10H
far pointer to DCB

Returns
AX =

OOOOH -

SUCCESS f never returns error}

Datalink

18 - 47

Sample Datalink Session
This is an example of a code fragment that performs the following functions:
1.

Calls the enable channel function to turn the channel on and enable an
address.

Calls the data link open routine to open a datalink portal, enable a protocol type and specify a line state change call-back for the portal.

Enables multicast addresses.

Requests transmit buffers.

Transmits frames to the port driver.

Closes the portal.

This example assumes Microsoft C making use of the nontransportable
construct of far pointers.
/* Working DCB */
mop_mon_sysid ()
{

unsigned char hardware_address[6];
unsigned open_mode ,pad_mode ,ptypev[2] ;
unsigned char multicast_address [6] ;
extern int line_state_change_far{);
extern int receive_complete_far{);
extern int transmit_complete_far{);
unsigned char cchar;
struct BUFFERS

/* Hardware address */
/* Multicast to enable */

{

unsigned char used;
unsigned char far *buffer;
unsigned char dest[6],src[6] ;
} buffers;
/* First thing to do is read the channel state to get our current hardware ~
/* address.
read_channel_state{&dcb_blk_l);
for (j=O;j<6;j++) hardware_address[j]=dcb_blk_l.dest_address[j];
printf (II\nThe current hardware address is: II);
print_address{hardware_address);
buffer_state=dcb_blk_l.operation;
printf (II\nThe port state is now: II);

18 - 48

Datalink

/* Now enable the channel using the hardware address from the port driver */
if (give_error (enable_channel (&dcb_blk_1 ,hardware_address »

SUCCESS)
{

return -1;
}

/* Stop MOP from running */
/* Now that we have enabled the channel successfully, open a portal in
/* PADDED Ethernet MODE.
pad_mode=PAD;
open_mode=Ethernet;
ptypev[0]=Ox60;
ptypev[1]=Ox02;

*/
*/

/* Start of MOP Ptype */
/* End of MOP Ptype */

multicast_address [0] =Oxab;
multicast_address[1]=OxOO;
multicast_address [2] =OxOO;
multicast_address[3]=Ox02;
multicast_address [4]=OxOO;
multicast_address [5]=OxOO;
if «give_error(dll_open(&dcb_blk_1,
pad_mode ,open_mode ,ptypev,
line_state_change_far,
transmit_complete_far,
receive_complete_far,
segrg.cs,-1») != SUCCESS) return -1;

/* We now have an open portal, so lets enable a multicast address

/* We will now send a system ID message (NOT USING THE DATALINK FUNCTION)
/* By building the message and transmitting it.

*/
*/

give_error(dll_enable_multicast(&dcb_blk_1,&multicast_address[O]»;
send_system_id(&multicast_address[O]);
while (1)
{

if (buffers.used == 1) dump_system_id();
/* Free up buffer for datalink layer use.
deallocate_buffer (&dcb_blk_1 ,buffers. buffer) ;

Datalink

18- 49

/* This will break out of the loop when the first character is typed */
if (kbd16(&cchar) == 0) break;
}

dll_close(&dcb_blk_l);
dll_enable_mop(&dcb_blk_l);

/* Close the portal */
/* And start MOP */

}

send_system_id(destination.dcb)
uchar destination[] ;
{

int i;
unsigned char far *buffer;
if (allocate_transmit_buffer(&dcb_blk_l) == SUCCESS)
{

for (i=0;i<6;i++) dcb_blk_l.dest_address[il=destination[il
buffer=dcb_blk_l.bh_address;
pokeb(buffer_off.buffer_seg.SYSTEM_ID); /* Save opcode */
pokew(buffer_off+l.buffer_seg.l) ;
/* Receipt number
pokew(buffer_off+3.buffer_seg.l);
/* Maint version *.
pokeb(buffer_off+5.buffer_seg.3);
/* length */
pokeb(buffer_off+6.buffer_seg.3);
/* version */
pokeb(buffer_off+7.buffer_seg.l);
/* 1. */
pokeb(buffer_off+8.buffer_seg.0);
/* o */
pokew(buffer_off+9.buffer_seg.2);
/* Funcions availal
pokeb(buffer_off+ll.buffer_seg.2);
pokew(buffer_off+12.buffer_seg.Ox41) ;

/* length */

/* ... */

xmit_callback=-l;
transmit_frame(&dcb_blk_l.buffer.15) ;
while (xmit_callback != 0) {}
deallocate_buffer(&dcb_blk_l.buffer);
}

else
{

printf (II\nBuffer allocation error in send_systemid");
}
}

dump_system_id()
{

18 - 50

Datalink

ptr_mop_msg=(struct mop_header far *)buffers.bh_buffer;
if (ptr_mop_msg->msg_type == SYSTEM_ID)
{

ptr_mop_data=(unsigned char far *)ptr_mop_msg;
printf ("\n------ System ID Message -----");
display_nodes(buffer_number);
info_type=-1;
i=sizeof(struct mop_header);
while (info_type != 0)
{

info_type=ptr_mop_data[i]+(ptr_mop_data[i+1]«S);
i=i+2;
if (info_type == 0) break;
switch (info_type)
{

case 1:
i++;
printf ("\nMaintenance Ver: %d.%d.%d",
ptr_mop_data[i++] ,
ptr_mop_data[i++] ,
ptr_mop_data[i++]) ;
break;
case 2:
i++;
printf ("\nFunctions: II);
i2=ptr_mop_data[i]+
(ptr_mop_data[i+1]«S);
printf ("%x ",i2);
i=i+2;
Ox1) printf ("LOOP
if «i2 "Oxi)
II) ;

i f «i2 "Ox2)

Ox2) printf ("DUMP

i f «i2 " Ox4)

Ox4) printf ("PRIM

i f «i2 " OxS)

OxS) printf ("MBL

II) ;
II) ;
II);

if «i2"Ox10) == Oxl0) printf ("BOOT
II) ;

i f «i2 " Ox20)

Ox20) printf ("CC

if «i2 " Ox40)

Ox40) printf

II) ;

("DLC");
i f «i2" OxSO) == OxSO) printf ("CCR
II) ;

Datalillk

18- 51

break;
case 7:
printf (II\nHardware address: II);
i2=ptr_mop_data[i++];
for (il=O;il<i2;il++)
{
}

i=i+i2;
break;
default:
i2=ptr_mop_data[i++] ;
i=i+i2;
break;
}

}
}
}

#define TRANSMIT Ox0500
transmit_frame (dcb_blk,buffer_addr , length)
unsigned int far *buffer_addr;
int length;
struct dcb *dcb_blk;
{

dcb_blk->bl=length;
dcb_blk->bh_address=buffer_addr;
return do_dll_call (TRANSMIT ,dcb_blk) ;
}

#define READ_CHANNEL Ox0800
read_channel_state(dcb_blk)
struct dcb *dcb_blk;
{
}

#define ENABLE_CHANNEL OxOdOO
enable_channel (dcb_blk, address)
uchar address [] ;

18 - 52

Datalink

struct dcb *dcb_blk;
{

int i;
for (i=O;i<6;i++) dcb_blk->source_address [i]=address [i] ;
return do_dll_call(ENABLE_CHANNEL,dcb_blk);
}

#define ENABLE_MOP OxOfOO
#define DISABLE_MOP Ox1000
dll_enable_mop(dcb_blk)
struct dcb *dcb_blk;
{
}

dll_disable_mop(dcb_blk)
struct dcb *dcb_blk;
{
}

#define OPEN Ox0100
#define CLOSE Ox0200
dll_open (dcb_blk,pad,mode,ptypev,
line_state , transmit_complete , receive_complete ,
cS,max_out)
uchar pad,mode,ptypev[] ,max_out;
uint line_state ,transmit_complete ,receive_complete ,cs;
struct dcb *dcb_blk;
{

int i;
dcb_blk->pad=pad;
dcb_blk->mode=mode;
for (i=O;i<2;i++) dcb_blk->ptype[i]=ptypev[i];
dcb_blk->line_state_off=line_state;
dcb_blk->rcv_callback_off=receive_complete;
dcb_blk->xmit_callback_off=transmit_complete;
dcb_blk->line_state_seg=cs;
dcb_blk->rcv_callback_seg=cs;
dcb_blk->xmit_callback_seg=cs;
return do_dll_call(OPEN,dcb_blk);
}

dll_close(dcb_blk)
struct dcb *dcb_blk;

Datalink

18- 53

{
}

#define ENABLE_MULTICAST Ox0300
#define DISABLE_MULTICAST Ox0400
dll_enable_multieast(deb_blk,multi_address)
uehar multi_address[];
struet deb *deb_blk;
{

int i;
for (i=O;i<6;i++) deb_blk->souree_address[i]=multi_address[i];
return do_dll_eall(ENABLE_MULTICAST,deb_blk);
}

dll_disable_multieast (deb_blk ,multi_address)
uehar multi_address[];
struet deb *deb_blk;
{

int i;
for (i=O;i<6;i++) deb_blk->souree_address [i]=multi_address [i] ;
return do_dll_eall(DISABLE_MULTICAST,deb_blk);
}

#define TRANSMIT Ox0500

transmit_frame (deb_blk,buffer_addr , length)
unsigned int far *buffer_addr;
int length;
struet deb *deb_blk;
{

deb_blk->bl=length;
deb_blk->bh_address=buffer_addr;
return do_dll_eall(TRANSMIT,deb_blk);
}

#define ALLOCATE_TRANSMIT_BUFFER Ox0600
#define DEALLOCATE_BUFFER Ox0700
alloeate_transmit_buffer(deb_blk)
struet deb *deb_blk;
{

18 - 54

Datalink

}
~eallocate_bufferCdcb_blk,buffer_addr)

unsigned int far *buffer_addr;
struct dcb *dcb_blk;
{

dcb_blk->bh_address=buffer_addr;
return do_dll_callCDEALLOCATE_BUFFER,dcb_blk);
}

Datalink

18 - 55

Local Area Transport
The LAT Ethernet protocol is a DIGITAL proprietary protocol. This section
only describes the functional interfaces for use by VAXmate applications. It
does not describe the LAT protocol.
The Local Area Transport, LAT, module provides a means for terminal emulators and other programs to communicate with a VAX/VMS host system. This
communication is done over the ThinWire Ethernet. The LAT subsystem is designed to eliminate the need for serial communications cabling between a
VAXmate workstation and a VAXIVMS host system.
The LAT software is an MS-DOS terminate and stay resident module,
LAT.EXE. An application accesses the LAT functions by issuing software interrupts through INT 6AH. The LAT software uses the Data Link interfaces to
access the network.
The LAT software does not interfere with other network uses of the workstation. In particular, applications can simultaneously use the LAT services and
the MS-Network and DECnet-DOS interfaces. The VAXmate LAT interface
supports multiple virtual terminals and other related services, such as simple
data transfers with appropriate software. When coupled to a terminal emulator,
the LAT software can support VAX/VMS interactive terminal sessions in a
fashion similar to a LAT terminal server.
The LAT subsystem provides a service directory facility that supports VAX
cluster services. In a VAX cluster, the user logs onto a service offered by one
or more cooperating DECnet nodes as opposed to logging onto a specific node.
This allows logging on to occur independent of whether a particular node is
functioning or overloaded. In addition, in most VAX clusters the individual
nodes are themselves a service. This facilitates logging on to a particular node
in the cluster. VAXIVMS LAT software running on the VAXmate workstation
automatically selects the cluster node with the lightest load. This provides a
form of load balancing for interactive jobs.
The following sections describe:
•

LAT services

•

LAT data structures

•

LAT functions

•

Sample terminal program

18 - 56

Local Area Transport

LAT Services
This section describes various LAT services including:

•
•

•
•
•
•

LAT command line
Service directory
Sessions and slots
Session start
Data exchange
Flow control
call-back routines
Closing a session

LAT Command Line
Assuming a path is defined to LAT.EXE or lies within the current default subdirectory, the LAT software is invoked either from a batch file or by the user
typing LAT at the MS-DOS prompt. A second invocation has no affect and
does not install a second copy of the software. If there is insufficient memory
present, LAT exits with an error code of 8 returned to MS-DOS. No error
message is issued to the user.
Three command line switches are provided. If you leave out a switch or specify
a -1 switch value. the default is used. There is no provision for command lines
that exceed one line in length.
The command line switches are:
•

/D:nn
This switch is used to increase the default size of the LAT service directory. The value nn is an unsigned integer representing the number of
entries in addition to the default of 10 entries. Each additional entry
causes an extra 47 bytes of memory to be allocated rounded to the
nearest 16-byte paragraph. An entry is assumed to be one service offered by one node.
The maximum number of entries is 1054 (1044 + default). This reserves a total of approximately 49,072 bytes for the service table. If the
overflow call-back is not enabled, the only effect of a service table overflow is that new services are not added to the table.
The default size of the directory is 10 entries = 470 bytes.

Local Area Transport

18 - 57

•

IG: 1, 2, 3, 32 ...

This switch is used to reduce the overhead of servicing multicast service
announcement messages, or to prevent the service table from filling
with unwanted service names. This control uses LAT group codes to
disable selectively the processing of multicast messages. Group code
control is only advised when the number of services at a site routinely
exceeds available memory on the workstation.
Each number represents a LAT address group code. Groups are numbered from 0 to 255. If the IG: switch is used, only the specified codes
are enabled.
The default is all group codes enabled.
For example, to enable group codes 0,2,3 and 54, invoke the LAT software by typing:
LAT /G:O,2,3,54

•

IR:n
This switch is used to set the number of retransmits permitted for a
circuit. The default is eight retransmits allowed before the circuit is
stopped. The minimum is four and maximum is 255.

Service Directory
The VAXmate LAT software listens to the Ethernet for messages from host
systems offering LAT services. These are multicast Ethernet messages that
identify a LAT server. The frequency at which a server identification message
is transmitted is a function of the VAXNMS configuration.
When the VAXmate LAT software receives a LAT multicast message, the
sending service is added to the service table maintained by the software. If the
service table is full, the service name is not kept. and an appropriate error
message is returned by a LAT status call. An application can also enable a
call-back notification when this error occurs.
Under certain conditions, a LAT server can become unreachable. The VAXmate
LAT software detects this condition when the number of retansmits to the
server reaches the maximum specified by the IR switch. If this occurs, the
service table entry for the server is marked as unreachable. Subsequent
requests to read the table do not return this server name. The server name
again becomes readable when the server receives a multicast LAT service
message.
A LAT application program can read the service table through the 6AH software interrupt.
You can specify that a preferred LAT server be entered into the service table
at LAT.EXE startup time. This forces a preferred LAT server into the tables
and eliminates waiting for the multicast message to arrive.
18 - 58

Local Area Transport

At startup time. the LAT software attempts to read the DECNODE.DAT file.
Within DECNODE.DAT, you can specify preferred LAT service names, which
are entered into the service table. If the number of preferred service names
exceed the size of the startup service table size, the LAT software automatically increases the size of the table to accommodate the number of entries.
You can specify or delete preferred nodes using the DECnet-DOS NCP utility.
LAT Sessions and Slots
A LAT session is conducted between an application and a LAT server. The
VAXmate LAT software creates one virtual circuit between itself and a particular LAT server. A VAXmate application or multiple VAXmate applications that
want to communicate with that server, do so over the single virtual circuit.
The actual LAT data structure definitions use the term SLOT as an alternative
for the term SESSION. A LAT slot is a unit of data being transmitted or
received as a part of the session. Slots are data or buffers of data that are
being exchanged between an application and the LAT server.
The VAXmate LAT software supports up to 4 virtual circuits and a maximum
of 10 slots.
Session Start
To start or open a session, the application passes a pointer to a data structure,
LAT's Session Control Block. (SCB}. The LAT SCB contains the name of the
desired host service. The first open call to a particular service name creates a
virtual circuit. All subsequent opens to the same service name use the same
virtual circuit. The open call returns a handle (S-bit integer} to refer to the
session in subsequent functions.
The LAT Session Control Block, provided by the application, is used by the
LAT software to store data and control its flow between the VAXmate workstation and the host node.
NOTE
It is the responsibility of the application to pass valid SCBs and
handles across the LAT interface. Failure to pass valid SCBs
and handles can produce unpredictable results.

Local Area Transport

18 - 59

Data Exchange
After the session is established, data received for the application program is
made available one character at a time. Characters are obtained using the Read
Data function.
.
The LAT software can transmit multiple characters in a packet to the host.
However. application programs can only transmit one character at a time to
the LAT interface.
Flow Control
Flow control is handled automatically by the protocol.
LAT Call-Back Routines
Application programs can specify an address to be called when certain conditions occur. This is termed a call-back routine. These routines are specified in
the SCB.
The following considerations apply to all LAT call-back routines.
•

call-back routines are accessed by means of a 'far call' and must end
with a 'far return'.

•

At the time of the call, interrupts are enabled.

•

MS-DOS may be interrupted at Call Back time. Do not execute MSDOS functions from within a call-back routine.

•

A call-back on receive is done once for each receiyed data buffer. It is
not done for each character received.

•

A call-back on transmit is executed when the transmit buffer is completely emptied by the circuit logic.

Closing the LAT Session
When a session is terminated and no other sessions remain on the virtual circuit, the LAT driver shuts down the virtual circuit.
NOTE
Failure to explicitly close the LAT session can produce unpredictable results. The LAT software needs to know when the application has finished a session.

Data Structures
The following data structures are used to communicate information between an
application and the LAT software.
18 - 60

Local Area Transport

The LAT Session Control Block
The LAT SeB structure is set up by the application. It is used to control data
exchange across the LAT interface. The seB is pointed at by the ES:BX register pair when a Open Session request is issued. After the Open Session,
ES:BX should not point at the SeB; the session handle is sufficient to access
the LAT services. After a session is opened, the SeB cannot be moved.
The LAT SeB is described below:
SCB

STRUC

dervice
node
port
session_stopped
table_overflow
transmit_notify
receive_notify
session_status
slot_state
local_credit s
vcb_pntr

DB
DB
DB
DO
DO
DO
DO
OW
OW
DB
DO

18 DUP (0)
18 DUP (0)
18 DUP (0)
Address of a call-back routine
0
0
Address of a call-back routine
Address of a call-back routine
0
Address of a call-back routine
0

back_slot
forward_slot
rem_slot_id
loc_slot_id
slot_byte_count
remote_credits
tx_slot_data

OW
OW
DB
DB
DB
DB
DB

0
0
0
0
0
0

0
0
0
0

Pointer to Virtual Circuit Block
vcb_offset, vcb_segment.

255 Dup(O); Transmit buffer Contains the actual transmit data.
Number of entries on Slot_ptr_table.
4
Four is the recommended number.

num_occupied
next_rx_slot
cur_buf_slot
Rx_Slot_Pntr

DB
DB
DB
OW

0
0
0
0

Slot_ptr_table

OW
OW
OW
OW

OFFSET slot_1
OFFSET slot_2
OFFSET slot_3
OFFSET slot3

Start of table of 5 session
buffer offsets.

OFFSET slot_n

Four entries is the recommended
table size.

Local Area Transport

18- 61

slot_l
slot_2
slot_3
slot_4

DB
DB
DB
DB

259 DUP(O)
259 DUP(O)
259 DUP(O)
259 DUP(O)

Session buffer 1
Session buffer 2
Session buffer 3
Session buffer 4

slot_n

259 DUP(O)

Four buffers are recommended.

SCB

ENDS

The SCB structure is further described in the following section:
•

Service, which is initialized by the application, is the name of the service requested. This is in ASCII format terminated by a null byte 10).
The LAT software converts lower case to upper case.

•

Node is RESERVED for future use.

•

Port is RESERVED for future use.

•

Session Stopped, which is initialized by the application, is the address
of a routine to call when the session has been stopped.
If the field contains 0, no call-back notification is given.

The LAT call-back routine is entered with the data in Table 18-4.
Table 18-4

LAT Call-Back Routine

Description

AH = 1

Stop session received.

AH = 2

Stop message received.
AL = Host reason code.

AH = 3

Circuit has failed due to excess retransmits.

AH = 4

Illegal buffer (slot) has been received. Type as follows:

18 - 62

AL = 1

An unknown SLOT TYPE value is received.

AL = 2

A non-zero SRC_SLOT_ID in a received Stop slot.

AL = 3
AL = 4

A zero SRC SLOT ID in a Start slot.
A Start slot received in the Run state without an intervening Stop slot.

AL = 5

A Reject slot received in the Run state.

AL = 6

A Data a or Data b slot arrives which contains datE
(consumed a remote credit), but no user buffer is
available (no credit was extended).

Local Area Transport

Table 18-4
Register

AH = 5

LAT Call-Back Routine (cont.)
Description
AL = 7

A Run slot with a zero SRC SLOT ID.

AL = 8

A start slot with an invalid service class is received.

AL = 9

The Attention slot must-be-zero field is not zero
while the LA'!'software is in the run state.

Illegal message has been received. Type as follows:
AL = 1

RESERVED

AL = 2

An unknown MSG_ TYPE in a received message.

AL = 3

A non-zero SRC_ CIR_ ID in a received Stop
message.

AL = 4

A zero SRC_ CIR_ ID in a Start or Run message.

All other AL values are reserved for future use.
AH = 6

User requested disconnect.

All other AH values are reserved for future use.
•

Table overflow, which is initialized by the application, is the address of
a routine to call when the LAT service table overflows.
If the field contains 0, no call-back notification is given.

This call-back routine has no data.
•

Transmit notify, which is initialized by the application, is the address of
the Call Back routine to call to signal a transmit completion. This callback is invoked when the transmit buffer is completely emptied. A
value of zero disables this option. It can be changed at any time, providing the specified routine is already in place and ready for use.
If the field contains 0, no call-back notification is given.

•

Receive notify, which is initialized by the application, is the address of
the CallBack routine to call to signal a receive has occured. This callback is invoked when the receive buffer is completely full. A value of
zero disables this option. It may be changed at any time, providing the
specified routine is already in place and ready for use.
lf the field contains 0, no call-back notification is given.

•

Session status is the current status of the session. See the section
"Session Status Word Definition" for a complete description.

•

Slot state is the protocol engine state of this session and is used by the
LA'!' software ( = halted I.

•

Local credits, which you should initialize to zero, is used by the lat
software.

Local Area Transport

18 - 63

•

VCB pntr is a Long Pointer to Virtual Circuit Block used for this
session and is used by the LAT software. The actual format of the
pointer is:
VCB_offset
VCB_segment

OW
OW

0
0

•

Back Slot is an index to the back SCB on this circuit and is used by
the LAT software.

•

Forward Slot is an index to the forward SCB on this circuit and is used
by the LAT software.

•

Rem_Slot_Id is used by the LAT software.

•

Loc_Slot_Id is used by the LAT software.

•

Slot Byte Count is the number of Tx slot data bytes to be transmitted
and used by the LAT software.
--

•

Remote_Credits is used by the LAT software.

•

Tx Slot Data is the transmit buffer that contains actual data to be
transmitted to the host.

•

Num Slots, which is initialized by the application, is the number of receive-data slot buffers.

•

Num_Occupied MUST BE ZERO and is used by the LAT software.

•

Next_ Rx_Slot MUST BE ZERO and is used by the LAT software.

•

Cur_Buf_Slot MUST BE ZERO and is used by the LAT software.

•

Rx Slot Pntr, which is initialized by the application, equals (Offset of
Slot_1 entry I + 4 and is used by the LAT software.

•

Slot Ptr Table is initialized by the application. Each entry points to a
slot -x field in the following data area. Slot Ptr Table is used by the
LA'f software.
-

•

Slot 1 through Slot n are the receive data buffer areas and are used by
the LAT software. These data buffers must completely reside in the
same data segment as the SCB.
The application programmer specifies the number of receive data buffers. Each receive data buffer consumes 259 bytes for the actual buffer
and 2 bytes for Slot Ptr Table entry. The minimum recommended
number of receive data buffers is two. For most configurations, specifing four is adequate.
NOTE
The programmer should refer to the Call Back section for further information on call-back routines. All pointers are in the
form of offset - segment.

18 - 64

Local Area Transport

Session Status Word Definition
This is the field labeled session status in the SCB.
Status is reported in the form of one byte of bit flags followed by one byte of
explanation. Bit set (= 1) means the condition is true.
Status Word - Check for circuit and session state PRIOR to status call.
Status Word - First Byte - Contains bit flags as described below:
Bit 7-5
Bit 4
Bit 3
Bit 2-1
Bit 0

Reserved
Host sent a stop slot (stop session command)
Circuit Failure, reason in second byte
Reserved
Transmit buffer busy

Status Word - Second Byte - Contains reason number code on circuit or session
failure as described below:
Value

OlH = Stop slot received.
02H = Stop message received.
03H = Circuit has failed due to excess retransmits.
04H = Illegal slot has been received.
05H = Illegal message has been received.
06H = User has requested disconnect.

