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DEC-15-ODUMA-A

December 1972

222 pages

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10MB

Document:	DOS-15 Users Manual
Order Number:	DEC-15-ODUMA-A
Revision:
Pages:	222
Original Filename:	http://bitsavers.org/pdf/dec/pdp15/DEC-15-ODUMA-A_DOS-15_Users_Manual_197212.pdf

OCR Text

DEC-15-0DUMA-A-D

-15
users manual

SOFTWARE SUPPORT CATEGORY
The software described in
this document is supported
by Digital Equipment Corporation under Category I,
as defined on page iii of
this document.

For additional copies, order No. DEC-15-0DUMA-A-D
from Software
Distribution Center, Digital Equipment Corporation, Maynard,
Massachusetts 01754

First Printing December, 1972

Your attention is invited to the last two pages of this
document. The "How to Obtain Software Information" page
tells you how to keep up-to-date with DEC's software.
Completion and return of the "Reader's Comments" page is
beneficial to both you and DEC: all comments received are
acknowledged and are considered when documenting subsequent manuals.

by Digital Equipment Corporation

DEC assumes no responsibility for the use or reliability
of its software on equipment which is not supplied by
DEC.
The material in this document is for information
purposes and is subject to change without notice.

The following are trademarks of
Corporation, Maynard, Massachusetts:
CDP
COMPUTER LABS
COMTEX-11
DDT
DEC
DECTAPE
DIBOL

Teletype

DIGITAL
EDU SYSTEM
FLIP CHIP
FOCAL
GLC-8
IDACS
INDACS

I<AlO

LAB-8
OMNIBUS
OS/8
OS/11
PDP
PHA

is a registered trademark

Corporation.

Digital

Equipment

QUICXPOINT
RAD-8
RSTS
RSX
SABR
TYPESET-8
UNIBUS

of· the

Teletype

SOFTWARE

SUPPORT

CATEGORIES

Digital Equipment Corporation (DEC) makes available four categories of software. These
categories reflect the types of support a customer may expect from DEC for a specified software
product. DEC reserves the right to change the category of a software product at any time.
The four categories are as follows:

Software

CATEGORY
Products Supported

Charge

This classification includes current versions of monitors, programming languages, and
support programs provided by DEC. DEC will provide installation (when applicable), advisory,
and remedial support at no charge. These services are limited to original purchasers of DEC
computer systems who have the requisite DEC equipment and software products.
At the option of DEC, a software product may be recategorized from Category I to
Category II for a particular customer if the software product has been modified by the customer
or a third party.

Software

Products

CATEGORY 11
that Receive Support

for

Fee

This category includes prior versions of Category I programs and all other programs avai 1able from DEC for which support is given. Programming assistance (additional support), as
available, will be provided on these DEC programs and non-DEC programs when used in conjunction with these DEC programs and equipment supplied by DEC.

CA TE GORY 111
Pre-Release Software
DEC may elect to release certain software products to customers in order to facilitate
final testing and/or customer familiarization. In this event, DEC will limit the use of such
pre-release software to internal, non-competitive applications. Category Ill software is only
supported by DEC where this support is consistent with evaluation of the software product.
While DEC will be grateful for the reporting of any criticism and suggestions pertaining to a
pre-release, there exists no commitment to respond to these reports.

CATEGORY IV
Non-Supported Software
This category includes all programs for which no support is given

iii

PREFACE

This manual is the prime document for the IX>S-15 Monitor Software
System and describes its features, concepts, programming, and operating procedures.

The first four chapters provide a general descrip-

tion of the DOS-15 System components, both hardware and software,
fundamental

syste~

concepts, and file structures.

The remaining six chapters deal with the DOS-15 system at a more
technical level.

They are primarily concerned with I/O programming

requirements and techniques under the Monitor, runtime keyboard commands, and operating procedures.

The information in these chapters

is directed primarily to readers wbo are familiar with either the
FORTRAN IV language or the PDP-15 assembly language, MACR0-15 (described in DEC-15-GFWA-D and DEC-l5~AMZC-D_, respectively). FORTRAN
users, however, need only be concerned with Chapters 7, 8, and 10,
since FORTRAN I/O considerations are specifically covered in the
PDP-15 FORTRAN IV Operating Enviromment manual (DEC-15-GFZA-D).
Detailed information on the internal operations of the DOS-15 Monitor
and its file structure as well as procedures for preparing usercreated system software are provided in the DOS-15 System Manual
(DEC-15-NRDA-D) .

Brief descriptions of all system programs with

applicable document numbers are contained in Chapter 2.
A quick reference summary of the command strings, operating procedures
and error messages for the Monitor and system programs is provided in
the DOS-15 Keyboard Command Guide (DEC-15-NGKA-D).

CONTltNTS

PREFACE
CHAPTER 1
1.1
1.1. l

DISK OPERATING SYSTEM
INTRODUCTION
System Features

1-1
1-2

SYSTEM HARDWARE
1.2
Minimum Hardware Requirements
1. 2.1
1.2.2.
Optional Hardware
1.2.2.1
Control X Feature
1.2.2.2.
Real-Time Clock
1. 2.3
The System Device

1-3·
1-3
1-5
1-5
1-6
1-6

SYSTEM SOFTWARE
How DOS is Supplied
DOS Checkout Package

1-6
1-10
1-10

1.3
1.3.l
1.3. 2
CHAPTER 2

SYSTEM PROGRAMS

2.1

INTRODUCTION

2-1

2.2
2.2.1
2.2.2
2.2.3

CHOICE OF LANGUAGES
FORTRAN IV Compiler
MACRO Assembler
FOCAL Programs

2-l
2-1
2-2
2-4

2.3

SYSTEM GENERATOR (SGEN)

2-4

2.4

PATCH SYSTEM UTILITY PROGRAM

2-5

CHAIN AND EXECUTE PROGRAMS
Advantages/Disadvantages of CHAIN
& EXECUTE
2.5.1.1
Advantages
2.s.1.2
Disadvantages

2-7
2-7

2.6

LINKING LOADER

2-8

2.7

DYNAMIC DEBUGGING TECHNIQUE (DDT) PROGRAM

2-9

2.8

DU"'IP PROGRA."'1

2-9

2. 9

MAGNETIC TAPE DU"'IP (MTDU"'IP) UTILITY PROGRAM 2-9

2.10

TEXT EDITOR PROGRAMS, EDIT, EDITVP AND
EDITVT

2-10

2.11

PERIPHERAL INTERCHANGE PROGRAM (PIP)

2-10

2.12

DECTAPE COPY (DTeOPY)

2-11

2.13

LIBRARY UPDA'rt PROGRAM

2-11

2.5
2.5.l

vii

2-7
2-8

2.14

SOURCE COMPARE PROGRAM (SRCCOM)

2-11

2.15

GRAPHIC-15

2-11

2.16

PDP-8 TO PDP-15 TRANSLATOR (8TRAN)

2-11

2.17

PDP-8 TO PDP-9 TRANSLATOR (89TRAN)

2-12

2.18

VP15A GRAPHICS SOFTWARE

2-12

CHAPTER 3

SYSTEM CONCEPTS
DOS-15 MONITORING FUNCTIONS
System Communication Table (SC0'-1.)
• Monitor/User Interaction

3-1

I/O COMMUNICATION
Device Independence
I/O Device Handlers
Device Assignment Table (.DAT)

3-4
3-4
3-5
3-5

3.3.1
3.3.2

FILE STRUCTURES
User File Directories and UIC's
Monitor Identification Code (MIC)

3-5
3-6
3-6

3.4

FILE PROTECTION

3-7

3.5

I/O BUFFERS

3-7

3.1

.3 .1.1
3.1. 2

3.2
3.2.1

3.2.2
3.2.3
3.3

3-2
3-3

3.6
3.6.l

CHOICE OF EXECUTABLE F'ORM
Relocatable Binary
3.6.2
Absolute Binary Forms
3.6.2.l
.ABS and .ABSP Binary
3.6.2.2
.FULL and .FULLP Binary

3-7
3-7
3-8
3-8
3-8

LOADER CONTROL
3.7
Globals
3.7.l
3.7.2
Program Loading
3.7.2.l
Page Mode Operation
Bank Mode Operations
3.7.2.2

3-8
3-9
3-9
3-9
3-9

ERROR DETECTION

. 3-10

3.8
CHAPTER 4

FILE STRUCTURES

4.1

INTRODUCTION

4-1

4.2

DEVICE ASSIGNMENTS

4-1

4.3
4.3.1
4.3.2
4.3.3

FILES
Records
Words
Data Modes

4-2
4-2

4.4

4-3

4.4.2
4.4.3

FILE STRUCTURES
File and Data Access Techniques
Sequential Access
Direct Access

4.5

MAGNETIC TAPE FILE STRUCTURE

4-5

4.4.l

4-2
4-3

viii

4-4
4-4
4-4

4.6

DECTAPE FILE STRUCTURE

4-6

4.7
4.7.1
4.7.2
4.7.3

DISK FILE STRUCTURE
User Identification Codes (UIC)
The User File Directory Table (.UFDT)
File Protection
Organization of Specific Files on Disk
The Disk Handlers

4-8
4-8
4-9
4-9
4-11
4-11

4.7.4

4.7.5
CHAPTER 5
5.1

DOS SYSTEM MACROS
INTRODUCTION

5-1

5.2
MONITOR-PROCESSED COMMANDS
5.2.1
Summary of DOS Monitor System Macros
5.2.2
DOS-15 System Macro Expansions
5• 2• 2. 1
• PUT
5.2.2.2
.GET
5.2.2.3
.GTBUF (Get Buffer)
5.2.2.4
.GVBUF (Give Buffer)
5. 2. 2. 5
.OVRLA
5.2.2.6
.EXIT
5.2.2.7
.TIMER
CHAPTER 6

PROGRA~MED

5-1
5-1
5-2
5-3
5-4
5-5
5-5
5-6
5-6
5-7

1/0 COMMANDS

6.1

INTRODUCTION

6-1

6.2
6.2.1
6.2.2

GENERAL I/O COMMUNICATIONS
.READ/.WRITE/.RTRAN Operations
.TRAN Operations

6-1
6-3
6-3

SEQUENTIAL FILE PROCESSING
Logical Record Format, IOPS and Image
Modes
6.3.1.1
Header Word Pair Format
6.3.1.2
Using the Header Word Pair

6-3

DATA MODES
6.4
IOPS Modes
6.4.1
6.4.1.1
IOPS ASCII
6.4.1.2
IOPS Binary
Image Modes
6.4.2
Dump Mode
6.4.3
6.4.4
Logical Record Terminators

6-6
6-7
6-7

6.5
6.5.1

6-14
~

6.3
6.3.1

I/O BUFFERS
Sn~rP

All~~~~i~~

=e c=-

---

6-3
6-4
6-4

6-9
6-10
6-12
6-12

o-.i.<t

6.6

SPECIFYING I/O DEVICES

6-16

6.7

I/O MACRO DESCRIPTIONS
.CLEAR
.CLOSE
.DLETE
.ENTER
.FSTAT
.INIT

6-16

6.7.1
6.7.2

6.7.3
6.7.4
6.7.5
6.7.6

6-17

6-17
6-18
6-18

6-19
6-20

6.7.7
6.7.8
6.7.9
6.7.10
6.7.11
6.7.12
6. 7 .13
6.7.14
6. 7. 15
6.7.16
6.7.17
6.8
6.8.l
6.8.2
6.8.3
6.8.4
6.8.5
6.8.6
CHAPTER 7

.MTAPE
.RAND
.READ
.RENAM
.RTRAN
.SEEK
.TRAN
.USER
.WAIT
.WAITR
.WRITE

6-21
6-21
6-22
6-23
6-23
6-24
6-25
6-26
6-27
6-27
6-28

USING I/O MACROS
Physical Device Capabilities
Device Handler Characteristics
I/O Macro Syntax
.Selecting an I/O Macro Sequence
Programming Example
File Integrity Considerations

6-29
6-29
6-29
6-2 9
6-31
6-33
6-44

SYSTEM INITIALIZATION

7.1

INTRODUCTION

7-1

7.2

HOW THE SYSTEM SOFTWARE IS SUPPLIED

7-1

7.3
SYSTEM STARTUP PROCEDURES
7.3.1
Disk Restoration (DOSSAV)
7.3.1.1
Operating Procedures
7.3.1.2
Commands
7.3.l.3
Examples of DOSSAV Commands
7.3.1.4
Error Messages and ~eanings
7.3.1.5
Restart Procedures
7.3.2
Loading and Starting the Monitor
7.3.2.1
Loading the Bootstrap
7.3.2.2
Bootstrap Restart Procedures

7-2
7-2
7-3
7-3
7-5
7-7
7-8
7-8
7-9
7-9

7.4

7-10

CHAPTER 8

SYSTEM MODIFICATION (TAILORING) PROCEDURES
KEYBOARD COMMANDS

8.1

INTRODUCTION

8-1

8.2
8.2.l
8.2.2
8.2.3

KEYBOARD C0"1111AND FOR~TS AND CHARACTERS
Keyboard Command Elements
Editing Features
When to Issue Keyboard Commands

8-2
8-2
8-2
8-3

8.3
8.3.l
8.3. 2
8.3.3

C0"1'1ANDS TO REQUEST SYSTE"-1 INFOR"1ATION
SCOM
INSTRUCT
REQUEST

8-3
8-3
8-5
8-8

8.4
8.4.1
8.4.2
8.4.3
8.4.4

COM~ANDS

RELATED TO FILE PROTECTION

8-8
8-8
8-9
8-9
8-9

8.5

8-10

8.5.1
8.5.2
8.5.3

COMMANDS DEALING WITH I/O DEVICE
ASSIGNMENTS
REQUEST
ASSIGN
KEEP ON/OFF

8.6
8.6.1
8.6.2

CORE ALLOCATION COMMANDS
BUFFS
X4K ON/OFF

8-13
8-13
8-14

8.7
8.7.1
8.7.2
8.7.3
8.7.4

CORE IMAGE SAVE/RESTORE COMMANDS
CTRL Q
QDUMP
PUT
GET

8-14
8-15
8-15
8-15
8-16

8.8
VT15 DISPLAY COM.~NDS
8.8.1
Operating Features
8.8.1.1
Display Modes
8.8.1.2
Clearing the Display Screen
8. 8.1.3
Editing
8.8.2
Display Command Description
8.8.2.1
VT ON/OFF
8.8.2.2
HALF ON/OFF
8.8.2.3
CTRL X
8.8.2.4
Command Default Settings

8-17
8-17
8-17
8-18
8-18
8-18
8-18
8-19
8-19
8-19

8.9
MISCELLANEOUS COMMANDS
8.9.1
API ON/OFF
8.9.2
33TTY ON/OFF
8.9.3
CHANNEL 7/9
8.9;4
LP ON/OFF
8.9.5
BANK ON/OFF - PAGE ON/OFF
8.9.6
DATE
8.9.7
TIME
8.9.8
TIMEST
8.9.9
LOG
8.9.10
HALT
8.9.11
CTRL D

8-19
8-19
8-20
8-20
8-20
8-20
8-21
8-21
8-22
8-22
8-22
8-22

8.10

SYSTEM PROGRAM LOADING COMMANDS

8-23

8.11
PROGRAM START/RESTART/CONTINUE COMMANDS
8.11.1
CTRL C
8.11.2
CTRL P
8.11.3
CTRL S
8 .11. 4
CTRL T
8.11.5
CTRL R

8-23
8-23
8-23
8-25
8-25
8-25

8.12
BATCHING KEYBOARD COMMANDS
0.12.1
Preparation
8.12.2
Operator Commands
0.12.2.1
BATCH
0.12.2.2
CTRL T
8.12.2.3
CTRL C
8.12.2.4
CTRL R
8.12.3
Job Control Commands
8.12.3.1
$JOB
8.12.3.2
$DATA
8.12.3.3
$END
8.12.3.4
$PAUSE
0.12.3.s
$EXIT
8.12.4
Restrictions

8-25
8-25
8-26

8.13

8-28

KEYBOARD ERHOR J)ETECTION AND HANDLIN<;

8-10
8-12
8-13

B-26
8-26

B-26
8-26
8-26
8-26
8-27
8-27
8-27
B-27
8-27

CHAPTER 9
9.1

I/O DEVICE HANDLERS
INTRODUCTION

9-1

DEVICE HANDLERS ACCEPTABLE TO SYSTEM
PROGRAMS
FORTRAN IV (F4)
9.2.1
MACR0-15
9.2.2
FOCAL
9.2.3
EDIT, EDITVP, and EDITVT
9.2.4
Linking Loader and DDT
9.2.5
PIP (Peripheral Interchange Program
9.2.6
'SGEN (System r,enerator)
9.2.7
9.2.8
PATCH
UPDATE
9.2.9
DUMP
9.2.10
CHAIN
9.2.11
}:XECUTE
9.2.12
SRCCOM (Source Compare)
9.2.13
9.2.14
DTCOPY (DECtape Copy)
8TRAN (PDP-8 to PDP-15 Translator)
9.2.15
89 TRAN (PDP-8 to PDP-9 Translator)
MTDUMP (Magtape User's Utility Program)
9.2.16
9.2

I/O HANDLER DESCRIPTIONS
9.3
9. 3 .1
Teleprinter Handler (TTA)
9.3.1.1
General Description
Device Dependent Characteristics
9.3.1.2
Program Control Characters
9.3.1.3
Paper Tape Punch Handlers (PPA,PPB, and
9. 3. 2
PPC)
9.3.2.1
General Description .
Device Dependent Characteristics
9.3.2.2
Paper Tape Reader Handlers (PRA and PRB)
9.3.3
DECtape Handlers (OTA, OTC, OTO, DTE,
9. 3. 4
and DTF)
General Description
9.3.4.1
9.3.4.2
Device Dependent Characteristics
DECdisk and Disk Pack Handlers (DKA/DPA,
9. 3. 5
DKB/DPB, and DKC/DPC)
General Description
9.3.5.1
Device Dependent Characteristics
9.3.5.2
Magtape Handlers (MTA, MTC, and MTF)
9. 3. 6
General Description
9.3.6.1
Device Dependent Characteristics
9.3.6.2
9.3.7
Line Printer Handler
9.3.7.1
General Description
9.3.7.2
Device Dependent Characteristics
Card Reader Handler (COB)
9 .3. 8
9.3.8.1
General Description
Device Dependent Characteristics
9.3.8.2
VP15A Storage Tube Display (VPA)
9. 3. 9
CHAPTER 10

9-2
9-3
9-4
9-5
9-6
9-6
9-7
9-7
9-8
9-8
9-8
9-9
9-9
9-9
9-10
9-10
9-10
9-10
9-11
9-11
9-11
9-13
9-14
9-14
9-15
9-15
9-17
9-17
9-18
9-18
9-18
9-20
9-23
9-23
9-25
9-25
9-25
9-26
9-27
9-27
9-28
9-29

OPERATING PROCEDURES

10.l

INTRODUCTION

10-1

10.2

EXAMPLE OF KEYBOARD OPERATIONS

10-1

10.3

EXAMPLE OF OPERATING PROCEDURES USING
COMMAND BATCHING MODE

10-9

10.4

ERROR DETECTION AND RECOVERY PROCEDURES

10-14

xii

APPENDIX A

PDP-15 IOPS ASCII STANDARD CHARACTER SET

A-1

APPENDIX

SAMPLE IOPS ASCII PACKING AND UNPACKING
ROUTINES

B-1

APPENDIX c

INPUT/OUTPUT DATA MODE TERMINATORS FOR
SPECIFIC DEVICE HANDLERS

C-1

APPENDIX D

IOPS ERROR CODES

D-1

APPENCIX E

LINKING LOADER AND SYSTEM LOADER ERRORS

E-1

APPENDIX F

•PDP-15 ASCII/HOLLERITH CORRESPONDENCE

F-1

APPENDIX G

DOS-15 CHECKOUT PROCEDURES

G-1

APPENDIX H

DOS TERMS AND ACRONYMS

H-1

INDEX

xiii

CHAPTER 1
DISK OPERATING SYSTEM

1.1

INTRODUCTION

The PDP-15 ~isk Qperating .§ystem (DOS-15) is an integrated set of
software designed to meet the demands of research, engineering,
and industrial environments. It includes the software necessary

fer rim,....1;e..:,..,,4 p-.1.oq.r;culUU~11u dnn P.;r1r.1~n1""··npcrati-nc:::_

DOC'

brings to the user the advantages of disk resident storage via
rapid access to the system's resources. The operating system
runs with a PDP-15/20 Central Processor having at least 16,384
18-bit words of main memory and the specific capabilities required
by the system (see Paragraph 1. 2, "System Hardware").
The System Monitor is an integrated set of commonly-used programs
for the development of user applications. These programs include
tools for:
Program Preparation,
Compilation,
Assembly,
Debugging, and
Execution of User Programs.
The DOS Monitor, the heart of the system, incorporates all the functions of the "Advanced Monitor System" plus the added power of
fully automatic random access file operation. The user controls
the operating system by instructions to the Monitor. The Monitor
runs the jobs, supervises data and file manipulation, and interacts
with the operator/user in a simple, conversational manner.
In the operating system; data on mass storage is handled by macro
statements used with the MACR0-15 symbolic assembler language, and
by the mass storage language elements incorporated into the FORTRAN
IV compiler.

1-1

1.1.l

System Features

Disk Resident
System Software

All DOS-15 system Software resides on either

Interactive

An interactive keyboard/program Monitor permits

Operation

device-independent programming and automatic

DECdisk or Disk Pack.

calling and loading of system and user programs.
I/O Device

Data and file manipulating I/O device handlers

Handlers

~re

Programmed

Input/Output programming is simplified by the

11onitor

use of a set of system commands which are

Commands

standardized for system-supported I/O devices.

Conversational

System Utility Programs interact with the operator/

Mode

user in a simple, conversational manner.

Dynamic Storage

The available disk storage is automatically allo-

Allocation

cated for optimum storage utilization.

Dynamic Buff er

Input/Output core is automatically optimized by

Allocation

the Monitor.

supplied for standard system peripherals.

It allocates only that space which

is required for the system and the user.
Disk File

Allows the most efficient use of disk capacity

Structure

and data retrieval for processing via:
o

System supported DECdisk and Disk Pack
devices, providing both economy and
storage capacity

Virtually unlimited data capacity (Disk
Pack= 83.7 million words, DECdisk - 2.09
million words)

Random/Sequential File access

File Protection through unique user
directories

1-2

User/user file independence - identically
named unformatted Input/Output (FORTRAN-IV)

Random Access - formatted as well as
unformatted Input/-Output (FORTRAN-IV)

User-Created
System Files

The user may easily incorporate his own software
into the operating system, thereby tailoring the
system to his hardware and software needs.

Programming

Several programming languages are offered:

Languages

FORTRAN IV, FOCAL, MACR0-15.

Bank and Page

Choice of SK (Bank Mode) or 4K (Page Mode)
direct addressability.

Modes

Bank Mode permits

DOS-15 operation on the PDP-9.
The system provides for several levels of user file protection.

Using

unique User Identification Codes, each user can be assured of his
file integrity.

Files are protected and invisible to other users.

The system provides privileged access to all files via a·supervisory
code maintained by the system owner or manager.

1.2

SYSTEM HARDWARE

The Disk Operating System is definedwithinthe limits of a particular
PDP-15 hardware system configuration; i.e., central processor model,
minimum and maximum core requirements, necessary features, and types
and numbers of peripheral devices.

The system software is distributed
DECtape or

as a Disk Restore system on

Magtape, and operates from DECdisk or Disk Pack with

DECtape or Magtape backup storage.
1.2.l

Minimum Hardware Requirements

The minimum equipment configuration for the DOS-15 software includes
the PDP-15 Central Processor with ~e following features:
16,384 18-bit, 800-NS core memory
35 Teleprinter
PC15 High-speed Paper Tape Reader and Punch
1-3

KE15 Extended Arithmetic Element
TC15 DECtape Control
1

TU56 Dual DECtape Transport or 2 TUSS DECtape

Transports,
or
TC59 Magtape Control
1 TUlO, TU20, or TU30 Magnetic Tape Transport
{7- or 9-track)

RF15 DECdisk Control
1 RS09 DECdisk Drive (262,144 words)
or
RP15 Dis~ Pack ~ontrol
1 RP02 Disk Pack Drive (10.24 million words)
1 RP02D Disk Pack
The PDP-15 hardware environment is illustrated in Figure 1-1.

MEMORY BANKS

r-,..--.

r--r-.,

f 4K ~ 4K I

I 4 K 1 4K I

L--t-.J L--t--'

~----'---.--- ...J __ -

REtco~~E :

I A~RIO~~~c

-------J

~~!.E.!!,R,!lP.J

INPUT/OUTPUT PROCESSOR

DATA

t--.---.--.......--.-...--.-...--t

___ .J

EXTENDED
ADDR
FL~~l";J~G I
ARITHMETIC
ELEMENT
INPUT/...__..-Jr - - - .J. - - - - OUTPUT
BUS
CENTRAL PROCESSOR UNIT

3 ....._4-r-'-5--'-6--'-7_.,_e_.._-r-_,
CHANNELS ._....._.,.........
l262K)

r::::l

~~
I
I

--------~-----~--

DECTAPE
rNTROL

-OTHER

ONE

~1
MAGTAPE
CONTROL

, -

L-t
I

HIGH SPEED
PAPERTAPE
STATION

--~

I
I

- - - - OPTIONAL SUBSYSTEMS

' -- ..

L-t

8 I

Fi9ure 1-1

Hard~are Environment

411

1.2.2

Optional Hardware

Additional hardware supported by the operating system is as follows:

up to 32,768 18-bit, 800-NS core memory
KA15 Automatic Priority Interrupt
KW15 Real Time Clock
FP15 Floating Point Processor
35 and/or 33 Teleprinter or LA3~ DECwriter
PC15 High Speed Paper Tape Reader and Punch
TC15 DECtape Control
4 TU56 Dual or 8 TUSS DECtape Transports
RFlS DECdisk Control
8 RS09 DECdisk Drives (262,144 words per drive)
RP15 Disk Pack Control
8 RP02 Disk Pack Drives (10,240,000 words per drive)
TC59 Magtape Control
8 TUlO, TU20 or TU30 (7- or 9-track) Tape Transports
Card Readers
CR03B 200 cpm Reader and Control
or
CR15 1000 cpm Reader and Control
VP15 Point Plotting Displays
VT15 Graphic Display Processor
VT04 Graphic Display Console
LK35 Keyboard
Line Printers
LP15 - 1000 lpm, 132 column line
or
- 356 lpm, 80 dolumn line
VWA Writing Tablet

1.2.2.1 CTRL X Feature - The Control X feature is available to the
user whose system configuration incl,udes a VT15 Display Processor or
a VT04 Display Console. This featute gives the capability of changing
from the hard copy output of the teleprinter to the soft copy output
of the VTlS Display.

_l-5

1.2.2.2 Real-Time Clock - The Real-Time Clock (on systems having
this option) runs continuously, in order to update an elapsed time
register. It can be used by the user to time jobs or to control
program execution.

In addition to the above, the user may adapt the system to incorporate
many other specialized peripherals, such as X-Y plotter, data acquisition equipment, etc. ·
1.2.3

The System Device

The system device for DOS-15 may be either the RF15 DECdisk, or the
RP02 Disk Pack.
The RF15 DECdisk equipment is composed of up to eight fixed-head,
rotating disks which are treated by DOS as one contiguous storage
area. The DOS Monitor provides for simultaneous use of the DECdisk
or Disk Pack as a system device, file device, and scratch device.
1.3

SYSTEM SOFTWARE

The PDP-15 Disk Operating System's service routines perform four primary tasks for all user applications (see Figure 1-2).
1.

Run-Time Aids - External routines from several
libraries are available to the user. The libraries may contain either user-designed routines
or those provided by DOS-15 which can be implicitly
or explicitly called.

Utilities - DOS-15 provides facilities for
efficient storage, flow, and retrieval of system
and user data. There are also system programs
that provide file verification and data buffer
allocation, file data manipulation, etc.

Program Preparation and Maintenance - There are
system programs to aid user program preparation
by preparing f ilc text for source programs and
l-6

LANGUAGES

DOS-1!1
MONITOR

llUN·TIME
AIDS

Piqure 1-2
PDP-15 Monitor Disk Operating System Software

1-1

programs to aid testing and maintenance of
object programs.
4.

Language Assembly and Compilation - Programs are
available to translate problem-oriented and procedure oriented languages into machine language
and to incorporate routines into complete, executable
programs.

The system software lets the user deal with many complex problems in
a simple and straightforward manner.

The system will perform all of

these functions:
1.

Write programs in three higher-level languages FORTRAN IV, FOCAL and MACR0-15.

Edit and debug the program prior to run.

Load and link programs.

4•

Run the program by :

handling I/O,

reading and writing named random-access files
on disk storage,

providing run-time device independence,

Batch process from paper tape or cards.

Listed in Table l-l are individual system programs in the PDP-15
Disk Operating System.
Table 1-1

DOS System Software
Program Name

System Functions

Description

MONITORS

DOS-15 Monitor

Allows system parameter
changes and device assignments.

LANGUAGES

FORTRAN IV

Compiler, Object Tim~'
System, Science Library.

FOCAL

An on-line interactive
algebraic language.

MACR0-15

A symbolic assembler
language.

1-8

Table 1-1

DOS System Software (Cont'd)
Program Name

System Functions
PREPARATION AND
DEBUGGING

UTILITIES
General

UTILITIES
System

OPERATING PROGRAMS

Description

DDT

A Dynamic Debugging Technique for FORTRAN and
MACRO programs.

DUMP

The capability to output
specified core locations.

EDIT

Text Editor providing
insertion, deletion, and
modification of symbQlic
text.

EDI'l'VP & EDITVT

Special versions of EDIT
which provide fast soft
copy editing on the VT or
VP display system.

PIP

Facilitates the manipulation and transfer of
data files from any input
to any output device.

DTCOPY

High-speed DECtape copy
program.

UPDATE

Binary program retrieval
and library update program.

SltCCOM

Source compare program.

MTDUMP

Magnetic Tape DUMP program.

8TRAN

Translates PDP-8 source
code into PDP-15 code.

89TRAN

Translates PDP-8 source
code into PDP-9 code.

SGEN

Provides the ability to
tailor the system structure to a particular hardware/software configuration.

PATCH

Makes corrections to systems programs on the
systems device, and adds
programs to the system.

Linking Loader

Loads relocatable programs
and required routines.

CHAIN & EXECUTE

Multiple segmentation of
large programs and overlays
to allow economy of core.

1-9 .

These programs are supervised by the Monitor to form an interactive
collection of service programs. This relationship is illustrated in
Figure 1-2.

1. 3.1

How DOS is Supplied

General purpose software is suppli~d to the PDP-15 user on two
DECtapes or one 7- or 9-track magnetic tape as a disk-restore initialization. The DOS-15 System tape(s) contain all of the standard PDP-15
DOS System Programs, Utility Progr~ms, and I/O Device Handlers supplied and supported by Digital Equipment Corporation. An unmodified
master system tape or tapes should,be maintained as a reference backup system. Users with the FP-15 Floating Point hardware are provided
with additional FP-15 routines on DECtape or Magtape.
1

1. 3. 2

DOS Checkout Package

Digital Equipment Corporation supplies a checkout package for the
DOS-15 which allows the user to te$t the System software for proper
installation on DECdisk or Disk Pa¢k. The package is available on
•
I
batch paper tapes in two versions, ,as follows:
RF.CHK
RP.ChK

For the RF15 DECd!sk system (DEC-15-CIDA-PA)
For the RP,112 DiskiPack system (DEC-15-CIAA-PA)

These programs provide the user with the ability to briefly test all
the basic system software suppliedifor DOS-15. For more information,
refer to Appendix G, DOS-15 Checkout Packaqe.

1-10

CHAPTER 2
SYSTEM PROGRAMS

2.1

INTRODUCTION

This chapter gives information necessary for the System's Manager and
Analyst to evaluate system programs to be run under DOS-15 control.
Each system program will assist the user in performing a particular
task in the process of application design and implementation. Considerations for system modification are reserved for DOS System Manual
DEC-15-NRDA-D.
2.2

CHOICE OF LANGUAGES

User source programs can be implemented at several levels depending
on those particular system features required for a given processing
environment. DOS-15 supports three levels of automation for object
program preparation:
1.
2.
3.
2.2.1

Compiler level language - FORTRAN IV
Assembly language - MACR0-15
Interpretive language - FOCAL
FORTRAN IV Compiler

The P.DP-15 FORTRAN IV compiler is a higher-level, procedure-oriented
language system that accepts statements written in the FORTRAN IV
language and produces a relocatable object program capable of being
loaded by the Linking Loader. All versions of PDP-15 FORTRAN IV
are based on the language of USASI Standard FORTRAN (XJ.9-1966). The
system is augmented by the Floating Point Processor, the FORTRAN IV
compiler, and an Object Time System.
Object time program capabilities include "floating point" instructions.
Subroutines written in either FORTRAN IV or MACR0-15 assembly language
can be loaded with and called by FORTRAN IV main programs. Comprehensive source language diagnostics are produced during compilation,
and a symbol table is generated for use in on-line debugging with DDT.

2-1

The system's Data-Directed Input-Output package permits input or output of ASCII data without reference to a FORMAT statement.

The

system can also perform memory-to-memory transfers (Encode/Decode)
moving data from memory to the I/O Buffer to memory.
There are three versions of the FORTRAN IV supported by DOS-15:
(1)

F4X (PDP-15 mode);

Point mode).

(2) F4X9 (BANK mode); and (3) FPF4X (Floating

Each version has its own Object Time System and Science

Library so that program routines may utilize all system hardware and
software features.
A FORTRAN IV program may be compiled and run in several different equipment environments.

The FORTRAN progranuner need not be too concerned

with the details of his environment since the FORTRAN Object-Time System (OTS) will ensure that his source statements generate the appropriate computer instructions.

For example, an arithmetic statement such

as A=A*B will appear the same in any FORTRAN IV program.

In the object

program it may be transformed to a subroutine call or a floating point
instruction, depending on the hardware configuration on which the program is produced.

FORTRAN data-transmission statements automatically

call a number of OTS subroutines which serve as an interface between
the user program and the Monitor.

These t'outines may also be called from

MACR0-15 assembly language programs.

Further, programs written in

FORTRAN IV can be linked to programs or routines written in the MACR0-15
assembly

language.

For more information concerning this higher-level prograrmning language,
refer to Volume One and Volume Two of the FORTRAN IV Reference Manual
(DEC-15-GFWA-D).
2.2.2

MACRO Assembler

The MACRO Assembler provides users with highly sophisticated macro
generating and calling facilities within the context of a symbolic assembler.

Some of the prominent features of MACR0-15 include:
The ability to:
(a)

define macros,

(b)

define macros within macros (nesting),

(c)

redefine macros (in or out of macro definitions),

(d)
(e)

call macros within macro definitions,
have macros call themselves (recursion)

( f)

combine up to three input files for one assembly.
2-2

Conditional assembly based on the computational results
of symbols or expressions.

Repeat functions.

Boolean manipulation.

Optional octal, symbolic, and cross-reference listings.

Two forms of radix control (octal, decimal) and two
text modes (ASCII and 6-bit trimmed ASCII).

Global symbols for easy linking of separately assembled
programs.

Choice of output format:

relocatable, absolute binary

(checksumriied), or full binary -- capable of being loaded
via the hardware READIN switch.
9.

Ability to utilize user-designed input/output macros.

10.

A Table of Contents option containing the page numbers
and text of all assembled .TITLE statements in the
program.

MACR0-15 permits the progranmer to use mnemonic symbols to represent
instruction operation codes, locations, and numeric quantities.
is essentially a comprehensive macro instruction generator.
gr~ncrator

This

permits easy handling of recursive instruction sequences,

changing only the arguments.
The assembler facilitates the development of instructions called
"macros" which, when used as a source statement, can cause a specific
sequence of instructions to be generated in the obiect program.
Refer to the PDP-15 MACR0-15 Assembler Manual (DEC-15-AMZC-D) for a
complete description

of the language.

The standard object code produced by MACR0-15 is in a relocatable format
which is acceptable to the Disk Operating System's Linking Loader
utility program.

Relocatable programs that are assembled separately

and use identical global symbols 1 where applicable, can be combined by
the Linking Loader into an executable program.
An output listing, showing both the progranuner's source coding and the
binary object program produced by MACR0-15, is printed if desired.
1 Symbols

which are referenced in one program and defined in another.
2•3

This listing includes all the symbols used by the programmer with
their assigned values. If assembly errors are detected, erroneous
lines are marked with specific letter error codes.
2.2.3

FOCAL Interpreter

FOCAL <rormulating Q_n-line £.alculations in ~lgebraic ~anguage) operates
in on-line conversational mode, using natural language and arithmetic
terms to establish a simplified environment for the computer aided
solution of business and scientific arithmetic problems. Included in
FOCAL are such features as:
1.

Linkage to assembly language (MACRO) routines to establish
a user library of commonly used functions.

Use of COMMON to facilitate chaining in the same manner
as FORTRAN IV.

With FOCAL, the user can generate mathematical models, plot curves,
solve sets of simultaneous equations in n-dimensional arrays, and do
much more. Refer to the PDP-15 FOCAL-15 Manual (DEC-15-DJZB-D) for
a complete description of this program.
FOCAL library conunands allow the user to save and then call programs
by name. These conunands result in files consistent with the DOS
file format. Such files can be manipulated by other DOS programs,
such as PIP and EDITOR. FOCAL has commands which allow the segmentation (chaining) of FOCAL programs.
The· ability to write FOCAL functions in MACRO assembly language and
subsequently interface these functions with the FOCAL interpreter
is an important feature. These functions are processed in the same
way as the normal internal functionswhich DEC supplies with the
interpreter.
2.3

SYSTEM GENERATOR (SGEN)

The System Generator (SGEN) is a standard DOS Utility program
used to modify disk resident system files. SGEN, provided as· part
of the general-purpose package, enables the user to tailor his system and add to the supplied software in order to develop a resident
software system unique to the installation or to his specific needs.

2-4

The user (System Manager) calls the system generator program via the
Monitor command "SGEN". When SGEN is loaded, it initiates an interactive question/answer sequence regarding the following system functions and parameters:
1.

Existence of an extra memory page,

Options,

Type of printer unit used,

Required device handler designations (i.e., the
standard I/O configuration the user wants for
the system programs),

Skip-Chain information - Priority Interrupt
Skip Chain contents and order,

Default assumptions, including: type of teleprinter used, use of additional 4K of core, etc.,

System device designation,

.DAT slot assignments,

Monitor Identification Code to designate the
privileged access by the System Manager,

10.

Default buffers that are needed at any time during
a user program,

11.

Default Files Protection Code.