Local Area Transport

18 - 65

LAT Functions
The LAT services are accessed through INT 6AH. The AH register contains
the function code for the requested service. Each access requires that FFH is
in the DH register.
NOTE
Application software must save and use the session handle returned from the open session service. Failure to use the correct
handle can cause the VAXmate software environment to hang.
Table 18-5 lists the available LAT functions, which are described in the
sections following the table.
Table 18-5

Interrupt 6AH: LAT Functions

Function

Description

AH = 03H

Get status

AH = DOH

Open session

AH = DOH

Close LAT session

AH = 02H

Read data

AH = 01H

Send data

AH = D5H

Get next service name

AH = D6H

LAT service table reset

AH = ODIH

Send break signal

18 - 66

Local Area Transport

Function 03H: LAT Get Status
Parameters
AH =
DH =
DL =

03H
FFH

xxx

Where xxx is the session handle returned from the
open session call

Returns
AH =

Status byte (Set bits indicate condition)
Bit 7-6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0

ES:BX =

Reserved

ES:DX =

Reserved

Reserved
Transmit buffer empty
Reserved
Session in start state
Session not active
Unable to queue transmit data
Receive data available

Local Area Transport

18 - 67

Function DOH: Open Session
This service creates buffers and starts the LAT session.
Parameters
AH =
AL =
ES:BX =
DH =

DOH
FFH
Long pointer to LAT Session Control Block, SCB.
FFH

Returns
AH =

OOH Success, or
7-5
4

3
2
1

o
DL =

Reserved
No more sessions available. A maximum of 5 sessions
per Virtual Circuit.
Data buffer specification error.
No more sessions available.
No more virtual circuit blocks.
Service not in table or name error.

Session handle for subsequent service requests over this session
connection.

If a virtual circuit to the selected service is not active, a virtual circuit to the
node offering the service is created in addition to the requested session.

Application software must save and use the session handle returned from the
OPEN SESSION service. Failure to use the correct handle can cause unpredictable results in the VAXmate software environment.

18 - 68

Local Area Transport

Function DOH: Close LAT Session
Parameters
AH =
AL =
DH =
DL =

DOH
OOH
FFH

xxx

Where xxx is the session handle returned from open session
call.

Returns
AX =
AX
AX =

OOOOH no error
OOOlH No such active session
0002H Session not in running state. Retry again after a short delay.

Before closing the session, the application should confirm that all data has been
transmitted. Any receive buffers not empty from this session are freed.

Local Area Transport

18 - 69

Function 02H Read Data
Parameters
AH =
DH =
DL =

02H
FFH

xxx

Where xxx is the session handle returned from open session
call.

Returns

AL =

Bit pattern as below. ISet bits indicate condition)
7
No character read
6-0
Reserved
Received Character

18 - 70

Local Area Transport

AH =

Function OlH: Send Data
Parameters
AL =
AH =
DH =
DL =

Character to be sent
OlH
FFH

xxx

Where xxx is the session handle returned from the open
session call.

Returns
AH =

OOH success, or

Bit 7
6-0

Unable to queue character
Reserved

Local Area Transport

18 - 71

Function D5H: Get Next LAT Service Name
This service is used by the application to read the entries in the service table.
To read the entire table, the application issues successive requests. The LAT
software does not report duplicate services or services that are unavailable because the network node is not currently reachable.
Parameters
AH =
ES:BX =
DH =

D5H
Long pointer to buffer for the returned service name. The buffer
must be at least 17 bytes long.
FFH

Returns
AH =
ES:BX =

18 - 72

OOH Success, or
FFFFH end of table - no service name available.
Long pointer to service name terminated by a zero byte.

Local Area Transport

Function D6H: LA T Service Table Reset
In addition to clearing the LAT service table. this function forces the Get Next
LAT Service request to return the first entry in the service table.
Parameters

AH =
DH =

D6H
FFH

Returns

Number of services entered into the service table. This number
varies with time as the service table fills.

FFFFH Service table has overflowed.

Local Area Transport

18 - 73

Function D IH: Send Break Signal
This service is analagous to sending a break signal through a modem.
Parameters
AH =

DH =
DL =

DIH
FFH

xxx

Where xxx is the session handle

AX =

OOOOH
8000H

Success, or
Unable to send break signal

18 - 74

Local Area Transport

Returns

Sample Terminal Program
The following is an example of a simple terminal program that can operate on
a VAXmate workstation or compatible computer.
TITLE
PAGE
NAME

A simple terminal to test the LAT driver.
60,132
term

;*****************************************************************************
;*
;*
;*
;*

;*
;*

:*
;*
;*
;*

;*
;*

This software is furnished under a license and may be used and copied
only in accordance with the terms of such license and with the
inclusion of the above copyright notice. This software or any other
copies thereof may not be provided or otherwi~e made available to any
other person. No title to and ownership of the software is hereby
transferred.

*
*
*
*

The information in this software is subject to change without notice
and should not be construed as a commitment by DIGITAL Equipment
Corporation.

*
*

DIGITAL assumes no responsibility for the use or reliability
software on equipment which is not supplied by DIGITAL.

its

*
*
*
*

;*****************************************************************************
cr
tab

EQU
EQU
If
EQU
lat_int EQU

13
9

10
6AH

Carriage return
Tab
Line Feed
LAT INTerrupt

;************************************************************************
*

;*
A simple terminal program using the PC

LAT Driver

To build:
MASM TERM;
LINK TERM;
EXE2BIN TERM TERM.COM

*
*
*
*

*
*
*

To invoke, after LAT is loaded:
TERM service_name

*
*
Local Area Transport

18- 75

:*
*
:************************************************************************
: Dummy segment used to determine if LAT Driver has been installed.
pageO

SEGMENT AT

ORG

Location of LAT INT in page zero.
DO

pageO

ENDS

cseg

SEGMENTPUBLIC 'codeseg'

ASSUME

CS:cseg,DS:cseg,ES:cseg,SS:NOTHING

ORG

100h

main

PROC

: Origin for .COM file
NEAR

start:
MOV
MOV
INT

DX,OFFSET hello_message
AH,9
21h

Issue greeting message to user.
Function = write string.
From MS-DOS

CLD
MOV
LODSB

SI,80H

Set to auto-increment.
Location of command line.
First byte = count in AL

CMP
JBE

JMP

AL,16
st_03
service_error

CMP
JA

Yes, this is an error.

Less than 17
No, we are fine.

JMP

service_error

MOV
MOV

CL,AL
CH,CH
DI,OFFSET Service

18- 76

Local Area Transport

XOR

Greater then 167

Count in CX
Destination in ES:DI

CH,CH

XOR

Zero out CH

LODSB
CMP
JE

Load first characters.
Space?
Spaces shall be evaporated!

STOSB

No, save the character.

LOOP copy_loop
MOV
AL,CH
STOSB

Copy the service name into the scb.
Terminate the string with a zero byte.

CALL
JZ

check_installation
st_Oi

Check to see if LAT is installed.
Yes, proceed.

MOV
MOV
INT
JMP

DX,OFFSET no_lat_message
AH,9
2ih
error_exit

Load pointer to no lat message.
Function = write string.
Call MS-DOS

CALL

lat_initialization

Execute the LAT init call.

XOR
MOV
INT
JZ

AX,AX
AH,Olh
i6h
rxd

;Zero AX and reset flags
;Keyboard poll
;From the BIOS
;No character at Kbd, check serial port

;Retrieve character from keyboard buffer
MOV
INT

AH,OOh
i6h

; Check it for an Fi
CMP
JNE

AX,3BOOh
yx_Oi

; Function , read character
;From the BIOS
Exit from terminal program
;Fi Key?
; No, continue.

Explicit stop now implemented!

Local Area Transport

18- 77

MOV
MOV
INT

AX,ODOOOh
DX,WORD PTR handle
lat_int

JMP

exit

yx_01 :
CMP AX,3COOh
JNE yx_02

; Function, close session.
; Session handle in DX.

;F2 key ?
; No, continue

Send a break signal
MOV AH,OD1H
MOV DX,WORD PTR handle
INT lat_int
yx_02:
CMP AL,OSh
JNE ml_01
MOV AL,07Fh

Send break signal

; Backspace?
No, continue.
; Yes, map to delete.

mL01:
; Send out the character
MOV
MOV

CX,100
AH,01h

; We will try and xmit 100 times.
;Function, port_write

txd:
MOV DX,WORD PTR handle
PUSH AX
INT lat_int
TEST AH,BOh

; Use handle given by LAT
;Preserve Ax destroyed by LAT INT
;Send the character via the BIOS
;Test for character sent

POP AX
JZ
rxd
LOOP txd

;Restore Ax
;Check for another character
;Try again if character not sent

;See if there is a character received
rxd:
TEST session_status,1000b
JNZ circuit_dead
MOV

18 - 78

AH,03h

Local Area Transport

Circuit stopped?

Status

MOV DX,WORD PTR handle
PUSH ES
INT lat_int
POP ES
TEST AH,Olh
JZ
main_loop

; Port
; Get status

; Character available?
; No character, poll keyboard again

Read the character from the LAT buffer.
MOV DX,WORD PTR handle
MOV AH,02h
INT lat_int
TEST AH,BOh
JNZ main_loop

;Use handle to LAT session
; Function , port_read
;From the BIOS
;Test for character received
; If so, try keyboard!

OR
JZ

AL,AL
main_loop

; Null?
; If so, don't display

CMP

AL,09h

; Tab?

AND
MOV
XOR
INT
JMP

AL,07Fh
AH,OEh
BX,BX
lOh
main_loop

;Mask out bit B
;function, write TTY
;Display page = 0
;BIOS write_teletype call
;AII done, poll keyboard again

exit:
MOV
INT

AX,4COOh
2lh

Normal MS-DOS exit

service_error:
MOV
MOV
INT

DX,OFFSET bad_service_mess ; Bad service message.
AH,9
Function = write string.
2lh
Call MS-DOS.

MOV
INT

AX,4COlh
2lh

main

Error level = 1
Call MS-DOS.

ENDP

lat_initialization

PROC

NEAR

Local Area Transport

18- 79

MOV
MOV
MOV
INT
OR
JZ

DX,OFFOOh
.BX, OFFSET scb
AX,ODOFFh
lat_int
AH,AH
lLgo

This INT is for LAT
ES:BX points to lccb
Extended function
Invoke LAT
Any errors?
AH = zero, no errors.

TEST AH,1
JZ
lL01

Service not in directory?
No.

MOV DX,OFFSET no_service_message
MOV AH,9
INT 21h

: Issue not in directory message.
Function = write string.
Call MS-DOS

li_01: : Use this general message for all other failures for now.
MOV DX,OFFSET init_failure : Send failure message to user.
MOV AH,9
Function = write string.
INT 21h
Call MS-DOS
JMP SHORT error_exit
Exit with error.
lLgo:
MOV WORD PTR handle,DX

Save handle to session

lLexit:
RET

lat_initialization

ENDP

circuit_dead

NEAR

MOV
MOV
INT
JMP

PROC

DX,OFFSET dead_message : Load offset to circuit dead message.
AH,9
Function = write string.
21H
Call MS-DOS
SHORT exit
Exit.

circuit_dead

ENDP

PAGE

:************************************************************************
:*
*

PRO C E E D U R E c h e c k _ ins t a l 1 a t ion

18 - 80

Local Area Transport

Entry: Nothing
Exit: Z flag set = LAT installed.

;'"
;'"
;'"

'"
'"
; "'''''''''''''''''''********'''****''''''***''''''**********'''**'''***'''************"'''''''*''''''**'''*'''''''''''''''
check_installation

PROC

NEAR

PUSH AX
PUSH CX
PUSH SI
PUSH DI
PUSH ES

Preserve registers.

CLD
XOR
MOV

Set the direction flag to forward.
Set ES to page zero.

ASSUME
LES
ASSUME
MOV
SUB
MOV
REPZ
POP
POP
POP
POP
POP

AX,AX
ES,AX
ES:pageO
DI,DWORD PTR lat_entry

ES:DI => lat_int entry

ES:NOTHING
CX,3
; Compare 3 bytes
Starting at entry -3
DI,3
SI,OFFSET lat_string
; Local string for compare.
CMPSB

Compare it!

ES
DI
SI
CX
AX

Restore registers.

RET
lat_string

'LAT'

check_installation

ENDP

PAGE
dead_message
hello_message
init_failure
no_lat_message

DB cr,lf, 'Circuit disconnected! ',cr,lf,'$'
DB cr,lf,'LAT test terminal now connecting. ',cr,lf,lf,'$'
DB cr,lf, 'Initialization call failed!' ,cr,lf,lf, '$'
DB cr,lf, 'LAT Driver not installed!',cr,lf,lf,'$'

Local Area Transport

18- 81

no_service_message DB cr,lf,'Requested service not in directory! ',cr,lf,lf,'
bad_service_mess
DB cr,lf,'Bad Service Name!',cr,lf,lf,'$'
handle

SCB

; Handle for LAT session

Session Control Block. Structure used by client application
to arrange for data exchange.

scb

LABEL

WORD

Service
Node
Port

DB
DB
DB

18 DUP (0)
18 DUP (0)
18 DUP (0)

Requested service.
Reserved for future use.
Reserved for future use.

***************************************************************
The following four call-back addresses must be initialized to 0
if call-backs are not desired for each condition.
Session_Stopped
Table_overflow
Transmit_notify
Receive_notify

DD
DD
DD
DD

o
o
o
o

Session stopped notification routine.
Service table overflow notification routiI
Routine to call when slot is transmitted.
Routine to call when a slot is received.

session_status
slot_state
locaLcredits

DW
DW
DB

o
o
o

Status word
Used by LAT Driver - initialize to 0
Used by LAT Driver - initialize to 0

vcb_offset
vcb_segment

DW
DW

o
o

Used by LAT Driver. Pointer to LAT
Driver's internal circuit block.

back_slot
forward_slot

DW
DW

Used by LAT Driver - initialize to 0
Used by LAT Driver - initialize to 0

; Transmit slot buffer - Contains actual transmit slot.
rem_slot_id
loc_slot_id
slot_byte_count
remote_credits

DB
DB
DB
DB

o
o
o
o

Db 255 Dup(O)
; Transmit data area

18- 82

Local Area Transport

Used by LAT Driver Used by LAT Driver Used by LAT Driver Used by LAT Driver -

initialize to 0
initialize to 0
initialize to 0
initialize to 0

Transmit slot data buffer.

»»»»> The following variable is initialized by the client application! !
Num_slots

Number of receive data slot buffers
in this structure. Value of 4 is suggested.

Num_occupied
Next_rx_slot
Cur_buf_slot

DB
DB
DB

0
0
0

Number of occupied slots.
Index
Next slot to be used for receive slot.
Index - Current slot sending characters to client.

;»> The following variable must be initialized by the client application!
DW

OFFSET Slot_l+4

Offset of the first character
to be taken by client.

;»> The following table of pointers must be initialized by the client
application!

;»»»

WORD

DW
DW
DW
DW

OFFSET slot_l
OFFSET slot_2
OFFSET slot_3
OFFSET slot_4

The following data definitions are the actual receive data buffers.

slot_l
slot_2
slot_3
slot_4
CSEG

LABEL

DB
DB
DB
DB

259 DUP(O)
259 DUP(O)
259 DUP(O)
259 DUP(O)

ENDS
END

start

Local Area Transport

18- 83

Session
This section describes the VAXmate MS-Network Session Level interface. This
is the recommended interface for applications that want to use network services provided by the Microsoft MS-Network environment. DIGITAL has added
a number of extensions to the standard MS-Network interface to support node
name and node address manipulation.
Application programs access the services of the MS-Network Session Level
through INT 2AH. The Session Level interface is implemented by a terminate
and stay resident emulation module named SESSION.EXE. This emulation
software uses DECnet-DOS as the network transport layer of the Microsoft
network architecture. Most session services are mapped into DECnet-DOS
services for subsequent processing by the network.
The standard unit of communication between applications using the session
level interface is the message. A program on one computer sends messages to
a program on another computer. The sender is notified if the message is not
received by the target application. The communication channel over which the
messages are sent is called a virtual circuit. Each program refers to the other
by a name. A virtual circuit is a communication channel between two named
programs. The session layer software translates program names into network
addresses and creates and maintains the virtual circuits between communicating applications.
In addition to name and message services, the session level provides a datagram service. Datagrams are small packets of data that are sent to other programs. Unlike messages, delivery of datagrams is not guaranteed. The sender
is not notified of delivery or non-delivery of the datagram. The session module
implements the datagram service by directly accessing the datalink.

18 - 84

Session

Figure 18-3 shows the general flow and interfaces between each of the layers
that are involved in implementing the session interface.

Application software,
MS-DOS/Redirector,
MS-DOS/Server,

MS-Network Session

1lL--'
---.---------'
I
datagram

Iservice
I

DECnet-DOS

INT 6D

Data Link

Figure 18-3

Session Interface Implementation

The VAXmate MS-DOS operating system redirects file and print 110 over the
network using the INT 2A interface provided by the MS-Network Session software. The operating system module responsible for distinguishing between local
and network file access is called the Redirector. The Redirector manages the
entire remote file access transaction. The Redirector communicates over the
network with file and print server software located on another VAXmate
workstation or on a VAXIVMS system. The Actual file access protocol used by
the Redirector is called the Server Message Block Protocol. 5MB protocol. The
5MB is just one of many protocols that can be used for network transactions
through the session level interface.
Session

18 - 85

Software Capabilities
An application accesses the MS-Network Session Level services through the
INT 2A interface. The INT 2A is issued with register AH = 1. This identifies
the access as an MS-Network Session Level request. As part of the access, the
application must define a Session Control Block, SCB for each request. The
fields in this data structure direct the session level and return status to the
application. The application points at the SCB using the ES:BX register pair.
The VAXmate workstation software provides a set of DIGITAL-specific extensions to the session level interface for manipulating node names and node addresses. The DIGITAL-specific services are accessed through the INT 2A
interface. The INT 2A is issued with register AH = OCR. This identifies the
access as a DIGITAL extension. As part of the access, the application must
define a DIGITAL Session Control Block, DSCB, for each request.
All INT 2A invocations that do not have AH set to 0, 1 or DCH are passed on
to the INT 2A service routine that was present before the Session Level software was loaded.
All MS-network functions can be performed synchronously. Certain functions
can be performed both synchronously or asynchronously. When an application
issues the synchronous form of a command, execution of the application stops
until the session level interface completes the request. When the asynchronous
form of a command is used, the application can test, or poll, for completion or
request that a routine be called upon completion. Completion routines are called
Asynchronous Notification Routines (ANR).
In addition to the INT 2A interface the session software supports an installation check function through the INT 2F interface. This request is supported for
compatibilty with industry standard versions of the MS-Network session
interface.

MS·Network Session Control Block
An application accesses the MS-Network Session Level services through the
INT 2A interface. The INT 2A is issued with register AH = 1 identifying this
request as an MS-Network Session Level request. As part of the access, the
application points at the Session Control Block, SCB, using the ES:BX register
pair.
An SCB is defined for each INT 2A invocation. This allows the application program to post multiple simultaneous session level requests.
The following is a C language structure description of the Session Control
Block. seB. This data structure is used for all MS-Network compatible session
accesses. Session Control Block data structure is described as follows:
18 - 86

Session

struct

scb

{

byte
byte
byte
byte
long
int
byte
byte
byte
byte
long
byte
byte
byte

scb_command;
/* function code */
scb_error;
/* error code */
scb_vcid;
/* virtual circuit identifier */
scb_num;
/* name number (for datagram) */
scb_baddr;
/* buffer address */
scb_Iength;
/* data buffer length in byte */
scb_rname[16] ; /* remote name */
scb_Iname[16] ; /* local name */
scb_rto;
/* receive timeout */
scb_sto;
/* send timeout */
scb_async;
/* address of ANR */
scb_resl;
/* reserved */
scb_done;
/* function pending flag */
scb_res2[14] ; /* reserved */

};

Table 18-6 describes the Session Control Block fields.
Table 18-6 Session Control Block Fields
Field Name

Size

scb command 1 byte

scb error

1 byte

scb vcid

1 byte

scb num

1 byte

Description
Contains the function request code. For functions
that support the asynchronous mode, the high order
bit of the byte is set to indicate asynchronous operation of the request.
Contains either an error or a 'command pending' flag
if the request is not completed. Do not poll this field
for request completion (see scb_donel.
FFH Reserved. Currently command
scb error =
pending for asynchronous notification.
o = Success
non-zero = Error
Contains the virtual circuit identifier. The Call and
Listen functions return this value, which must be
filled in prior to issuing Send or Receive requests.
The virtual circuit identifier, which is in the range I
to 31, is used by Send and Receive to identify the
virtual circuit to use for sending or receiving.
Used as a part of datagram support. The Add Name
function returns the value, which is used by Send
Datagram. Receive Datagram, and Send Broadcast.
The VAXmate workstation implementation of the
session level always sets scb num to one. All other
values are reserved for future use. It has a potential
range of 1 to 254.
Session

18 - 87

Table 18-6 Session Control Block Fields (cont.)
Field Name

Size

Description

scb baddr

4 bytes

Contains the address of the data to be transferred.
This field is in double-word format (DO
segment:offset).

scbJength

2 bytes

Contains the length, in bytes. of the data to be
transferred.

scb rname

16 bytes

Contains the remote network name, which must be
upper case. All 16 bytes must be used. Session supports a maximum of 72 simultaneous network
names, including the name of this workstation.

scb lname

16 bytes

Contains the local network name, which must be
upper case. All 16 bytes must be used. The session
level supports a maximum of 72 simultaneous network names.

scb rto

1 byte

Contains the receive timeout for a virtual circuit. The
value represents the number of 500 ms. ticks, and is
set by a Call or Listen function and holds for the life
of the circuit. A zero results in the use of the
transport level default. In this implementation, the
default is zero ticks.

scb sto

1 byte

Contains the send timeout for a virtual circuit. The
value represents the number of 500 ms. ticks, and is
set by a Call or Listen function and holds for the life
of the circuit. A zero results in the use of the
transport level default. In this implementation, the
default is zero ticks.

scb_async

4 bytes

Contains the address of the Asynchronous
Notification Routine, ANR. This field is in doubleword format (DD segment:offset). If this field is zero
and the asynchronous form of the function is used,
then scb done must be polled to determine completion. The ANR routine is called at interrupt time
with interrupts masked off. Upon completion of the
ANR, the application must issue an IRET
instruction.

scb res

1 byte

Is a reserved field. which must be initialized to O.

scb done

1 byte

Is a status field filled in by session. The value OFFH
means the function is not yet complete. Another
value indicates completion.

scb res2

14 bytes

Is a reserved field, which must be initialized to O.

18- 88

Session

DIGITAL-Specific Session Control Block
The VAXmate workstation software provides a set of DIGITAL-specific extensions to the session level interface for manipulating node names and addresses.
The INT 2A is issued with the register AH = DCH. Each request includes a
DIGITAL Session Control Block, DSCB, pointed at by the ES:BX register
pair.
The DIGITAL session level functions are synchronous. There is no
asynchronous support. The DIGITAL Session Control Block, DSCB, structure
is described below:
struct

dscb

{

unsigned char
unsigned char
unsigned char
unsigned char
unsigned int

dscb_cmd;
/* function number */
dscb_err;
/* return code */
dscb_index;
/* index number of node entry */
dscb_name[16];/* node name padded with spaces */
dscb_num;
/* node number */

};

Table 18-7 describes the DIGITAL session control block fields.
Table 18-7 DIGTIAL Session Control Block Fields
Field Name

Size

Description

dscb cmd

1 byte

dscb err

1 byte

Holds the function code for the requested DIGITALspecific service.
Contains the status of the completed request.

dscb index

1 byte

Is the index of the node name into the internal name
table maintained by session. This index is used in
certain services to allow the application to cycle
through all the known node names. Index values are
in the range zero to (number of names)-( 1). The table
can contain a maximum of 72 names. The first name
in the table is the name of this workstation.

dscb name

16 bytes

dscb num

2 bytes

Is a 16-byte node name. All 16 bytes are used for the
name. For names shorter than 16 bytes, the name is
padded with space characters in the high order bytes.
Is the DECnet area number and node number associated with the name found in dscb name. The
format of this field is:
area number = bit 15 through bit 10.
node number = bit 9 through O.
Session

18 - 89

Synchronous Requests
For synchronous requests, application execution is suspended until all network
Activity associated with the request is completed.
The flow of control for a typical synchronous request is:
1.

The application makes an INT 2A synchronous request.

Control passes to the session-level software.

If appropriate for this request, a series of calls are made to the

DECnet-DOS transport layer.
When appropriate, session makes both synchronous and asynchronous
calls to the transport software. Depending on the request made by the
application to session, any mix of synchronous and asynchronous
requests can be made to the transport software.
4.

Upon completion of all transport functions, the SCB is updated and
scb done is set.

Control is returned to the application.

Asynchronous Requests
The asynchronous form of a command is specified by setting the high-order bit
of the command function code. Software issuing an asynchronous request regains control immediately after the request is issued. In most cases the request
will be satisfied at a later time. To determine completion of the request, the
application must specify an Asynchronous Notification Routine as a part of the
request or poll the scb_done field.
The session level software only invokes an ANR for requests involving a nonzero scb async field. A value of zero in the scb async field means the application must poll the the scb_ done field,
While an asynchronous request is outstanding, the SCB for that request must
remain unchanged. The session level software uses the SCB for control and
status reporting.
The flow of control for a typical asynchronous request is:
1.

The application makes an INT 2A asynchronous request.

Control passes to the session level software.

If appropriate for this request, a series of calls are made to the

DECnet-DOS transport layer.
When appropriate, session makes both synchronous and asynchronous
calls to the transport software. Depending on the request made by the
18 - 90

Session

application to session, any mix of synchronous and asynchronous
requests can be made to the transport software.
4.

Control is returned to the application.

Upon completion of all asynchronous transport functions, the SCB is
updated, scb done is set, and if specified, the applications ANR is
invoked.
-

Asynchronous Notification Routine
The Asynchronous Notification Routine, ANR, is specified as a part of the
Session Control Block for each request. The SCB field scb async contains a
zero value or a valid pointer to the ANR. An ANR is invoked only upon completion of asynchronous session requests.
When an asynchronous request completes. the session software starts execution
of the ANR, which is entered with interrupts off. Because the asynchronous
notification may have interrupted processing by MS-DOS, the ANR cannot
issue any MS-DOS cal1s. It is recommended the ANR not enable interrupts.
and complete its processing quickly. The ANR is exited by executing an IRET
instruction.