Careful planning -is necessary to ensure that the most efficient system
will be developed for the user's particular needs. For more information, refer to the DOS-SGEN Utility Program Manual, (DEC-15-YWZB-DN12).
2.4

PATCH UTILITY PROGRAM

PATCH is used to: (1) make corrections to the binary version of system
programs on the system device, (2) examine and change any word in any
DECdisk or Disk Pack block, or (3) convert relocatable binary programs
into system programs. Further, it has the capability of patching all
system software.
Facilities - provide for:
1.

The selection, examination and alteration of registers
within DOS System programs, and any data word block on
mass storage, including the system information blocks,
SYSBLK and COMBLK7

2-s

The installation of suitable relocatable programs
into a user system as a non-relocatable System program;

The loading of absolute programs into a user system
as a System program.

The PATCH user must first be logged in under the Monitor Identification
Code (MIC) to have access to system files. Binary programs which are
not in system program format (e.g., relocatable link-loadable programs,
and XCT programs which are executable files built by the System program CHAIN) cannot readily be corrected by using PATCH.
With PATCH the user can:
1.

Select a System program to be patched.

Select a single block to be patched.

Obtain an octal printout of the contents of a particular location in a program.

Alter the content of the listed location by simply
typing the desired content in octal.

Use the READ command to either replace or patch a
system program via Paper Tape input. This enables
the user to easily make corrected copy available for
instant use without requiring reassembly, regeneration of a system or core patching. This is most useful for handling small updates or new versions of a
program.

Select and open specific word locations within
SYSBLK or COMBLK.

Select and examine registers within a system +O area.

Automatically convert relocatable binary files into
system program format and load the converted file
onto the system device, provided disk space has been
reserved by SGEN. This feature permits user programs
to be called directly from the Monitor. It also enables
the program to completely overlay its loader, to make
the most effective use of core storage.

For more information concerning this System Utility program, refer to
the PATCH Utility Program Manual (DEC-15-YWZB-DNS}.
2-6

2.5

CHAIN AND EXECUTE PROGRAMS

The programs CHAIN and EXECUTE allow the user to segment programs in
order to construct and run a system of core overlays in an easy and
straightforward manner.
CHAIN reserves portions of user core (called COMMON blocks) from one
segment to another so that the program segments can communicate.

The

FORTRAN IV compiler and the MACR0-15 assembler can reserve COMMON
blocks for future segmentation.

This method of segmentation permits

multiple overlays of executable code, constants, variables, arrays,
and labeled COMMON blocks.
Both system programs are required for segmentation:

CHAIN - processes a version of the Linking Loader
Code (Object Program code) allowing the user to
build all the various segments (or chains) of his
program into an absolute (not relative) executable
(XCT) type file.

EXECUTE - a control program which initiates loading
of an executable file and transfers control from one
segment chain to another.

At load-time, Execute is

faster than the Linking Loader.
CIIJ\IN organizes subroutines into units called LINKS, which may overlay
each other.

Several LINKS may overlay a larger LINK without overlay-

ing each other.

A LINK is loaded into core when a subroutine within

the LINK is called, and remains resident until overlayed.

A LINK's

core image is not recorded or "swapped out" when it is overlayed.

The

same image is brought into core each time a LINK is loaded.

For maxi-

mum run-time efficiency, segments must be processed serially.

See

the PDP-15 CHAIN and EXECUTE Manual for detailed instructions
(DEC-15-YWZB-DN2).
Advantages/Disadvantages of CHAIN & EXECUTE

2.5.1
2.s.1.1
1.

Advantages
CHAIN
a.
can build an operable program whose core requirement "is
larger than that of the run-time machine;
b.

Can be used to create elaborate overlay structures;

Is more efficient than using the .OVRLA System Macro
(see 5. 2. 2. 5) ;
'}.-7

2.5.1.2

2.6

Allows the user to request a detailed load map;

Generates core image files which are smaller than
relocatable binary files.

EXECUTE
a.

Its loader is more core efficient than the Linking Loader since Linking Loader code is processed
only once;

Is smaller at load time than the Linking Loader;

Gives faster execution times.

Disadvantages

One additional step is required to process Object Code
in preparation for run time.

DDT (Dynamic Debugging Technique) cannot be used with
a segmented program.

At run-time, the execution of a segmented file requires
a certain amount of processing overhead.

LINKING LOADER

The Linking Loader loads any FORTRAN IV or MACRO object program which
exists in relocatable format. Its tasks include relocation of programs,
loading of called external subroutines, retrieval and loading of implied subroutines, and building and relocation of the necessary symbol
tables. See "Linking Loader" in the PDP-15 Utility Programs Manual
(DEC-15-YWZB-DNS) for detailed instructions.
The loader first loads all the named programs included in the keyboard
command string. It then additionally loads and links all requested
library subprograms. The requested library subprograms are loaded
from the device handler directory (IOS), the external (user) ·library,
if one exists, and the bank or page mode system library (BNK or PAG).
In addition, the loader can type out a core map which specifies the
name~d address of each program, subprogram, library routine, .GLOBL
and common block loaded.

2-8

2.7

DYNAMIC DEBUGGING TECHNIQUE (DDT) PROGRAM

DDT provides on-line debugging facilities that enable the user to load
and operate his program in a real-time environment while maintaining
strict control over each program section. DDT allows the operator to
insert and delete breakpoints, examine and change registers, patch
programs, and search for specific constants or word formats.
A breakpoint halts operation when the program flow arrives at the
designated location. The DDT breakpoint feature allows the insertion
and simultaneous use of up to four breakpoints, any or all of which
may be removed with a single keyboard command. The search facility
allows the operate~ to specify a search through any part or all of
an object program with a printout of the locations of all registers
that are equal (or unequal) to a specified constant. This search
feature also works for portions of words, as modified by a mask.
With DDT, registers may be examined and modified in either instruction
format or octal code, and addresses may be specified in symbolic relative, octal relative, or octal absolute. Patches may be inserted in
either MACRO source language or octal. For more information, refer
to the 0ynamic Debugging Technique, Utility Program {DEC-15-YWZB-DNl).

2.8· DUMP PROGRA.~
DUMP gives the user the ability to output, on any device specified,
core locations that have been preserved on disk via the CTRL Q {tQ)
disk blocks nnt-n ,.n:v ~ .....:Loo. Po"' .,..,.,..,. i.n.Cv.L111a.1.. .lu11 .Lerer t;O tne Keyboard Command Guide (DEC-15-NGKA-D}.
2.9

MAGNETIC TAPE DUMP {MTDUMP) UTILITY PROGRAM

The MTDUMP program provides the userwho employs magnetic ta~e as a
storage medium with the ability to view and manipulate any named
portion (i.e., file) of a tape.
Some of the features provided by MTDUMP are:
a.

Piles may be output (dumped) onto any system device
in any of four possible formats.

Conunents may be inserted into a DUMP file.
2-9

Files may be copied onto another tape.

Magtape directories can be listed and cleared.

For more information, refer to the MTDUMP, Utility Program
(DEC-15-YWZB-DN4).
2.10

TEXT EDITOR PROGRAMS, EDIT, SDITVP AND EDITVT

The Text Editor provides the ability to read alphanumeric text from
paper tape, DECdisk and Disk Pack, DECtape, etc.
The user can then examine and correct the text, writing it back on
paper tape, Disk Pack~ DECdisk, and DECtape devices. Progranuners
can also use the Text Editor to create new symbolic programs.
The Editor operates on lines of symbolic text delimited by carriage
return (CR) or ALT MODE characters. These lines can be read into a
buffer, selectively examined, moved, deleted, or modified, and written out. New text may be substituted, inserted. or a99ended
·1·ne programs .isu.L'rVP an<1 EDITVT are similar to EDIT except that they
permit text to be displayed on the VPlSA Graphic Display and VTlS
(CRT). Refer to the EDIT Utility Program Manual (DEC-l5-YWZB-DN6).
2.ll

PERIPHERAL INTERCHANGE PRO~'(PIP)

PIP can transfer data files from any input device to any output
device. It can be used to
(1)

refresh file directories,

(2)

list file directory contents,

(3)

delete, insert, segment, or combine files,

(4)

perform code conversions,

(5)

assign protection codes,

,(6}

transfer files, or

(7)

copy the entire contents of disk and DECtape storage units.

It may also be used to update and allocate restricted disk storage
surfaces. Refer to the PIP (DOS Monitor) Utility Manual
(DEC-15-YWZB-DN13).

2-10

2.12

DECTAPE COPY (DTCOPY)

This program permits high speed copying of DECtape to DECtape units.
The advantage of DECtape Copy over the PIP copy function is that DECtape Copy is faster.

For more information concerning this utility

program, refer to the Keyboard Command Guide (DEC-15-NGKA-D).
2.13

LIBRARY UPDATE PROGRA~

This system program gives the user the capability to examine, extract,
and update the binary library files on mass storage devices.

For more

information, refer to the UPDATE Utility Program Manual
(OEC-15-YWZB-DN7).
2.14

SOURCE CO~PARE

PROGRA~

(SRCCOM}

The SRCCOM program compares any two symbolic source programs (ASCII}
and indicates their differences.

This program is useful for program

identification and/or verification, proofing an edited program, comparison of old and new versions of the same program, etc.

For more

information, refer to the SRCCOM Utility Program Manual
(DEC-15-YWZB-DNll}.
2.15

GRAPHIC-15

Within this stand-alone system, VT-15 Graphics Software programs are
used to compile display commands, define display elements, and direct
linking, displaying and deleting of the elements necessary for a DOS
resident graphics run-time system.

Subprograms provided include: sub-

picture routines, main display file routines, input routines, relocating routines, and system I/O device handlers resident in the DOS I/O
Service (IOS} directory.

For more information refer to the GRAPHIC15

Programming Manual (DEC-15-ZFSA-D).
2.16

PDP-8 TO PDP-15 TRANSLATOR (8TRAN)

This program is used as an aid in translating programs written in the
assembly

languages of the Digital PDP-8 computer (PAL III, MACR0-8}

into MACR0-15 form.
pr~ram,

The translator does not produce an executable

but translates a major portion of the PDP-8 code into equi-

valent MACR0-15 code and indicates those areas of the 8 program which
must be reviewed and processed by the programmer.
tion see the PDP-15 8-TRAN Manual (DEC-15-ENZA-D).

2-11

For more informa-

2.17

PDP-8 TO PDP-9 TRANSLATOR (89TRAN)

The PDP-8/PDP-9 Translator· is used to translate programs written for
PDP-8 in PAL I I I or MACR0-8 assembly language to MACR0-9 assembly
language.

This tra_nslator is available as a DOS system program for

a user installation consisting of several DEC computers including a
PDP-8, a PDP-9, and a PDP-15. For detailed information concerning
this program, refer to the STRAN Manual, DEC-09-ENZA-D.

2.18

VP15A GRAPHICS SOFTWARE

The VPlSA Graphics Software package consists of a group of routines
which can be used with either FORTRAN IV or MACR0-15 programs to
operate the VP15A Storage Tube Display.

Included in the package

are an I/O device handler, text, point-plotting, and other routines,
all described in the VP15A Graphics Software Manual (DEC-15-UXSA-D).

2-12

CHAPTER 3
SYSTEM CONCEPTS

3.1

DOS-15 MONITORING FUNCTIONS

There are three sections to the DOS-15 Monitor:
Monitor,

(1) the Resident

(2) the Nonresident Monitor, and (3) the System Loader.

The Resident Monitor remains in core when system or user programs
are running, and acts as the interface between the program
and the system's facilities.

During program operation, the Resident

Monitor has general control over the system.
1.

It functions to:

Maintain orderly program flow,

Handle teleprinter I/O,

Act on Monitor calls,

Validate and transmit I/O calls to device handlers,

Announce error diagnostics.

The operator may alter the structure of the Resident Monitor via
commands to the Nonresident Monitor.

The Nonresident Monitor allows

the operator to interrogate and alter many key parts of the system,
in order to set up the system for the next program.
1.

It functions to:

Set I/O conditions by assigning physical devices to
logical unit numbers,

Supply system information,

Save or restore core images,

Load and Execute system and user programs,

Change default system parameters.

Normally, at the end of a particular program, the operator, the Batching Command String, or the program itself returns control to the Nonresident Monitor.

At that point, the operator or the Batching Command

String sets up the system for the next program and calls it in via
commands to the Nonresident Monitor.
The System Loader (.SYSLD) builds the Resident Monitor according to
prior commands to the Nonresident Monitor.

It loads (a) all core-

image system programs and all handlers for those system programs,

3-1

(b)

the Linking Loader or (cl EXECUTE.

In almost all cases, a change

of program involves actions by the System Loader.

The System Loader,

however, is completely invisible to the user except for LOAD errors,
such as insufficient core.
The DOS-15 Software System provides an interface between the system
or user-created program and the external world of I/O devices.
simplifies I/O programming.

This interface is comprised of a function-

ally related group of software called the f.nput/~utput
tem. or simolv IOPS.

This

E_rogramming ~s

This is a conceptual term which encompasses

(1)

the I/O device handling routines within DOS-15,

(2)

a portion of the Monitor which is used in dispatching I/O commands to them, and

(3)

a Monitor routine for printing error messages.

I/O device handlers are provided for all standard devices (see Chapter
9).

These handlers relieve the user of the burden of I/O service,

file! management, overlapping I/O considerations and unwanted device
dependence.

I/O commands and data modes are standardized and are

recognized by DOS-15 device handlers. This facilitates device independence.

For example; a non-file structured device handler such as the

paper tape reader will ignore (rather than declare an error) a command
to "seek a file"

(which is required for file structured devices prior

to issuing commands to read).

There are other features of the system

which contribute to device independence; they are discussed in later
paragraphs.
3.1.1

System Communication Table {SCOM)

The System Communication Table (SCOM) is a set of registers that are
referenced by the Monitor, I/O device handlers, and other system programs.

It acts as a common parameter area for information required by

both the System Loader and Monitor.

User programs may also utilize

the information in this table as desired.
Table begins at absolute location 100 8

The System Communication

{Bank~).

The following list briefly outlines some of the SCOM table functions:
Free Core Limits
Option Availability
System and user Program Start Addresses
Handlers

3-2

Interrupt Levels
Magtape Status Register
Number of Buffers Allocated
Number of Words/Buffer
Number of Entries in Mass Storage Busy Table
User Identification Code
Software Control switches
Date (MMDDYY)
Time (HHMMSS) and other Clock Information
Default Protection Code for Files
A complete list of the SCOM table functions is given in the DOS System
Manual (DEC-15-NRDA-D).
3.1.2

Monitor/User Interaction

The console teleprinter is the primary user-system interface for
DOS-15 program control. This control is implemented by commands to
the Monitor, which accepts the three types described below:
1.

Commands which perform special services

Commands which load systEI!\ programs

Control character commands which provide system
control while running user or system programs.
NOTE
In the context of this manual, the term "console
keyboard" designates any one of several keyboard/
printer/display I/O devices which could be used
by the Monitor as the system command console device (generally, a Model 33 or 35 teleprinter).

The operator at the keyboard types commands to allocate system resources, load and start System and user programs, terminate program
operation, and exchange information with the Monitor. Most of the
Monitor's keyboard commands are issued prior to loading programs and
are interpreted by the Nonresident Monitor, since it is not resident
in core during system or user pr09ram execution. Durinq program execution, a small set of keyboard commands is available for general
program control. These commands arc interpreted by the teleprinter's
I/O device handler (which is part of the resident portion of the
Monitor), and are used to control program start and restart, dumping
of core, and the reloading of the Nonresident Monitor. Details on
the DOS-15 commands which can be issued from the console keyboard are
described in Chapter 8.
3-3

The keyboard col'!llllands are, however, not strictly limited to input from
tb,1,'!.k.eyho_pr-4~-'!!hesMon-i.tc.E-~-op-e-:1:.~.:ct-e-d··in ·a.- ~uUU1rano Bal:Cnl.ng Mpde
Ln which keyboard col'!llllands can be issued either from punched cards or
paper tape with minimum operator intervention. Similarly, the Monitor's
responses to col'!llllands are not strictly limited to a keyboard device's
printer or display, but may also be output to other devices including
the VT15 Display or a line printer, when available.
3.2

I/O COMMUNICATION

The Monitor, by means of Device Handlers and Priority Interrupt (PI)
or optional Automatic Interrupt (API), permits simultaneous operation
of I/O devices along with overlapping computations.
A system or user program initiates an I/O function by means of a
Monitor cpl'!lllland (system macro), which is interpreted within the
Monitor as a legitimate I/O call. The I/O call includes a logical
I/O device number as one of its arguments. The Monitor establishes
the logical/physical I/O device association by means of a special
table. When this has been accomplished, the Monitor passes control
to the. appropriate device handler to initiate the I/O function,
after which control is returned to the system or user program._
The system or user program retains control until an interrupt (PI or
API) occurs1 at this time the device handler takes control, in order
to perform and/or complete the specified I/O function. The program
may continue computation or other processing while waiting for
I/O completion. This feature allows the programmer to make optimum
use of available time.
3.2.l

Device Independence

In the DOS Monitor environment, the system manager may set ~p default
device associations (correspondence between logical/physical devices)
during system generation. Just prior to loading a system or user
program, a user may change these associations via the ASSIGN keyboard
command. This capability adds true device independence to DOS-15.
All device handlers are nonresident in the sense that only those handlers
required by a program are loaded into core.

3-4

3.2.2

I/O Device Handlers

Users are spared the task of writing system software to handle input/
output to all standard system peripherals, since appropriate routines
(Device Handlers) are supplied with the DOS Monitor.

These routines

process file and data level commands to the peripheral device.

They

generally perform the following functions:
1.

Drive I/O devices,

Block Data Records for Devices, if necessary

Manipulate files,

Optimize device timing,

Allocate/Deallocate Storage Space on the device,

Request/Return core space.

All communication between user programs and I/O device handlers is
made via I/O Macros.

Macros are covered in Chapters 5 and 6.

There may be available in the system several handler versions for a
particular device (e.g., DKA, DKB, DKC).

Each represents different

compromises between core use and handler flexibility.

Device handlers

are covered in depth in Chapter 9.
3.2.3

Device Assignment Table (.DAT)

The DOS Monitor contains a Device Assigmnent Table (.DAT), with an entry for each device used.

Since the contents of the table can be al-

tered by commands to the Monitor, actual I/O devices may be changed
without altering the program references (logical device units) to these
devices.
3.3

Refer to Chapter 4 for more information concerning .DAT.

FILE STRUCTURES

A file structure, as defined for obS-15, is a method of recordinq, linking and cataloging data files.

Each peripheral device has.an associ-

ated file structure which governs the manner in which data arc stored.
Card files and paper tape files are always organized as sequential files and both files and records are processed sequentially.
A file or record in the middle of the medium can only be accessed
after all preceding items have been processed.

This is a restric-

tion which is a consequence of the nature of the storage medium.
In contrast, DOS-15 provides direct access to files stored on

3-5

DECtape or disk. The system maintains directories on these devices
that point to each file on the device. Hence, such devices are called
"directoried" or "file-oriented". Both DECtape and l'.iagnetic tape
{Magtape) permit the user to operate either in a directoried or a
non-directoried (sequential) mode. The system maintains a minidirectory for each file which points to each physical block in the file.
The user of the PDP-15 Disk Operating System is not required to preallocate file storage; the operating system provides the file storage
space dynamically on demand. Not only is this convenient for the user
because he does not have to worry about allocation when he is creating
files, but it conserves storage by preventing large portions of storage
from being unnecessarily tied up. More information on this topic can
be found in Chapter 4.
3.3.1

User File Directories and UIC's

On DECtape, there is only one directory for the whole tape. On disk,
there is a central directory, called the ~aster ~ile ~irectory (MFD),
but each user can have his own !!_ser ~ile ~irectory (UFO). The MFD
points to each UFO. Each UFO is named by a unique three character
User Identification Code (UIC). The User File Directory Table (.UFDT)
is part of the Resident Monitor associated with the Device Assignment
Table. It indicates the User Identification Code (UIC) associated with
every .DAT slot (i.e., each logical device). Disk I/Oto a particular
.DAT slot will go to files in the UFO named by the corresponding .UFDT
slot.
The Monitor finds User File Directories by seeking associated User
Identification Codes (UIC's), which are all listed in the Master File
Directory. The UIC is necessary for all directory-oriented I/O to the
disk. A programmer may identify himself (LOGIN) to the system with
only one UIC at a time, but he may have as many UIC's as he wishes,
provided each is unique and none is reserved 1 • Further, programs may
simultaneously reference files under several different UIC's.
3.3.2

Monitor Identification Code (MIC)

A three-character Monitor Identification Code (MIC) is established at
system generation time to provide privileged access by the System Manager. When the System Manager uses the ~IC, all system and user files
are open for reference or change. This code acts as a key to temporarily remove file protection. System generation, modification of system
1 'rhe

programs and listings of the entire disk directory are allowed only
under the Monitor Identification Code.
3.4

FILE PROTECTION

OOS-15 offers a simplified form of file protection. Each User File
Directory has a protection code (optionally specified in commands to
PIP), and each file has a protection code (optionally specified in
the .ENTER command or a command to PIP). The protection codes are
in effect only when a user tries to reference a file listed under a
UIC other than the one currently logged in to the system. If a
User File Directory is protected, then the protection is provided for
any file in the directory. For more information, refer to Chapter 6.
The default protection code for the files is established at system
generation time. Users may temporarily change the file default protection code via the PROTECT command to the Monitor.
(See Chapter 8.)
3.5

1/0 BUFFERS

Two Monitor conunands allow any handler or user program to call the
Monitor to allocate and deallocate buffers. Each buffer is obtained
from a "buffer pool" as needed. For more information, refer to
Chapter 6.
3.6

CHOICE OF EXECUTABLE FORM

The object code usually produced by FORTRAN IV and MACR0-15 is relocatable binary which is made absolute by CHAIN, or loaded at run
time by the Linking Loader. In addition to relocatable output, the
MACR0-15 user may specify non-relocatable types of output code.
3.6.1

Relocatable Binary

A relocatahle object program may be loaded into any part of memory,
regardless of which locations are assigned at assembly or compile
time. To accomplish this, the address portion of some instructions
must have a relocation constant added to it. This relocation constant
is added during segmentation, by CHAIN, or at load time by the Linking Loader. It is equal to the difference between the actual memory
location that an instruction is loaded into and the location that
was assigned to it at assembly time. The language processors use
codes to identify storage words as relocatable, absolute, or external.
3-7

Relocatable Binary object programs may be placed into and executed
from any part of memory, regardless of the core locations assigned to
the instructions by the language translator. The primary advantage
of such a system is that it enables the user to easily write and load
into core memory many programs (e.g., the main program and several
subroutines) with no necessity for prior core mapping. Relocatable
Binary is always produced by FORTRAN and is produced MACR0-15 when
there are no .ABS or .FULL pseudo-ops.
3.6.2

Absolute Binary Forms

Absolute Binary object code is produced using the MACRO Assembler's
.ABS, .ABSP, .FULL, or .FULLP pseudo-ops as described below. Programs
assembled with these pseudo-ops are loaded and executed independently
of the DOS-15 System software. Re~er to the MACRO Assembler Manual
(DEC-15-AMZC-D) for more information.
3.6.2.1 .ABS and .ABSP Binary - The .ABS and .ABSP binary forms are
checksummed binary coded programs or instructions assembled as .ABS
(Absolute Binary) and assigned to occupy specific or absolute locations in core memory. These programs can only be loaded into or
executed from the locations assigned by the language translator.
The task of placing multiple routines into core for execution becomes
a tedious one. Absolute binary does have the advantage of a smaller
loader, thus enabling the user to execute a larger program than is
possible using relocatable binary. Ordinarily, the Assembler will
precede the output with an Absolute Binary Loader which will load
the punched output at object time. The loader is itself loaded via
Hardware Read-in Mode.
3.6.2.2 .FULL and .FULLP Binary - The .FULL and .FULLP binary forms
are unchecksummed binary consisting solely of 18-bit storage words.
Programs assembled in this form are output on paper tape and are
loaded via Hardware Read-in Mode.
3.7

LOADER CONTROL

As indicated in the previous section, CHAIN and the Linking Loader
make relocatable object programs absolutely addressed. In addition,
they join relocatable programs by supplying definitions for global
symbols which are referenced in one program and defined in another.

3-8

3.7.1

Globals

The global feature is another of the programmer conveniences provided
by the MACR0-15 Assembler. It allows the user to provide a symbolic
linkage between separately assembled programs including: a main program, subprograms, and general subroutines in system (Bank or Page)
Libraries or user Libraries.
In MACRO, the pseudo-op .GLOBL, followed by a list of symbols, is used
to define to the Assembler two types of global symbols:
1.

Internal Globals - defined in the current program
and referenced by other programs.

External Symbols - referenced in the current program and defined in another _program. Each external
symbol will be used by the Linking Loader or CHAIN
to store the actual address. All references to external symbols should be indirect references, as
memory banks may have to be crossed.

The FORTRAN equivalents to external and internal .GLOBL's are CALL and
SUBROUTINE. The Linking Loader and CHAIN use this information to relocate and then link the programs to each other.
3.7.2

Program Loading

At program load time, the user, via appropriate keyboard commands, can
select either Page or Bank Mode program loading and execution. Two
versions of the Linking Loader and System Library are provided - one for
each mode.

3.7.2.1 Page Mode Operation - The DOS Monitor Page Mode System
loads and relocates user programs in 4K pages and permits address
modification via the index register (Index Addressing). In Page
Mode, the loader obtains library routines from the library in the
PAG System file directory. The Page ~ode System is supplied as
standard software with PDP-15 systems.
3.7.2.2 Bank Mode Operation - The optional Bank ~ode system permits
direct accesing within SK banks, but does not permit the use of the
index register for address modification. This system is useful to

3-9

the PDP-15 user who prefers direct addressing up to BK, or who wisnes
to take advantage of the extensive library of PDP-9 programs available
from the Digital Equipment Computer User's Society (DECUS). All
core-image system programs run in Bank Mode. In Bank ~ode, the
loader obtains library routines from the library in the BNK System
file directory.
3.8

ERROR DETECTION

Comprehensive error checking and recovery are provided by the DOS-15
Monitor, the loaders, and the I/0 system as follows:
a.

DOS-15 Monitor Errors - error conditions related to
system devices, illegal device assignment, program
name, and command references.

Linking and System Loader errors - memory overflow,
input data errors, unresolved globals, and illegal
.DAT Slot requests.

IOPS Errors - all Input/Output device and data errors.

Detailed lists of errors that occur in the latter two categories can
be found in Appendices D and E~- .re~pectively. The Monitor Errors, when
they occur, are easily understood and recovery will be self-evident.
The automatic core-dump commands QDUMP or CTRL Q will condition the
Monitor to dump memory on the "save" or "CTRL Q" area of one of the
units of the system device, in the event of an unrecoverable error.
Terminal errors are not reported to the user's operating programs:
there are, however, a few I/0-detected errors that are reported to the
user for program use, e.g., parity, checksum, and buffer overflow errors
are indicated in special control words of each IOPS data record (see
Chapter 6). Error detection and recovery are discussed in Chapter 10.
After error messages are output, the user may optionally restart the
program (CTRL P), dump core (CTRL Q), or return control to the Nonresident Monitor (CTRL C). Other options are available to the user
when errors occur: these will be discussed in succeeding chapters of
this manual.

3-10

CHAPTER 4
FILE STRUCTURES

4.1

INTRODUCTION

This chapter will define those concepts and facilities of the DOS-15
system that are available for storage and retrieval of data from PDP-15
mass-storage hardware/software systems, including DECdisk (RF), Disk
Pack (RP), Magtape (MT), and DECtape (OT).
A large part of any progranuning task is accepting input and producing
output. Therefore, it is necessary to understand the Input/Output
process to take full advantage of the Disk Operating System's features.
4.2

DEVICE ASSIGNMENTS

As stated in the previous chapter, device assignment is managed through
the Monitor's Device Assignment Table (.DAT). The .DAT associates
logical device units with physical ones through "slot" numbers, which
correspond to the logical device numbers.
Device assignment slots are assignable via the Monitor ASSIGN command
at run time. Refer to Section 8.5 of Chapter 8 for more information.
Default assignments are defined duri~g system generation (see ~
I
Utility Program Manual (DEC-YWZB-DNl~).
Information in each program
indicates which "slots" are required'. for that program. These slots
are called the "active slots". The loaders use the information about
active slots to bring in handlers for the devices named by the active
slots. At run time, then, each slot contains the physical device unit
number (if any), and a pointer to the appropriate device handler, which
was brought in by the loader. Without device assignment on a .DAT
slot, a program's call to that slot will result in an I/O error -- the
slot will not point to a handler. Depending on the system generation,
as many as seventy-three entries may be in the .DAT for program device
assignment.
Each 1/0 command under DOS-1$ references a .DAT slot. These commands
pass control to the appropriate device handlers via a Monitor routine
that uses the pointers in the .DAT. These device handlers are
responsible for transferring data between the program and I/O devices,

4-1

They also initiate the physical reading or writing of files and perform
opening and closing of files and other functions peculiar to a given
hardware device.

Each slot then links the device-driving functions

within a specified device handler to the program.

The handlers all test

for functions which they cannot service; for example, trying to rewind
a card reader.

Some functions are ignoredl others are illegal and

cause error messages to be output to the console teleprinter.

All de-

vice handlers operate either with or without the Automatic Priority
Interrupt (API) option.
4.3

FILES

A file is a collection of related records treated as a unit.

Inventory Control, for example, one line of an invoice forms an item,
a complete invoice forms a record, and the complete set of such
records forms a file.

The word "file" is used in the general sense

to mean anv _cgll_~ctig_n_gf j nf_gnna_t-_i_pp __;terns c:jmj Jar to

purpose, form and content.

anctb

,...

;

"File" may also be generally applied to

external storage media such as papertape, punched cards, a Magtape,
a DECtape, DECdisk platters, and a Disk Pack.
4.3.1

Records

In DOS-15, a record is a set of one or more related data words accessible to the user as one item through .READ and .WRITE MACRO program
statements or FORTRAN language statements.
and .WRITE).

(Chapter 6 describes .READ

The smallest addressable logical item within the file

is this logical record.
4. 3. 2

Words

A word is the least addressable physical data unit and is the information vehicle for Buffer Header and Data Modes.
I/O Buffers are internal to, and must be defined by, each program.
With the exception of certain block transfers, a buffer contains a
single record.

Under most of the Data ~odes (described below), the

first two words in an I/O buffer (i.e., a record) provide system information and cannot be used for data.

This Header Word Pair with-

in an I/O buffer is detailed in Chapter 6.

On blocked devices

(Disk and DECtape), these header word pairs govern the physical
structure within the file.
Header Word Pair.

Before output, the user must set up the

On input, the Header Word Pair arrives with Data

Mode Information and certain error indicators.

4-2

The user is

responsible for checking the various header parameters to determine if
the data was read without error.
4.3.3

Data Modes

The Monitor allows data transmission to or from a system or user program in several different modes which structure internal data storage.
Two modes, IOPS ASCII and IOPS Binary, offer the advantages of device
independence. All handlers accept IOPS ASCII data, and most accept
IOPS Binary. Three other data modes, Dump, Image Alphanumeric and
Image Binary, allow the user to take advantage of device dependent
characteristics. For more information, refer to Chapter 6.
·4,4

FILE STRUCTURES

As stated in Chapter 3, a file structure is a method of recording,
linking, and cataloging data files. File structuring, in general, is
applicable to all I/O device, including cards, paper tape, printers,
keyboards, etc. In DOS-15, however, file structures are associated
with Mass Storage devices only. A file structure dictates the file
and record access methods. This organizational structuring is important because a file can be effective for a user application only if it
is designated to meet specific requirements. A user must consider
the following factors:
SIZE

Growth of the file may require a change
in file structure or data mode,

ACTIVITY

The need to access many different records
within a file (percentage of activity) or
to frequently access the same records (an
active file) will influence information
retrieval efficiency. This requires the
user to select the right method for each
job task.

VOLATILITY

The number of additions and deletions to
a file will affect the efficiency of the
structures used.

4-3

4.4.1

File and Data Access Techniques

The usual technique for applications using Magtape is sequential access to the data file and sequential access of the data records.
This access is also characteristic of most uni-directional media,
such as cards, paper tape, keyboards, printers, and displays.
Another technique, which in DOS-15 is apflicable only to the disks,
ca.u-.\- ~'"·"'"~ ~ r :
involves·random-access (an
alternate term is "direct-access") to a
file and random-access of data records within the file.
A third and intermediate technique, which is normally used on DECtape
and on disk, employs .random-access to a file and sequential access to
the file's data records. The formal term is "random-sequential file
structure"; the informal term is "DECtape file structure".
4.4.2

Sequential Access

Sequential access is a storage retrieval technique in which a file
and the records within it must be retrieved in the sequence in which
they physically occur. Sequential access, when applied to the
process of locating the beginning of a file or a data record within
the file, means that the time required for such access is dependent
on the necessity for waiting while non-desired files or records are
processed in turn.

4.4.3

Records can only be retrieved sequentially, beginning
with the first record and accessing each subsequent
record in turn.

Direct retrieval is not possible, since no directory
exists to the physical locations of the records.

Additions and deletions are only accomplished by
copying the entire file.
Direct Access

Direct access to a file or to a data record within the file means
that the time required for such access is independent of the location
of the file or record relative to other files or records.
Direct access should be considered as a valuable access method when
retrieving selected records from random files: but it is not suited

4-4

for sequential retrieval of records. The direct access technique
makes it possible to process only the affected record during a file
update.

This reduces data sorting.

The main advantage of direct access processing is that it requires
fewer processing steps. Along with its advantages, however, a direct
access application requires special considerations by the system pro~
..,,-~,.,..--.. ~:<Jti\o.~--..,.rr .. u.Li:.t:<<.:-C:'°acc·es·s-systi'!m nfT"T"~t"s :1:rom backup on a
tape system because the old record on a direct access device is
destroyed when the updated record is written over it.
4.5

~GNETIC

TAPE FILE STRUCTURE

The DOS software provides for industry-compatible magnetic tape (Magtape) as either a directoried or a non-directoried medium. The
magnetic tape handlers communicate with a single Tape Control Unit
(TCU) with up to eight magnetic tape transports.
When used as a non-directoried medium, there are a number of major differences between Magtape and other mass storage devices such as DECtape
or Disk. Magtape is well suited for handling data records of variable
length; such records, however, must be treated in serial fashion. The
physical position of any record may be defined only in relation to the
preceding record.
When used as a directoried medium, Magtape assumes the external operating characteristics of DECtape (described in 4.6).

Sequential tape files are written one after the other, starting at the
physical beginning of the tape. These files are separated from one
another by End-of-File marks (hardware-detected) or by an End-of-Record
line (software-detected). (Refer to Figure 4-1, Sequential Data Access.)
To read the Nth file on a tape, the user must first rewind to the begin·ning of the tape and then skip serially through N-1 files to the desired
file. Sequential tape files need not have a filename, only a known
position relative to the files on the tape.
Data records within a file are recorded in sequence. Sequential statements direct records to and ·from memory in the sequence in which they
are physically on the device. To access the Mth record within the Nth
file,the user first locates the beginning of the file (skipping N-1
files) and then skips through M-1 records.
4-5

DESIRED
f - - s c A N - - - - - - - - - DATA RECORD
I

}DI~ ~ ~l~J~ ~ ~

'--y------1

~ Fr-E /
BEGINNING OF PHYSICAL MEDIUM
~

r11JQ
/

FILE

END OF FILE

Figure 4-1

Sequential Data Access

This sequential access method does not need a tape-resident directory
to point to files.

It is, therefore, called "non-directoried" in DOS.

The non-directoried access method is generally applicable to unit-

...

r.Tt,.,""• '"'"

- - -.- Tr.c- --, - A-,...- r

n•T ..-.
r
I
I Ir

,... .... ..., •• ,..,.,.T,.,_
:"') I n: I II I I I K,.. '_

If magnetic tape transports could identify absolute positions on a
tape, there would be no need to do sequential file access.

The trans-

port could search to a known location, and start processing.

Then,

an extra body of information (a directory) on the tape could point
to each file.
DECtape has this capability.
In directoried mode, files are given unique names.

The name and posi-

tion of the beginning of a file are recorded in a directory.
tories are at fixed location (Block 1~~ 8 ) on the tape.

Direc-

DECtape direc-

tories point to the first block of each file and each block points to
the next.

DECtape directories also maintain bit maps which indicate

which tape blocks each file occupies and a map to show all occupied
blocks on the tape.

The file directory is fixed in size; consequently,

the number of files that may be recorded is limited by the amount of
storage available on the device (1100 8 blocks) and/or by the number
of file name slots in the directory (56 maximum).

4-6

USER FILE DIRECTORY
FILE#1
NAME
LOCATION

USER PROGRAM
POINTER

FILE#2
NAME
.~

LOCATION

•
•
•
FILE#n
NAME
LOCATION

SCAN

DESIRED
DATA RECORD

-----------

10 I~ ffa ~ ~ ~I I~ ~ ~ ~I I~ ~ ~ ~ ~ ~I~

FILE#1

FILE#2

FILE#3

BEGINNING OF PHYSICAL MEDIUM
15-0117

Figure 4-2,

UFO

Directoried Data Access

MFD
USER 1
UFD

USER 2
USER 3

•
•
•
F~E
UFD

•

FILE
NAME
LOCATION
RIB

•
•
•
•

i--'

JODOO[]]
RIB
BLOCK I

BLOCK 2
BLOCK 3

,._

BLOCK 4
BLOCK ~

Figure 4-3,

Disk Data Access

4-7

File structures which employ a directory allow simpler and, in the long
run, faster access to a file (the beginning of a file).

See Figure 4-2.

This is a distinct advantage over those devices which do not use a
directory and must therefore rely on a file's position relative to
other files in order to locate it.
Programmers need not use the directory capabilities of DECtape.

They

can treat DECtape as magnetic tape by issuing magnetic tape I/O commands.

-Then no directory or identifying information of any kind is

recorded or referenced on the tape and operation is similar to that
of magnetic tape (described in 4.5).

The DECtape handlers with their

respective I/O functions allow the use of either of thse modes.
4.7

DISK FILE STRUCTURE

The DOS-15 disk file structure is in some ways analogous to DECtape
file structure.

Ordinarily, each disk user has a directory which

The DECtape, however, has only one directory, but the disk has as many
directories as users have cared to establish.

Whereas DECtape direc-

tories may reference only a maximum of 56 10 files, the number of files
associated with any one directory on the disk is limited only by the
available disk space.

A single disk file's size is also limited by

the available space, as is true with DECtape.
The DECtape directory is in a known location ••. at block

19~.

Since the

disk may have a variable.number of directories, the Monitor must know
how to find each user's directory,

It, therefore, maintains a Master

File Directory (MFD) at a known location,

and the Master File Directory

points to each User File Directory (UFO).

DOS-15 allows only those

users who know a special code, called the Monitor Identification Code
(MIC), to have access to the MFD.