Network Addressing
The standard MS-Network supports a 20-byte network address. The session
software provides the transport level with the network address of the messages
destination. The transport level uses this address to route the message to its
destination.
The VAXmate workstation implementation of the MS-Network session level
uses DECnet addresses in place of the standard 20-byte addresses. The session
software maps a network name into a DECnet node address, which consists of
an area number and node number.
For more information on DECnet node numbers, addressing in a DECnet network, and user control over node names and numbers, refer to:
•

The VAXmate system administration documentation

•

DECnet·DOS Programmers Reference Manual

•

DECnet·DOS User's Guide

•

DNA General Description and other manuals in the DIGITAL Network
Architecture series. For the titles of this series, see the "Introduction"
in this chapter.
Session

18 - 91

Session Level Services
The VAXmate session level interface accessed through INT 2A provides two
distinct sets of services. The first is the MS-Network compatible functions
specified with AH = 01H. The second is a set of DIGITAL-specific functions
specified with AH = DCH.
Table 18-8 lists the services offered by the session level interface. Table 18-9
lists the DIGITAL-specific session level extensions.
Table 18-8

Interrupt 2A: MS-Network Compatible Services

Synchronous

Asynchronous

10H
llH
12H
14H
15H
16H
17H
20H
21H
22H
23H
30H
31H
32H
33H
34H
35H

90H
91H
92H
94H
95H
96H
97H
AOH
A1H
A2H
A3H
BOH
B1H
B3H
B4H

Service
CALL
LISTEN
HANG UP
SEND
RECEIVE
RECEIVE ANY
SEND DOUBLE
SEND DATAGRAM
RECEIVE DATAGRAM
SEND BROADCAST
RECEIVE BROADCAST
ADD NAME
DELETE NAME
RESET
STATUS
NAME STATUS
CANCEL

All other function codes are reserved for future use.
Table 18-9

Interrupt 2A: DIGITAL-Specific Session Extensions

Function Code

Service

Description

OOH
01H
02H
03H
04H
05H
06H
07H

decfunccheck
decfuncadd
decfuncdelnum
decfuncdelname
decfuncreadnum
decfuncreadname
decfuncreadindex
decfuncdelall

extension check
add node entry
delete node by number
delete node by name
read node by number
read node by name
read node by index
delete all nodes

All other function codes are reserved for future use.
18 - 92

Session

MS-Network Compatible Session Level Services
An MS-Network session level access is performed by setting register AH = 1,
pointing ES:BX at a session control block (SCBI and doing an INT 2AH.
When control is returned to the application from the session level. the AH and
AL registers contain the return status. Status is also returned in the appropriate field of the SCB.
For a synchronous request:
Upon Return

AX = non-zero

Error has occurred.
AH = 01H
AL = error code
scb error = error code

AX = OOH

Success
scb error = 0

For an asynchronous request:
Upon Return

AX = non-zero

AX = OOH

Error has occurred.
AH = 01H
AL = error code
scb error = error code
Function successfully started.
SCB fields pending completion of
request.
Upon completion of request, SCB fields
updated, and error code, if any, in
scb error.

Session

18 - 93

MS-Network Session Level Return Codes
Table IS-10 lists the possible MS-Network session level interface error codes
returned in scb_error, and the service requests that can generate these errors.
Table IS-10

Error Codes Returned by Session

Error Code

Description

Service Request

OOH

Success

All services

01H

Illegal buffer length

SEND
RECEIVE
STATUS
NAME STATUS
SEND DATAGRAM
RECEIVE DATAGRAM
RECEIVE ANY
SEND BROADCAST
RECEIVE BROADCAST

03H

Illegal command

All services

05H

Command timed out

Any asynchronous command

06H

Message incomplete,
issue another command

RECEIVE ANY
RECEIVE
STATUS

OSH

Session number
out of range

SEND
RECEIVE
HANGUP

09H

No resource available

All services

OAH

Session closed

RECEIVE
SEND
RECEIVE ANY
HANGUP

OBH

Command canceled

STATUS
ADD NAME
DELETE NAME
CALL
LISTEN
SEND
SEND DOUBLE
RECEIVE
RECEIVE ANY
SEND DATAGRAM
RECEIVE DATAGRAM
SEND BROADCAST
RECEIVE BROADCAST

18 - 94

Session

Table 18-10

Error Codes Returned by Session (cont.}

Error Code

Description

Service Request

ODH

Duplicate name

ADD NAME

OEH

Name table full

ADD NAME

llH

Local session table full

CALL
LISTEN

I2H

Session Open rejected

CALL

I3H

Illegal name number

NAME STATUS
RECEIVE DATAGRAM
SEND DATAGRAM
SEN D BROADCAST
RECEIVE BROADCAST

I4H

No call name

CALL

I5H

Name not found or
no valid name

DELETE NAME

I6H

Name in use

ADD NAME

I8H

Session ended abnormally

SEND
RECEIVE
HANGUP

I9H

Name conflict detected

ADD NAME

2IH

Interface busy

All services

22H

Too many commands
outstanding, retry later

All services

23H

Reserved

All services

24H

Command completed
while cancel occurring

CANCEL

Command not valid
to cancel

CANCEL

Internal error. can
result from an invalid
address file

CALL
LISTEN
SEND DATAGRAM
RECEIVE DATAGRAM

26H
3IH

Session

18 - 95

Table 18-10

Error Codes Returned by Session (cont.)

Error Code

Description

Service Request

32H

Transport not installed

STATUS
CANCEL
LISTEN
CALL
SEND
SEND DOUBLE
RECEIVE
RECEIVE ANY
HANGUP
SEND DATAGRAM
RECEIVE DATAGRAM
SEND BROADCAST
RECEIVE BROADCAST

4XH

Network Error
X may have any value

All services

Asynchronous command
is not yet finished

All services

FFH

The DECnet·DOS transport can generate error codes that do not correspond to
the session level errors described in this list. These errors and their codes are
described in the DECnet·DOS Programmer's Reference M anu.al.
Transport error codes that cannot be directly mapped to a session level error
code, are passed directly through the interface to the application. Such
transport error codes are mapped into the following format.
DECnet·DOS error code

the number SOH

To determine the error represented by the error code being returned from the
DECnet·DOS transport. subtract SOH from the number returned in scb error.
The error description can then be found in the DECnet·DOS Programmer's
Reference M anu.al.

18 - 96

Session

Function OOH and Function B800H: Check for Presence of MSNetwork Session
Two functions are provided to support this request. The first is the recommended function accessed through the INT 2A interface. The second function
is accessed through the INT 2F interface and is present only for compatibility
with industry-standard versions of the MS-Network session interface.
The INT 2A function allows an application to determine the presence of the
Session software.
The check is performed by setting register AH = 0 and doing an INT 2A. If
the network software is installed, upon return AH will have a non-zero value.
Parameters
AlI =
ES:BX =

OOH
not applicable

Returns
AH =

non-zero
OOH

Session is present
Session not present

The INT 2F function is provided for compatibility with other vendor's versions
of the MS-Network session level interface.
The check is performed by setting register AX = B800H and doing an INT
2F. If the network software is installed, upon return AL will have a value of 1.
Parameters
AX =
ES:BX =

B800H
not applicable

Returns
AL =

OlH
OOH

Session is present
Session not present

BX =

08H

Always

Session

18 - 97

Function 358: Cancel (synchronous)
This service allows an application to cancel a pending request. The request to
cancel is identified by pointing at its SCB.
Data may be lost when a command is canceled. If the canceled command is a
receive, then data is lost only for that command, and the virtual circuit remains active and usable.
Canceling a request 'is a form of completing the request. The canceled SCB will
be updated. A request that normally invoked an Asynchronous Notification
Routine will cause that routine to be invoked.
The following commands can be canceled.
• Listen
• Receive
• Receive Any
• Receive Datagram
• Receive Broadcast
Parameters
AH =

01H
Far pointer to SCB

ES:BX =

scb command =
8cb-error =
scboaddr =

35H
OOH
far pointer to SCB to cancel

OOH
21H
22H

Success
Interface busy
Too many outstanding commands, retry
later
Command completed during cancel
operation
Command not valid to cancel
Transport not installed
Network error, x may be any value

Returns
scb error =

24H
26H
32H
4xH

18 - 98

Session

Function 32H: Reset (synchronous)
Reset the session software. All data, virtual circuits, and status are lost. This
resets the entire session level, not just one virtual circuit. The session software
is not completely reset to its initial state on startup.
The parameters scb vcid and scb num are reserved for future use. They should
be set to zero by the application. If they are zero, then default values will be

used in future session implementations.
Parameters
AH =
ES:BX =

OlH
Far pointer to SCB

scb command =
scb-error =
scb-vcid =
scb-num =

32H
OOH
RESERVED, Must Be zero
RESERVED, Must Be Zero

Returns
scb error =

OOH
4xH

Success
Network error, x may be any value

Session

18 - 99

Function 33H: Status (synchronous~
Function B3H: Status (asynchronous)
Returns overall transport status information for this VAXmate workstation.
Information is loaded into the buffer supplied by the application and pointed to
by scb_ baddr.
Parameters
AH =
ES:BX =

01H
Far pointer to SCB
scb command

33H Synchronous
B3H Asynchronous
OOH
Length. in bytes, of the data to be
transferred
RESERVED
Far pointer to status buffer
Address of ANR or zero for
asynchronous form of request. Not required for synchronous request

scb error =
scb)ength =
scb rname =
scboaddr =
scb=async =

Returns
scb error ==

OOH
01H
05H
06H
19H
21H
22H
32H
4xH

Success
Illegal buffer length
Command timed out
Message incomplete
N arne conflict detected
Interface busy
Too many outstanding requests, retry later
Transport not installed
Network error, x may be any value

The data area pointed to by the scb baddr contains the status buffer as
described in table 18-11.
Table 18-11

Session Status Buffer

Field Name

Size
(bytes)

Description

SSB HIDI

SSB JMPRI
SSa-HRD
SSB-SVER
SSB-DUR
SSB-CRC

Ethernet address of this workstation, low
order byte first
Jumper status: reserved, returns zero
Hardware status: reserved. returns 128
Session software version. in BCD format
Duration of reporting period
Number of CRC errors

18 - 100

Session

2
2
2

SSB ALIGN

Number of alignment errors

Session

18 - 101

Table 18-11

Session Status Buffer (cont.)

Field Name

Size
(bytes)

Description

SSB COL
SSB-ABORT
SSB-NSENT
SSB-NRECD
SSB-RETRAN
SSB-NRSRC

2
2

Number of collisions detected
Number of aborted transmissions
Number of successfully transmitted packets
Number of successfully received packets
Number of retransmissions
Number of times the receiver exhausted its
resources
Reserved
Reserved
Reserved
Maximum number of free command blocks
Reserved
Reserved
Reserved
Reserved
Maximum message data size, which is 4096
for this implementation of session
Number of names in the immediately following list, (value is is always 1 for this
implementation)
Name of this workstation
RESERVED for future use
Status of this VAXmate workstation, 4 =
active, 5 = inactive

4
4
2
2

SSB RES4
SSB-RES5
SSB-RES6
SSB-RES7
SSB-RES8
SSB-RES9
SSB-RESI0
SSB-RESll
SSB-MAXMSG

SSB NNAMES

SSB NAMO
SSB-NUMO
SSB-NAMSTATO

16
1
1

SSB NAMn
SSB-NUMn
SSB-NAMSTATn

16
1

2
2
2

4
2
2
2
2

Name n, not present in this implemenation
RESERVED for future use
Status of name n, 4 = active, 5 = inactive,
not present in this implemenation

SSB MAXMSG, maximum message data size is the recommended maximum
message size for applications that are communicating with VAXmate and
VAXNMS file and print servers. For this implementation, maximum message
size is 4096 bytes. However, the session interface can send and receive
messages as large as 65536 bytes.
This implementation of the session level only returns SSB NAM,
SSB NUM and SSB NAMSTAT status for this workstation. Consequently,
the value of SSB_NNAMES always equals 1.

18- 102

Session

Function 30H: Add Name (synchronous)
Function BOH: Add Name (asynchronous)
This function is provided for compatibility with industry-standard implementations of the MS-Network session level interface, and to facilitate the execution
of MS-Network compatible application software. This function does not actually
add a name to the name and node tables. To add a name or node number, use
the DIGITAL-specific function Add A Node, decfuncadd, described later in this
manual.
The name cannot start with the character '*' or OOH or FFH and should not
start with the strings "MSNET" or "IBM". For non-VAXmate workstation implementation of the session level, this call makes a name known to the network
software.
It is recommended, but not required, that names be unique across a network.
The node numbers must be unique across the network for the network is to
function properly.
Parameters
AH =
ES:BX =

OIH
Far pointer to SCB
scb command =
scb error ==
scb-Iname =
scb:=async =

30H synchronous
BOH Asynchronous
OOH
Narne to be added
Address of ANR or zero for
asynchronous form of request. Not required for synchronous request.

Returns
scb error =

scb num =

OOH
Success
ODH
Duplicate name in this workstation
OEH
Name table full
I5H
Name not found or Not a valid name
I6H
Name in use
I9H
Name conflict detected
2IH
Interface busy
22H
Too many outstanding requests, retry later
4xH
Network error, x may be any value
reserved for future use

Session

18 - 103

Function 31H: Delete Name (synchronous)
Function BIH: Delete Name (asynchronous)
This function is provided for compatibility with industry standard implementations of the MS-Network session level interface. It is provided to facilitate the
execution of MS-Network compatible application software. This function does
not actually delete a name from the name and node tables. To actually delete a
name or node number from the network tables use the DIGITAL-specific functions Delete Entry Given Node Number, Delete Entry Given Node Name, or
Delete All Node Entries.
For non-VAXmate workstation session level interfaces, this function removes a
name from the network. A name may not be deleted if a virtual circuit is in
use that has the name as an endpoint.
Parameters
OIH
Far pointer to SCB

AH =
ES:BX =

scb command =
scb error =
scb-Iname =
scb=async =

31 H synchronous
B I H asynchronous
OOH
name to be deleted
address of ANR or zero for
asynchronous form of request. Not required for synchronous request

Returns
scb error =

OOH
I5H
I6H
2IH
22H
4xH

18- 104

Session

Success
Name not found or Not a valid name
Name in use
Interface busy
Too many outstanding requests, retry later
Network error, x may be any value

Function 34H: Name Status (synchronous)
Function B4H: Name Status (asynchronous)
This command returns information about a specific name and its associated
Virtual Circuit.
Parameters
AH =
ES:BX =

OlH
Far pointer to SCB
scb command =
scb error =
scb=length =
scb baddr =
scb-Iname =
scb=async =

34H synchronous
B4H asynchronous
OOH
Length of buffer pointed at by
scb baddr
Far-pointer to status buffer
Name to return status on
Address of anr or zero for
asynchronous form of request. Not
required for synchronous request.

Returns
scb error =

OOH
OlH
19H
21H
22H
4xH

Success
Illegal buffer length
Narne conflict detected
Interface busy
Too many outstanding requests, retry later
Network error, x may be any value

The scb baddr field points to a area of length scb length which contains the
following:
SB NUM
SB-NRA
SB-VCN
SB NVC

Name number of name being reported on
Number of virtual circuits associated with this name
Number of receive datagram and receive broadcast
commands outstanding
Number of receive any commands outstanding

Session

18 - 105

The remaining information is returned about each virtual circuit (36
bytes eachl
1 byte
Virtual circuit id#
SB I VCID
SB-CSTATE
1 byte
State of the virtual circuit
SB-CLNAME 16 byte
Local name
SB-CRNAME 16 byte
Remote name
SB-CNRC
Number of outstanding receive
1 byte
commands
SB I NSC
Number of outstanding send
1 byte
commands
SB I STATE

18 - 106

Session

Values:
3 = Normal
4 = Hang-up pending

Function lOH: Call (synchronous)
Function 90H: Call (asynchronous)
Call creates a virtual circuit between this node and another node that issued a
listen. This node must identify the node it is calling in the scb marne field.
The listening node, which does not identify the calling node, posts a listen and
waits to be called. The scb marne must correspond to a scb lname in an
outstanding listen command on some machine on the MS-Network network.
The node named in the scb marne field must be in the VAXmate workstation
list of known nodes. The node list is updated with entries when the network is
started by the user using one of the network management utilities or by the
application invoking the DIGITAL-specific add node functions described in this
section. If the user uses the DECnet-DOS NCP utility to add a node to the
network tables, the user must remember to specify the MS-NET switch as a
part of the name and number definition. Otherwise, the node name is not
added to the list maintained by the session software.
The fields scb rto and scb sto do not take affect until the virtual circuit is
established by-the DECnet-DOS transport software. If a virtual circuit is not
established within approximately one minute, a timeout error occurs.
Parameters
AH =
ES:BX =

OlH
Far pointer to SCB

scb command =
scb error =
scb-rto =
scb sto =
scb lname =
scb-rname =
scb=:async =

10H synchronous
90H Asynchronous
OOH
Number of 500 ms time ticks for receive timeout
Number of 500 ms time ticks for
transmit timeout
Name of this node
Name of target node
Address of ANR or zero for
asynchronous form of request. Not required for synchronous request

Session

18 - 107

Returns
scb error =

OOH
05H
06H
OBH
I4H
I5H
I6H
I9H
2IH
22H
32H
4xH

scb vcid =

Virtual Circuit ID

lS- lOS

Session

Success
request timed out
Message incomplete, issue another request
Command canceled
No call name
Name not found or Not a valid name
Name in use
Name conflict detected
Interface busy
Too many outstanding requests, retry later
Transport not installed
Network error, x may be any value

Function IIH: Listen (synchronous)
Function 91H: Listen (asynchronous)
Listen waits for a call from any node that specifically wants to communicate
with this node. The listen request completes normally when a call with
scb rname that matches the listen scb lname, is made somewhere on the network. Upon completion, this node is informed of the name of the caller and the
Virtual Circuit ID of the circuit communication can now proceed
The fields scb rto and scb sto do not take affect until the virtual circuit is
established by-the DECnet-DOS transport software.
Parameters
AH =
ES:BX =

01H
Far pointer to SCB
scb command =
scb error =
scb-rto =
scb sto =
scb lname =
scb=async =

11 H synchronous
91 H asynchronous
OOH
Number of 500 ms time ticks for receive
timeout
Number of 500 ms time ticks for transmit
timeout
Name of this node
Address of ANR or zero for asynchronous
form of request. Not required for
synchronous request.

Returns
scb error =

OOH
09H
OBH
llH
15H
21H
22H
32H
4xH

Success
No resources available
Command canceled
Local session table full
Name not found or Not a valid name
Interface busy
Too many outstanding requests, retry later
Transport not installed
Network error, x may be any value

scb vcid =

Virtual Circuit ID of the Virtual Circuit the nodes can
now communicate over

scb rname =

Name of node that issued CALL to this node

Session

18 - 109

Function 12H: Hangup (synchronous)
Function 92H: Hangup (asynchronous)
Hangup ends a virtual circuit. Any pending receive commands are terminated.
Any pending send commands will complete before the hangup completes.
Parameters
AH =
ES:BX =

01H
Far pointer to SCB
scb command =
scb error =
scb-vcid =

12H synchronous
92H asynchronous
OOH
Virtual Circuit ID of the Virtual Circuit
to hang-up
Address of ANR or zero for
asynchronous form of request. Not required for synchronous request

Returns
scb error =

18 - 110

OOH
08H
OAH
18H
21H
22H
32H
4xH

Session

Success
Invalid Virtual Circuit ID
Session closed
Session ended abnormally
Interface busy
Too many outstanding requests, retry later
Not installed
Network error, x may be any value

Function 14H: Send (synchronous)
Function 94H: Send (asynchronous)
Send data on a virtual circuit. More than one send command can be outstanding. The commands are processed in FIFO order. Each send may specify a
message length of 0 to 65536 bytes. The recommended maximum message
length is the value of the field SSB MAXMSG that is returned by the Status
function. The length specified by SSB MAXMSSG is guaranteed to be accepted by DIGITAL-developed file and-print servers.
Parameters
AH =

ES:BX =

0IH
Far pointer to SCB
scb command =
scb error =
scb-vcid =
scb_length =
scb baddr =
scb:=async =

I4H synchronous
94 H asynchronous
OOH
Virtual Circuit ID of the Virtual Circuit to
send the data over
Length of buffer pointed at by scb baddr.
o to 65535 bytes
Address of buffer to send
Address of ANR or zero for asynchronous
form of request. Not required for
synchronous request

Returns
scb error =

OOH
OlH

05H
08H
OAH
OBH

I8H
2IH
22H
32H
4xH

Success
Illegal buffer length
Command timed out
Session number out of range
Session closed
Command canceled
Session ended abnormally
Interface busy
Too many outstanding requests, retry later
Transport not installed
Network error, x may be any value

Session

18 - 111

Function 17H: Send Double (synchronous)
Function 97H: Send Double (asynchronous)
Send two buffers of data on a virtual circuit. This has the effect of concatenating successive buffers into a single message on the virtual circuit.
Parameters

AH =
ES:BX =

01H
Far pointer to SCB
scb command =
scb error =
scb-vcid =
scb_length =
scb baddr =
scb-rname =

17H synchronous
97H asynchronous
OOH
Virtual Circuit 10 of the Virtual
Circuit to send the data over
Length of first buffer pointed at by
scb baddr. 0 to 65535 bytes
Adaress of first buffer to send.
The length and address of the second
buffer to send
Length = first 2 bytes, low order byte
first
Address = next four bytes
Offset = first two bytes
Segment= next two bytes
Address of ANR or zero for
asynchronous form of request Not required for synchronous request

Returns
scb error =

18 - 112

OOH
01H
05H
08H
OAH
OBH
18H
21H
22H
32H
4xH

Session

Function I5H: Receive (synchronous)
Function 95H: Receive (asynchronous)
This service allows you to receive data on a virtual circuit. If an application has
receive and receive any requests outstanding at the same time, the received
messages are posted in the order of receive followed by Receive Any. This
allows a specific receive to take precedence over a general receive.
If multiple Receive commands are outstanding. they are processed in FIFO
order. When the Receive completes, scb length is updated to the actual
message length. If the message transmitted is larger than the available buffer
space in scb baddr, then the message-incomplete error is returned in scb error.
The application can retrieve the next portion of the message by issuing another
Receive request.

Parameters
AH =
ES:BX =

0IH
Far pointer to SCB
scb command =
scb error =
scb-vcid =
scbJength =
scb baddr =
scb=async =

I5h synchronous
95h asynchronous
OOh
Virtual Circuit ID of the Virtual
Circuit to receive the data over
Length of the buffer pointed at by
scb baddr
Adaress of buffer to receive into.
Address of ANR or zero for asynchronous form of request. Not required for synchronous request.

Returns
scb error =

OOH
0IH
05H
06H
08H
OAH
OBH
I8H
2IH
22H
32H
4xH

Success
Illegal buffer length
Command timed out
Message incomplete, issue another receive request
Incorrect Virtual Circuit ID
Session closed
Command canceled
Session ended abnormally
Interface busy
Too many outstanding requests, retry later
Transport not installed
Network error, x may be any value
The actual length of the message received

Session

18 - 113

Function I6H: Receive Any (synchronous)
Function 96H: Receive Any (asynchronous)
Receive Any receives the next message on any virtual circuit associated with
this VAXmate node. If an application has Receive and Receive Any requests
outstanding at the same time, the received messages are posted in the order of
Receive followed by Receive Any. This allows a specific receive to take precedence over a general receive.
If multiple Receive Any commands are outstanding, they are processed in

FIFO order.
When the Receive Any completes, scb length is updated to the actual message
length. If the message transmitted is larger than the available buffer space in
scb baddr, then the message-incomplete error is returned in scb error. The application can retrieve the next portion of the message by issuing-another
Receive or Receive Any request.
Parameters
AH =
ES:BX =

OlH

Far pointer to SCB
scb command =
scb error =
scb-num =
scb}ength =
scb baddr =
scb=async =

18- 114

Session

I6H synchronous
96H asynchronous
OOH
RESERVED: must be one for future
compatibility
Length of the buffer pointed at by
scb baddr
Adc:Tress of buffer to receive into.
Address of ANR or zero for
asynchronous form of request. Not required for synchronous request.

Returns
scb error =

scb vcid =
scb length =
scb-rname =

OOH
01H
05H
06H
OAH
OBH
13H
18H
19H
21H
22H
32H
4xH

Success
Illegal buffer length
Command timed out
Message incomplete, issue another receive request.
Session closed
Command canceled
Illegal scb num, RESERVED for future use.
Session ended abnormally
Name conflict detected
Interface busy
Too many outstanding requests, retry later
Transport not installed
Network error, x may be any value
Virtual Circuit ID of the Virtual Circuit data was received over.
The actual length of the message received.
Name of remote node that sent the message.

Datagram Commands
Datagrams are short packets of data sent to one or more nodes. The network
does not guarantee the delivery of a datagram. Datagram lengths must range
from 46 to 512 bytes. Because the session software does not pad a datagram
message to the minimum Ethernet packet length, the minimum length packet
you can transmit is 46 bytes.
For a node to receive a datagram, a datagram receive must be outstanding at
the time a datagram is sent.
The actual order in which datagrams are received is not guaranteed to be the
same order in which they were transmitted.