Figure 4-3, Disk Pata Access,

illustrates the organization of the disk.

4.7.1

user Identification Codes (UIC)

The Monitor finds User File Directories by seeking associated User
Identification Codes (UIC's) which are all listed in the Master File
Directory.

The UIC is a three-character code that is necessary for

4-8

all directory-oriented I/O ~to the disk.
a new User File Directory by:

A programmer may establish

'U \-"..........

1.
2.
3.

Logging in his new UIC to the Monitor,
Calling PIP,
Issuing an "N...,.DK)" conunand.

This establishes a new User File Directory, or refreshes (wipes clean)
an old directory under that UIC. The "enter file" I/O conunand will
also create a UFO, if none exists.

4.7.2

The User File Directory Table (.UFDT)

The Monitor must have a way of knowing which User File Directory to
reference when a program issues I/O canmands to the disk. It makes
the association between disk I/O conmands and User File Directories
by using a User File Directory Table (.UFDT). There are as many
entries in the User File Directory Table as there are slots in the
Device Assignment Table. Figure 4-4, Relationship Between the .DAT
~nd the .UFDT, shows how the two cJnpare. Disk I/O to a particular
.DAT slot will affect files in the User File Directory named in the
corresponding .UFDT slot. Progranmers may modify .UFDT slots before
loading a program, and programs thEmselves may alter .UFDT.
4.7.3

File Protection

DOS-15 offers a simple form of file protection. Each User File
Directory has a protection code and each file has a protection code.
The protection codes only protect a progranuner's files from other
users - not from himself.· If a user File Directory is protected,
then the protection codes for each file are in effect. If the user
File Directory has been specified as unprotected, then no protection
is provided for any file in the directory. There are three protection states possible for files in a protected User File Directory.
File Protection Codes:
1

Unprotected, with the exception that the file
may not be deleted and the number of blocks may
not change, if the directory is protected.

Write protected, if directory protected.

Read/Write protected, if directory protected.

4-9

Comment

.UFDT Contents

.DAT/.UFDT Number

.DAT Contents

nondisk handler

This UIC is irrelevant

disk handler

I/O to this slot
will go to files
in UICl
I/O to this slot
will go to files
in UIC 2

-15

none assigned

This UIC is irrelevant

The operator has logged in under u1p 1. He has assigned some nondisk
handler to .DAT+N, the DECdisk to .pAT+2, and the Disk Pack unit ~ to
.DAT+l, and NON (no handler) to .DA~ -15. In addition, he has changed
the .UFDT assignment for .UFDT+l toiurc 2 • I/Oto .DAT+N will not
reference the UIC, since UIC's are felevant only to disk I/O. I/O to
.DAT+2 will reference urc 1 , while ryo to .DAT+l will reference u1c 2 •
The UIC for .DAT -15 is irrelevant,! since no handler is assigned.

Figure 4-4
Relationship Between the .DAT and the .UFDT

4-.10

User File Directories may have one of two protection states:
File Directory Protection Codes
~

Unprotected

Protected

The default protection code for User File Directories is always 1,
protected.

The default protection code for files is established at

system generation time.
4.7.4

Organization of Specific Files on Disk

The disk handlers write out files sequentially, just as the DECtape
handlers do.

'"\t t.O

On the close of an output file, the disk handlers also
t.A"
'C. 'ft.\f. __, 1""

fill out a Retrieval Information Block (RIB).

The RIB performs the

same functions as the file bitmap on DECtape, and associates the
logical sequence of blocks in the file with the physical locations of
the blocks on the disk.

The disk handlers use the RIB to implement

random access and to delete files.

After a user has created a disk file, he can access records sequentially
as with DECtape files.

He can also read and write physical blocks of

that file by referencing relative block numbers.

The user is prohibited,

however, from changing the total number of blocks in the file.

4.7.5

The Disk Handlers

The disk handlers allow as many concurrently open input or output
files as there are .DAT slots available to the user, and buffers
available to the disk handler.

The disk handlers operate under a

dynamic buffer allocation scheme.

Whenever the Monitor loads a sys-

tem or user program, it allocates buffer space.
the buffer pool.

This space is called

Whenever a program opens a disk file, the handler

obtains a buffer from the buffer pool.
The handlers return the
buffer when the program closes the file.
The buffers in the buffer pool are available to programs, as well as
to disk handlers.

Whenever a program is using a buffer, however, it

is unavailable to any other program.

4-11

CHAPTER 5
DOS SYSTEM MACROS
5.1

INTRODUCTION

This chapter contains detailed reference information concerning DOS-15
System Macros. I/O Macros (those which have a .DAT slot number as one
argument) are discussed in Chapter 6.
5.2

MONITOR-PROCESSED COMMANDS

The MACR0-15 assembler permits the use of higher-level system instructions called ".System Macros" which, when used as a source statement,
can cause a specific sequence of Monitor operations to occur at runtime.
'fhese System Macros are referenced (called) in user programs by writing
a statement consisting of a system Macro name followed, if needed, by
a tab, space or spaces, plus a list of arguments separated by commas.
Macro statements are terminated by either a space or spaces (~),a
For eyample·
tab ( :oil , or a car_riage return C_J )
.TIMER
5.2.1

Summary of DOS Monitor System Macros

Table 5-1, Summary of System Macros, summarizes the non-I/O macros
which the Monitor implements. The following paragraphs describe the
individual system macros in detail.
Table 5-1

Summary of System Macros

Name

Description

.EXIT

Requests the System Loader to bring in the Nonresident
Monitor.
overlays core with the contents of a named file •
Requests a buffer from the buffer pool •
Returns a buffer to the buffer pool •
Requests the System Loader to load the named core-image
program.
creates a file containing the current core image •
Initializes a time interval after which program control
passes to a user specified subroutine.

• GET
• GTBUF
• GVBUF
.OVRLA
• PUT
.TIMER

s-1

5.2.2

DOS-15 System Macro Expansions

The following standards apply to the descriptions of the .system and I/O
Macros presented in this chapter and in Chapter 6:
A.

Format Conventions
1.

Upper case terminology must be used as stated in the
FORMAT Description.

Lower case terminology indicates user-supplied information,
as defined by ARGUMENTS.
'

Names for user-supplied parameters indicate maximum length
of field by the number of characters in the name. Thus,
"namptr" may be a maximum of six character long, and
"num" may be a maximum of three characters.

Brackets ([ ]) indicate optional quantities.

A bracket on its side (...,) indicates a space.

Quantities listed vertically and enclosed in braces ({ })
indicate the user must choose one from the group.

The expansions indicate how one might write an expanded
macro directly to the assembler.
(Any fields in the macro
desiqnated as decimal radix must be octal radix when
included in an expansion.) The expansions may appear
different from expansions produced by the assembler. They
are, however, functionally :equivalent.

Sixbit File Representation

Many of the System and I/O Macros halve a "namptr" argument which points
to a 3-word block of core in the user's program containing the Sixbit
representation of a file name and extension. This is simply an
abbreviated form ~f ASCII in which the rightmost 6 bits of the ASCII
code are used. This allows 3 characters to be packed in one word of
storage. Sixbit packing can be accomplished either .by the user
program or by the MACR0-15 Assembler's .SIXBT pseudo-op.
(Refer to
the MACR0-15 Assembler Manual (DEC-15-AMZB-D). The example following
paragraph 6.8.5 demonstrates the use of .SIXBT.

5-2

s.2.2.1

Creates a file which contains the current core image.
The file's name and extension will be that found in
the locations pointed to by namptr. See also .GET •
.MACR0-15 does not expand the .PUT Macro. The following
FORMAT statement illustrates how the user might
formulate his own macro. The Resident Monitor, however, does recognize the command illustrated in the
EXPANSION section.
FORMAT:
.PUT...,f,namptr,u
ARGUMENTS:
f = (function) determines the startup loca-

tion for a .GET with f~4,
or a GET Keyboard command
to the Nonresident Monitor.

Subsequent load will start at the
location following the EXPANSION.

f = 1

Subsequent load will start at
current CTRL P address

Subsequent load will start at
current CTRL T address

Subsequent load will start at
current CTRL S address

namptr ~

Pointer to the address of a 3-word,
.sIXBT representation of the name
and extension of the file to be created (unused spaces must contain nulls).

u = (unit)

the unit number of the device associated with .DAT-14 on which the
desired file is to be placed.

EXPANSION:
LOC+.fJ
LOC+l
LOC+2

CAL+f
26
u * 1.0.fJ.fJ.fJ~+namptr

5-3

5.2.2.2

.GET
Overlays core with the contents of the file whose name
is indicated by the Macro argument namptr. The file
must have been created by a .PUT System Macro, or a PUT
command to the Nonresident Monitor, and it must reside
on the device associated with .DAT-14. .GET destroys
the current contents of .SCOM, including DATE and TIME.
See also the .PUT System Macro, and the PUT and GET
commands to the Nonresident Monitor.
MACR0-15 does not expand the .GET Macro. The following
FORMAT statement illustrates how the user might formulate
, his own macro. The Resident Monitor, however, does recognize the command as illustrated in the EXPANSION section.
FORMAT:
.GETL-.lf,namptr,u
ARGUMENTS:

(function) - determines startup location
after overlay.
f

f
f

= .0

Start at location after
expansion of System Macro
that created the file. If
file was created via a .PUT
command to the Nonresident
Monitor, load core from the
file, and await a command
from the console keyboard.
= l Start at CTRL P
Ref er to
address
the DOS-15
Reference
= 2 Start at CTRL T
Manual for
address
more
informa3 Start at CTRL S
tion.
address
4 Start at the location specified by the .PUT. System Macro.
If the file was created via a
PUT call to the Nonresident
Monitor, load core, and await
command from the console keyboard.

namptr = Pointer to the first word of a thrAeword .SIXBT representation of the file name
and extension for the core image to be
loaded.
(Unused spaces must contain nulls.)
u

(unit)

The unit number of the device associated with .DAT-14 on which the
desired file is to be found.

EXPANSION:
LOc+.0
LOC+l
LOC+2

CAL+f
25
u*l.0.0.0n+namptr

s-i4

5.2.2.3

.GTBUF (Get Buffer)
Requests a buffer from the buffer pool. If a buffer is
available from the pool, the Monitor will return the address of the first word of the buffer in the AC. If no
buffer is available, the Resident ~onitor will return
777777 in the AC. On return, execution begins at LOC+3.
LOC+2 can be used as desired. This Macro gives user
programs as well as handlers access to buffers.
FORMAT:
.GTBUF
ARGUMENTS:
none
EXPANSION:
LOC+/6
LOC+l
LOC+2

5.2.2.4

CAL+/I
21

.GVBUF (Give Buffer)
Allows a user to return to the buffer pool a buffer
obtained via a .GTBUF System Macro.
FORMAT:
.GVBUF
ARGUMENTS:
None, at assembly time, but.

AT RUN TIME, the program must load LOC+2 with
the address of the buffer to be freed. If LOC+2
does not contain the address of an allocated buffer, the AC will contain 777777
on return.
EXPANSION:
LOC+J
LOC+l
LOC+2

CAL+J

22
fl

(Load with first address of buffer)

s-s

5.2.2.5

.OVRLA
Requests the System Loader to bring and start the core
image system program whose name is pointed to by the
Macro argument namptr. If there is not enough room in
core to load the program requested, the Resident Monitor
will return control to LOC+3.

WARNI£'!G
All I/O should be completed before

issuing an .OVRLA.
FORMAT:
• qy HI .A. •n!'!r!pt!'
JLJilfiilV:!C??Y8

namptr •

(name pointer) first address of the
two-W6id .SIXB1 reptes-entation of the name of the program ~o oe orougnt in.

EXPANSION:

5.2.2.6

LOC+JI
LOC+l

CAL+/I

LOC+2

namptr

.:.!KIT.
Requests the System Loader to bring in the Nonresident
Monitor. Current contents of core are lost. All unclosed output files are destroyed, all input files are
closed.
FORMAT:

.EXIT
ARGUMENTS:
none

EXPANSION:
LOC+JI
LOC+l

CAL+/I
15

5-6

5.2.2.7

.TIMER
Allows programs to schedule routines to be called after
specific time intervals.
Refer to Chapter 2 of the DOS-15 System Manual
(DEC-15-NRDA-D) for programming rules for
these routines.

FORMAT:

.TIMER....,nnnnnn,addres
ARGUMENTS:
nnnnnn • (time interval) number (in decimal
radix) of clock ticks from "now"
after which the subroutine is to be
called

fl < nnnnnn~2 1 8 -1
add res

address of the routine to be called
after the specified number of ticks.

EXPANSION:
LOC+/I

CAL+/I

LOC+l
LOC+2
LOC+3

14
-nnnnnn
addres

CHAPTER 6
PROGRAMMED I/O COMMANDS

6.1

INTRODUCTION

This chapter describes the concepts, conunands and methods for incorporating input/output commands in MACR0-15 assembly language programs.
FOCAL and FORTRAN users need noti:;rlrl iljsneral, be concerned with the
contents of this chapter, since each of these languages has its own
I/O capability.
The DOS-15 IOPS is the interface between any program and the external
world of I/O devices. I/O device handlers are provided for all standard devices and are described in Chapter 9. These handlers relieve the
user of the burden of I/O considerations and unwanted device dependence.
6.2

GENERAL I/O COMMUNICATIONS

Unuer DOS-15, all I/O transfers and subsidiary I/O operations are
initiated by programmed I/O commands called I/O Macros, as shown in
Table 6-1. These I/O Macros are macro instructions which have a .DAT
slot as one argument. As with System Macros, they are permanently
defined in the MACR0-15 Assembler.

As can be seen from Table 6-1, there are four I/O Macros within the
DOS-15 Software System which effect data transfer: .READ, .WRITE,
.RTRAN and .TRAN. The first three permit operation using the standard
DOS file structures described in Chapter 4 and provide the most
device independent approach to I/O programming. The .TRAN Macro functions independently of DOS-15 file structures,

6-1

Table 6-1
SYNOPSIS OF DOS-15 I/O MACROS

Macro

Function

.CLEAR 1

Initializes a directory on a directoried mass storage
device. All data on the device is lost and fresh bit
maps and directories are written.

.CLOSE 1

Terminates use of a file.
In the case of output files on
the disk, fills out the Retrieval Information Block (RIB)
for later .RTRAN cormnands.

.DLETE 1

Deletes a file from a directory on a mass storage device.

---

t---------- --- --- ----- -----------------

.ENTER

·----~--------

------------1

Primes a directoried mass storage device to accept an output file.

r------

---

.FSTAT

Checks the directory on a mass storage device for the
existence of a named file.

.INIT 1

Initializes the device and device handler.

.MTAPE

Provides special conunands for industry compatible magnetic
tape.

.RAND

Opens a disk file for rapdom processing via .RTRAN macros.

.READ

Transfers a logical record, or the requested number of words,
whichever is smaller, from the device to the user's I/O
buffer.

I--------- --

.RENN-1 1

----

Renames a file in a directory of a mass storage device.

---- --t-

.RTRAN

Allows input and output to access any bl.ock in a preexistent file on the disk (any word i f RF).

t------

.SEEK

Checks for a named file in a directory on a mass storage device.
If the file is present, prepares it as an input file.

.TRAN

Gives independence from DOS-15 file structure by allowing
input and output access to Magtape, or to any block on disk
or DECtape located by its physical block number. A file
can be opened for SEQ or random access and still be .TRANed
via the same .DAT slot without destroying the file structure.

.USER

Allows programs to change the .UFDT.

.WAIT

Waits for I/O already started to complete, then continues.

.WAITR

Waits for 1/0 alread__y_ started to c omo le_te__._ ____th_e n cQ.ll.t.i.n_ue s .
I f I/O not done, passes control to the specified address.

.WRITE

Transfers data from user's I/O buffer to the device.

1 1\t completion of these operations, the buffer is given back to the
buffer pool, i f disk or DECtape "A" version handler I/O.

6-2

6.2.l

.READ/.WRITE/.RTRAN Operations

.READ and .WRITE Macros permit the user to sequentially input and output records of a file consisting of ASCII lines or binary data to any
device in the standard set of PDP-15 I/O devices. The .RTRAN Macro
provides the user with random access tophysicalblocks when using
the DECdisk and Disk Pack devices. Initially, files are created
sequentially (.WRITE) and can subsequently be accessed both sequentially
(.READ) and randomly (.RTRAN).
6.2.2 .• TRAN Operations
The last data transfer macro (.TRAN) functions only on mass storage devices. It provides I/O transfer capability at the device level without regard for established file structures. This type of transfer
provides for user-designed file structuring.
Much of the remainder of this chapter is devoted to I/O progranuning
within the DOS-15 file structures and, specifically, to the methods
and considerations involving the creation of sequential files. Little
can be said here about the utilization of the .TRAN and .RTRAN Macros
since the system places the burden of data structuring, interpretation,
checking and packing on the programmer.
6.3

SEQUENTIAL F!LE PROCESSING

I/O operations under DOS consist of the transfer of ASCII or binary
logical records between buffer areas in the system or user program
and I/O devices represented by the device handlers in IOPS.
(A logical
record is defined as theamountof ASCII or binary data which is transferred to or from a program as the result of the execution of a single
.WRITE or .READ I/O Macro.) The size of each logical record depends
upon the structure of the data (Data Mode) and the device or set of
devices addressed. The format and data structure of each logical
record output in IOPS and Image Data Modes is described beiow. For
Dump Mode, however, no particular requirements are placed on the user
by the system. Dump mode is provided to permit user-created data
structures within the DOS-15 file structure.
6.3.1

Logical Record Format, IOPS and Image Modes

Each logical record to be output in !OPS and Image Modes must be
formatted as shown in Figure 6-1. The record, consisting of 2n
6-3

18-bit words contains a two word header (called header word pair)
followed by 2n-2 words of ASCII or binary data.

Word fa
Word 1
Word 2

lst word of header
2nd word of header

}

2n-2 words of data

)

Word 2n

Figure 6-1

header word
pair
ASCII
or
Binary
Data

IOPS and Image Mode Logical
Records Format

The header word pair is a communications link between the user's pro'Jram and the I/O device handlers in IOPS.
It is divided into vuri0us
f i<~lds which contain information about the data which resides in the
record.

The information in some fields is supplied by the program to

assist the device handlers in writing records and subsequently retrieving them.

Other fields contain information which is provided by the

device handlers for use by the user or system program when
records during input.

ver}fy~ng

Refer to paragraph 6.4.3 for explanation of Dump

Mode record format.
6.3.l.l

Header Word Pair Format

header word pair.

Figure 6-2 shows the format of the

Of particular significance is the Word Pair Count;

it specifies the number of word pairs of data in each logical record.
In addition, for all Data Modes except Dump Mode, it is the prime
logical record terminating condition when using mass storage devices.
This term should not be confused with the Word count, which is an
argument used in I/O Macros.

The Word Count gives the actual size of

the I/O buffer which contains the logical records prior to output and
after input operations
6.3.l.2

(see 6.7}.

Using the Header Word Pair

The program must calculate and then set the appropriate word pair count
in bits 1-8 of header word zero, unless they have already been set by
a device handler on input (i.e., an input device handler set up the
header word pair for each record read).

This count overrides the word

count passed to IOPS by the .WRITE system Macro.

6-4

The I/O mode field,

bits 14-17, is set by the device handler from the I/O mode argument
specified in the .WRITE Macro.

The checksum word need not concern

the user since checksums are computed by !OPS (when using IOPS Data
Modes).

9---11

WORD PAIR COUNT, INCLUDING
HEADER WORD PAIR

UNUSED

VALIDITY BITS'
OO•DATA CORRECT
01 •PARITY ERROR

I.__..___......