Session

18 - 115

Function 20H: Send Datagram (synchronous)
Function AOH: Send Datagram (asynchronous)
Send a datagram to a specific node. The network does not verify that everyone
(or anyone) actually received the datagram. The ordering of datagrams is not
guaranteed.
Parameters
01H
Far pointer to SCB

AH =
ES:BX =

scb command =
scb error =
scb-num =

scb baddr =
scb-rname =

20H synchronous
AOH asynchronous
OOH
RESERVED: must be one for future
compatibility
Length in bytes of the buffer pointed
at by scb_baddr in the range 46 to
512
Address of buffer to transmit from
Name of remote node to send datagram to
Address of ANR or zero for
asynchronous form of request. Not required for synchronous request.

Returns
scb error =

18 - 116

OOH
01H
OBH
14H
15H
19H
21H
22H
328
4xH

Session

Success
Illegal buffer length
Command canceled
No Call name
Name not found or not a valid name.
Name conflict detected
Interface busy
Too many outstanding requests, retry later
Transport not installed
Network error, x may be any value

Function 21H: Receive Datagram (synchronous)
Function AIH: Receive Datagram (asynchronous)
When the Receive Datagram completes, scb length is updated to the actual
datagram length. If the datagram transmitted is larger than the available
buffer space in scb baddr, then the message-incomplete error is returned in
scb error. The application can retrieve the next portion of the datagram by
issUing another Receive Datagram request.
Parameters
AH =
ES:BX =

01H
Far pointer to SCB
scb command =
scb error =
scb-num =
scb_length =
scb baddr =
scb=async =

21 H synchronous
AIH asynchronous
OOH
RESERVED: must be one for future
compatibility.
Length in bytes of the buffer pointed
at by scb baddr
Address of buffer to receive into
Address of ANR or zero for
asynchronous form of request. Not required for synchronous request.

Returns
scb error =

scb length =
scb-rname =

OOH
01H
06H
OBH
13H
19H
21H
22H
32H
4xH

Success
Illegal buffer length
Message incomplete. issue another receive request
Command canceled
RESERVED Illegal name number
Narne conflict detected
Interface busy
Too many outstanding requests, retry later
Transport not installed
Network error, x may be any value
Actual length of datagram received.
Name of remote node datagram was received from.

Session

18 - 117

Function 22H: Send Broadcast (synchronous)
Function A2H: Send Broadcast (asynchronous)
Send Broadcast sends a broadcast datagram. A datagram is sent to all machines on the local network that have an outstanding Receive Broadcast command. If the machine performing the send also has an outstanding Receive
Broadcast command, it will receive its own datagram.
As with the Send Datagram request. the network does not verify that everyone
(or anyone) actually received the broadcast datagram. The ordering of broadcast
datagrams is not guaranteed.

Parameters
AH =
ES:BX =

01H

Far pointer to SCB
scb command =
scb error =
scb-num =

scb baddr =
scb:=async =

22H synchronous
A2H Asynchronous form = A2H
OOH
RESERVED: must be one for future
compatibility
Length in bytes of the buffer pointed
at by scb baddr in the range 46 to
512
Address of buffer to transmit from
Address of ANR or zero for
asynchronous form of request. Not required for synchronous request.

Returns
scb error =

OOH
01H

OBH
19H
21H
22H
32H
4xH

18 - 118

Session

Success
Illegal buffer length
Command canceled
Name conflict detected
Interface busy
Too many outstanding requests, retry later
Transport not installed
Network error, x may be any value

Function 23H: Receive Broadcast fsynchronous)
Function A3H: Receive Broadcast (asynchronous)
Receive Broadcast requests the receive of a datagram sent using the send
broadcast command. If a receive broadcast command is not outstanding at the
time a broadcast datagram is sent, then it will not be received.
Parameters
AH =
ES:BX =

01H
Far pointer to SCB

scb command =
scb error =
scb)ength =
scb baddr =
scb:=async =

23H synchronous
A3H asynchronous
OOH
Length in bytes of the buffer pointed
at by scb baddr
Address of buffer to receive into
Address of ANR or zero for
asynchronous form of request. Not required for synchronous request.

Returns
scb error =

scb length =
scb-rname =

OOH
01H
06H
OBH
13H
19H
21H
22H
32H
4xH

Success
Illegal buffer length
Message incomplete, issue another receive request
Command canceled
RESERVED Illegal name number
Narne conflict detected
Interface busy
Too many outstanding requests, retry later
Transport not installed
Network error, x may be any value
Actual length of datagram received.
Name of remote node datagram was received from.

Session

18 - 119

DIGITAL-Specific Session Level Services
The DIGITAL-specific functions support the manipulation of network name and
node number entries that are found in the memory resident tables.
The memory resident tables are called the volatile database. The permanent
database consists of the disk resident node tables. The permanent database is
loaded into memory at network startup time. To update the permanent database, the VAXmate workstation user should use one of the network management utilities described in the VAXmate system administration documentation.
The DIGITAL-specific session level functions are:
•

Digital Function Check

•

Add an entry into node table

•

Delete entry by node number

•

Delete entry by node name

•

Read entry by node number

•

Read entry by node name

•

Read entry by index into the table (0-71)

•

Delete all entries

A DIGITAL-specific session request is performed by setting register AH =
DCH. resetting dscb err to zero, pointing ES:BX to the address of DIGITAL
Session Control Block, and doing an INT 2AH function call.
The values returned in dscb err are:
00
01
02
03
04
05
06
07
08
09

Function completed successfully
Table full, cannot add another entry
Duplicate name, node name is currently used by another entry
Duplicate number, node number is currently used by another entry
No entry with given node name
No entry with given node number
No entry with given index
Index given is out of range
Illegal function number
Out of resource, currently there is no stack space available to perform
the function, try again later
OA Cannot delete own node entry

18 - 120

Session

Function 008: DIGITAL Function Check (decfunccheck)
Function check is used to confirm the presence of the DIGITAL-developed
session level module. In addition, this function returns status on the availability
of internal resources for supporting further network services. The far pointer in
the field dscb name points to a string containing path and file name of the
DECNODE.DAT permanent database file.
Parameters
AH =
ES:BX =

DCH
Far pointer to DSCB
dscb cmd =
dscb-err =
dscb-name =

OOH
OOH
first double word contains far pointer to
DECNODE.DAT path string.

Returns
dscb err =

OOH
09H

Success
Out of resource

Session

18 - 121

Function OlH: Add a Node (decfuncadd)
This function adds a node name and its node number to the memory resident
list of nodes known to the session software. A node must appear in this list
before any communication with that node is possible. The node names and node
numbers must be unique within this VAXmate workstation.
Parameters
AH =
ES:BX =

DCH
Far pointer to DSCB
dscb cmd =
dscb-err =
dscb-name =
dscb-num =

01H
OOH
16 byte node name padded with spaces
node number

Returns
dscb err =

18 - 122

Session

OOH
01H
02H
03H
09H

Success
Table full
Duplicate node name
Duplicate node number
Out of resource

Function 02H: Delete Entry Given the Node Number
(decfuncdelnum)
This service removes a node name and number from the memory resident list
of known nodes. The node name and node number of this workstation cannot
be deleted with this function. To remove the node name and node number of
this workstation, the Delete All Node Entries function must be used.
Parameters
AH =

DCH
Far pointer to DSCB

ES:BX =

dscb cmd =
dscb-err =
dscb-num =

02H
OOH
node number

Returns
dscb err

OOH
05H
09H
OAH

Success
Node number
not found
Out of
resource
Cannot delete
own node
entry

Session

18 - 123

Function 03H: Delete Entry Given Node Name (decfuncdelname)
This service removes a node name and number from the memory resident list
of known nodes. The node name and node number of this workstation cannot
be deleted with this function. To remove the node name and node number of
this workstation, the Delete All Node Entries function must be used.
Parameters
AH =
ES:BX =

DCH
Far pointer to DSCB
dscb cmd =
dscb-err =
dscb-name =

03H
OOH
16 byte node name padded in highorder bytes with spaces

Returns
dscb err =

18 - 124

OOH
04H
09H
OAH

Session

Success
Node name not found
Out of resource
Cannot delete own node entry

Function 04H: Read Node Entry Given Node Number
~decfuncreadnum)

This service allows an application to use the node number to determine the
node name and its position in the memory resident list of known nodes.
Parameters
AH =
ES:BX =

DCH
Far pointer to DSCB
dscb cmd =
dscb-err =
dscb-num =

04H
OOH
node number

Returns
dscb err =

OOH
05H
09H

dscb index
dscb-name

Position in internal node table
I6-byte node name padded in the high-order bytes with spaces

Success
No entry with given node number
Out of resource

Session

18 - 125

Function 05H: Read Node Entry Given Node Name
(decfuncreadname)
This service allows an application to use the node name to determine the node
number and its position in the memory resident list of known nodes.

Parameters
AH =
ES:BX =

DCH
Far pointer to DSCB
dscb cmd =
dscb-err =
dscb-name =

05H
OOH
I6-byte node name padded in the high
order bytes with spaces

Returns
dscb err =

OOH
04H
09H

dscb index =
dscb-num =

18- 126

Session

Success
No entry with given node name
Out of resource
Position in internal node table
Node number

Function 06H: Read Node Entry Given Index (decfuncreadindex)
This services returns the node name and node number for a given index position in the memory resident list of nodes.
The value dscb index ranges from 0 to 71. Seventy-two is the maximum
number of node name and number pairs contained in the session internal
database.
Parameters

AH =

ES:BX =

DCH
Far pointer to

DSCB
dscb cmd =
dscb-err =
dscb-index =

06H
OOH
Position in internal node table

Returns

dscb err

dscb name =
dscb num =

OOH
06H
07H
09H

Success
No entry at the given index
Index out of range
Out of resource
16 byte node name padded in the high order bytes
with spaces
Node number

Session

18 - 127

Function 07H: Delete All Node Entries (decfuncdelall)
This service deletes all entries in the memory resident node list of the session
level. Note that the node name and node number of this workstation will also
be deleted.
Parameters
AH =
ES:BX =

DCH
Far pointer to DSCB
dscb cmd =
dscb-err

07H
OOH

Returns
dscb err =

18 - 128

OOH
09H

Session

Success
Out of resource

Server Message Block (SMB) Protocol
The Server Message Block (SMB) protocol allows the VAXmate workstations
running the MS-DOS operating system and the VAXmate network software to
access and share files stored on a server.
Functions and data are passed between a server and a workstation with a
Server Message Block (SMB). The 5MB data structure and functions are
described in:
•

ServerlRedirector File Sharing Protocol
Microsoft Corporation and Intel Corporation
Intel Part Number 136329-001

•

IBM Personal Computer Seminar Proceedings,
Volume 2, Number 8, October 1984
IBM Corportation
IMPORTANT
DIGITAL's implementation of the 5MB protocol is based on the
guidelines in the above documents and other applicable industry
standards. DIGITAL is not responsible for inaccuracies or errors
in those documents. DIGITAL's implementation of the 5MB
protocol is subject to change according to changes in industry
standards.

The 5MB protocol allows for extended functions, which are identified by the
function code FFH. The actual function code is stored in the reserved field
5MB REH.
DIGITAL's implementation of the 5MB protocol includes one extended 5MB
function, the Get Current Date and Time function, which is described in the
next section.

Server Message Block Protocol

18 - 129

Extended Function DOH: Get Current Date and Time
Parameters
None
Returns
10 signed 16-bit word parameters. The return parameters are:
•
•
•
•
•
•
•
•
•
•

Year
Month (for example, January = 1)
Day of month
Day of week (for example, Sunday = 0)
Hour (0 -24)
Minutes (0-59)
Seconds (0-59)
Milliseconds (0-999)
Timezone in minutes west (or east) of Greenwich (for example, Eastern
= 300, Switzerland = -60)
Current local daylight savings correction, in minutes (usually + 60 or 601

This function returns the local date and time. The workstation must adjust the
time by the returned time zone offset to produce coordintated universal time,
UTe. or Greenwich mean time, (GMT). If the server and the workstation are in
different time zones, note that the returned time zone is that of the server.
The following C language definitions describe the date and time information
returned by the server:
#define date_year
#define date_month
#define date_day
#define date_week
#define date_hour
#define date_minute
#define date_second
#define date_mills
#define date_zone
#define date_savings

18 - 130

smb_vwv[O]
smb_vwv[l]
smb_vwv[2]
smb_vwv[3]
smb_vwv[4]
smb_vwv[5]
smb_vwv[6]
smb_vwv[7]
smb_vwv[8]
smb3wv[9]

Server Message Block Protocol

Appendix A
Support Code for Examples
This appendix describes several subroutines and include files that support the
program examples, but are not specific to a particular hardware example.

File: SUPPORT.ASM
This file contains assembly language subroutines that could not be written in
the C programming language .
•••••••••••••••••••••••

•

••

•••••••••••••••••••••

•••••

••

•••••••••••••••••••••••••••

••••••••• ,.

t. t t • • • • • • • • • • • • • • • • "

; declare some C compiler compatible segment types
•••••••••••••••••••••••••••••••••

_TEXT
_TEXT
CONST
CONST
_BSS
_BSS
_DATA
_DATA
DGROUP

,., ••••

J ••••• I

I. "

•••••••••••

•••••••••••••••••••••••••••

J, •••••• , •• , I • • • • • I ' "

•• '

•••••• ,

•••••••

SEGMENT BYTE PUBLIC 'CODE'
ENDS
SEGMENT WORD PUBLIC 'CONST'
ENDS
SEGMENT WORD PUBLIC 'BSS'
ENDS
SEGMENT WORD PUBLIC 'DATA'
ENDS
GROUP CONST, _BSS, _DATA
ASSUME CS: _TEXT, DS: DGROUP, SS: DGROUP, ES: DGROUP

EXTRN _rtc_int_hand:NEAR
EXTRN _kyb_int_hand:NEAR
EXTRN _mouse_int:NEAR
EXTRN _fdc_int_hand:NEAR
EXTRN _hdc_int_hand:NEAR
EXTRN _coml_int:NEAR
EXTRN _modem_int:NEAR
EXTRN _printer_int:NEAR

Support Code for Examples

A-I

_TEXT SEGMENT

t., ••••••• ,. t,., ••••• "., ••
At interrupt time, the current data segment is unknown. The following
statement provides storage for the interrupt time data segment.
Later, this storage is initialized to the value of the interrupt time
data segment .
........................................................................
t"
I'
I'.' ••••••• ,., •••••• ,., t " " " " " " " " t , •• "
•••••••••••••••••••••••••••

••••• , . , . , ••• "

••

•••

••••••• ,

•• t

•••••••••••••••••••••••••••••••••••••••••••••

•• ,

•••••••••• " , . , . ,

••

•••• "

••

; place to store data segment

.........................................................................
t,.",.", t."."" ••
•• , . It •••••• ,

_ini_it_ds

• • • • • • • • • " . , ••••• " . , ••••• , . " . , •• " ,

- C callable routine to store the interrupt time data
segment so that the correct data segment can be used at
interrupt time

parameters: ds register
uses: cs:it_ds (1 word of R!W storage in cs segment)
returns: nothing
..........................
, ................................ ,
t.
t " " " " t., ••••••• t""'" t • • • • • , . , t • • t"•"•"• •

.". I

••••••••

•••

PUBLIC _ini_it_ds
_ini_it_ds PRDC NEAR
mov
word ptr cs:it_ds, ds
ret
_inLit_ds ENDP

A-2

........

••••••••

Support Code for Examples

save it for later

................................................................................................................................
.... , .... , ....... .... .......... ........ ...............
,"""',
,
"
,
,
The following routines provide entry points for each of the hardware
interrupt vectors. At the entry point, the ax register is saved and a
pointer to the interrupt handler is loaded into ax. Then a jump is
made to comhand. The comhand routine saves additional registers,
calls the interrupt handler through ax, and on return from the
handler, it restores the registers including ax.

parameters: none
uses: none
(see comhand, it restores the ax register)
returns: nothing
................................................................................................................................................
•••••••••••••••••••••••••••••• ,

••••••• I

PUBLIC _hdw_int_08
_hdw_int_08 PRDC NEAR
iret
_hdw_int_D8 ENDP

•• '

•••••••• "

••••• , •••••••••••••••

re-vector INT 08R

PUBLIC _hdw_int_09
_hdw_int_09 PRDC NEAR
j re-vector INT 09R
push
ax
j save ax
mov
ax, offset _TEXT:_kyb_int_hand
jmp
short comhand
_hdw_int_09 ENDP
PUBLIC _hdw_int_Oa
_hdw_int_Oa PRDC NEAR
iret
_hdw_int_Oa ENDP
PUBLIC _hdw_int_Ob
_hdw_int_Ob PRDC NEAR
push
ax
mov
ax, offset _TEXT:_modem_int
jmp
short comhand
_hdw_int_Ob ENDP
PUBLIC _hdw_int_Oc
_hdw_int_Oc PRDC NEAR
push
ax
mov
ax, offset _TEXT:_coml_int
short comhand
jmp
_hdw_int_Oc ENDP

re-vector INT OAR

re-vector INT OBR
save ax

re-vector INT OCR
save ax

Support Code for Examples

A- 3

PUBLIC _hdw_int_Od
_hdw_int_Od PRDC NEAR
iret
_hdw_int_Od ENDP

re-vector INT ODH

PUBLIC _hdw_int_Oe
_hdw_int_Oe PRDC NEAR
; re-vector INT OEH
push
ax
; save ax
mov
ax, offset _TEXT:_fdc_int_hand
jmp
short comhand
_hdw_int_Oe ENDP
PUBLIC _hdw_int_Of
_hdw_int_Of PRDC NEAR
iret
_hdw_int_Of ENDP

re-vector INT OFH

PUBLIC _hdw_int_70
_hdw_int_70 PRDC NEAR
; re-vector INT 70H
push
ax
; save ax
mov
ax, offset _TEXT:_rtc_int_hand
jmp
short comhand
_hdw_int_70 ENDP
PUBLIC _hdw_int_71
_hdw_int_71 PRDC NEAR
iret
_hdw_int_71 ENDP
PUBLIC _hdw_int_72
_hdw_int_72 PRDC NEAR
iret
_hdw_int_72 ENDP

re-vector INT 71H

re-vector INT 72H

PUBLIC _hdw_int_73
_hdw_int_73 PRDC NEAR
re-vector INT 73H
push
ax
save ax
mov
ax, offset _TEXT:_printer_int
jmp
short comhand
_hdw_int_73 ENDP

A-4

Support Code for Examples

PUBLIC _hdw_int_74
_hdw_int_74 PROC NEAR
push
ax
mov
ax, offset _TEXT:_mouse_int
jmp
short comhand
_hdw_int_74 ENDP
PUBLIC _hdw_int_75
_hdw_int_75 PROC NEAR
iret
_hdw_int_75 ENDP

re-vector INT 14K
save ax

re-vector INT 168

PUBLIC _hdw_int_76
_hdw_int_76 PROC NEAR
; re-vector INT 768
push
ax
; save ax
mov
ax, offset _TEXT:_hdc_int_hand
jmp
short comhand
_hdw_int_76 ENDP
PUBLIC _hdw_int_77
_hdw_int_77 PROC NEAR
iret
_hdw_int_77 ENDP

re-vector INT 178

Support Code for Examples

A-fj

...................................................................... ,' ,
••••••••••••••••• t ••• I t t " " "

I."""

t., I '"

t ' . " , t"

" ' ••••• , . , ' , . , ••• , '

The following routine is a common intermediate interrupt handler.
It saves and restores volatile registers and calls the handler.
parameters: ax = pointer to interrupt handler
uses: none (ax was previously saved and is restored here)
returns: nothing

.........................................................................
• • • , " , • • • • • • , • • • • • • • , • • • • • • • • • • • • • , • • • • • • t t •• t t . , t t t t t • • • • • • • • • • • • • • • t • •

PUBLIC comhand
comhand
PROC NEAR
push
bx
push
cx
push
dx
push
es
push
ds
mov
ds, word ptr cs:it_ds
call
ax
pop
ds
pop
es
pop
dx
pop
cx
pop
bx
pop
ax
iret
comhand
ENDP

A-6

Support Code for Examples

common handler
save bx
save cx
save dx
save e8
save ds
retrieve IT data segment
call the C function
restore ds
restore es
restore dx
restore cx
restore bx
restore ax
return from interrupt

.........................................................................
•••

•••

I."'"

••

•••••

••

•• '

••••••••

•• t

•••••••••••••

••••

The following routine is a C compatible function that does WORD I/O.
parameters: stack contains the port and value
uses: dx and ax (which are saved and restored)
returns: nothing

.........................................................................
•

•

It' •

PUBLIC
_outw

••••

•

••• J ••• ,

•

••••

J •••••••• I

••••••••••••• ,

_outw
PROC NEAR

push
mov
push
push

bp
bp,sp
dx
ax

save bp
set up frame pointer
save dx
save ax

mov
mov
out

dx, WORD PTR [bp+4]
ax, WORD PTR [bp+6]
dx, ax

C port parameter
C word value
output word to port

pop
pop
pop
ret

ax
dx
bp

restore ax
restore dx
restore bp

_outw

•••••••••••

ENDP

Support Code for Examples

A-7

.........................................................................
......................................
, ............. , ........ , ..........
_int_off - C callable routine to disable CPU interrupt

parameters: none
uses: ax
returns: state of IF flag when this routine was called

.........................................................................
• , ••• ""'" II" II. "" "'1'" '" '" "" •••••••• I.' ••••• "" """ I •••• "
PUBLIC _int_off
_int_off PRDC NEAR
pushf
pop
and
cli
ret

push flags
pop flags to ax
isolate IF bit
interrupts off
return IF state to caller

ax
aX,0200H

............................................................... , ........ .
••••••••••••••• " "

•••• t •••••••••••••••••••••••••••••••••• I

••••••• """

_int_on - C callable routine to enable CPU interrupt
parameters: [sp + 2] a state of IF when _int_off was called
uses: nothing
returns: nothing

..•.••••
, .... , ................................................................ .
, ••••.. " .......•..•..... I ...•. I.' •...•.••••......••.....•••••.• , ••
PUBLIC _int_on
_int_on PRDC NEAR
push
mov
test
pop

bp
bp,sp
word ptr [bp + 4], OffffH
bp
int_on1

sti

save frame pointer
setup new frame pointer
test previous IF state
restore frame pointer
don't set interrupt if zero
interrupts on

return to caller

_TEXT ENDS
END

A-8

Support Code for Examples

File: EXAMPLE.H
The include file, EXAMPLE.H, contains the structure declaration, MESSAGE.
The MESSAGE structure is used in each of the hardware example's menus.
Additionally, this file contains some common constant definitions and some
function return types.

/***********************************************************************/
/* define MESSAGE structure type

/***********************************************************************/
typedef struct
{

int row;
int col;
char *mess;

/* row location of text */
/* col location of text */
/* the message to display */

} MESSAGE;

/***********************************************************************/
/* define some widely used constants

/***********************************************************************/

#define ON
#define TRUE
#define OFF
#define FALSE

-1
-1
0
0

/***********************************************************************/
/* declare some return types

/***********************************************************************/
void int_onO;
int int_off 0 ;
int get_key 0 ;
int rb_out 0 ;
int rb_inO;
void init_rbO;
int cursor_off();
void shw_date 0 ;
void shw_timeO;

Support Code for Examples

A-9

File: KYB.H
The include file, KYB.H, defines the names of the LK250 function keys as the
value returned by the keyboard interrupt handler. These are the same values
returned by the ROM BIOS.

/ •••••••••• *************************************************************/
/* kyb.h - define function key names as value returned by ROM BIOS
/*
Note: keyboard demo return. same VALUES as the ROM BIOS
/*
All function keys return NULL byte, then this value

*/
*/
*/

/*.*******************.*************************************************/
#define Fl Ox3b
#define F2 Ox3c
#define F3 Ox3d
#define F4 Ox3e
#define F6 Ox3f
#define F6 Ox40
#define F7 Ox4l
#define F8 Ox42
#define F9 Ox43
#define FlO Ox44
#define Fll Ox8f
#define F12 Ox9O
#define F13 Ox9l
#define F14 Ox92
#define F16 Ox93
#define F16 Ox94
#define F17 Ox96
#define F18 Ox96
#define F19 Ox97
#define F20 Ox98

A-10

Support Code for Examples

/* Function key Fl */
/* Function key F2 */
/* Function key F3 */
/* Function key F4 */
/* Function key F6 */
/* Function key F6 */
/* Function key F7 */
/* Function key F8 */
/* Function key F9 */
/* Function key FlO */
/* Function key Fll */
/. Function key F12 ./

/* Function key F13 */
/* Function key F14 */
/* Function key F16 */
/* Function key F16 */
/* Function key F17 */
/* Function key F18 */
/* Function key F19 */
/* Function key F20 */

File: RB.H
The include file, RB.H, declares the ring buffer control structure, RING BUFF.
In the example programs, the ring buffer control structure is used for all serial
communications devices.
/***********************************************************************/
/* define a ring buffer control structure
*/
/***********************************************************************/
typedef struct
{

char *pbs;
char *pbe;
char *pbh;
char *pbt;
int size;
int count;
int high_lim;
int low_lim;
}

/* pointer to buffer start */
/* pointer to buffer end + 1 */
/* pointer to buffer head */
/* pointer to buffer tail */
/* buffer size */
/* # of characters in buffer */
/* buffer near full limit */
/* buffer near empty limit */

RING_BUFF;

Support Code for Examples

A-ll

File: VECTORS.C
The file VECTORS.C contains two C functions, iv init and iv rest. The function. iv init. initializes the indicated interrupt vector with the address of an
example interrupt handler. It does this by saving the current interrupt handler
address and installing an interrupt handler address from one of those in the
assembly language source file SUPPORT.ASM. The function, iv rest, restores
the previously saved interrupt handler address.
-

/***********************************************************************/
/* declare the external interrupt vector entry poiuts
*/
/***********************************************************************/
extern int hdw_int_700;
extern int hdw_int_710 ;
extern int hdw_int_720 ;
extern int hdw_int_730 ;
extern int hdw_int_740 ;
extern int hdw_int_750 ;
extern int hdw_int_760 ;
extern int hdw_int_770 ;
extern int hdw_int_080;
extern int hdw_int_090;
extern int hdw_int_OaO;
extern int hdw_int_ObO;
extern int hdw_int_Oc 0 ;
extern int hdw_int_OdO;
extern int hdw_int_Oe 0 ;
extern int hdw_int_Of 0 ;

A- 12

/* real time clock */
/* redirect to int OAH, old irq2 */
/* Ethernet controller */
/* serial printer port */
/* mouse port */
/* 80287 error */
/* hard disk controller */
/* unassigned */
/* 8254 counter/timer */
/* keyboard */
/* reserved - slave controller */
/* optional modem/COM2 serial port */
/* COMl serial port */
/* unassigned */
/* diskette drive controller */
/* optional LPTl parallel printer port */

Support Code for Examples

/***********************************************************************/
/* declare storage for old vectors and define an array of new vectors */
/***********************************************************************/
int (far *old_iv[16]) 0;
int (far *new_iv[16]) 0

/* array of far pointers to functions */
/* array of far pointers to functi~ns */

{

bdw_int_70,
bdw_int_71,
bdw_int_72,
bdw_intJ3,
bdw_int_74,
bdw_int_75,
bdw_int_76,
bdw_int_77,
bdw_int_08,
bdw_int_09,
bdw_int_Oa,
bdw_int_Ob,
bdw_int_Oc,
bdw_int_Od,
bdw_int_Oe,
bdw_int_Of
};

Support Code for Examples

A- 13

/*****************************.*****************************************/
/* iv_init() - Based on the interrupt number, this routine saves the
*/
/*
old vector and installs a new vector. It is assumed
*/
/*
that the new vector does not link to the old vector.
*/
/***********************************************************************/
/* interrupt vector initialize */
/* interrupt number for vector */
{

/* This declaration declares a 32-bit pointer that points to */
/* another 32-bit pointer (the interrupt vector) that points */
/* to a function (the interrupt handler), which returns an */
/* integer value (because a pointer to void is illegal) */
int (far * far *piv)();
int i_flag;

/* far pointer to a far pointer to a function */
/* CPU IF state */

piv = (int (far * far *)(»«long)int_num « 2);/* pointer to vector */
if(int_num > OxOf) int_num -= Ox70;
/* adust index into array */
old_iv[int_num] = *piv;
/* save old vector */
i_flag = int_off();
/* no interrupts allowed */
*piv = new_iv[int_num];
/* install new vector */
int_on(Lflag) ;
/* allow interrupts */
}

A- 14

Support Code for Examples

/***********************************************************************/
/* iv_rest() - Based on the interrupt number, this routine restores
*/
/*
the previously saved vector.
*/
/***********************************************************************/
/* interrupt vector restore */
/* interrupt number for vector */
{

/* far pointer to a far pointer to a function */
/* CPU IF state */

piv = (int (far * far *)(»«long)int_num « 2);/* pointer to vector */
if(int_num > OxOf) int_num -= Ox70;
/* adjust index into array */
i_flag = int_off();
/* no interrupts allowed */
*piv = old_iv[int_numl;
/* restore old vector */
int_on(Lflag) ;
/* allow interrupts */
}

Support Code for Examples

A-15

File: RB.C
The file, RB.C, contains two C functions, rb in and rb out. The function, rb in,
stores characters in a ring buffer. the function, rb out;-retrieves characters from a ring buffer. In the example programs, ring-buffers are used for all serial
communications devices.
#include "rb.h"
/***********************************************************************/
/* rb_out() - get character from ring buffer
*/
/***********************************************************************/
int rb_out(prb. pc)
register RING_BUFF *prb;
char
*pc;

/* pointer to ring buff struct */
/* put retrieved char here */

{

if (prb->count)

/* any characters in buffer 1 */

{

*pc = *prb->pbt++;
if(prb->pbt == prb->pbe)
prb->pbt = prb->pbs;
intr_flg = int_off();
prb->count--;
int_on(intr_flg);
if(prb->count == prb->low_Iim)
return(O);
else return(l);

/* get character from buffer */
/* time to wrap pointer 1 */
/* wrap to start of buffer */
/* no interrupts allowed */
/* decrement count */
/* allow interruppts */
/* buffer near empty 1 */
/* indicate restart flow */
/* normal process */

}

else return(-l);
}

A- 16

Support Code for Examples

/* nothing available */

/***********************************************************************/
/* rb_in() - put charater in to ring buffer
*/
/***********************************************************************/
int rb_in(prb, c)
register RING_BUFF *prb;
char c;

/* pointer to ring buff struct */
/* character to put in buffer */

{

int

intr_flg;

i f (prb->count
{

prb->size)

return(-l);

/* buffer absolutely full ? */
/* can't do anything */

}

else
{

*prb->pbh = c;
if(++prb->pbh == prb->pbe)
prb->pbh = prb->pbs;
intr_flg = int_off();
prb->count++;
int_on(intr_flg);
if(prb->count >= prb->high_Iim)
return(O);
else return(1);

/* put character in buffer */
/* advance ptr, wrap ptr ? */
/* wrap to start of buffer */
/* no interrupts allowed */
/* increment count */
/* allow interrupts */
/* buffer almost full ? */
/* indicate almost full */
/* allow more to come in */

}
}

Support Code for Examples

A-17

File: DEMO.C
The file, DEMO.C, contains several functions that support the example programs. The primary function, demo, displays the main menu and drives all of
the example programs.
#include "video.h"
#include "kyb.h"
#include "example.h"
char glb_attr = Ox07;

/* default attribute byte */

/***********************************************************************/
/* disp_str() - at specified location, display a string of text
*/
/***********************************************************************/
disp_str(row, col, pc)
/* row of start location */
/* column of start location */
/* pointer to beginning of null terminated string */

int row;
int col;
char *pc;
{

while(*pc) disp_t(row, col++, *pc++, glb_attr);

/* display the line */

}

/***********************************************************************/
/* disp_menu() - display a menu from an array of MESSAGE
*/
/***********************************************************************/

MESSAGE *pm;

/* pointer to an array of MESSAGE structures */

{

clear_vid_mem();
/* clear the screen */
cursor_off (0, 0);
/* turn the cursor off */
shw_dateO;
/* display the date */
shw_timeO;
/* display the time */
for( ; pm->mess; pm++)
/* do until null message detected */
disp_str(pm->row, pm->col, pm->mess, glb_attr); /* display string */
}

A- 18

Support Code for Examples

/***********************************************************************/
/* get_fkey() - get a function key and return it's value
*/
/***********************************************************************/
unsigned char get_fkey()
{

unsigned char c;

/* temporary storage for key value */

while (1)

/* until break out */

{

if(get_key(&c)
chk_dt();

>= 0 && c == 0)

break;
/* function key 1 */
/* update date and time while waiting 1 */

}

while(l)

/* until return */

{

if(get_key(kc)
chk_dt();

>= 0)

return(c);
/* return function key */
/* update date and time while waiting 1 */

}
}

/***********************************************************************/
/* get_keys() - get string of characters from keyboard input buffer
*/
/***********************************************************************/
get_keys (row , col, pc)
int row;
int col;
char *pc;

/* get string of char from input buf */

/* row location to start displaying keyboard input */
/* column location to start displaying keyboard input */
/* where to store keyboard input */

{

char c;
int tcol

col;

/* temporary storage */
/* remember the start column */

Support Code for Examples

A-19

*pc = ' ';
while (1)

/* clear the first location */
/* do forever, actually until a return key */

{

cursor_on(row, tcol);
while (1)

/* position cursor and turn it on */
/* do forever, actually until we have a key */

{

if(get_key(&c) < 0)
if(c == OxOO) beep();
else break;
chk_dtO;

/* get scan code from input buff */
/* no function keys please */
/* otherwise, break out */
/* update date and time while waiting ? */

}

while(get_key(&c) < 0)
chk_dtO;
if(c == OxOd)

/* get char from input buff */
/* update date and time while waiting ? */
/* return key ? */

{

*pc = OxOO;
cursor_off (0, 0);
return;

/* terminate input string with a null */
/* turn cursor off */
/* return to caller */

else if(c == Ox08)

/* back space ? */

}
{

i f (tcol > col)
{

/* room to back up ? */

*(--pc) = ' '; /* remove last character and decrement pointer */
disp_t(row, --tcol, *pc, glb_attr);
/* redisplay line */
}

else beepO;

/* if can't back up, then beep */

else if(c == OxOO)

/* function or modified key ? */

}

{

while(get_key(&c) < 0)
chk_dtO;
beepO;

/* dump key that follows */
/* update date and time while waiting ? */
/* let them know we dumped it */

}

else
{

*pc++ = c;
/* concatenate to input string */
disp_t(row, tcol++, c, glb_attr);
/* redisplay line */
}
}
}

A- 20

Support Code for Examples

/***********************************************************************/
/* chk_dt() - See if time to display date or time

/***********************************************************************/
chk_dt()
{

extern int time_flag;
extern int date_flag;
int intcflag;

/* located in real time clock interrupt handler */
/* located in real time clock interrupt handler */
/* temporary storage for CPU IF state */

if (time3Iag)

/* time flag set by RTC handler ? */

{

shw_timeO;
intr_flag = int_off();
time_flag = 0;
int_on(intr_flag);

/* display the time */
/* no interrupts please */
/* clear the time flag */
/* allow interrupts */

}

if (date_flag)

/* date flag set by RTe handler ? */

{

shw_dateO;
intr_flag = int_off();
date_flag = 0;
int_on(intr_flag);

/* show the date */
/* no interrupts please */
/* clear the date flag */
/* allow interrupts */

}
}

Support Code for Examples

A- 21

/***********************************************************************/
/* main() - execute all examples from main menu

/***********************************************************************/
main 0
{

static MESSAGE mmain[] =

/* opening menu */

{

3, 24, "VAXmate Hardware Programming Example" },
6, 24, "Fl. CMOS / Real Time Clock" },
6, 24, "F2. 8264 Timer .t Speaker" },
7, 24, "F3. Video System" },
8, 24, "F4. Keyboard" },
9, 24, "F6. Serial Communications" },
{ 10, 24, "F6.
Mouse" },
{ 11, 24, "F7. Diskette Drive" },
{ 12, 24, "F8. Hard Disk" },
{ 13, 24, "FlO. Exit From Demo" },
{ 14, 24, "Fll. Warm Boot" },
{ 0, 0, o },
{
{
{
{
{
{

};

static MESSAGE caution[] =

/* caution menu */

{

3, 30,
6, 31,
{ 6, 30,
{
7, 33,
{ 10, 33,
{ 11, 33,
{ 0, 0,
{

"***** WARNING *****" },

{

"THIS DISK EXAMPLE" },
"CAN DESTROY THE DATA" },
"ON YOUR DISK" },
"Fl. Continue" },
"FlO. Main Menu" },

o },

};

int intr31ag;
int key;

A- 22

/* temporary storage for CPU IF state */
/* temporary storage for input key */

Support Code for Examples

intr_flag = int_off();
/* no interrupts while I take over hardware */
set_mode(3);
/* set the video mode to ROM BIOS default */
clear_vid_mem();
/* clear the screen */
ini_it_ds();
/* initialize pointer to interrupt time data segment */
/* initialize peripheral interupt controllers */
picinitO;
dma_initO;
/* initialize dma controller */
rtc_initO;
/* intialize real time clock */
kyb_initO;
/* initialize keyboard */
dma_open(2);
/* open dma channel 2 for diskette controller */
fdc_initO;
/* initalize diskette controller */
hdc_initO;
/* initialize hard disk controller */
int_on(intr_flag);
/* allow interrupts */
while (1)
{

disp_menu(mmain) ;
switch(get_fkey(»

/* display the main menu */
/* get function key for menu selection */

{

case Fl:
rtcO;
break;
case F2:
tim_spkO;
break;
case F3:
videoO;
break;
case F4:
kyb_exmO;
break;

/* run real time clock example ? */

/* run timer/speaker example ? */

/* run video example ? */

/* run keyboard example ? */

case F5:
soO;
break;

/* run serial example ? */

case F6:
mouse 0
break;

/* run mouse example ? */

Support Code for Examples

A- 23

case F7:
/* run diskette controller example 7 */
for(key = 0; (key != Fl) tt (key !- FlO); )
/* abort 7 */
{

disp_menu(caution);
key = get_fkey();

/* display caution message */
/* get a function key */

if(key == Fl) fdc();
break;

/* proceed to example '? */

}

case F8:
for (key

/* run hard disk controller example '? */
0; (key != Fl) tt (key != FlO); )
/* abort 7 */

{

disp_menu(caution);
key = get_fkey();

/* display caution message */
. /* get function key */

if(key == Fl) hdc();
break;

/* proceed to example '? */

}

case FlO:
intr_flag
rtc_restO;
kyb_restO;
fdc_restO;
hdcrestO;
clear_vid_mem();
cursor_on(O, 0);

/* exit from demo '? */
/* no interrupts please */
/* restore old real time clock vector */
/* restore old keyboard vector */
/* restore diskette contoller vector */
/* restore hard disk controller vector */
/* clear the screen */
/* move cursor to top left and turn it on */

/* restore normal MSDOS state of interrupts */
/* master's slave input (IRQ2) always on after reset */
imask(O, 0, 1);
/* timer on */
imask(O, 1, 1);
/* keyboard on */
imask(O, 6, 1);
/* diskette controller on */
imask(l, 3, 1);
/* serial printer port on */
imask(l, 6, 1);
/* hard disk controller */
int_on(intr_flag);
/* allow interrupts */
exit(O);
/* normal exit */
case Fll:
sys_reset 0 ;
break;
}

}
}

A- 24

Support Code for Examples

/* warm boot '? */

int far *warm_boot = (int far *)Ox00400072;
int (far *p_reset)()
(int (far *)(»OxffffOOOO;
*warm_boot = Ox1234;
(*p_reset) 0 ;

/* indicate warm boot */
/* call boot code */
/* and never return */

}

Support Code for Examples

A- 25

Appendix B
80286 Instruction Set
Instruction

Operation

AAA
AAD
AAM
AAS
ADC
ADD
AND
ARPL
BOUND
CALL
CBW
CLC
CLD
CLI
CLTS
CMC
CMP
CMPS
CWD
DAA
DAS
DEC
DIV
ENTER
ESC
HLT
IDIV
IMUL
IN
INC

ASCII adjust for addition
ASCII adjust for division
ASCII adjust for multiply
ASCII adjust for subtraction
Add byte or word with carry
Add byte or word
AND byte or word
Adjust RPL field of selector
Detect values outside prescribed range
Call procedure
Convert byte into word
Clear carry flag
Clear direction flag
Clear interrupt enable flag
Clear task switched flag
Complement carry flag
Compare byte or word
Compare byte or word string
Convert word to double word
Decimal adjust for addition
Decimal adjust for subtraction
Decrement byte or word by 1
Unsigned divide by byte or word
Make stack frame for procedure parameters
Escape to extension processor
Halt until interrupt or reset
Integer divide byte or word (signed)
Integer multiply byte or word (signed)
Input byte or word
Increment byte or word by 1

80286 Instruction Set

B-1

Instruction

Operation

INS
INT
INTO
IRET
JA/JNBE
JAE/JNB
JB/JNAE
JBE/JNA
JC
JCXZ
JE/JZ
JG/JNLE
JGE/JNL
JL/JNGE
JLE/JNG
JMP
JNC
JNE/JNZ
JNO
JNP/JPO
JNS
JO
JP/JPE
JS
LAHF
LAR
LDS
LEA
LEAVE
LES
LGDT/LIDT
LLDT
LMSW
LOCK
LODS
LOOP
LOOPE/LOOPZ
LOOPNE/LOOPNZ
LSL
LTR
MOV
MOVS
MUL

Input byte or word string
Interrupt
Interrupt if overflow
Interrupt return
Jump if above/not below or equal
Jump if above or equal/not below
Jump if below/not above or equal
Jump if below or equal/not above
Jump if carry
Jump if register CX is 0
Jump if equal/zero
Jump if greater/not less or equal
Jump if greater or equal/not less
Jump if less/not greater or equal
Jump if less or equal/not greater
Jump
Jump if not carry
Jump if not equal/not zero
Jump if not overflow
Jump if not parity/parity odd
Jump if not sign
Jump if overflow
Jump if parity/parity even
Jump if sign
Load AH register from flags
Load access rights byte
Load double-word pointer to DS and word register
Load effective address
Restore stack for procedure exit
Load double-word pointer to ES and word register
Load global/interrupt descriptor table
Load local descriptor table register
Load machine status word
Lock bus during next instruction
Load byte or word string
Loop with CX as a counter
Loop while equal/zero and CX not equal to 0
Loop while not equal/not zero and CX not equal to 0
Load segment limit
Load task register
Move byte or word
Move byte or word string
Multiply byte or word unsigned

B-2

80286 Instruction Set

(80286 Instruction Set - cont.)

Instruction

Operation

(80286 Instruction Set - cont.)

NEO
NOP
NOT
OR
OUT
OUTS
POP
POPA
POPF
PUSH
PUSHA
PUSHF
RCL
RCR
REP
REPE/REPZ
REPNE/REPNZ
RET
ROL
ROR
SAHF
SAR
SBB
SCAS
SOOT/SlOT
SHL/SAL
SHR
SLOT
SMSW
STC
STO
STI
STOS
STR
SUB
TEST
VERRNERW
WAIT
XCHO
XLAT
XOR

Negative byte or word
No operation
NOT byte or word
Inclusive-OR byte or word
Output byte or word
Output bytes or word string
Pop word off stack
Pop all registers from stack
Pop flags off stack
Push word onto stack
Push all registers onto stack
Push flags onto stack
Rotate left through carry byte or word
Rotate right through carry byte or word
Repeat
Repeat while equal/zero
Repeat while not equal/not zero
Return from subroutine
Rotate left byte or word
Rotate right byte or word
Store AH register in flags
Shift arithmetic right byte or word
Subtract byte or word with borrow
Scan byte or word string
Store global/interrupt descriptor table register
Shift logical/arithmetic left byte or word
Shift logical right byte or word
Store local descriptor table register
Store machine status word
Set carry flag
Set direction flag
Set interrupt enable flag
Store byte or word string
Store task register
Subtract byte or word
Logical AND of operands (only sets flags)
Verify a segment for read or write
Wait for BUSY not active
Exchange byte or word
Translate byte (from look-up table)
Exclusive-OR byte or word

80286 Instruction Set

B-3

Appendix C
VT220 and VT240
Terminal Emulators
This appendix is divided into three parts:
VT220 Emulator

Discusses the differences in characteristics and
functionality between the VAXmate workstation's
VT220 emulator and DIGITAL's VT220 terminal.

VT240 Emulator

Discusses the differences in characteristics and
functionality between the VAXmate workstation's
VT240 emulator and DIGITAL's VT240 terminal.

Tables

Contains the DEC multinational, ISO Latin-I, and
special graphics character set tables.

Wherever the words VT220 or VT240 emulator are used, it means the VT220
or VT240 terminal emulator for the VAXmate workstation.
For more information on the DIGITAL VT220 and VT240 terminals, see the:

•
•

VT220 Series Programmer's Reference Manual
VT240 Series Programmer's Reference Manual

It is assumed that you have read the VAXmate User's Guide.

VT220 and VT240 Terminal Emulators

C- 1

VT220 Emulator and VT220 Terminal
Differences
This part of the appendix describes the VT220 emulator and VT220 terminal
differences.

Saving and Restoring Set-Up Selections
The VT220 emulator supports saving and recalling Set-Up selections from userspecified files. The VT220 terminal supports the saving and recalling of only
one set of Set-Up selections.

Video Differences
Scrolling
There is no smooth scroll/jump scroll option in the VT220 emulator. The
VT220 emulator is always in jump scroll.

Blinking Characters Remapped
The VT220 emulator does not support blinking characters. Use the Display
Set-Up screen to select how the blink attribute is displayed. The settings are:
•
•
•

Normal video ldefault)
Reverse video
Underscore

No Control Representation Mode
The VT220 emulator does not support either a Set-Up selection or the function
of control representation mode.

Font Selection
The VT220 emulator supports a Display Set~Up selection of font sizes that the
VT220 terminal does not. The settings are:
•
•
•

c- 2

Normal ldefault)
Small
Automatic

VT220 Emulator and VT220 Terminal Differences

Communications Differences
LAT Protocol Support (Network Terminal Services)
Normally a terminal can only connect to a host using a serial port. The VT220
emulator supports a Communications Set-Up selection of Network Terminal
Services, which provides for Thin Wire ethernet connection using a LAT
protocol.

No Split Baud Rate
The VT220 emulator does not support split baud rate. It transmits and receives
at the same baud rate, as specified in the Speed selection in Communications
Set-Up.

Session Logging
The VT220 emulator supports an Action Set-Up selection of session logging, in
which the characters received from the host are written to a file. The VT220
terminal does not.

Autotyping Characters
The VT220 emulator supports an Action Set-Up selection of autotyping, in
which characters read from a file are sent to the host. The VT220 terminal
does not.

VT220 Emulator and VT220 Terminal Differences

C- 3

Keyboard Differences
Keyboard LEDs
The LK250 keyboard has four LEDs,but the VT220 emulator supports only
the Lock LED. The Lock light behaves in the same way for both a VT220
terminal and "the VT220 emulator. The other LEDs (NumLock, Hold, and
Speciall are always off for the VT220 emulator.
In the VT220 emulator, when Lock is turned on in the Control Panel, pressing
the Shift key while you press a letter key, produces a lowercase letter.
Conversely, when Lock is off, pressing the Shift key while pressing a letter
key, produces an uppercase letter.

Alternate Characters
Alternate character keys are only available through the MS-Windows Control
Panel country settings. For more information, see the VAXmate User's Guide.

Keyclick
The user cannot change keyclick volume in the VT220 emulator Set-Up.
Keyclick volume can be selected by using the MS-Windows Control Panel. For
more information, see the VAXmate User's Guide.
In addition, the VT220 emulator keys always click if the volume has not been
set to off by the Control Panel.

Autorepeat Selection
Autorepeat settings (on or off) cannot be selected with Set-Up in the VT220
emulator. Use the MS-Windows Control Panel to make this selection. For more
information, see the VAXmate User's Guide.

C- 4

VT220 Emulator and VT220 Terminal Differences

Character Sets
DEC MCS to ISO Latin-l 8-bit Transition
The VT220 terminal does not support the ISO Latin-l 8-bit character set, but
the VT220 emulator does.
The user-preference supplemental character set is selected in General Set-Up to
be either the DEC multinational character set or the ISO Latin-l character set.
The user-preference character sets, DEC MCS and ISO Latin-l 8-bit, are found
in the tables at the end of this appendix.
The factory default user preference character set is the DEC multinational
character set.

Language Selection
The VT220 terminal supports a Set-Up selection for the national language to
be used with the National Replacement character set (NRC). The VT220 emulator does not.
This selection depends upon the country keyboard selection reported in the
Preferences menu in the MS-Windows Control Panel. The country keyboard is
determined during MS-Windows configuration Setup.

Compose Sequences
The VT220 terminal supports only DEC MCS (multinational character sets)
Compose sequences. The VT220 emulator supports both Compose sequences
and ISO Latin-l Compose sequences.
The set of Compose sequences in effect at any given time is determined by
selecting of Multinational character set in General Set-Up.
Enabling or disabling the warning bell from the Keyboard Set-Up screen does
not effect the Compose sequence error bell, which is always enabled.

VT220 Emulator and VT220 Terminal Differences

C- 5

Additional VT220 Emulator Escape Sequences
This section lists the additional escape sequences accepted and returned by the
VT220 emulator. For more information about escape sequences and character
sets, see the tables at the end of this appendix.

Assign User-Preference Supplemental Character Set (DECAUPSS)
To assign a user-preference supplemental character set, use the following
escape sequences:
DEe Supplemental:

Des

9/0

3/0

ISO Latin-1 Supplemental:

2/1

DeS

9/0

3/1

7/5

2/5

3/5

9/12

2/1

7/5

4/1

9/12

Request User-Preference Supplemental Character Set
(DECRQUPSS)
To request a user-preference supplemental character set, use the following
escape sequence:
eSI

9/11

2/6

7/5

When this sequence is received, the VT220 emulator returns the DECAUPSS
sequence indicating the currently selected user-preference character set.

Select User-Preference Supplemental Coded Character Set (SCS)
To select the user-preference supplemental coded character set, use the following escape sequence:
Ese

1/11

2/1

3/12

The escape sequence designates the currently selected user-preference character
set into the G-set indicated by Ig.
Ig

I G-set

--------+-------( 2/8
) 2/9
* 2/10
+ 2/11

C- 6

GO
G1
G2
G3

VT220 Emulator and VT220 Terminal Differences

Select DEC Supplemental Coded Character Set (SCS)
To select the DEC supplemental coded character set, use the following escape
sequence:
ESC
1/11

Ig
2/1

2/5

5
3/5

The escape sequence designates the DEC supplemental character set into the
G-set indicated by Ig.