1/0 MOOE

__,.._~._-......__.....__

_.._

__.

tO •CHECKSUM ERROR
It• BUFFER OVERFLOW

110 MODE:
0000• IOPS BINARY
ooot •IMAGE BINARY
OOtO•!OPS ASCII
0011 •IMAGE ALPHANUMERIC

HEADER
WORD I

t4..-----+t7

CHE~~k~~O~~L-r-"'--"'---..._~......_-_.__......~__,..__..__..__......~.....- _ ._

BINARY INPUT

COUNT

HEADERS
WORD 0

0100 •UNUSED
0101 •EOF I LOGICAL)
OttO•EOM (PHYSICAL)
0 It I• TAPE LABEL

_ _

.....- ..... _.__..... _..___.___..____..___.___.___..__....__...__

_...._~

_.__~

CHECKSUM:
TWO'S COMPLEMENT OF HEADER WORD 0 PLUS DATA
WORDS (O•CHECKSUM NOT COMPUTED)
IS-0645

Figure 6-2.

Format of Header Word Pair

Before Input

The user need not be concerned with the header word pair since it will
be set up by the device handler during input to enable the user to
determine the status of his record after input has terminated.

6-5

During Input

The Word Count (specified in the .READ Macro) is used by the device
handler to determine the maximum number of locations provided in the
user's input buffer for the data being read. If the Word Count is ex-

the handler sets the validity bits of header word S as required to
indicate the error.
D.

After Input

Header word S of each logical record input should be examined by the
user program to determine whether errors have occurred. Specifically,
the validity and I/O Mode bits should be tested. If both checksum and
parity errors are detected by a handler, priority is given to a parity
error and the checksum error will not be indicated. IOPS ignores checksum errors on binary input if bit S of word S is set to 1. When examining the I/O Mode Bits (bits 14-17) the occurrence of a buffer overflow condition means that the user program's I/O buffer, as specified
by the Word Count in the .READ Macro, is not large enough to contain
the record just read. The portion of the record which caused the
_ _oye;::f.lnw is 1 osto

In "'dditi"Ri !OPS uses the I,lC ~od;; Bit:; tv in<'.!i

end-of-file (EOF) has been reached; otherwise, these bits specify the
Data Mode of the Record.
6. 4

DATA MODES

The device handlers within IOPS allow data transfers via .READ and
.WRITE Macros in one of the five Data Modes listed below:
IOPS Binary
!OPS ASCII
Image Binary
Image Alphanumeric
Dump

(Mode Sl
(Mode 2)
(Mode 1)
(Mode 3)
(Mode 4)

Data Modes permit the user to select the data structuring features of
the system which are important to his application. The device independent features of the system can be enhanced through the use of the IOPS
Modes, which are standardly used by all DOS-15 System programs (e.g.,
both FORTRAN IV and MACR0-15 accept source programs in the form of IOPS

6-6

ASCII files and produce object code as IOPS Binary files).

Conversely,

if specific device dependent features are desired, Image and Dump Modes
can be used (primarily applicable when used with non-mass storage devices).
6.4.l

IOPS Modes

The IOPS Data Modes, both ASCII and Binary are the standard data structures of the DOS Software System.

Using these modes, all ASCII and

Binary data input is verified and converted into standard records regardless of its original form on the input device.
programs must format data into standard

Before output,

IOPS records.

On output, !OPS

calculates checksums and either reconverts the data to the form required
by the output device or, in the case of mass storage devices, stores the
data in the standard record format.
6.4.l.l

IOPS ASCII

IOPS ASCII is used by DOS-15 System
Software as the standard ASCII Data Mode.
It accommodates the entire
7-bit ASCII

(1968) 128 character set as shown in Appendix A.

All

alphanumeric data, whatever its original form on input (i.e., 8-bit
ASCII, Hollerith, etc.) or final fQrm on output, is converted
internally by the non-mass storage device handlers and stored in
core and on mass storage devices a$ "5/7 ASCII".

This term refers

to the internal packing and storage scheme used for IOPS ASCII
in which five 7-bit ASCII characte~s are packed into two contiguous 18-bit words.

Figure 6-3 shows this relationship.

0
WORD 0

I ST CHARACTER

0-2
WORD I

7----------+13

3RD CHARACTER

5-7

2ND CHARACTER

3
4 TH CHARACTER

Figure 6-3

14----•17
3RD CHARACTER
, -4

10----------16
5TH CHARACTER

5/7 ASCII Packing Scheme

6-7

ASCII packed

17
UNUSED

in this form can be stored "as. is" on any mass storage device. I/O
requests involving 5/7 ASCII should be made using an even word count
argument to accommodate the paired data. ASCII data is ordinarily input or output character-by-character via non-mass storage devices such
as teleprinter, line printer, paper tape reader and punch. It can
also be stored on mass storage devices in 5/7 form (see Figures 6-4
and 6-5). On paper tape an IOPS ASCII character is defined as a 7-bit
character with even parity in the eighth (high order) bit, in keeping
with USASCII standards. Further, IOPS performs a parity check on
input, prior to the 5/7 packing and on output IOPS generates the correct parity.
Non-parity IOPS ASCI'I occurs in data originating at a Model 33, 35,
or 37 Teleprinter, without the parity option. This data always appears
with the eighth (high order) bit set to 1. Apart from parity checking,
the IOPS routines handleIOPSASCII ·and non-parity IOPS ASCII data identi·
cally.

TAPE CHANNEL

8 7 6 5 4
3 2 I
FEED
. DIRECTION

M~~~:~

1 :
•. e

e e
e e

}

ABC~

IN 517 ASCII

••• •

..-..__..._.!.- - - . . . . . .

' - - - - - 7 · B I T ASCII CODE
' - - - - - - - - P A R I T Y BIT !EVEN PARITY)
1&-0641

IOPS ASCII on Paper Tape

Figure 6-4

WORD PAIR COUNT

2
CHECKSUM
- - - - . . ---l 1HEADER WORD PAIR
t-- - - - .
A
B
C
t--C~--.)-'----"'--.....1

Figure 6-5

ABC.)
IN 517 ASCII

IOPS ASCII in I/O Buffers
and on Mass Storage Devices
6-8

Each logical record is an alphanumeric line, and a Carriage Return (CR)
or ALT MODE. CR (or ALT MODE) is a required line terminator in IOPS
ASCII mode to non-mass storage. Unused character positions in the IOPS
Word Pair after the CR or ALT MODE are ignored. Control character scanning is performed by some device handlers for editing or control purposes
(refer to Chapter 9).

On input, each IOPS ASCII .READ results in a 5/7 packed ASCII line being
placed,in the program's I/O buffer. If this line is to be interpreted,
it must be unpacked by the program. Conversely, on output each .WRITE
assumes that the data in the user's I/O buffer is a 5/7 packed ASCII
line. Thus, it is up to the program performing IOPS ASCII data transfers to unpack each input line and pack each output line. Appendix B
contains assembly listings of generalized packing and unpacking routines
which can be incorporated into user programs as required.
IQPS Binary _ IOPS Binary data is blocked in an even number
6.4.1.2
of words, with each block preceded by a two-word header (see Figure
6-6). On paper tape (see Figure 6•7), IOPS uses six bits per frame,
with the eighth channel always set to 1, and the seventh channel containing the parity bit (odd parity) for channels 1 through 6 and
channel 8. The parity feature supplements the checksumming as a
data validity provision in paper tape IOPS binary.
IOPS binary.
WORD PAIR COUNT
(INCLUDING HEADER WORD PAIR)

0 I

t7
0

CHECKSUM

HEADER
} WORD PAIR

}
} """ .,.,,
}

PAIRS OF 18-BIT

---------- ···-----

Figure 6-6

IOPS Binary in I/O Buffers and on Mass Storage Devices

6.-9

TAPE CHANNEL
87654
321
FEED

DIRECTION
OF TAPE
MOVEMENT

• o o o o o o o o
• o o o o o o o o
e o o o o o o o o
•

111 6-BIT BYTE
2nd 6-BIT BYTE
3rd 6-BIT BYTE

0 0 2-,.0

6-BITS OF BINARY WORD
PARITY BIT (ODO PARITY)
MUST ALWAYS BE PUNCHED

Figure 6-7
6.4.2

IOPS Binary Data on Paper Tape

Image Modes

Image Mode data, both Image Alphanumeric and Image Binary, is read,
written and stored (on mass storage devices) in the form established by
the source or terminal device.

These modes permit the user to take

advantage of the data structuring features peculiar to non-mass storage
devices.

These modes are strictly device dependent and no checking,

packing or interpretation of data is performed.

For example, when deal-

ing with Alphanumeric data the teleprinter editing features RUBOUT and
CTRL U, described in 9.3.l are ignored, as well as the IOPS ASCII line
terminators Carriage RETURN and ALT MODE.

With the line printer, how-

ever, Carriage RETURN and ALT ~ODE are accepted as legal line terminators.

Image Alphanumeric Mode results in the transfer of all eight bits of
an ASCII character to or from an I/O buffer (see Figures 6-8 and 6-9).
Image Binary data is unchecksummed binary and appears on paper tape, in
I/ O buffers and on mass storage devices as shown in Figures 6-10 and
6-11.
/WORD PAIR COUNT

,I'

HEADER WORD PAifl

CHECKSUM

A
B

ABC~
FOUR 8-BIT
CHARACTERS
(RIGHT JUSTIFIEOl

1!5-0652

Figure 6-8

Image Alphanumeric Data in I/O Buffers
and on Mass Storage Devices
6-10

TAPE CHANNEL

.-. .. • . ABC~
••
3 2

8 7 6 5 4

·-·-1

OF TAPE
MOVEMENT

FEED

}

••
• ••
• _......._
• • ·......:
....t

FOUR B·EllT
CHARACTER

ALL EIGHT CHANNELS

1!1·06H

Image:Alphanumeric Data
on Paper Tape

Figure 6-9

WORD PAIR COUNT
D

HEADER WORD PAIR

0
001 010 011

100 101

l10

DATA WOllD l'IUR

000 000 000 000 000

OOO

CONTAINING 123456181

15-0154

Image Binary in I/O Buffers
and on Mass Storage Devices

Figure 6-10

1 .•

TAPE CHANNEL

8 7 6 5 4

DIRECTION
OF "DIPE

MOVEMENT

3 2 1

....... FEED
~.

• •••

REPRESENTS OCTAL
} NUMBER 123456

• • ••••
•

!..

&•BIT BINARY to0E
(3 FRAMES/WORDI

IGNORED
MUST ALWAYS BE PUNCHED
IS-0655

Figure 6-ll

Image Binary on Paper Tape

6-11

6.4.3

Dump Mode

Dump Mode permits complete freedom in data structuring in the context
of a file structured environment 1 •

Data input or output in Dump Mode

is not interpreted, checked or packed and record length is not limited
by the software.

Dump Mode is used to output from, or load directly

into, any core memory area.

All data transferred are treated strictly

as 18-bit binary words (i.e., core images).
used.

No Header Word Pair is

Each .READ or .WRITE statement in Dump Mode requires arguments

which merely define the core starting address of the area input or
output and the number of words (Word Count) to be transferred.

Dump

Mode is normally used with mass-storage devices although paper tape
I/O is possible.

With paper tape, data is interpreted on output or

input as three six-bit frames per 18-bit word (see Figure 6-11).

6.4.4

Logical Record Terminators

IOPS detects the end of each logical record transferred using a predefined group of terminators or terminating conditions.

These logical

record terminators vary with the Data Mode in effect, the particular
device or set of devices involved, and the transfer direction (input
or output).

Table 6-2 summarizes the terminating conditions for logi-

cal records during input and outputforeach IOPS Data Mode.

Detailed

information on terminating conditions for each I/O device handler
is provided in Appendix C.

1 The .TRAN System Macro (paragraph 6.7.13) permits user specified
file structuring as well as data structuring. A Dump Mode transfer
can be thought of as effectively a file structured .TRAN.

6-12

Table 6-2
LOgical Record Terminators

Data Mode

Output

Input

- --!OPS ASCII

Carriage RETURN or ALT MODE
Word Pair Count 1
EOM
Word Count 2
EOF 1

Carriage RETURN
ALT MODE
Word Pair Count 3

!OPS Binary

Word Pair Count
EOM
Word Count 2
EOF 1

Image Alphanumeric and
Image Binary

word Pair Count 1
Word Count
EOM
EOF 1

Word Pair Count

Dump

Word Count
EOM
EOF 1

Word Count

Word Pair Count

--------

..,
1

Mass storage only.
word count is exceeded before a terminator is encountered, IOt>S
sets bits 12 and 13 of Header Word ~ to 3 (Buffer Overflow).

2 If

3 If the Word Pair Count is 1 or less, the line is ignored; if greater
than l, ignore the count and accept Carriage RETURN or ALT MODE (nonfile oriented devices only). Bulk storage devices require a word
Pair Count greater than 1 and less than 177 8 ; otherwise an IOPS 23
error will occur.

6-13

6.5

I/O BUFFERS

6.5.l

Space Allocation

Bach system or user program which is to perform I/O operations must
allocate an I/O Buffer for each I/O device and unit (i.e., a .DAT
slot) that is to be used simultaneously. This can be accomplished
by, but is not limited to, one of the methods described below.
Static buffer allocation can be accomplished through the use of the
MACR0-15 Assembler's .BLOCK pseudo-op as described in DEC-15-AMZC-D.
A tag must be used to permit referencing of the buffer in each I/O
Macro. For example:

INBUF

.DEC
.BLOCK 52

OTBUF

.BLOCK 254
.OCT

/CREATES 52(10) WORD BUFFER
/CALLED INBUF
/CREATES 254(10) WORD BUFFER
/CALLED OTBUF

Dynamic buffer allocation can be performed through the use of the
Monitor Macros .GTBUF and .GVBUF described in Chapter 5. Alternatively,
the user can create a buffer at execution time from free core by simple
calculation, using the information contained in the System Communication Registers, .SCOM+2 and .SCOM+3 (absolute locations 102 and 103).
These registers contain the lowest and highest addresses of the registers in unused core, respectively.

6.5.2

Size Considerations

When choosing a maximum I/O buffer size to specify in the Word Count
arguments for .READ and .WRITE I/O Macros, both the set of possible
devices and the Data Mode must be considered. As a general rule,
when using IOPS and Image Modes, the maximum logical record size can
never exceed the maximum buffer sizes specified in Table 6-3, These
are based on physical device limitations. In Dump Mode, however, there
are no restrictions on buffer size except for the absolute bounds of
core itself; a logical record can occupy any number of physical blocks
on a mass storage device. Programs which are to communicate with a
number of devices using IOPS or Image ~odes must limit the output
buffer size to that of the device with the smallest maximum buffer.
Conversely, in setting-up input buffers, the size must be at least as
large as that for the device with the largest maximum buffer size.

6-14

Table 6-3
Maximum I/O Buffer Sizes for !OPS and Image Mode Transfers
Device
DECdisk

ax. Buffer Size 1

Data Modes

Comments
!OPS and Image Modes
permit more than one
logical record (depending on its size)
per physical block.
Dump Mode records can
span an unlimited number of blocks.

(DK)

254

(3768)

All

Disk Pack (DP)

254

C376 8 l

All

DECtape (OT)

255

(3778)

All

Magtape (MT)

255

(3779)

All

Teleprinter (TT)

!OPS ASCII

Allows for 80 5/7
packed characters
(though only 72 are
printable)

Image Alphanumeric

(Allows for 72 characters)

Paper Tape
Reader (PR)

All

Paper Tape
Punch (PP)

All

Line Printer LP-15
(80 column)
84

Line Printer LP-15
(132 column)

(708)

136

Card Reader (CD)

!OPS ASCII

Allows for 80 5/7
packed characters

Image Alphanumeric

Allows for 80
characters

!OPS ASCII

Allows for 132 5/7
packed characters.

Image Alphanumeric

Allows for 132
characters

!OPS ASCII

Allows for 80 5/7
Qacked
cha:cg_cters__n_l n.,
- .
a handler supplied
Carriage RETURN.
.

VPlSA Storage
Tube Display

(429)

!OPS ASCII

Allows for 80 5/7
characters (only 72
can be displayed)

Image Alphanumeric

Allows for 72
characters

0ctal representation of buffer sizes is shown for values returned after
issuing a .!NIT and indicating the maximum size which can be used for
!OPS Modes. Other sizes shown can be used with Image Modes as
specified.

6-15

For example:

Consider the I/O buffer requirements for a program which

must be capable of transferring !OPS ASCII lines to either a teleprinter or the DECdisk.

The maximum I/O buffer size for the tele-

printer is 34 10 locations and for the DECdisk is 254 10 locations.
Therefore, the user should choose the smaller size since his program
must deal with both.

More importantly, if the ASCII records stored

on the DECdisk were greater than 34 locations in length, the user
could not transfer them back to the teleprinter without truncation
or reformatting.
6.6

SPECIFYING I/O DEVICES

As mentioned in preceding chapters, the Monitor maintains a Device
Assignment Table (.DAT), which has "slot" numbers that correspond directly to logical device numbers.

Each .DAT slot contains a pointer to

a device handler and a unit number when applicable (for Disk Pack,
DECtape or Magnetic Tape units) .

All I/O communication in the DOS-15

Monitor environment is accomplished by the logical/physical device
associations provided by the Device Assignment Table.
When writing a MACR0-15 program which uses I/O Macros, it is necessary to incorporate the MACR0-15 Assembler's .IODEV pseudo-op somewhere
in the program to specify to CHAIN or the Linking Loader which logical
device numbers (.DAT slots) are to be used.

The .IODEV pseudo-op

causes the Assembler to generate a code in the object program which
instructs CHAIN or the Linking Loader to load the device handlers associated with the specified .DAT slots.
For example:

.IODEV 3,5,6

causes the device handlers assigned to

.DAT slots 3, 5 and 6 to be loaded with the program issuing the pseudoop.
6.7

I/O MACRO DESCRIPTIONS

The paragraphs which follow describe the function of the I/O Macros,
the information to be provided by the user (arguments), and the assembly
language expansion of each 1 ,

Either the I/O Macros or their assembly

language expansions can be incorporated directly in MACR0-15 programs.
Typical I/O command sequences are discussed in paragraph 6.8.4.

1
Paragraph 5.2.2 describes conventions and symbology used in presenting the I/O Macros.

6-16

6.7.l

.CLEAR
Initializes all bit maps and directories on the device.
Eliminates all references to files in the directory of
the device associated with the named .DAT slot.
In order to avoid clearing a directory when its files are
still in use, the directory is checked for open files.
If there are no open files, ~he directory is cleared;
otherwise, an IOPS 1{6 error message (file still active)
results .
. CLEAR may only be used unde~ the MIC, because it will
destroy the system.
FORMAT:
• CLEARa...if-J ds
ARGUMENTS:
ds= .DAT slot (octal radix)
EXPANSION:

(all values below are octal)
LOC+f6
LOC+l

6. 7. 2

CAL

[-]ds&777

.CLOSE
When directed to a .DAT slot used for input: Clears
all flags related to that .DAT slot. This deactivates
the .DAT slot, and another .INIT will be necessary
to use the .DAT slot in the future. Any allocated buffer is returned.
When directed to a .DAT slot used for output: Allows
all associated output to finish, and then writes an
end-of-file (EOF) 1 software indicator in the last
header word pair. If the .DAT slot is associated with
a directoried device, any earlier file of the same name
and extension is deleted from the directory. Operation
then continues as for input files (above).
FORMAT:
.CLOSE._..[-]ds
ARGUMENTS:
ds = .DAT slot (octal radix)
EXPANSION:

(all values below are octal)
LOc+f6
LOC+l

CALa...i[-J ds&777
6

f6fH{6jS
776773

6-17

6.7.3

.DLETE
Deletes a file from the directory of the device associated
with the named .DAT slot.
If the specified file cannot be found, the contents of
the AC will be ~ on return.
FORMAT:
• DLETE ...,[ - ] ds , namptr
ARGUMENTS:
ds

•

.DAT slot number (in octal radix)

namptr

Pointer to the address of the first of 3
words containing the .SIXBT representation
of the name and extension of the file to be
deleted (unused spaces~ contain nulls).