I G-set

--------+-------( 2/8
) 2/9
* 2/10
+ 2/11

GO
Gl
G2
G3

Select ISO Latin-! Supplemental Coded Character Set (SCS)
To select the ISO Latin-l supplemental coded character set, use the following
escape sequence:
ESC

1/11

2/1

A
4/1

The escape sequence designates the ISO Latin-l character set into the G-set
indicated in Ig.
Ig

I G-set

--------+-------- 2/13
2/14
/ 2/15

Gl
G2
G3

VT220 Emulator and VT220 Terminal Differences

C- 7

Primary Device Attribute (DA)
The VT220 emulator responds to the primary Device Attributes (DAI request
with the additional parameter:
14

This parameter supports the 8-bit Interface Architecture.

In a typical exchange between the host and the VT220 emulator, the VT220
emulator responds to the service code and attribute inquiries with the following
sequence:
CSI ? 62; 1; 2; 3; 4; 6; 1; 8; 9; 14; c

Secondary Device Attribute (DA)
In a typical exchange between the host and the VT220 emulator, the VT220
emulator responds to the terminal identification code, firmware version level,
and hardware options inquiries with the following sequence:
CSI > 20; Pv; Po c

Announcing ANSI Conformance Levels
To announce is to indicate which subset of code extension facilities are going to
be employed by subsequent information interchange until the occurrence of another announcer function.
The following escape sequence is taken from ANSI standard x3.134.1:
ESC
1/11

SP
2/0

F*
4/1

Identifies

------------+--------------L 4/12
M 4/13
N 4/14

Level 1
Level 2
Level 3

Levels 1 and 2 assume that ASCII characters are designated into 00 and invoked into OL, and that the ISO Latin-1 Supplemental Set is designated into
01 and invoked into OR.
Level 3 assumes that ASCII characters are designated into 00 and invoked
into OL.

C- 8

VT220 Emulator and VT220 Terminal Differences

Printing
Printer Options
The VT220 terminal supports a Set-Up selection of printer settings, such as
stop bits and speed, but the VT220 emulator does not. The printer speed and
stop bits are adjusted by using the MS-Windows Control Panel.

Print Terminator
The VT220 terminal supports Set-Up selection of print terminator, but the
VT220 emulator does not. Every VT220 emulator print job ends with a form
feed, except for the output in printer controller mode.

Print Size
The VT220 emulator supports a Set-Up selection for print size, but the VT220
terminal does not. The settings are:
•
•

Normal (default)
Compressed

VT220 Emulator and VT220 Terminal Differences

C- 9

VT240 Emulator and VT240 Terminal
Differences
This part of the appendix describes the VT240 emulator and VT240 terminal
differences.

Saving and Restoring Set-Up Selections
The VT240 emulator supports saving and recalling Set-Up selection from userspecified files. The VT240 terminal only supports the saving and recalling of
one set of Set-Up selections.

Video Differences
Video Modes
The VT240 terminal operates in only one video mode, an 800 x 240 Text &
Graphics video mode. The VT240 emulator operates in either of two video
modes:
•
•

Fast Text Only
Text & Graphics

The Text & Graphics video mode is an 800 x 252 video bitmap. The 12 extra
scan lines are used to display error messages and status information.

Automatic Video Mode Switching
The Fast Text Only video mode cannot display sixel graphics, ReGIS graphics,
or Dynamic Redefinable character sets jDRCS). When either sixel graphics,
ReGIS, or DRCS escape sequences are received, the VT240 emulator automatically switches to the Text & Graphics video mode.

Scrolling
There is no smooth/jump scroll option in the VT240 emulator. The VT240
emulator is always in jump scroll.

No Control Representation Mode
The VT240 emulator does not support either a Set-Up selection or the function
of control representation mode.

132 Column Text
The Fast Text Only video mode is an 80 x 25 character display mode. The
25th line displays error messages and status information. When operating in
132 column mode using the Fast Text Only video mode, only 80 of the 132
columns can be seen at one time.

C- 10

VT240 Emulator and VT240 Terminal Differences

Pressing:
Shift/right arrow
Shift/left arrow

Displays columns 52-132
Displays columns 1-80

Underlined Characters
The VT240 emulator cannot display underlined characters in the Fast Text
Only video mode. Characters intended to be underlined in this video mode are
displayed with the bold attribute.
If true underlined characters are desired, select Text & Graphics video mode

from the Display Set-Up screen.

Line Attributes
When using the VT240 emulator in the Text & Graphics mode, all line attributes display as they would on a VT240 Terminal.
When using the VT240 emulator in Fast Text Only mode. some line attributes
display differently for double width and double height/double width.

Double Width Lines for Fast Text Only
When using double width characters in the Fast Text Only mode, they are
displayed as that character followed by a space. For example:
t est

Double Height/Double Width Lines for Fast Text Only
When using double height/double width characters in the Fast Text Only mode,
they are displayed as that character followed by a space with a blank line inserted before the next line of characters.
For example, entries of the word "test" on two separate lines would
display as:
t est
t est

Because double height takes up two lines, the text is on the first line followed
by a blank line on the second line.

VT240 Emulator and VT240 Terminal Differences

C- 11

Communications Differences
LAT Protocol Support (Network Terminal Services)
Normally a terminal can only connect to a host using a serial port. The VT240
emulator supports a Communications Set-Up selection of Network Terminal
Services that provides for LAT connection through a LAT protocol.

Session Logging
The VT240 emulator supports session logging, in which characters received
from the host are written to a file. The VT240 terminal does not.

Autotyping Characters
The VT240 emulator supports autotyping, in which characters read from a file
are sent to the host. The VT240 terminal does not.

Keyboard Differences
Keyboard LEDs
The LK250 keyboard has four LEDs, but the VT240 emulator supports only
the Hold Screen and Lock LEDs. The Hold and Lock LEDs behave in the
same way for both a VT240 terminal and the VT240 emulator. The other LEDs
'NumLock and Special) are always off for the VT240 emulator.

Alternate Characters
Alternate character keys are available on the VT240 emulator as they are on
the VT240 terminal.
To obtain alternate character key outputs, hold down the Ctrl key while
pressing the Alt key, then press the alternate character key.

No "Printer to Host" Mode
The VT240 Terminal supports a feature called Printer to Host mode, this mode
is not implemented in the VT240 emulator.

C- 12

VT240 Emulator and VT240 Terminal Differences

Character Sets
DEC MCS to ISO Latin-l 8-bit Transition
The VT240 terminal does not support the ISO Latin-l 8-bit character set, but
the VT240 emulator does.
The user-preference supplemental character set is selected in General Set-Up to
be either the DEC multinational character set or the ISO Latin-l character set.
The user-preference character sets, DEC MCS and ISO Latin-l 8-bit, are found
in the tables at the end of this appendix. The factory default user preference
character set is the DEC supplemental character set.

Compose Sequences
The Compose sequences are handled by the MS-DOS operating system using
the KEYB program. If KEYB is loaded the user can use Compose or dead
diacritical sequences to create characters that do not exist as standard keys on
the keyboard. Compose mode is entered from the keyboard by pressing the
Compose key or a dead diacritical key. For more information on KEYB, see
Chapter 17 of this manual.

Additional VT240 Emulator Escape Sequences
This section lists the additional escape sequences accepted and received by the
VT240 emulator. For more information about escape sequences and character
sets, see the tables at the end of this appendix.

User-Preference Supplemental Character Set (DECAUPSS)
To assign user-preference supplemental character sets, use the following escape
sequences:
DEC Supplemental:

DCS
9/0

ISO Latin-l Supplemental:

0
3/0

DCS
9/0

2/1

1
3/1

u
7/6

2/1

%
2/6

u
7/6

6
3/6

A
4/1

ST
9/12

VT240 Emulator and VT240 Terminal Differences

C-13

Request User-Preference Supplemental Character Set
(DECRQUPSS)
To request a user-preference supplemental character set, use the following
escape sequence:
CSI

9/11

2/6

u
7/5

When this sequence is received, the VT240 emulator returns the DECAUPSS
sequence indicating the currently selected user-preference character set.

Select User-Preference Supplemental Coded Character Set (SCS)
To select the user-preference supplemental coded character set, use the following escape sequence:
ESC

1/11

2/1

3/12

The escape sequence designates the currently selected user-preference character
set into the G-set indicated by Ig.
Ig

I G-set

--------+--------

C- 14

( 2/8

) 2/9
* 2/10
+ 2/11

G1
G2
G3

VT240 Emulator and VT240 Terminal Differences

Select DEC Supplemental Coded Character Set (SCS)
To select the DEC supplemental coded character set, use the following escape
sequence:
ESC
1/11

Ig
2/1

5
3/5

2/5

The escape sequence designates the DEC supplemental character set into the
G-set indicated by Ig.

I G-set

--------+-------( 2/8
) 2/9
* 2/10
+ 2/11

GO
Gl
G2
G3

Select ISO Latin-l Supplemental Coded Character Set (SCS)
To select the ISO Latin-1 supplemental character set, use the following escape
sequence:
ESC
1/11

Ig
2/1

A
4/1

The escape sequence designates the ISO Latin-1 character set into the G-set
indicated in Ig.
Ig

I G-set

--------+-------- 2/13 I
. 2/14 I
/ 2/15 I

Gl
G2
G3

Primary Device Attribute (DA)
The VT240 emulator responds to the primary Device Attributes (DA) request
with the additional parameter:

This parameter supports the 8-bit Interface Architecture.

In a typical exchange between the host and the VT240 emulator. the VT240
emulator responds to the service code and attribute inquiries with the following
sequence:

VT240 Emulator and VT240 Terminal Differences

C- 15

CSI ? 62; 1; 2; 3; 4; 6; 7; 8; 9; 14; c

Secondary Device Attribute (DA)
In a typical exchange between the host and the VT240 emulator, the VT240
emulator responds to the terminal identification code, firmware version level,
and hardware options inquiries with the following sequence:
CSI > 21; Pv; Po c

1/11

2/0

4/1

Identifies

------------+--------------L 4/12
M 4/13
N 4/14

Level 1
Level 2
Level 3

Levels 1 and 2 assume that ASCII is designated into 00 and invoked into OL,
and that the ISO Latin-l supplemental set is designated into Oland invoked
into OR.
Level 3 assumes that ASCII is designated into 00 and invoked into OL.

c- 16

VT240 Emulator and VT240 Terminal Differences

This page is intentionally blank.

VT240 Emulator and VT240 Terminal Differences

c- 17

Table C-1

DEC MCS - ASCII Graphics Set (0-7)

COLUMN

BITS

b8
b7

rROW

b4 h3 b2 bl

NUL

2
3
4

o 0
0

SOH

STX I

ETX

EOT

ENQ

ACK

BEL

8
9

10
11

1 0

0
0
0

10
16
10

40
J1
10
41
33

60
48
30
61
49
31

100
64
40
101
65
41

110
80
50
111
81
51

1
1
1
1
1
3
3
3
4
4
4
5
5
5
6
6
6
7
7
7

10
8
8

11
9
9

11
10
A

13
11
8

14
11
C

1 1

15
13
0

DCl
(XON)

DC2

17
II

n
18
11

DC3
(XOFF)

13
19
13

DC4

14
10
14

NAK

15
11
15

SYN

16
11
16

ETB

!
11

$
%
&

CAN ,.

EM
SUB

31
16
lA

43
35

2
3

13
44
36
14
45
37
15
46
38
16
47
39

(
)

50
40
18
51
41

63
51
33
64
51
34

A
B
C
0

5
6

66
54
36

67
55
37

70
56
38

57
39
58
3A

105
69
45
106
70
46
107

131
89
59

111
74
4A

131
90
5A

[

133
91
58

;

54
44
1C

74
60
3C

114
76
4C

35
19
10

55
45
10

75
61
30

115
77
40

76
61
3E

116
78
4E

77
63
3F

16
14
E

17
15
F

36
30
IE
37
31
IF

56
46

1E
57

115
85
55

111
73
49

34
18
lC

81
51
113
83
53
114
84
54

113
75
48

ESC

V
W

,
]
A

117
79

,
a

130
88
58

73
59
38

110
72
48

53
43
18

101
66
41
103
67
43
104
68
44

116
86
56
117
87
57

19
51
41
1A

61
50
31

65
53
35

31
15
19

41
34

OLE

I
I

0
I

0
0

134
91
5C
135
93
50

b
C

e
f

140
96
60
141
97
61
141
98
61
143
99
63
144
100
64

160

145
101
65
146
101
66
147
103
67

111

161
113

161
114

n
163
115
73
164
116

165
117
75

166
118
76
167
119
77
170
110
78

150
104
68

151
105
69

151
106
6A

111

153
107
68

{

173
113
78

136
94
5E

137
95
5F

154
108
6C
155
109
60
156

110
6E
157
111
6F

171
121

79
171
7A

174
114
7C
175
115
70

}

...

176
116
7E

DEL

177
121

GR CODES
I
r---.C1 CODES-~-t-·I - - - - - - ( D E C SUPPLEMENTAL
GRAPHICS)--------I·

1_ ...

KEY
ASCII CHARACTER

ESC

1/11

COLUMN/ROW

OCTAL

DECIMAL

HEX

'--_---I.._...J

LJ-0839

C- 18

Character Set Tables

Table C-2

DEC MCS - Supplemental Graphics Set (8-151

1
0

200
128
BO

DCS

220
'44
90

PU1

221
'45
91

PU2

222
'46
92

203
'3'
B3

STS

223
'47
93

204
'32
84

CCH ,4B
94

202
'30
B2

IND
NEL

205
'33
B5

300
'92
CO

320
208
DO

30'
'93
C,

32'
209
D'

302
C2

263
179
B3

244
'64
M

264
'80
84

245
'65
AS

265
'8'
B5

266
lB2
B6

240
160
AO

260
176
BO

26'

242
'62
A2

262
178
B2

243
'63
A3

224

177

225
149
95

SPA

226
'50
96

246
'66
A6

EPA

227
'5'
97

247
'67
A7

267
'83
87

:-a:

250
'68
A8

270
'84
88

25'
'69
A9

252
170
AA

253

SSA

206
'34
86

ESA

207
'35
87

HTS

2'0
'36
88

230
'52
98

HTJ

211
'37
89

23'

VTS

2'2
'38
8A

232
'54
9A

PLD

213
'39
BB

PLU

214
'40
BC

153
99

CSI

233
'55
9B

234
'56
9C

254
'72
AC

215
,4'
BD

OSC

235
'57
9D

255
173
AD

SS2

2'6
'42
8E

.!36

'58
9E

256
174
AE

SS3

217
'43
8F

APC

237
159
9F

257
175
AF

24'
'6'
Al

0
0

12
1

0
0

20'
129
Bl

11
1

171

V4
'/2

271
'85
89
272
'86
BA
273
lB7
BB
274

'88
BC
275
'B9
BD
276
'90
BE

277
19'
BF

,
0
,

15
1

1
0

BITS

b6
b5
b4 b3 b2 bl

rROW

340
224
EO

360
240
FO

34'
225
E1

36'
24'
F1

362
242
F2

363
243
F3

322
210
02

342
226
E2

343
227
E3

COLUMN

'94

303
'95
C3

323
211
03

304
'96
C4

324
212
D4

344
228
E4

364
244
F4

325
2'3
D5

ill

345
229
E5

365
245
F5

, ,

346
230
'6

366
246
F6

347
23'
E7

(]It

367
247
F7

,,,

370
248
F8

371
249
F9

, 9

372
250
FA

, , 10
, , , 11

305
'97
C5

306
'98
C6

307
'99
C7

310
200
C8

326
2'4
06

327
2'5
07

330
2'6
D8

311
20'
C9

3'2
202
CA

3'3
203
CB

314
204
CC

,
I
A

3'5
205
CD

,
A

U
00

332
218
DA
333
219
DB
334
220
OC
335
221
DD
336
222
DE

3'6
206
CE
317
207
CF

33'
217
09

337
223
OF

,
e

•
ir

,
I

350
232
E8
35'
233
E9
352
234
EA
353
235
EB
354
236
EC

355
237
ED

•I

356
23B
EE

...

357
239
EF

,
0
A

,
U
A
U

373
25'
FB

·u

374
252
FC

375
253
FO
376
254
FE

377
255
FF

, , , 13
, , , 14
, , , , 15
0

L
r - - CO CODES--~'I - - · - - - - - - - - - ( A S C IGLCODES
I GRAPHIC
LJ-OB40

Character Set Tables

C-19

Table C-3

ISO Latin-1 Character Set (0-7)

BB
B7

B6B5r-____O_O~------~r_----~+_----~~----~~------~------~r_----~

KEY r---,----,
ASCII CMARACTE R

ESC

COLUMN ROW

OCTAL

DECIMAL

L....._..J......:"...J HEX

C- 20

Character Set Tables

Table C-4 ISO Latin-l Character Set (8-15)

BB
87

Character Set Tables

C- 21

Table C-5

DEC Special Graphics Character Set

COLUMN

BITS
B4 83 B2 81

o 000
o 0 0

NUL

o 0 1

o 0

o 1 o 0

o 1 0

o 1 1 0

1 000

1 1

o 0 1

o 1 0

o 1 1

o 0

o 1

,,,

,,,,

KEY ,...---,.........,
ASCII CHARACTER

ESC

, '11

COLUMN: ROW

OCTAL

DECIMAL

HEX

......_"'--.....

C- 22

B7 0
B6
B5

Character Set Tables

!:.i::::::j:.:1 ~~~~L~~i,S DIFFERENCES

Bibliography

MOS Microprocessors and Peripherals 1985 Data Book (Order Number
04426A)
Advanced Micro Devices
901 Thompson Place
P.O. Box 3453
Sunnyvale, CA 94088
8/16-Bit Mu.lti-Chip Microcomputer Data Book
Hitachi America, Ltd.
Semiconductor and IC Division
2210 O'Toole Avenue
San Jose, CA 95131
1-408-942-1500
IBM Personal Computer Seminar Proceedings
Volume 2, Number 8, October 8, 1984
IBM Corporation
Editor, IBM Personal Computer Seminar Proceedings
4629
Post Office Box 1328
Boca Raton, FL 33432
Microsystem Components Handbook (Publication Number 230843)
Intel Literature Sales
P.O. Box 58130
Santa Clara, CA 95052-8130
1-800-548-4725

Bibliography 1

ServerlRedirector File Sharing Protocol (Publication Number 136329-001)
Microsoft Corporation and Intel Corporation
Intel Literature Sales
P.O. Box 58130
Santa Clara, CA 95052-8130
1-800-548-4725
MS-Windows Software Development Kit Programmer's Reference
MS-Windows Software Development Kit Programmer's Utility Guide
MS-Windows Software Development Kit Programming Guide
Microsoft Corporation
16011 NE 36th Way
Box 97017
Redmond, WA 98073-9717
8-Bit Microprocessor & Peripheral Data
Motorola, Inc.
MOS Integrated Circuits Group
Microprocessor Division
3501 Ed Bluestein Blvd.
Austin, TX 78721
1-512-928-6800
Series 8000 Microprocessor Family Handbook
National Semiconductor Corporation
2900 Semiconductor Drive
Santa Clara, CA 95051
1-408-737-5000
Microcomputer Products
NEC Electronics
401 Ellis Street
Mountain View, CA 94043
1-415-960-6000
Microprocessor Data Manual 1986
Signetics Corporation
811 E. Arques Avenue
P.O. Box 3409
Sunnyvale, CA 94088-3409
1-408-991-2000
1984 Data Communications Products Handbook
1986 Storage Management Products Handbook
Western Digital Corporation
Marketing Communications Manager
2445 McCabe Way
Irvine, CA 92714
1-714-863-0102
2

Bibliography

DECnet-DOS Programmer's Reference Manual (AA-EB46B-TV)
DECnet-DOS User's Guide (AA-EB45B-TV)
DECnet-VAXmate Programmer's Reference Manual (AA-GV34A-TH)
DECnet-VAXmate User's Guide (AA-GV36A-TH)
DECnet Digital Network Architecture Phase IV General Description
(AA-N149A-TC)
DECnet Digital Network Architecture Phase IV Control Functional
Specification (AA-K182A-TK)
DECnet Digital Network Architecture Phase IV Routing Functional
Specification (AA-X435A-TK)
DECnet Digital Network Architecture Phase IV Maintenance Operations
Functional Specification (AA-X437A-TK)
DECnet Digital Network Architecture Phase IV Network Management
Functional Specification (AA-X436A-TK)
DECnet Digital Network Architecture Phase IV Data Access Protocol (flAP)
Functional Specification (AA-Kl77A-TK)
The Ethernet, A Local Area Network, Datalink Layer and Physical Layer
Specification, Version 2.0 (AA-K759B-TK)
Digital Equipment Corporation, Intel Corporation, Xerox Corporation
November 1982
VT220 Series Programmer's Reference Manual (EK-VT220-RM)
VT240 Series Programmer's Reference Manual (EK-VT240-RM)
VAXmate User's Guide (Q6A93-GZ)

To order DIGITAL documentation:
DIGITAL EQUIPMENT CORPORATION
P.O. Box CS2008
Nashua, New Hampshire 03061

Bibliography 3

Index
802.3 Compatible mode 18-6
80287 error interrupt 15-151
8254 interval timer 6-1
block diagram 6-1
registers 6-8
8259A interrupt controller
initialization command words 3-5
initialization sequence 3-5
input/output ports 3-3
operation command words 3-11
registers 3-3
A
Acknowledge
LK250 keyboard responses 8-31
Active cycle
DMA controller 4-3
Add name for session 18-101
Add node for session 18-120
Address generation
DMA controller 4-5
Address map
input/output 2-4
Alarms 5-12
Alias I/O port addresses 13-5

Alternate status register 12-25
Anomalies
keyboard processing 17-11
ANSI Character Set 17-74
ANSI functions
not supported 17-79
ANSI support
inside a window 17-79
ANSLSYS 16-5
Cursor control functions 16-5
Erase functions 16-7
installing 16-5
Keyboard key reassignment function 16-12
Reset mode function 16-11
Set graphics rendition function
16-8
Set mode function 16-10
AnsiToOem 17-55
Asynchronous
communications 9-1
interrupt 15-70
memory cycles 13-40
notification routine 18-90
requests 18-89
serial communications interface
17-62
serial mouse interface 10-2

Index

Attribute code 7-6
Auto-initialize
DMA controller 4-4
Automatic LED control 15-108
Available (IRQ15) interrupt 15-151
B
BACKSPACE
to abort compose sequence 17-5
Base and current
address register 4-7
vvord register 4-8
Basic interrupt 15-132
Baud rate 9-16
mouse 10-2
Beep function 6-18
Begin virtual mode function 15-96
Bell sound 6-18
Bits
DMA controller
vvrite all 4-11
vvrite single mask 4-11
Block transfer mode
DMA controller 4-3
Boot block, DIGITAL hard disk
15-134
Bootstrap interrupt 15-133
Buffer overrun
LK250 keyboard responses 8-30
Bus 13-3
16-bit expansion 2-9
16-bit local 2-9
8-bit expansion 2-9
arbitration 13-3
master mode 13-40
slave mode 13-40
timing and structure 2-9

2 Index

Button position 10-3

c
C programming language
subroutines A-I
Call function for session 18-105
Call-back
for datalink
line state change 18-9
user 18-8
for LAT 18-58
Cancel
alarm function 15-140
function for session 18-97
Cascade mode
DMA controller 4-4
Case conversion tables 16-29
Cassette input/output interrupt 15-88
Change register 11-6
Character
code 7-6
count 17-77
count function 15-114
pattern 7-9
position mapping 7-7
set provided in the custom font
17-74
Check for presence of session 18-96
ClearCommBreak 17-65
Clock tick interrupt 15-5
Close
datalink portal 18-20
device function 15-89
LAT session 18-67
CloseComm 17-64
CloseLat 17-68
CMOS configuration
updated 14-10

CMOS RAM
shutdown byte read during hard
reset 14-13
Coax transceiver interface 13-2
Color
map functions 15-32
select register 7-39
COMlIserial interrupt 15-6
COM2/modem interrupt 15-6
Combination keys 15-107
break 15-108
extended self-test 15-108
pause 15-108
print screen 15-108
system request key 15-107
system reset 15-107
Commands
counter-latch, three-channel
counter and speaker 6-12
disable keyboard, keyboardinterface controller 8-12
diskette drive controller 11-19
enable keyboard, keyboardinterface controller 8-12
incremental stream mode (mouse)
10-3
interface test, keyboard-interface
controller 8-12
invoke self-test (mouse) 10-3
keyboard-interface controller 8-9
mouse (table) 10-2
prompt mode (mouse) 10-3
pulse output port, keyboardinterface controller 8-12
read port 1, keyboard-interface
controller 8-12
read port 2, keyboard-interface
controller 8-13
read test inputs, keyboardinterface controller 8-13
read-back, three-channel counter
and speaker 6-13

read, keyboard-interface controller
8-10
self-test 8-12
vendor reserved function (mouse)
10-3
write port 2 8-13
write status register 8-13
write, keyboard-interface controller
8-10
Command and result register sets
diskette drive controller 11-20
Command codes
disable autorepeat 8-24
disable key scanning and restore
to defaults 8-28
echo 8-26
enable autorepeat 8-24
enable key scanning 8-28
enter DIGITAL extended scan
code mode 8-23
exit DIGITAL extended scan code
mode 8-23
invalid commands 8-23
keyboard mode lock 8-25
keyboard mode unlock 8-25
LEDs on/off 8-26
LK250 keyboard 8-22
request keyboard id 8-23
resend 8-29
reserved 8-25, 8-26, 8-29
reset 8-29
reset keyboard led 8-24
restore to defaults 8-28
set autorepeat delay and rate 8-27
set keyboard led 8-23
set keyclick volume 8-24
Command register 4-9, 10-12, 12-10
keyboard-interface controller 8-5,
8-9
Command state
diskette drive controller 11-18
Communications 17-61