(all values below are octal)

EXPANSION:

6. 7. 4

LOC+~

CAL+l~~~...,[-)ds&777

LOC+l
LOC+2

2
namptr

• ENTER

Initializes a directory for a new output file. The file
will be placed on the device associated with the .DAT
slot named as one of the parameters to the macro. Transfers control to the Monitor error handler to print the
appropriate error message if there is no available space
in the file directory.
FORMAT:
.ENTER...,[-)ds,namptr,p
ARGUMENT:
ds

.DAT slot (octal radix)

namptr = Pointer to the address of the first
of three words containing the.• SIXBT
representation of the name and exten_sion of the file to be created.
p = Disk file protection code to be assigped.
Possible values for p:
1
2
3

file is unprotected
file is WRITE protected
file is READ/WRITE protected

If p is omitted, default protection code
is used.
6-18

6.7.4

{Cont.)
EXPANSION:

(all values below are octal)
LOC+~

CAL+l~~~*p...,[-)ds&777

LOC+l
LOC+2

namptr

6.7.5" .FSTAT
Checks the status of a file in a directory. Ignored
by non-directoried devices. The namptr parameter
points to the name and extension of the file whose
status is desired. On return, the AC will contain
the first block number of the file, if the directory
lists a file with the indicated name. The contents of
the AC will be zero on return if the specified file
is not on the device. It is recommended that programmers use .FSTAT prior to executing .SEEK if they wish
to retain program control when a file is not in the
directory.
Bits ~ through 2 of LOC+2 must be set to zero prior
to the execution of the CAL. On return, these bits
of LOC+2 will contain a code indicating the type of device associated with .DAT slot ds.
non-directoried device
DECtape file structuring
2 = RF DECdisk file structure
3
RP Disk Pack file structure
4
Magtape

FORMAT:
.FSTAT._.,[-)ds,namptr
ARGUMENTS:
ds

namptr

EXPANSION:

.DAT slot bctal radix)
Pointer to the address of the first
of tnree words containing the .SIXBT
representation of the name and extension of the file (unused spaces ~
contain nulls).

(all values below are octal)
LOC+~

CAL+3~~~~[-)ds&777

LOC+l
LOC+2

namptr

6-19

6.7.6

.INIT
Initializes a device and device handler.
Programmers must give a .INIT prior to giving any
I/O conunands referencing the named .DAT slot. Any
.DAT slot initialized via a .INIT must eventually
be closed via a .CLOSE.
The handler that services any .INIT will return (in
LOC+3 of expansion) the maximum size of the line
buffer allowed for that handler.
For example, DTA
will return 377 (255 10 ) in LOC+3, and DKA will
return 376 (254 10 ) in LOC+3 of the expansion.
FORMAT:
.INIT'-'(-]ds,dd,restrt
ARGUMENTS:
ds

.DAT slot (octal radix)

Direction of data flow
~

- file will be an input file
1 - file will be an output file

restrt

EXPANSION:

Restart address. Although restrt must
be included to avoid assembly time
errors, it has meaning only for .INIT
conunands referencing .DAT slots assigned
to the teleprinter.

(all values below are octal)
LOC+J
LOC+l
LOC+2
LOC+3

CAL+dd*l~J-'-'[-Jds&777

NOTE:

Bits 5, 6 and 8 of LOC+~ provide added
information for the GRAPHIC-15 software
the line printer handler and the disk
handlers. See the individual handler
descriptions for more information.
Bit 7 of LOC+~ should always be ~-

1
restrt
~ (Handler will return maximum buffer
size in LOC+3.)

6-20

6. 7. 7

.MTAPE
Performs functions unique to industry-standard magnetic
tape, i.e., functions for non-directoried magnetic tape.
Limited functions are also provided on DECtape and disk
(see Chapter 9). See descriptions of appropriate handlers for more information.
FORMAT:
.MTAPE~(-Jds,nn

ARGUMENTS:
ds

.DAT slot number (in octal radix)

code number bf magnetic tape function
or configuration:

fl.0 - rewind to load point
,02 -

/B ,04
,05
,06
,07
1.0

EXPANSION:

12
13
14
15
16
17

(all values below are octal)
LOC+!if
LOC+l

6.7.B

backspace record
backspace file
write end-of-file
skip record
skip file
skip to logical end of tape
7-channel, even parity,2,0.0 bpi
7-channel, even parity, 556 bpi
7-channel, even parity, 8.0.0 bpi
9-channel, even parity, 8.0.0 bpi
7-t::hannel, odd parity, 2,0,0 bpi
7-channel, odd parity, 556 bpi
7-channel, odd parity, Bfif!if bpi
9-channel, odd parity, 8J3!if bpi

CAL+nn*l!ifj3~....,[-)ds&777

.RAND
Opens a disk file for random access via .RTRAN macros. Returns
the number of blocks in the file in LOC+3 of the expansion.
FORMAT:
• tV\NIJ._,L -J

us, namptr

ARGUMENTS:

namptr

EXPANSION:

.DAT slot (octal radix)
Pointer to the first word of a 3-word,
.SIXBT representation of the file to
be opened (unused spaces must contain nulls) •

(all values below are octal)
LOC+!if
r.oc+ i
LOC+2
LOC+3

CAL+5!if,0~.__.[-lds&777

nanu;itr
,0
6-21

6'.7.9

.READ
Returns the next logical record to the user's I/O buffer.
If the record is longer than the user's I/O buffer, the
handler will fill the buffer and the rest of the record
will be lost.
If the record is shorter than the user's
I/O buffer, the handler will use only the part of the
buffer it needs.
The handlers use several indicators
to determine the length of record. Appendix c, Input/
Output Data Mode Terminators, shows which handlers use
wl;lat indicators for each data mode.
Since I/O operations and in~rnal data transfers may
proceed asynchronously with ~amputation, a .WAIT command
must be used after a .READ command before the user attempts to access the data in his I/O buffer, or to read
another line into it.
The user should always check bits 14 through 17 of the
first word of the I/O buffer' for end-of-medium and endof-f ile conditions. In non-Dump modes, the user should
also interrogate bits 12 and 13 of the first word of the
I/O buffer to ensure that the record was read without
error.
FORMAT:
.READ~[-Jds,m,bufadd,wdc

ARGUMENTS:
ds

•

.DAT slot (octal radix)
Data Mode, as follows:
~

1
2
3
4

buff add
wdc

.....
~

Data Mode
Data Mode
Data Mode
Data Mode
Data Mode

is
is
is
is
is

IOPS Binary
Image Binary
!OPS ASCII
Image Alphanumeric
Dump Mode

address of user's I/O buffer

= word count (decimal radix) , including the two-word header.
wdc should
equal the length of the buffer at
bufadd.

EXPANSION: (all values below are octal)

LOC+,S
LOC+l

CAL+m*l,S.S,S....,[-]ds&777
l,S

LOC+2

bufadd
-wdc

LOC+3

6-22

6.7.10

.RENAM
Renames a file (useful only with directoried devices).
The old name and extension are pointed to by namptr;
the new name must be located at namptr+3. The AC
will be zero on return if the file specified at
namptr cannot be found·

FORMAT:
.RENAM.._.[-Jds,namptr
ARGUMENTS:
.DAT slot (octal radix)

namptr = pointer to tbe old name and extension (new n~e is at namptr+3) •
(Unused spaces must contain nulls.)
(all values below are octal)

EXPANSION:

6. 7 .11

LOC+~

CAL+2~~~"-"[-]ds&777

LOC+l
LOC+2

namptr

.RTRAN
Allows random access to blocks in a file opened via a
.RAND I/O macro. Programmer may read or write into
any block of a file, but may not change
the length of the file.
FORMAT:
.RTRAN.._.[-]ds,d,r.elblk,bufadd,beg,wdc
ARGUMENTS:
ds = .DAT slot (octal radix)
d = direction:
~

- direction is input
1 - direction is output

relblk = block nwnber (octal radix) relative to beginning of the file •••
first block is block 1, etc.
bufadd • address of I/O buffer in user's
core space.
beg

first physical word of physical
block to be :read or ..citten ••• ignored for disk pack ..• must be
octal radix, ,0<_beg<_375.

wdc

nwnber of words, starting with
beg, to be read or written ••.
ignored for disk pack ••. must be
DECIMAL radix, .0<_cnt<~(253-beg).
6-23

6.7.11

(Cont, )
EXPANSION: (all values below are octal)
LOC+/6
LOC+l
LOC+2
LOC+3
LOC+4

CAL+4/6/61'-'[-]ds&777
2

d*4.0Jlflfljl+relblk
bufadd
-beg
.DEC
-wdc

LOC+S

6. 7. 12

. SEEK
Opens a file for input on a directoried device.
is ignored by non-directoried devices.

SEEK

If the file is listed in the device's directory, the
handler reads the first block of the file into a
buffer.
(A subsequent .READ will obtain the
first logical record in the user's I/O buffer.)
If the file is not listed in the device's directory,
the handler will pass control to the error handling
routine in the Monitor. If the user wishes to retain
control in the case that the desired file is not in
the directory, he should first issue a .FSTAT command.
FORMAT:
.SEEK'-'[-]ds,namptr
ARGUMENTS:
ds
namptr

EXPANSION:

.DAT slot (Qctal radix)
pointer to 1;.he three-word .SIXBT
representation of the name and extension of ~he file to be opened
for input. ·(Unused spaces must be
null-filled.)
(all values beiow are octal)

LOC+.0
LOC+l
LOC+2

CAL'-'[-Jds&777
3
namptr

6. 7 .13

• TRAN
Allows device-dependent, non-directoried input and output to any mass storage device. Users address such
blocks by their physical locations. .TRAN should be
followed by a .WAIT macro, to ensure that the transfer
has been completed.
FORMAT:
.TRAN~[-Jds,d,blknum,bufadd,wdc

ARGUMENTS:
ds

.DAT slot (octal radix)

d ~ direction of transfer:

J
1
2
3
NOTE:

inptlt,forward
output, forward
input, backward (DECt~pe on!y)
output, backward (DECtape only)

DECtape blocks must be read in the direction they were written in, in order
to obtain meaningful results.

blknum • block number (octal radix) of block
at which to start input or output;
I/O with word count larger than one
block will continue with the next
contiguous block; end of tap~ or
disk will cause IOPS error.
bufadd

address of I/O buffer; I/O buffer
must be at least as long as wrdcnt.

wdc = number of words to be transferred
(decimal radix)

EXPANSION (all values below are octal):
Loc+i
LOC+l
LOC+2
LOC+3
LOC+4

CAL+d*l-jf~[-Jds&777

13
blknum
bufadd
-wdc

6-25

6. 7. 14

• USER
Allows users to dynamically assign UIC's to desired UFDT
slots, thus pe:anitting access to UFD's other than the UFO
specified at LOGIN time (refer to paragraph 8.4). Protection for the specified UFO and its files remains in effect. .USER must be issued before the .INIT of the I/O
sequence for which UFO change is desired (see example
below).
FORMAT:
• USER....,[-] ds ,uic
ARGUMENTS:
ds = .UFDT/.DAT slot nwnber (octal radix)
uic •

EXPANSION:

(UIC) the .SIXBT representation of the
three-character User Identification
Code

(all values below are octal)
LOC+~

LOC+l
LOC+2

CAL...,I-Jds&777
23
uic

For example:
.USER liABC
.INIT 1
.USER l,CDE
.SEEK l,FILE
.CLOSE l
.INIT l
.SEEK l,Fl:LE

(;his .S.EK searches for FILE under th:l
LUFD called ABC

rThis .SEEK searches for FILE under th'J
LUFD called COE.

. 6-26

6.7.15

.WAIT
Obtains and holds control until the user's I/O buffer is
available after an I/O operation. Should be used before accessing an !/O buffer after .READ, .WRITE, .TRAN,
and .RTRAN commands.
FORMAT:
• WAIT.._,[-] ds
ARGUMENT:
ds = .OAT slot (octal radix)
EXPANSION:

(all values below are octal)
CAL._.[-]ds&777
12

LOC+fa

LOC+l
6.7.lG

.WAITR
Returns control to the address specified as an argument
to the CAL, if I/O is not complete. If I/O is complete, returns control to next location after macro
expansion. It is the user's responsibility to return to the .WAITR conunand, or do another one.
FORMAT:
.WAITR

[-]ds,waitad

ARGUMENTS:
ds

.DAT slot (octal radix)

waitad = address 'to which control will be
returned, if I/O is incomplete.
EXPANSION:

(all values below are octal)
I

LOC+SI
LOC+l
LOC+2

CAL+lSISI'
12

waitad

6-27

(-] ds&777

6. 7 • l 7

• WRITE
.WRITE transfers a logical record from the user's I/O
buffer to the handler's buffer.
The .WRITE conunand establishes the mode in which data is
transferred. The Header Word Pair Count determines the
maximum amount of data to be transferred in all modes
except Dump, which references the "wrdcnt" argument.
The only limits on data transferred in Dump Mode are
the size of core and the capacity of the device accepting the data. On physically blocked devices, such as
DECtape and disk, the handler will start from its
current position in a block and fill successive
blocks until the transfer is complete. If a Dump Mode
transfer does not completely fill the last block used,
a subsequent Dump Mode transfer will fill that block,
before using any other.
'
.WAIT or .WAITR must be us~d after a .WRITE command,
before the user's I/0 buff~r is used again, to ensure
that the transfer to the device has been completed.
FORMAT:
.WRITE.._,{-]ds,m,buf~dd,wdc

ARGUMENTS:
ds = .DAT slot (octal radix)

· m • data mode for transfer

J1 - IOPS Binary

Image Binary
2 - IOPS ASCII
3 - Image Alphanumeric

1 -

4 - Dwnp

bufadd • address of usek•s I/O buffer containing
data to be trahsferred.
wdc = word count, number of words to be transferred (decima~), (relevant for Dump
Mode transfers: only) •
EXPANSION (all values below are octal)
LOC+fl

LOC+l
LOC+2

CAL+m*l-f1J1..,.{-]ds&777
ll

bufadd
LOC+3 -wdc

6-28

6.8

USING I/O MACROS

The progranuner must observe certain conventions when incorporating I/O
Macros into a program. In general,_ consideration must be given to:
0
0

ci
0

6.8.l

The physical device and its capabilities
I/O device handler characteristics
The I/O Macro Syntax
The I/O Macro Sequence for the desired file access/
structure (see Chapter 4)

Physical Device Capabilities

The considerations involved here are obvious and need little comment.
Simply stated, the user must understand the gross differences between
various devices. For example, a.READ cannot be issued to a line
printer. Similarly, binary data cannot be output to a teleprinter.
6.8.2

Device Handler Characterist4cs

Many of the standard PDP-15 I/0 de~ices available to DOS-15 users are
provided with several hand_l,e_x:_ 'IT~X:.~~()11._l:I ~ __ These versions vary from one
to another as to the I/O Macros anq Data Modes which are acceptable to
them. Some versions permit the fu~l set of I/O Macros and Data Modes
to be used, while others incorporate a subset of these features. These
limited capability handlers are provided primarily for use where core
allocation is a problem, since they are smaller than those with
greater capability. The user must be aware of these handler differences, particularly if he wishes t¢ utilize device dependent characteristics. Detailed descriptions Of the DOS-15 device handlers are
provided in Chapter 9.
6.8.3

I/O Macro Syntax

The order in which I/O Macros are used is important to the.success of
an I/O transfer. There are basic rules of syntax which must be adhered to in order to avoid run time I/O (!OPS errors) errors. These
rules apply to any I/O sequence directed to the same .DAT Slot.
1.

.INIT must always be issued before any other I/O
Macro. It initializes the handler associated
with the referenced .DAT slot for either input or
output. Subsequent .INITs can be used to unconditionally terminate an unwanted I/O operation.

6-29

Table 6-4
Legal I/O Macro Combinations
Commands

Commands which rn~ ...E_recede
Director__y_ Maintenance
Misc.
File Str~ture Initialize
Data Transfer
1-INIT .FSTAT joRENAM .DLETE .CLEAR .SEEK .ENTER .RAND .MTAPE .READ .WRITE .RTRAN .TRAN .WAIT .WAITB. .CLOSE

wliicl'l ma~ Misc.

follow:

.RAND
.MTAPE

.READ

.CLOSE

x
x
x
x
x
x
x

x
x
x
x

x
x
x

.USER

.FSTAT
.RENAM
.DLETE
.CLEAR
.SEEK
.ENTER
t·
°'
w
0

x
x
x
x
x
x
x
x
x

x
x
x
x
x
x
x
x

.INIT

.WRITE
.RTRAN
.TRAN
.WAIT
.WAITR

Notes:

x
x

x
x
x

x
x
x
x
x

x
x

?
?
?

x
x
x

x
x
x
x
x
x

? = Illogical Combination

x = Legal combination
Blank = Illegal Combination

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
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x

.CLOSE (or .MTAPE Rewind, for Magtape) must always
be the last Macro issued in the sequence. It terminates the current I/O operation and use of the associated .DAT Alot. Another .INIT must be issued if
subsequent transfers are to be made via this .DAT slot.

I/O transfers to directoried devices (DECdisk, Disk
Pack, DECtape or Magtape) require the use of .SEEK
before .READ, .ENTER before .WRITE and .RAND before
.RTRAN.

4·.

Intermixing of .SEEK, .ENTER, .MTAPE, and .RAND
Macros in the same I/O sequence (i.e., occurring
between an .INIT and a .CIPSE referencing the same
.DAT slot) is illegal.

The acceptability of specific combinations of I/O Macros is shown in
Table 6-4.
6.8.4

Selecting an I/O Macro Sequence

The user has the capability of selecting conunand sequences which empha9ize either device independence or ~evice dependence, as his needs
dictate. Much of the device independence of the DOS-15 System is obtained by usil'Vil I/O Macro sequences which are general· enough to be
acceptable to a wide t:\lnge._o_f de.vitfe._bandl.ers. These sequences are
based on sequential file access via the .READ and .WRITE I/O Macros,
which are recognized by all DOS-15 Pevice Handlers. Simply by using
.INIT - .READ (or .WRITE) - .CLOSE :sequences along with the applicable
IOPS Data Modes, a user's program has the capability of communicating
with all non-mass storage devices (including teleprinter, paper tape
reader and punch, line printer, ca~d reader and VP-15 display). By
adding the .FSTAT, .SEEK, and .ENTER Macros, the same program can,
in addition, utilize the system's mass storage devices (including
DECdisk, Disk Pack, DECtape and Magtape). The examples below further
illustrate these sequences.
Example 1 - Typical Output Sequence
.IODEV 1

/Use .DAT slot 1

•. I.NIT

/Initialize .DAT slot 1 for output (l)

1, l, RSTRT

Optional check for existing file and
device type, e.g., .FSTAT, .RENAM,
.OLETE, etc.