Index 3

connector signals 9-19
extended self-test loopback test
14-10
full asynchronous parallel 17-61
full asynchronous serial 17-61
LAT support 17-62
Communications functions
ClearCommBreak 17-65
CloseComm 17-64
EscapeCommFunction 17-65
FlushComm 17-65
GetCommError 17-66
GetCommEventMask 17-65
GetCommState 17-65
OpenComm 17-63
ReadComm 17-64
SetCommBreak 17-65
SetCommEventMask 17-65
SetCommState 17-65
TransmitCommChar 17-64
WriteComm 17-63
Compose sequences 16-23, 17-4
aborting 17-5
default set 17-5
handling 17-4
how recognized 16-23
pointer table
format 16-24
use 16-24
translation table
format 16-24
use 16-24
two key 17-5
Configuration list 14-11
display 14-11
Console server identify self 18-42
Constant values
DMA controller
programming example 4-15
Control Panel 17-6
Control register 11-3
register A 7-41

4 Index

register B 7-43
registers 7-3, 7-41, 7-43
Control signals
speed indicator 9-17
speed select 9-17
Control word register 6-11
Controller
functions 13-2
keyboard-interface 8-1
Counter and speaker example 6-20
Counter signals 6-3
Counter-latch command
three-channel counter and speaker
6-12
CPU 13-3
Creating keyboard map tables 16-22
CRT Controller 7-3
CRTC registers
data 7-25
index 7-25
register RO 7-28
register Rl 7-28
register RIO 7-33
register Rll 7-34
register R12 7-34
register R13 7-34
register R14 7-35
register R15 7-35
register R16 7-36
register R17 7-36
register R2 7-29
register R3 7-29
register R4 7-30
register R5 7-30
register R6 7-31
register R 7 7-31
register R8 7-3
register R9 7-33
Crystal oscillator 13-4
CTI - see coax transceiver interface

13-2
Ctrl and Alt keys
Del keys used for soft reset 14-12
with Home key for diagnostics
14-10
Cursor control functions 16-5
Custom LAT application interface
17-66
Cylinder number
high register 12-8
low register 12-8
D

.DEF files 17-10, 17-72
ID for LAT 18-55
Data
controller 13-3
link interface 13-1
structures accessed by LANCE
13-3
transfer 13-40
Data exchange for LAT 18-58
Data registers 7-39, 11-5, 12-3
accessing 7-26
keyboard-interface controller 8-5
Data structures
DMA controller
programming example 4-17
Data transfers
DMA controller 4-4
rate register 11-6
Datagrams 18-113
defined 18-83
Datalink communication block (DCB)
18-7
functions 18-11
close a portal 18-20
deallocate buffer 18-26

disable a channel 18-38
disable multicast address 18-22
enable a channel 18-37
enable multicast address 18-21
external loopback 18-41
initialization 18-15
MOP start and send system ID
18-45
MOP stop 18-45
network boot request 18-36
open a portal 18-17
read channel status 18-27
read counters 18-32
read DECparm address 18-39
read portal list 18-29
request transmit buffer 18-25
set DECparm string address
18-40
transmit 18-23
overview 18-5
parameters 18-16
port driver 18-5
program example 18-46
read portal status 18-30
receive 18-10
return codes 18-12
transmit 18-10
user call-back routines 18-8
Date and time structure 16-3, 16-4
Dead diacritical keys 16-24, 17-4
how recognized 16-24
Deallocate buffer for datlink 18-26
DEC private RAM
powerup test checks 14-8
decfuncadd 18-120
decfunccheck 18-119
decfuncdelall 18-126
decfuncdelname 18-122
decfuncdelnum 18-121
decfuncreadindex 18-125

Index 5

decfuncreadname 18-124
decfuncreadnum 18-123
DecGetKbdCountry 17-8
DECnet DOS session level interface
13-1
DECparm address string 18-40
DecSetAutorep 17-7
DecSetComposeState 17-5, 17-9
DecSetKClickVol 17-7
DecSetLockState 17-6
DecSetNumlockMode 17-10
DECWIN.H 17-85
Delete
entry given node name for session
18-122
entry given node number for
session 18-121
name for session 18-102
node entries for session 18-126
Demand transfer mode
DMA controller 4-3
Device is busy function 15-98
Diagnose command 12-21
Diagnostic initialization procedure
14-12
hardware initialized 14-12
memory sized 14-12
Diagnostic loopback 9-10
Diagnostics
extended self-test 14-10
hard reset 14-13
keyboard-interface controller 8-4,
8-12
powerup test 14-1, 14-8
processor board tests 14-14
ROM 14-1, 14-8
ROM extended self-test 14-10
soft reset 14-12

6 Index

DIGITAL
function check for session 18-119
hard disk boot block 15-134
input register 12-26
session control block (DSCB)
18-85, 18-88
session functions 18-118
DIGITAL extended functions
extended codes and functions
15-116
set modem control 15-85
DIGITAL extension functions
character count 15-114
extended mode 15-77
key notification 15-111
keyboard buffer 15-115
keyboard table pointers 15-120
parallel port retry 15-131
printer type 15-129
redirect parallel printer 15-127
request keyboard id 15-118
retry on timeout error 15-86
return days-since-read counter
15-140
return DIGITAL configuration
word 15-99
send break 15-84
send to keyboard 15-119
set baud rate 15-87
DIGITAL extension interrupts
basic 15-132
bootstrap 15-133
local area network controller
(LANCE) 15-149
mouse port 15-150
Direct memory access and LANCE
13-3
Disable
autorepeat keyboard-interface controller command codes 8-24
channel for datalink 18-38
key scanning and restore to

defaults 8-28
keyboard command 8-12
multicast address for datalink
18-22
Disk input/output UfO) interrupt
15-38
hard disk errors 15-40
hard disk functions 15-40
hard disk parameter tables 15-41
Disk parameters 16-14
Diskette
errors 15-59
functions 15-59
parameter tables 15-59
interrupt 15-143
Diskette drive controller
change register 11-6
command and result register state
11-20
command register 11-7
command state 11-18
commands 11-19
control register 11-3
D 11-17
data register 11-5
data transfer rate registers 11-6
DMA mode 11-1
DTL 11-16
EOT 11-16
execution state 11-20
extended self-test loopback test
14-10
GPL 11-16
H 11-15
head/unit select register 11-8
hlt/nd 11-15
internal registers 11-7
main status register 11-4
N 11-16
NCN 11-17
operational states 11-18
PCN 11-17
programming 11-18

programming example 11-27
R 11-15
register sets for
format track 11-24
read data 11-21
read deleted data 11-22
read id 11-23
read track 11-23
recalibrate 11-26
scan equal 11-24
scan high or equal 11-25
scan low or equal 11-25
seek 11-27
sense drive status 11-27
sense interrupt status 11-26
specify 11-26
write data 11-21
write deleted data 11-22
registers 11-2
result state 11-20
result state
invalid commands 11-20
SC 11-16
srt/hut 11-14
status register 0 11-9
status register 1 11-10
status register 2 11-12
status register 3 11-13
STP 11-17
Diskettes
extended self-test use of 14-10
DispatchMessage 17-4
Display
on VAXmate 17-73
processor 7-3
Divisor latches 9-15
DLL.EXE 18-5
dll close 18-20
dll deallocate 18-26
dll disable chan 18-38
dll- disable- mul 18-22

Index

dll- enable- chan 18-37
dll enable mul 18-21
dll_ext_loopback 18-41
dll init 18-15
dll network boot 18-36
dll_open 18-17
dllJeadecparm 18-39
dll read chan 18-27
dll read counters 18-32
dllJead_plist 18-29
dllJead_portal 18-30
dllJequest_xmit 18-25
dll_setdecparm 18-40
dll transmit 18-23
DMA channel programming examples for
disabling 4-22
DMA controller
active cycle 4-3
address generation 4-5
auto-initialize 4-4
base and current address register
4-7
base and current word register 4-8
block transfer mode 4-3
cascade mode 4-4
command register 4-9
data transfer 4-4
demand transfer mode 4-3
idle cycle 4-3
mode 4-12
modes and restrictions 4-1
operation 4-2
priorities 4-5
programming example 4-15
data structures 4-17
disabling DMA channel 4-22
initializing 4-18
opening DMA channel 4-19

8 Index

preparing DMA channel 4-20
registers 4-7
request register 4-13
single transfer mode 4·3
states 4-2
status register 4-11
temporary register 4-14
write all mask bits 4-11
write single mask bit 4-11
DMA mode 11-1
DRQ 13-40
E

Echo
keyboard-interface controller command codes 8-26
LK250 keyboard responses 8-30
Edit keypad 17-3
Enable
autorepeat 8-24
channel for datalink 18-37
key scanning 8·28
keyboard command 8·12
multicast address for datalink
18-21
Enable/disable
256 character graphic font function 15-30
additional key codes 17-77
End-of-interrupt command
issuing 3-26
Enter
DEC Mode 17-76
DIGITAL extended scan code
mode 8·23
Erase functions 16·7
Error handling
keyboard-interface controller 8-14
LK250 keyboard 8-31

Error register 12-5
EscapeCommFunction 17-65
Ethernet
CRC bits 13-3
preamble 13-3
sync pattern 13-3
transmission 13-8
Execute controller internal diagnostics function 15-56
Execution state
diskette drive controller 11-20
Exit
DEC Mode 17-76
DIGITAL extended scan code
mode 8-23
Expansion box
bus connectors 2-11
operating ranges 2-10
slot power ratings 2-10
technical specifications 2-10
Extended
codes and functions 15-116
mode function 15-77
scan code mode 17-2
Extended keyboard functions
enable/disable additional key codes
17-77
enter DEC mode 17-76
exit DEC mode 17-76
Extended keyboard functions (not
supported)
character count 17-77
get/set table pointer 17-78
key notification 17-77
keyboard buffer 17-77
request keyboard id 17-78
Extended self-test
CMOS configuration update 14-10
diskette drive controller 14-10
double-sided, high-intensity disks
used in 14-10

firmware diagnostics 14-10
hardware initialization 14-10
horizontal bar 14-10
loopback test
on communications 14-10
on mouse serial ports 14-10
on printer 14-10
memory sized 14-10
real-time clock 14-10
video failures 14-10
Externalloopback 18-41
F

Fetch next character from keyboard
17-75
File structure
LCOUNTRY 16-27
Firmware diagnostics
error codes 14-8
error values 14-8
extended self-tests 14-10
horizontal bar 14-8, 14-10
initialization procedure 14-8
ROM BIOS and 14-8
self-tests 14-8
Fixed disk register 12-25
Fixed priority
DMA controller 4-5
Floppy disk interrupt 15-7
Flow control for LAT 18-58
FlushComm 17-65
Focus
changing for repeating key 17-11
FONT 16-15
Font file structure
FONT. COM 16-17
GRAFTABL.COM 16-18
Font files

Index

loading 16-19
Font RAM
accessing 7-9
color map support function 15-31
functions 15-31
programming 7-9
Font sizes
terminal emulation 17-73
FONT. COM
affect on KEYB.COM 16-16
affect on SORT.EXE 16-16
font file structure 16-17
Fonts
description 16-16
Format track 15-66
command 12-17
function 15-47
diskette drive controller
register sets 11-24
Functional description of network
hardware interface 13-2
Functions
datalink 18-11
interrupt vector A-12
LAT 18-64
retrieving characters from a ring
buffer A-16
session 18-91
DIGITAL-specific 18-118
storing characters in a ring buffer
A-16
support for example programs
A-18
GDI 17-2
printer support 17-83
Get
Country Code Function 16-3
current date and time for 5MB
18-128
MS-DOS OEM Number Function
16-3

10 Index

next LAT service name 18-70
status for LAT lS-65
Get/SetTable Pointer 17-78
GetCommError 17-66
GetCommEventMask 17-65
GetCommState 17-65
GetLatService 17-71
GetLatStatus 17-69
GetMessage 17-4
GRAFTABL 16-16
GRAFTABL.COM
font file structure 16-1S
Graphics
character table pointer interrupt
15-145
device interface 17-2
format memory maps 7-10
mode 7-10
H

Hangup for session 18-10S
Hard disk
boot block, DIGITAL 15-134
interrupt 15-151
parameter tables interrupt 15-146
reset function 15-53
types 16-13
Hard disk controller
alternate status register 12-25
command register 12-10
cylinder number high register 12·8
cylinder number low register 12-S
data register 12-3
diagnose command 12-21
DIGITAL input register 12-26
error register 12-5
features 12-1
fixed disk register 12-25

format track command 12-17
programming example 12-27
read sector command 12-13
read verify command 12-19
registers 12-1
restore command 12-11
SDH register 12-9
sector count register 12-7
sector interleave 12-18
sector number register 12-7
seek command 12-12
set parameters command 12-22
status register 12-23
write precompensation register
12-4
write sector command 12-15
Hard reset 14-13
causes 14-13
shutdown byte 14-13
Hardware
extended self-test 14-10
initializing 14-8
retriggable one-shot 6-4
starting with Ctrl/Alt/Del 14-12
system tests at startup 14-1
triggered strobe 6-7
Hardware interrupts
80287 error 15-151
available (lRQ15) 15-151
clock tick 15-5
COMlIserial 15-6
COM2/modem 15-6

floppy disk 15-7
hard disk 15-151
keyboard 15-5
local area network controller
(LANCE) interrupt 15-149
mouse port 15-150
nonmaskable interrupt 15-3, 15-76
real-time clock 15-148
redirect to interrupt OAH 15-148
serial printer port 15-150

110 cycle, wait states introduced by
LANCE 13-40
ICONEDIT.EXE 17-83
Icons
unique 17-83
Idle cycle
DMA controller 4-3
IEEE 802.3 specification 13-2, 13-4
10BASE2 specifications 13-40
Illogical keyboard messages 17-12
In-service register 3-16
Include files
LK250 keyboard A-I0
ring buffer control structure A-II
structure declaration A-9
Incremental stream mode command
10-3
Index register
accessing 7-26
Industry-standard functions
begin virtual mode 15-96
cancel alarm 15-140
close device 15-89
device is busy 15-98
diskette
errors 15-59
functions 15-59
parameter tables 15-59
enable/disable 256 character
graphic font 15-30
execute controller internal diagnostics 15-56
font RAM and color map support
15-31
format a track 15-47, 15-66
hard disk reset 15-53
initialize

Index 11

asynchronous port 15-72
diskette subsystem 15-61
drive characteristics 15-49
entire disk subsystem 15-42
printer 15-125
interrupt completion handler 15-98
keyboard input 15-109
keyboard state 15-11 0
keyboard status 15-109
move a block of memory 15-93
open device 15-89
read
character and attribute at
cursor position 15-19
current video state 15-27
cursor position 15-14
long 15-50
long 256 byte sector 15-58
one or more disk sectors 15-44
one or more track sectors 15-63
pixel 15-24
real-time clock 15-137
system clock 15-136
recalibrate drive 15-55
receive character 15-74
return
asynchronous port status 15-75
change line status 15-68
current drive parameters 15-48
drive type 15-57, 15-67
printer status 15-126
RTC date 15-138
size above one megabyte 15-95
status code of last 110 request
15-43, 15-62
seek to specific cylinder 15-52
service system request key 15-91
set
a wait interval 15-90
alarm 15-139
color palette 15-22
cursor position 15-13
cursor type 15-12
page 15-16

Index

real-time clock 15-138
RTC date 15-139
system clock 15-136
termination 15-90
test drive ready 15-54
transmit character 15-73,15-124
TTY write string 15-28
verify one or more disk sectors
15-46
verify one or more track sectors
15-65
wait (no return to user) 15-92
write
character and attribute at
cursor position 15-20
character at cursor position
15-21
character using terminal emulation 15-25
long 15-51
one or more disk sectors 15-45
one or more track sectors 15-64
pixel 15-23
Industry-standard functions with
DIGITAL extensions
set drive find media type for
format 15-69
set video mode 15-10
Industry-standard interrupts
80287 error 15-151
available (lRQ15) 15-151
diskette parameter tables 15-143
floppy disk 15-7
hard disk 15-151
hard disk parameter tables 15-146
keyboard break 15-141
nonmaskable interrupt 15-3, 15-76
print screen 15-4
read configuration 15-35
read light-pen position 15-15
real-time clock 15-148
redirect to interrupt OAH 15-148
return memory size 15-37

revector of interrupt 13H 15-145
RTC alarm 15-148
serial printer port 15-150
timer tick 15-141
video parameters 15-142
Industry-standard interrupts with
DIGITAL extensions
asynchronous communications
15-70
cassette input/output 15-88
clock tick 15-5
COMlIserial 15-6
COM2/modem 15-6
disk input/output (110) 15-38
graphics character table pointer
15-145
keyboard 15-5
keyboard input 15-101
printer output 15-123
video input/output 15-8
time-of-day 15-135
Initialization for datalink 18-15
Initialize
asynchronous port 15-72
diskette subsystem 15-61
drive characteristics 15-49
entire disk subsystem 15-42
printer 15-125
Input/output registers
video processor 7-22
InquireLatServices 17-70
Installing
ANSI.SYS 16-5
options, extended self-test 14-10
INT 11H support 17-82
INT 12H support 17-82
INT 15H support 17-83
Interface
signals, monitor 7-44
test command, keyboard-interface
controller 8-12

Internal registers
diskette drive controller
C 11-15
command 11-7
D 11-17
DTL 11-16
EOT 11-16
GPL 11-16
H 11-15
head/unit select 11-8
hlt/nd 11-15
N 11-16
NCN 11-17
PCN 11-17
R 11-15
SC 11-16
srt/hut 11-14
status register 0 11-9
status register 1 11-10
status register 2 11-12
status register 3 11-13
STP 11-17
International support
FONT 16-15
GRAFTABL 16-16
Interrupt
completion handler function 15-98
enable register 9-4
identification register 9-6
line status 9-10
modem status 9-10
on terminal count
three-channel counter and
speaker mode 6-4
Interrupt
2A 18-83, 18-91
6A 18-64
6D 18-11
Interrupt 21H
function 30H 16-3
function 38H 16-3
Interrupt

Index

address map 2-6
controller register, accessing 3-4
controllers. programming example
3-21
line, IRQ10 13-40
processing 3-18
request lines 3-2
request register 3-16
Invalid commands
keyboard-interface controller command codes 8-23
Invoke self-test command 10-3

J
Joystick support function 15-91
Jumpers
processor board testing 14-14
K

Kernel 17-2
Key buffering notification enabled
15-113
Key combinations 15-107
break 15-108
extended self-test 15-108
pause 15-108
print screen 15-108
system request key 15-107
system reset 15-107
Key mappings
LK25017-13
Key notification 17-77
enabled 15-112
function 15-111
KEYB.COM. 16-19
how affected by FONT. COM 16-16
Keyboard
break interrupt 15-141
14 Index

buffer interface 8-1
buffer function 15-115
driver 17-2
illogical messages 17-12
input function 15-109
input interrupt 15-101
interface lines 8-12
interrupt 15-5
key reassignment function 16-12
layout, LK250 15-103
LEDs 17-4
LK250 17-2, 8-1
map file structure 16-25
map tables
creating 16-22
MS-Windows extensions 17-5
processing anomalies 17-11
scan codes 15-104
setting user preferences 17-6
state function 15-110
status function 15-109
table pointers function 15-120
translation 15-121
Keyboard extensions
DecGetKbdCountry 17-8
DecSetAutorep 17-7
DecSetClickVol 17-7
DecSetComposeState 17-9
DecSetLockState 17-6
DecSetNumlockMode 17-10
enable/disable autorepeat 17-6
return keyboard nationality 17-6
select compose processing 17-6
select Numlock processing 17-6
set keyclick volume 17-6
set Shift key 17-6
Keyboard handling
inside a window 17-75
outside a window 17-78
Keyboard mode
lock 8-25
toggling 17-4
unlock 8-25
Keyboard remapping 16-19

Keyboard-interface controller 8-1
command byte bit definitions 8-10
command codes
disable autorepeat 8-24
disable key scanning and restore
to defaults 8-28
echo 8-26
enable autorepeat 8-24
enable key scanning 8-28
enter DIGITAL extended scan
code mode 8-23
exit DIGITAL extended scan
code mode 8-23
invalid commands 8-23
keyboard mode lock 8-25
keyboard mode unlock 8-25
LEDs on/off 8-26
request keyboard id 8-23
resend 8-29
reserved 8-25, 8-26, 8-29
reset 8-29
reset keyboard led 8-24
restore to defaults 8-26
set autorepeat delay and rate
8-27
set keyboard led 8-23
set keyclick volume 8-24
command register 8-5, 8-9
commands 8-9
data registers 8-5
diagnostics 8-4
disable keyboard 8-12
enable keyboard 8-12
error handling 8-14
interface test 8-12
keyboard responses
acknowledge 8-31
buffer overrun 8-30
echo 8-30
release prefix 8-31
resend 8-31
self-test failure 8-31
self-test success 8-30
physical interface

to the CPU 8-1
to the keyboard 8-1
port bit definitions 8-3
pulse output port 8-13
read port 1 8-12
read port 2 8-13
read test inputs 8-13
self-test 8-12
status register 8-6
write port 2 8-13
write status register 8-13
Keypad
edit 17-3
numeric 17-3
Keys
Numlock 17-3
reserved under MS-Windows 17-5
L

LANCE
broadcast address 13-22
buffer descriptors, see LANCE
message descriptors 13-27
buffer management 13-17
control and status registers 13-3
control register 13-3
CRC 13-22
CSRO 13-5, 13-6, 13-7, 13-8, 13-18
CSRO-CSR3 13-5
CSR1 13-4, 13-5, 13-6, 13-7, 13-13
CSR2 13-4, 13-5, 13-6, 13-7, 13-14
CSR3 13-4, 13-6, 13-7, 13-15
CSRs 13-5
data buffers 13-3, 13-4
data chaining 13-27
data structures 13-3
descriptor entry 13-27
descriptor rings 13-4
Ethernet data stream 13-27
initialization block 13-3, 13-18,
13-27

Index

base address 13-18
mode 13-19
logical address filter field 13-22
logical address mask 13-4
message descriptors 13-27
mode of operation 13-4
physical address field 13-19
physical address mask 13-4
polling 13-27
programming 13-3
programming sequence 13-4
receive and transmit descriptor
rings 13-3, 13-4, 13-28
location of 13-4
number of entries 13-4
receive descriptor ring pointer
field 13-23, 13-24
receive descriptor rings
receive message descriptor 1,
rmd1 13-30. 13-27
receive mode 13-3
register address port 13-5, 13-7
register data port 13-5, 13-6
RMD213-32
RMD3 13-33
status register 13-3
TMDO 13-34
TMD1 13-35
TMD213-37
TMD3 13-38
transmit
descriptor ring pointer 13-25
message descriptors 13-27
mode 13-3
LANCE - see Local Area Network
Controller 13-2
LANCE interrupt 15-149
LAT
ID switch 18-55
IG switch 18-56
IR switch 18-56
call-back routine 18-58. 18-60
closing a session 18-58
command line 18-555

Index

custom application interface 17-66
data exchange 18-58
flow control 18-58
functions 18-64
close session 18-67
get next service name 18-70
get status 18-65
open session 18-66
read data 18-68
send break signal 18-72
send data 18-69
service table reset 18-71
overview 18-54
program example 18-73
service directory 18-56
session control block 18-59
session start 18-57
session status word 18-63
slots 18-57
LAT control blocks 17-62
LAT functions
CloseLat 17-68
GetLatService 17-71
GetLatStatus 17-69
InquireLatServices 17-70
OpenLat 17-67
ReadLat 17-68
SendLatBreak 17-70
WriteLat 17-69
LAT support 17-62
Latches, divisor 9-15
LCB 17-62
number available 17-62
LCOUNTRY 16-27
file structure 16-27
LEDs 17-4
automatic control 15-108
color indications 14-8
during powerup test 14-8
110 board 14-8
memory board option 14-8

processor board 14-8
supported 17-4
LEDs on/off
keyboard-interface controller command codes 8-26
Line
control register 9-7
LAT state change call-back 18-9
status interrupt 9-10
status register 9-11
Listen for session 18-107
LK250 keyboard 8-1, 17-2
command codes 8-22
control functions 8-3
error handling 8-31
key mappings 17-13
layout 15-103
logical interface 8-2
pass-through mode 8-2
physical interface 8-2
programming example 8-46
responses 8-30
acknowledge 8-31
buffer overrun 8-30
echo 8-30
release prefix 8-31
resend 8-31
self-test failure 8-31
self-test success 8-30
scan codes 8-15
and industry-standard equivalent
values 8-17
translated but not used 8-21
system powerup 8-2
translate mode 8-2
U.S. and foreign legends 8-31
Loadable device drivers
ANSI.SYS 16-5
Loading font files 16-19
Local area network controller 13-2
(LANCEI interrupt 15-149
Local Area Transport

see LAT 18-54
Loop services 18-42
Loopbacks
diagnostic 9-10
M

Main status register 11-4
Maintenance operations protocol
console server identify self 18-42
loop services 18-42
network boot request 18-43
remote read counters 18-43
Mapping
asynch serial comm devices to
LAT services 17-62
character position 7-7
input/output 2-4
interrupt address 2-6
memory 2-3
Memory
sizing
and initializing 14-8
during extended self-test 14-10
without initializing 14-12
use in real mode 14-8
use in virtual protected mode 14-8
three-channel counter and speaker
6-3
Memory map
physical 2-3
Messages
illogical keyboard 17-12
Mode register, 4-12
1 10-10
2 10-11
Mode-dependent values
set cursor type function 15-12
Modem
connector signals 9-21

Index

control register 9-9
programming exceptions 9-17
status interrupt 9-10
status register 9-13
Monitor
interface signals 7-44
specifications 7-44
MOP 18-42
start and send system ID 18-45
stop 18-45
Mouse 10-1, 17-61
asynchronous serial interface 10-2
baud rates 10-2, 10-11
button position 10-3
commands (table) 10-2
communication 10-2
data bytes 10-2
encoders 10-1
extended self-test loopback test
serial ports 14-10
incremental stream mode command 10-3
invoke self-test command 10-3
movement 10-3
port interrupt 15-150
position 10-3
programming example 10-14
prompt mode command 10-3
reports 10-4 - 10-7
request mouse position command
10-3
self-test 10-3
serial interface 10-2, 10-8
command register 10-12
mode register 1 10-10
mode register 2 10-11
status register 10-9
serial interface registers 10-8
transmit holding register and
receive buffer 10-8
Signetics
SCN2261 enhanced
programmable communications
interface 10-2, 10-8
18 Index

transmit holding register and receive buffer 10-8
vendor reserved function command
10-3
Mouse reports
position (byte 1) 10-4
position (byte 2) 10-5
position (byte 3) 10-5
self-test (byte 1) 10-6
self-test (byte 2) 10-6, 10-7
self-test (byte 3) 10-7
Move a block of memory 15-93
Movement 10-3
MS-DOS Date and Time Structure
16-3, 16-4
MS-Network
compatible session services 18-92
session level interface 13-1
MS-Windows
applications programming interface 17-2
entry points
AnsiToOem 17-55
OemToAnsi 17-58
Mulicast address
enable 18-21
disable 18-22
format 18-7
Multiplex messages 18-6
N

Name status for session 18-103
Network
addressing 18-90
boot request 18-36, 18-43
hardware interface 13-1
interconnect, CSR 13-17
Network interface 13-2
CSR 13-5
external interconnect 13-40

physical I/O ports 13-5
register description 13-5
system bus interconnect 13-40
Network software 18-1
components 18-2
data link 18-5
overview 18-2
NI - see Network Interface 13-2
NI CSR 13-40
No return to user function 15-92
Nonmaskable interrupt 15-3, 15-76
Normal keyboard functions
fetch next character input from
keyboard 17-75
return current shift status 17-76
test for character available 17-75
Not supported functions
joystick support 15-91
Numeric keypad 17-3
Numlock
toggling numeric keypad 17-3

o
OemToAnsi 17-58
Open
datalink portal 18-17
device function 15-89
LAT session 18-66
OpenComm 17-63
OpenLat 17-67
Operational states
diskette drive controller 11-18
p

Parallel
bit stream, converted by LANCE
13-3

port retry function 15-131
Parameters
disk 16-14
Pass-through mode
keyboard 8-2
Peripheral interrupt controller
initializing 3-24
Pointer
diskette parameter tables 15-143
graphics character table pointer
15-145
hard disk parameter tables 15-146
video parameters 15-142
Poll command 3-17
Port driver 18-5
Portal
close 18-21
defined 18-5
read list 18-29
read status 18-30
Powerup test 14-1, 14·8
LEDs 14-8
RAM checks 14-8
self-test error codes 14-8, 14-10
sequence 14-1
Print screen 15-4
Printer
connector signals 9-20
extended self-test loopback test
14-10
GDI support 17-83
output interrupt 15-123
to Host mode C-12
type function 15-129
Priorities
DMA controller 4-5
rotation 3-13
Processor board
testing 14-14
Processor modes
real mode 14-8
Index

virtual protected mode 14-8
Programming
diskette drive controller 11-18
Programming examples
counter and speaker 6-20
datalink 18-46
diskette drive controller 11-27
DMA controller 4-15
constant values 4-15
data structures 4-17
disabling DMA channel 4-22
initializing 4-18
opening DMA channel 4-19
preparing DMA channel 4-20
interrupt controllers 3-21
LAT 18-73
LK250 keyboard 8-46
mouse 10-14
real-time clock 5-15
three-channel counter/timer 6-16
UART (8250A) 9-22
video controller 7-45
modem control 9-17
Prompt mode command 10-3
Pulse output port command
keyboard-interface controller 8-13
R

RAM
system
powerup test checks 14-8
Rate generator 6-5
Read
channel status for datalink 18-27
character and attribute at cursor
position function 15-19
command 8-10
configuration interrupt 15-35
current video state function 15-27
cursor position function 15-14

20 Index

data command 11-21
data for LAT 18-68
datalink counters 18-32
DECparm string address 18-39
deleted data command 11-22
id command 11-23
light-pen position function 15-15
long 256 byte sector 15-58
long function 15-50
node entry given index for session
18-125
node entry given node name for
session 18-124
node entry given node number for
session 18-123
one or more disk sectors function
15-44
one or more track sectors 15-63
pixel function 15-24
port 1 command 8-12
port 2 command 8-13
portal list for datalink 18-29
portal status for datalink 18-30
real-time clock function 15-137
sector command 12-13
system clock function 15-136
test inputs command 8-13
track command 11-23
verify command 12-19
Read-back command
three-channel counter and speaker
6-13
ReadComm 17-64
ReadLat 17-68
Real mode 14-8
Real-time clock
address map 5-3
addressing 5-2
alarm registers 5-12
automatic alarm cycles 5-12
avoiding update cycles 5-13
battery backup source 5-2

data register ranges 5-11
data registers 5-10
extended self-test 14-10
features 5-1
interrupts 5-14
programming example 5-15
register A 5-4
register B 5-6
register C 5-8
register D 5-9
registers 5-3
update cycle 5-13
Real-time clock interrupt 15-148
Recalibrate command
diskette drive controller
register sets 11-26
Recalibrate drive function 15-55
Receive
any for session 18-112
broadcast for session 18-117
buffer/transmitter holding register
9-3
character function 15-74
datagram for session 18-115
for datalink 18-10
for session 18-111
message descriptor, see RMD
13-29
Redirect
parallel printer function 15-127
to interrupt OAH interrupt 15-148
Redirector 18-84
Register sets
format track command 11-24
read data command 11-21
read deleted data command 11-22
read id command 11-23
read track command 11-23
recalibrate command 11-26
scan equal command 11-24
scan high or equal 11-25
scan low or equal 11-25

seek command 11-27
sense drive status command 11-27
sense interrupt status command
11-26
specify command 11-26
write data command 11-21
write deleted data command 11-22
Registers
8250A UART 9-2
diskette drive controller 11-2
C 11-15
change 11-6
control 11-3
D 11-17
data 11-5
data transfer rate 11-6
DTL 11-16
EOT 11-16
GPL 11-16
H 11-15
head/unit select 11-8
hlt/nd 11-15
internal 11-7
main status 11-4
N 11-16
NCN 11-17
PCN 11-17
R 11-15
SC 11-16
srt/hut 11-14
status register 0 11-9
status register 1 11-10
status register 2 11-12
status register 3 11-13
STP 11-17
DMA controller 4-7
base and current address 4-7
base and current word 4-8
command 4-9
mode 4-12
request 4-13
status 4-14
temporary 4-14
interrupt enable 9-4

Index

interrupt identification 9-6
keyboard-interface command 8-9
keyboard-interface controller
command 8-5
data 8-5
status 8-6
line control 9-7
line status 9-11
modem control 9-9
modem status 9-13
receive buffer/transmitter holding
9-3
special purpose 9-18
three-channel counter and speaker
6-8
control 6-11
system 6-9
video controller
color select 7-39
control register A 7-41
control register B 7-43
status 7-37, 7-38
write data 7-39
Release prefix
LK250 keyboard responses 8-31
Remapping
keyboard 16-19
Remote read counters 18-43
Repeating key
changing focus 17-11
Request
line, DMA 13-40
mouse position command 10-3
register 4-13
transmit buffer for datalink 18-25
Request keyboard id 17-78
function 15-118
keyboard-interface controller command codes 8-23
Resend
keyboard-interface controller command codes 8-29

Index

LK250 keyboard responses 8-31
Reserved
keyboard-interface controller command codes 8-25, 8-26, 8-29
Reset
for session 18-98
keyboard-interface controller command codes 8-29
keyboard led
keyboard-interface controller
command codes 8-24
mode function 16-11
processor 14-13
Restore command 12-11
Restore to defaults
keyboard-interface controller command codes 8-28
Result state
diskette drive controller 11-20
Retry on timeout error 15-86
Return
asynchronous port status function
15-75
change line status function 15-68
current drive parameters function
15-48
current shift status flag 17-76
days-since-read counter function
15-140
DIGITAL configuration word
15-99
drive type function 15-57, 15-67
keyboard nationality 17-6
memory size above one megabyte
function 15-95
memory size interrupt 15-37
printer status function 15-126
RTC date function 15-138
status code of last 110 request
15-62, 15-43
Return codes

datalink 18-12
session 18-93
Revector of interrupt 13H interrupt
15-145
RMDO 13-29
ROM BIOS
available (IRQ15) interrupt 15-151
basic interrupt 15-132
bootstrap interrupt 15-133
clock tick interrupt 15-5
COMlIserial interrupt 15-6
COM2/modem interrupt 15-6
during soft reset 14-12
firmware diagnostics and 14-8
initialization procedure 14-12
loading operating system 14-12
local area network controller
(LANCE) interrupt 15-149
mouse port interrupt 15-150
nonmaskable interrupt 15-3, 15-76
print screen interrupt 15-4
read configuration interrupt 15-35
real-time clock interrupt 15-148
redirect to interrupt OAH interrupt 15-148
return memory size interrupt
15-37
revector of interrupt 13H interrupt
15-145
RTC alarm interrupt 15-148
serial printer port interrupt 15-150
ROM BIOS 80287 error interrupt
15-151
ROM BIOS asynchronous communications interrupt 15-70
extended mode 15-77
initialize asynchronous port function 15-72
receive character 15-74
retry on timeout error 15-86
return asynchronous port status
15-75
send break 15-84

set baud rate 15-87
set modem control 15-85
transmit character 15-73
ROM BIOS cassette input/output interrupt 15-88
begin virtual mode 15-96
close device 15-89
device is busy 15-98
interrupt completion handler 15-98
joystick support 15-91
move a block of memory 15-93
open device 15-89
return DIGITAL configuration
word 15-99
return memory size above one
megabyte 15-95
service system request key 15-91
set a wait interval 15-90
termination 15-90
wait (no return to user) 15-92
ROM BIOS disk I/O interrupt 15-38
diskette errors 15-59
diskette functions 15-59
diskette parameter tables 15-59
execute controller internal diagnostics 15-56
format track 15-47, 15-66
hard disk
errors 15-40
functions 15-40
parameter tables 15-41
reset function 15-53
initialize
diskette subsystem 15-61
drive characteristics 15-49
entire disk subsystem 15-42
read long 256 byte sector 15-58
read long 15-50
read one or more disk sectors 1544
read one or more track sectors 1563
recalibrate drive 15-55
return change line status 15-68

Index

return current drive parameters
15-48
return drive type 15-57, 15-67
return status code of last 110
request 15-43, 15-62
seek to specific cylinder 15-52
set drive and media type for
format 15-69
test drive ready 15-54
verify one or more disk sectors 1546
verify one or more track sectors
15-65
write long 15-51
write one or more disk sectors 1545
write one or more track sectors
15-64
ROM BIOS diskette
errors 15-59
functions 15-59
parameter tables 15-59
interrupt 15-143
ROM BIOS floppy disk interrupt
15-7
ROM BIOS graphics character table
pointer interrupt 15-145
ROM BIOS hard disk
interrupt 15-151
parameter tables interrupt 15-146
ROM BIOS initialization procedure
14-12
ROM BIOS interrupt
02H 15-3, 15-76
05H 15-4
08H 15-5
09H 15-5
OBH 15-6
OCH 15-6
OEH 15-7
llH 15-35
12H 15-37

24 Index

18H 15-132
19H 15-133
1BH 15-141
1CH 15-141
10H 15-142
1EH 15-143
40H 15-145
41H 15-146
46H 15-146
4AH 15-148
70H 15-148
71H 15-148
72H 15-149
73H 15-150
74H 15-150
75H 15-151
76H 15-151
77H 15-151
ROM BIOS Interrupt 10H 15-8
enable/disable 256 character
graphic font 15-30
font RAM and color map support
15-31
read character and attribute at
cursor position 15-19
read current video state 15-27
read cursor position 15-14
read light-pen position 15-15
read pixel 15-24
scroll active page down 15-17
scroll active page up 15-17
set color palette 15-22
set cursor position 15-13
set cursor type 15-12
set page 15-16
set video mode 15-10
TTY write string 15-28
write character and attribute at
cursor position 15-20
write character at cursor position
15-21
write character using terminal
emulation 15-25

write pixel 15-23
ROM BIOS interrupt 13H 15-38
diskette errors 15-59
diskette functions 15-59
diskette parameter tables 15-59
execute controller internal diagnostics 15-56
format a track 15-47, 15-66
hard disk
errors 15-40
functions 15-40
parameter tables 15-41
reset 15-53
initialize
diskette subsystem 15-61
drive characteristics 15-49
entire disk subsystem 15-42
read long 256 byte sector 15-58
read long 15-50
read one or more disk sectors
15-44
read one or more track sectors
15-63
recalibrate drive 15-55
return
change line status 15-68
current drive parameters 15-48
drive type 15-57, 15-67
status code of last I/O request
15-43, 15-62
seek to specific cylinder 15-52
set drive and media type for
format 15-69
test drive ready 15-54
verify one or more disk sectors
15-46
verify one or more track sectors
15-65
write long 15-51
write one or more disk sectors
15-45
write one or more track sectors
15-64
ROM BIOS interrupt 14H 15-70

extended mode 15-77
initialize asynchronous port 15-72
receive character 15-74
retry on timeout error 15-86
return asynchronous port status
15-75
send break 15-84
set baud rate 15-87
set modem control 15-85
transmit character 15-73
ROM BIOS interrupt 15H 15-88
begin virtual mode 15-96
close device 15-89
device is busy 15-98
interrupt completion handler 15-98
joystick support 15-91
move a block of memory 15-93
open device 15-89
return digital configuration word
15-99
return memory size above one
megabyte 15-95
service system request key 15-91
set a wait interval 15-90
termination 15-90
wait (no return to user) 15-92
ROM BIOS interrupt 16H 15-101
character count 15-114
extended codes and functions
15-116
key notification 15-111
keyboard buffer 15-115
keyboard input 15-109
keyboard state 15-11 0
keyboard status 15-109
keyboard table pointers 15-120
request keyboard 10 15-118
send to keyboard 15-119
ROM BIOS interrupt 17H 15-123
initialize printer 15-125
parallel port retry 15-131
printer type 15-129
redirect parallel printer 15-127

Index

return printer status 15-126
transmit character 15-124
ROM BIOS interrupt 1AH 15-135
cancel alarm 15-140
read real-time clock 15-137
read system clock 15-136
return
days-since-read counter 15-140
RTC date 15-138
set alarm 15-139
set real-time clock 15-138
set RTC date 15-139
set system clock 15-136
ROM BIOS interrupt vectors 15-1,
15-2
ROM BIOS keyboard
break interrupt 15-141
input interrupt 15-101
interrupt 15-5
character count 15-114
extended codes and functions
15-116
keyboard buffer 15-115
keyboard input 15-109
keyboard notification 15-111
keyboard state 15-11 0
keyboard status 15-109
keyboard table pointers 15-120
request keyboard ID 15-118
send to keyboard 15-119
ROM BIOS printer output interrupt
15-123
initialize printer 15-125
parallel port retry 15-131
printer type 15-129
redirect parallel printer 15-1Z7
return printer status 15-126
transmit character 15-124
ROM BIOS time-of-day interrupt
15-135
cancel alarm 15-140
read real-time clock 15-137
read system clock 15-136

26 Index

return days-since-read counter
15-140
return rtc date 15-138
set alarm 15-139
set real-time clock 15-138
set rtc date 15-139
set system clock 15-136
ROM BIOS timer tick interrupt
15-141
ROM BIOS video
modes 15-10
parameters interrupt 15-142
ROM BIOS video input/output interrupt 15-8
enable/disable 256 character
graphic font 15-30
font RAM and color map support
15-31
functions 15-9
read character and attribute at
cursor position 15-19
read current video state 15-27
read cursor position 15-14
read light-pen position 15-15
read pixel 15-24
scroll active page down 15-17
scroll active page up 15-17
set color palette 15-22
set cursor position 15-13
set cursor type 15-12
set page 15-16
set video mode 15-10
tty write string 15-28
write character and attribute at
cursor position 15-20
write character at position 15-21
write character using terminal
emulation 15-25
write pixel 15-23
ROM diagnostics 14-1, 14-8
extended self-test 14-10
powerup test 14-1, 14-8
Rotating priority

DMA controller 4-5
RTC alarm interrupt 15-148
S

Scan codes 15-102
LK250 keyboard 8-15, 8-17
translated but not used 8-21
Scan equal command
diskette drive controller
register sets 11-24
Scan high or equal command
diskette drive controller
register sets 11-25
Scan low or equal command
diskette drive controller
register sets 11-25
Scroll active page down function 1517
Scroll active page up function 15-17
SDH register 12-9
Sector
count register 12-7
interleave 12-18
number register 12-7
Seek command 12-12
diskette drive controller
register sets 11-27
Seek to specific cylinder 15-52
Select
compose processing 17-6
numlock processing 17-6
Self-test command
keyboard-interface controller 8-12
Self-test failure
LK250 keyboard responses 8-31
Self-test success
LK250 keyboard responses 8-30
Send

break signal for LAT 18-72
broadcast for session 18-116
data for LAT 18-69
datagram for session 18-114
double for session 18-110
for session 18-109
Send break function 15-84
Send to keyboard function 15-119
SendLatBreak 17-70
Sense
drive status 11-27
interrupt status 11-26
Serial
data 9-1
printer port interrupt 15-150
bit stream, converted by LANCE
13-3
interface adapter 13-2, 13-3
Server message block 18-127
Service
directory 18-56
table reset for LAT 18-71
system request key function 15-91
Session
start for LAT 18-57
status word 18-63
for LAT 18-57
asynchronous notification routine
18-90
asynchronous requests 18-89
functions 18-91
add a node 18-120
add name 18-101
call 18-105
cancel 18-97
check for presence 18-96
delete all node entries 18-126
delete entry given node name
18-122
delete entry given node number
18-121
delete name 18-102

Index

DIGITAL function check 18-119
DIGITAL-specific 18-118
hangup 18-108
listen 18-107
name status 18-103
read node entry given index
18-125
read node entry given node
name 18-124
read node entry given node
number 18-123
receive 18-111
receive any 18-112
receive broadcast 18-117
receive datagram 18-115
reset 18-98
send 18-109
send broadcast 18-116
send datagram 18-114
send double 18-11 0
status 18-99
MS-Network compatible services
18-92
network addressing 18-90
overview 18-83
return codes 18-93
status buffer 18-100
synchronous requests 18-89
Session control block (SCB) 18-85
fields 18-86
for LAT 18-59
Set
a wait interval function 15-90
alarm function 15-139
autorepeat delay and rate 8-27
baud rate function 15-87
color palette function 15-22
country code function 16-3
cursor position function 15-13
cursor type function
Mode-dependent values 15-12
DECparm string address 18-40
drive and media type for format
function 15-69

28 Index

graphics rendition function 16-8
keyboard led 8-23
keyclick volume 8-24
mode function 16-10
modem control function 15-85
page function 15-16
parameters command 12-22
real-time clock function 15-138
RTC date function 15-139
system clock function 15-136
video mode function 15-10
SetCommBreak 17-65
SetCommEventMask 17-65
SetCommState 17-65
Shift key
affect on numeric keypad 17-3
SIA - See Serial Interface Adapter
13-2
Signals
communications connector 9-19
modem connector 9-21
printer connector 9-20
Signetics
SCN2261 enhanced programmable
communications interface 10-2,
10-8
Single transfer mode
DMA controller 4-3
Slots for LAT 18-57
5MB
get current date and time 18-128
overview 18-127
Soft reset 14-12
Software interrupts
asynchronous communictaions
15-70
basic 15-132
bootstrap 15-133
cassette input/output 15-88
disk input/output (i/o) 15-38

keyboard break 15-141
keyboard input 15-101
print screen 15-4
printer output 15-123
read configuration 15-35
return memory size 15-37
revector of interrupt 13h 15-145
RTC alarm 15-148
time-of-day 15-135
timer tick 15-141
video input/output 15-8
Software triggered strobe
three-channel counter and speaker
6-6

SORT 16-30
Sort tables 16-32
creating 16-30
SORT.EXE
how affected by FONT. COM 16-16
Sorting
format 16-30
Special purpose register 7-23, 9-18
Specify command
diskette drive controller
register sets 11-26
Speed
indicator control signal 9-17
select control signal 9-17
Square wave model
three-channel counter and speaker
mode 6-5
Standard applications support 17-74
temporarily suspending 17-79
Standard communication of the
VAXmate workstation 13-2
Startup
diagnostics 14-1, 14-8
diagnostics test modes 14-1
Status
buffer for session 18-100

for session 18-99
Status register 4-14, 7-3, 10-9, 12-23
A 7-37
B 7-38
keyboard-interface controller 8-6
Status response
three-channel counter and speaker
6-14
STDUS.KEY 16-25
changing to 16-25
Subroutines
assembly language A-I
Synchronous requests 18-89
SYSREQ 17-5
System
bus 13-2, 13-40
configuration list
during extended self-test 14-10
newly installed options 14-10
powerup 8-4
RAM powerup test checks 14-8
register 6-9
T

Temporary register 4-14
Terminal emulation
font size 17-73
Termination function 15-90
Test
drive ready function 15-54
for character available 17-75
reports for mouse self-test 10-3
Text modes 7-6
cursor rate 7-8
cursor size 7-8
ThinWire
Ethernet 13-3
interconnect 13-3

Index

network interface 13-4
Three-channel counter and speaker
control word register 6-11
counter and speaker example 6-20
counter-latch command 6-12
mode 0 6-4
mode 1 6-4
mode 2 6-5
mode 3 6-5
mode 4 6-6
mode 5 6-7
mode definitions 6-3
modes of operation 6-3
programming example 6-16
read-back command 6-13
status response 6-14
system register 6-9
Time-of-Day interrupt 15-135
Timer tick interrupt 15-141
Toggling keyboard mode 17-4
Translate mode
keyboard 8-2
TranslateMessage 17-4
Translating
attribute data 7-18
graphic color data 7-18
the keyboard 15-121
Transmit
character function 15-73, 15-124
for datalink 18-10, 18-23
holding register and receive buffer
10-8
descriptor ring pointer 13-26
TransmitCommChar 17-64
Transport error codes 18-95
TTY write string function 15-28

u
UART (8250AI registers 9-2

30 Index

programming example 9-22
Universal asynchronous receiverl
transmitters (8250A UART) 9-1
User call-back routines for datalink
18-8

v
VAXmate
address decode logic 13-5
diagnostics 13-4
expansion box 13-40
110 board 13-1
110 bus 13-5
110 functions 13-2
memory option 13-40
network software 18-1
video display memory 13-40
workstation
base configuration 1-1
optional components 1-2
Verify
one or more disk sectors function
15-46
one or more track sectors 15-65
Video
input/output interrupt 15-8, 15-9
modes for the ROM BIOS 15-10
parameters interrupt 15-142
Video controller
color select register 7-3 9
control register A 7-41
control register B 7-43
enhancements to industry-standard
features 7-2
graphic features 7-2
industry-standard features 7-1
programming example 7-45
status register A 7-37
status register B 7-38
text modes 7-6
unavailable industry-standard fea-

tures 7-2
video modes 7-5
write data register 7-39
Video memory 7-3
Video modes 7-5
handling inside a window 17-79
no ROM BIOS
DIGITAL-extended 7-12, 7-14
ROM BIOS
industry-standard 7-11, 7-13
ROM BIOS
DIGITAL-extended 7-15, 7-16,
7-17
Video processor
input/output registers 7-22
look-up table 7-18
Virtual protected mode 14-8
VT220
additional emulator escape sequences C-6
announcing C-8
character set differences C-5
communications differences C-3
DA C-8
DECAUPSS C-6
DECRQUPSS C-6
differences between emulator and
terminal C-2
keyboard differences C-4
printing C-9
SCS C-6, C-7
video differences C-2
VT240
additional emulator escape sequences C-13
announcing C-16
character set differences C-13
communications differences C-12
DA C-15, C-16
DECAUPSS C-13
DECRQUPSS C-14
difference between emulator and
terminal C-10

keyboard differences C-12
Printer to Host mode C-12
SCS C-14, C-15
video differences C-10

w
Windows
keyboard extensions 17-5
layer 17-2
reserved keys 17-5
Write
all mask bits 4-11
character and attribute at cursor
position 15-20
character at cursor position 15-21
character using terminal emulation
15-25
long 15-51
one or more track sectors 15-64
one or more disk sectors 15-45
pixel 15-23
Write command
keyboard-interface controller 8-10
Write data command
diskette drive controller register
sets 11-21
Write data register 7-39
Write deleted data command
diskette drive controller register
sets 11-22
Write port 2 command
keyboard-interface controller 8-13
Write precompensation register 12-4
sector command 12-15
single mask bit 4-11
status register command keyboardinterface controller 8-13
WriteComm 17-63
WriteLat 17-69

Index

Technical Reference Manual
Volume 2
AA-HD95A-TK

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o
o
o
o
o
o
o
o
o
o

Fair

Poor

o
o
o
o
o
o
o
o
o
o
o

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