6-31

Example {cont•dl

IProces~ data for output!
• ENTER l, NAME
-----.WRITE l,2,BUFF,34
.WAIT l

/Output a record to .DAT slot l
/from BUFF in IOPS ASCII Mode.
/Wait till buffer is free

Yes

.CLOSE 1
.SIXBT
np1~@@SRC"

NAME
BUFF

.BLOCK 42

/File name in .SIXBT
:;spaces are null filled (i.e., @=null)
-/l~-buf fer

Example 2 - Input Sequence
.IODEV l

'
.!NIT

l,~,

;/Use .DAT slot 1
RSTRT

./Initialize .DAT slot 1 for

input(~)

Optional check for existing file and device type
(e.g., .FSTAT, .RENAM,
and .DLETE Macros) .
• SEEK
~---~.READ

.WAIT

l,NAME
l,2,BUFF,34

Process input data

Yes

RSTRT

.CLOSE

NAME
BUFF

.SIXBT
"FIL@@@SRC" /File name in .SIXBT. Spaces are
.BLOCK 42
/null filled (i.e., @=null)
/I/O buffer

6-32

Device dependent I/O programming is: bas-ed in large part on the use of
device-specific I/O Macro sequences and to a lesser degree on the structure (Data Mode) of the data. For example: .RTRAN can only be
used with disk handlers; non-mass storage devices do not need .SEEK
or .ENTER for operation (they igno~e them). Furthermore, the interpretation of data using the Image and Dump Data Modes becomes the
user's responsibility, rather than the handler's. The user who does
not need device independence can eliminate unnecessary instructions
in his program and obtain addition~l free core for other purposes.
For instance, assume that:in the pr~vious examples a directoried device
was never to be used. The programqer could then economize by eliminating all I/O Macros associated with II/O on directoried devices such as
.SEEK, .ENTER, .CLEAR, .DLETE, .FS~T.
Figure 6-12 shows the relationship ,between standard I/O Macro sequences
and the various I/O devices and file structure/access features of the
DOS-15 system. Except for .INIT and .CLOSE, there is no implied order
to the macros in any partic~lar I/O sequence shown (the reader should
refer to paragraphs 6.7 .an~: 6.8.3.l for this information).
6.8.5

Progranming Example

The following example illustrates the use of I/O Macros in a Macro-15
·Assembly Language program. The program accepts an ASCII line from the
teleprinter keyboard, creates a file on' the disk (or if the .DAT slot
is properly assigned, on any bther directoried device), reads the file
back from the disk, and prints it tjn the teleprinter. Before subsequent keyboard inputs, the program :prints the following message on
the teleprinter:
FILE ALREADY PRESENT! 1
DO YOU WISH TO KEEP IT?

(YORN AND CR).

By typing a Yon the keyboard, the file previously .created is saved
and a new file is created for the next line input from the keyboard.
By typing an N rather than a Y, the next line input from the keyboard
is written on the disk using the filename associated with the line
previously typed (that line will be deleted).
The name of the file is initially ECHO 001. A new file name is
created each time a Y is typed in response to the above message by

6-33

.INIT

No -

(i.e., Tele rinter, Paper Ta e, Line Printer,
etc.)

(i.e., DECdisk, Disk Pack, DECtape,
Mag tape)
No

.FSTAT
.RENAM
.DLETE
.CLEAR

Random

.SEEK
.READ
.MTAPE

.MTAPE
.READ

or
.ENTER
.WRITE
.MTAPE

.RAND
.RTRAN

.READ

or
.WRITE

or
.TRAN

.WRITE

.WAIT

or
.WAITR

Figure 6-12
I/O MACROS APPLICABLE TO SPECIFIC DEVICES AND DATA ACCESS TECHNIQUES
6-34

fncrement±m,r--the--locaticm--±n--the- prrqrm11 called-NA:MB+2 -which---initial-ly

contains the "001" extension of theJfl..le name in Sixbit trimmed ASCII
_(.SIXBT pseudo-op). This produces
series of uniquely named files
(one each time a Y is typed) as fol~ows: ECHO 001, ECHO 002, ECHO 003,
ECHO 004, etc.

The arguments used by the I/O Macrop in this program are given symbolic
names by means of MACR0-15 direct ai signment statements at the beginntng of the program. These names p llllit the programmer to change the
real values of these arguments rea "ly and also facilitate recall.
~ae ~isting shown below is the sour ~li•tin9 and is followed by an as$embly listing which shows how Macr s are expanded at assembly time.
The reader may wish to compare.thes
with the Macro descriptions in the beginninq of this
Programming Example - Source Listing

, TITLE DK ECHO
i) 151<•7

TTl•6
TT0•5
Jl'.j•0
riUTa1

!OPS•2

,lODEV
, !NU

.-INIT
, PUT
,F'STU

JMP

,WRITE
,R(AO
,·WA IT
.-EJECT
LAC
l)iA

WRITE

REAOOT

JMP
,[l'\IH'R
,WRITE
,WAIT
,CLOSE
,lNlT
,'S£EK
;RE Ari

~EST

,WAIT
,EJE:CT
I WR I Tl
;WAIT
,CLOSE
,CL.OS£
,CL.05l
JMP

!5'617

DISi<, OUT, RE STRT
TTl1IN1R[STRT
TTO,OUT1RESTRT
D ISi<, NAME

UPDATE
TTOrlOPS,"SGl114
TTlrlOPS 1BUF',ER134
TTI

uosw
NEWF'IL
OIS!<,NAM[
OISK1IOPS18UF,ERr34
nJSK
nlSK
OISKrl11j,R£$TRT
lllSK,NAME
OISK1IOPS18UF'F'(R,34
OISK
TTO,fOPS,BUrrER,34
TTO
TTO
TT l

OlSK
BEGIN

_6~35

/JNITIALJlE OJSK OUTPUT,
/TELETYPF lNPUT1
/ANO TELETYPE OUTPUT
/IS rlLE PRESENT1
/NO• l~PuT KEYBOARD
/YES, OUTPUT MSG1 ANO HSC2
/TYPE A GO AMEAO SYMBOL r>>
/INPUT IOPS ASCII F'ROH KEYBOARD
/WAIT UNTIL INPUT COMPLETE

/TEST UPDATE SWITCH
I~ REPL.Ar.r INPUT FILE
l•l•SAVE INPUTI CRlATE NEW OUTPT
/CREATE l'\IEW OISI< rlLE
/OUTPUT nATA ON OtSK
/WAIT UNTIL OUTPUT COHPLFTEO
!CLOSE F'tLE
/lNITIALtlE OISK INPUT
/LOCATE rlLE "NAME"
/READ INTO B!JHER
/WAIT UNTIL RE:AD COMPLETE
/OUiPUT TO TELETYPE
/WAIT UNTIL OUTPUT COHPLFTE
/TERMINATE TtL.ETYPE OUTPUT,
/TELETYPF' INPUT,
/ANU DISK INPUT/OUTPUT
/LOOP FO~ UPDATE oPTlON

UPDATE

,WRITE
·,WA l T

·,·EJECT
I

WR lTE

·:WA IT
,READ
,'!ljAI i'
LAC
ANO
SAD

JM!'
I) i!"'

YES

JM!'

CLC
OAC
JMP

N[WrtL

LAC
LRS

TT01IOPS1MSGi134

/OUTPUT MSCi1
/ANU MSG2

TTO

TT0110PS,MSG2134
TTO

ION
/TELETYPr
/REAO RESPONSE
/WAIT UNTIL. READ COMPLETE
/GET flRST WORD
/SAVE r1RST SEVEN BJTS
/IS CHAR A V?

TTl,IOPS,COM,8
TT I
C0"4+2
C7740fHJ

(544000
YES

uosw

/N01 SET TO REPLACl INPUT rtLE
/L,OOP TO READ KEYBOARD
/SET UPDATE SW, TO SAVE
/lNPUT1 CREATE NEW OUTPUT
/LOOP TO READ KEYBOARD
/CWANG[ OT
/LEAST srGN!flCANT DIGIT 0,
/SIXBT VALUE or L.AST CMAR JN EXT
/STHJP orr HIGH PAHT or COO[

REAOKB

uosw

REAOKB
NAME•2
3

RTR
RAR

LRS

/LEAST StGNJrlCANT DIGIT or
/SJXST VALUE or MJOOl.E C~AR tN EXT
/STHtP orr HIGH PART or SIXBT CODE

RTR
RAFI

u.s
A'-10

TAO

u~s

RTL
RAL.

LLS

RH.
RAI.
LLS

AND
XOR

/PUT BACK IN AC
/STHJP or HIGH ORDER PART or R£"4AJNING
ISIXBT COO[ ~OR LAST EXT CMAR
/INCREMENT TO MAKE NEW EXT
/REVERSE PROCESS TO r1x uP EXT IN
!PROPEi< SllCBT

6
( 777

<1
6

3
C070707
C6~606eJ

11AC

~.JAME•c

J'1P

_.RITE

/TO CRlATE Nf.W OUT~UT
/wPC fOR HEA'JER woHo 0

MSG2:MSG1/2•1~0e
~

"'1SG2

,ASCtl "FILE ALREADY "
·, ASC 11 "PRESE.NT ! I "<15>
,EJECT

/WPC rcR HEADER WOHD 0

~SG3:MSG2/2•1~00

",ASCII «no YOU WISM TO KEEP IT ?"

MSG3

,'ASCII "CV ORN ANO CR>
C0M-"1SG312•10'1J0
91

COM

11urn:R
"JAME

uosw

,'ASCt I ">"<17!'>)
,BLOCK 11:'

,BLOCK
,S!XAT

, END

13EG Ii~

"ECH0~-001"

>"<175>

Programming Example - Assembly Listing

DAGE

OIC[ClolO

, Tl TLE DIC[Cl-IO

1
2

0i.IH07 A
11l08H6 A

DISK•7
TT 1•6
TT0•5
Jlll•ll
0Uh1

0H005 A

4
5

11l0H!01 A
"2'01/JU A
0HH2 A

?
8
;

Ot<ECl-40

02'1

IOPSs2

00H0 R

R 01!11007 A •G
l111l 2101 R 00011101 A •G
00Hl2 R 00087'1 R •G
?10003 R 0000021 A •G

BEGIN

r.!!l!IH£1

....i

.INl T TTl1lN1RESTRT
CAL.• I N•UH TTU777

R 11100912!6 A •G
:110'305 R 000801 A •G
li'leel06 R 000074 R •G
00007 R 011.1001!11 A •G

R[SHlT•0

,!NIT
no.ouT,RE5TRT
CAL•OUT•1Hf!I TT0'777
R[STi;h0

START

,FST AT OISK,"'AME
CAL +31111'0 OISl<&777

SlA

•·'0'12~,
~l"'i?l21

R 6C!01 '2!3

JMP

"'~~21

R[A'Jl<B
~02005

•G

l'11'2l22 R ~l'!0011 A •G
~ "1210223 l:i •G

~·'-.".'123

•G

:2'n4

777736 A •G

/IS FILE PR£SENT7

2
lllAHE

/AND TELETYPE OUTPUT

A •G
910215 R 0~0002 A •G
["('1016 R 1?~0301 R •G
M•n1 R ?40200 A

/TEL.ET'IPE INPUT,

:"1Hlll 0 q CH!IU!115 A •G
•0Cl'11 q ce00c1 A •G
'."(:·<112 ii ""0e74 R •G

A •G

/INJTULUC DISK OUTPUT,

~0""04

•'!0013 q 0000~0
?01114 q
(·'0014 q 01113007

,JOU[V 5' 6'.,
, l"'llT
OISK,OUT,ltiSTRT
CA&.•OUT•tlHlllJ D!SK&~77
1
R[STRhil

UPDATE

I \olR I TE
TT01lOPS1MSG3,34
CAL+Jl)PS•:l.000 TT0&777
11

"°SGJ

, '.JEC

.,.34

,EJECT

11110, INPUT l<EYSOARO
/YES, OUTPUT MSG1 ANO MSG2
IT'IPE A GO AMEAO SYM90L C>>

Programming Example - Assembly Listing (Cont.)

PAGE

OKECHO r01

OK ECHO
,READ
TTJ,IOPS1BUFFER,34
CAL.•tOFSdllH TTl&777
1"
BUH ER

R 002006 A *G
12'0026 R 000010 A •G
00"'27 R 0fll0237 R •G
•G
0003QJ R 777736 A •G
710el25

~'0"31 R
.~0032 R

18
19

<71
I

20
21
22

200304 R

N!034

7402~0

<:'10J35 R
(~0<'36

600136 R
WRITE

!';

•'0(1136 R :il00£C7

A •C
A •G

iM137 R

"~00e:4

•'t"~4~'

111ei0301 R •G

,OEC

,.34
,WAlT
TTl
CAI. TTU771
12

:ii000e6 A *G
000012 A •G

001!'33

NAM[
,WRITE OJSK1IOPS,BurrER11•
CAL• 1OPSdllH DJSK'777

ree-41 R ti1rl'20rl7 A •C
:"10~42 R 11100011 A •G
r1~il'43 R ee02J7 R •G

BU,F"ER
,DEC
.,34
,WAIT
I:" J SIC
CAI. 0 I SK°'777
12
,CL.OSE r" I SK
CAL. DISt<&717

;1M4r; r<

2/J

2' ~rn c:l 77 A •G
R 0001112 A •G

A •G
.•e1115r ;:i 1iH"001iJ6 A •G
ie;,41

r?~!ll0'17

'.'C('51 R
l~0ii'51

[' ei(~00 7 A

•G

rt\2152 ~ \" "\ll;H" 1 A •G
.'k!r.!5.3 ~ (J~074 R •G
~·00'54

;

22'002'0 A •G

J~PUT

C01o1PL..£TE

/TEST UPDATE SWITCH

II REPLAC[ JNPUT "L!

ld•SAVE JNPUTI C"Eli'E N!:W OUTPT

/C"EATt NEW DISK 'ILE

/OUTPUT DATA ON DISK

:'ri'e!44 R 777736 A •G
~~\"46

uDSW
LAC
Si A
JMP
NEWF'll.
,[NTER OlSK,NAME
+CAL..•1000 OJSK&777

/WAIT UNTIL

•Ci

IJNPUT lOPS ASCII rRoH KEV90ARO

/WA tT UNTii. OUTPUT COMPL£TCD
/CLOSE F'ILC

REAOOT

,tNIT

OISK,IN,RE5TRT
DISt<&777

CAl.•tt.!•1~00

i;;EST>;T•0

,EJlCT

/lNITIALIH DISK INPUT

Programming Example - Assembly Listing (Cont.)

PAGE
27

OKECMO

01<tci;o e2'1

,SEt.K
O!SK1NAMI:
CAI. OlSK&77'1

00055 R ~01H7 A •C
('!00!56 R 00H03 A *G
ll0'1157 R 000301 R •G

NAME

,READ
OlSK,IOPS,eurrcR,34
CAL.• t OFS.11!1H DJSK&777

C"01H>"1 R 002007 A •G

·~21361 R 0H010 A •G
"'""62 R 011!0237 R •G

aur~tR

002163 R 777736 A •G

936

,ore

ei0064 R fllf!IU07 A •tt

·~11!065

R ~~0"12

!'10066 R 002005 A •G
00067 R 00e011 A •G
(l!IJ0?e' R 00el237 R •G

, WR l TE tTo,10Ps,eurrcR,34
CAt.•tOPS.lHI TT0&77?

/OUTPUT TO T£LETYP[

BUVf"EA
,OE~

.,;H

A •G
a0n3 R 000012 A •G

CAI. TT0&177
12

00n4 q

GllJ2!?4 R eue05 A •G
le'"'75 R 000006 A •G
'J0'l76 q 0002'06 A •G
viefl.77 R 0;,0;;,~6 A •c;

35
11eH"•.· R e'l"L'~e'7
1'11'1"1 R 0017<'26
<l~102

R 6e"U;02'

•G

A •G
~

TTO

/WAIT UNTIL OUTPUT COMPLETE

,ci..ost TTO
CAL. TT0&717

/T[RMlNAT[ TEL.£TVP£ OUTPUTt

,WAIT

~llJ011JiC5

/WAIT UNTIL READ COMPLETE

•G
~Hll"71 R 777736 A •G
.~€Vl72

,WAIT
DlSK
CAI. CISK&717

12__

A •G

/Rt AC INTO eunu

•G

IL.0CATE FILE "NAME"

RESTRT

,CL,OSE TT I
CAL TTl&777
6
,CL,DS( DJSK
CAI. DlSK&777
6
J~P

,EJl:.CT

A[GlN

ITEL.ETVPE INPUT,
/ANO DISK INPUT/OUTPUT
/LOOP roR UPOATE OPTiOI'¥

Proqramminq EXample - Assembly Listinq (Cont.}

CIAGE
37

Ol<EC~ci

f.110103 R
~01'1.1.J

~01

QK[CMO

~02H5

A •G

UPDATE

0011!4 R 121H011

14SG1

R 777736 A •G

•34

,occ

•c

,WAIT
HO
CAL TT0&771
12
,WRITE tT0,10PS1HIG2,34
CAL• t OPS.UH TT0&777
11

00107 q e 00 1110 5 A •c
Cli1110 R "H012 A •G

00111 R 121e2005 A •G
00112 R 011!0011 A •G
ib0113 R fl!0e177 R •G

',.•·
0

llrz'114

41
•2

~~0122

/ON

,DEC
.. 3 ..

,WAIT
TTO
CAL. TT0&777

,READ
TTI I JCPS1COH,8
CAL• t OPS•UIH TTU777

0r.2et06 A •G

ei0~011il A •G
'H.'!1'11227 R •G
•G
q 777770 A •G

/TELETYPE
/READ RESPONSE

COH
,CEC

,iicAIT

44
45

::'10123 R' 001iHl06 A •G
('10124 R trneu2 A •G
'11'.1125 q 21'.112'231 R
r0126 P '5l"l?3<5 R

•6

r~121

~4V!l3.:'6

SAD

47
48

.'013::"

6:2'~133

Jl'IP

~e131

R 1411'3l4

49
50

C'l'132

6~en1

~lH
J~P

~~"13J

1seu1 A

/ANO MSG2

'1SG~

•G
R 777736 A •G

00115 R 00HllJ5 A •G
:.'!0116 q 0Ht/J12 A •G
~0117
~U2i7
~0121

/OUTPUT MSC1

0111105 =I 0H163 R •G
0~106

A •C

,wRITE TTO,tOPS1"4SG1,J4
CAL•tOPSe1000 TT0&777

TTt

IWAJT UNTIL READ C0"4PLCT£

CAL TTl&777

YES

L.AC

COM+2

•~~o

177401110
15440210

Cl.C
E.Jl:.CT

YES
IJOSW
i:iEAOl(B

/GET FIRST WORO
/SAVE 'IRST SEVEN SITS
/IS CMAR A Y'f
/NO, SET TO REPLACE iNPUT rlLE
/LOOP TO RE40 KEYBOARD
/SET UPOA TE SW 1 TC SAVE

Programming Example - Assembly Listing (Cont.)

PAGE
51
52
53
!54
55
!56
'5 7
58
59
60
61
62
63

Ol<ECMO

OK(C:"40 Y.'01

00134 R 040334 R
::10135 ~ 6 02' 2121 R
0e'136 ~ 2Z0303 R
00137 R 64121503 A

OAC
JMP
NEWF"tl.

RTR
RAR

(ll!U40 R 742020 A
11l0141 R 740iil20 A
PJC142 R 640503 A

I.RS

00143 R 742020 A
Nl144 R 740020 /I.
00145 R 640636 A
00146 R 500307 R

RAR
1.1.s
ANO

00147 R 3403Ul R
00150 R 640506 A

«1

I.RS

..
Cl'I

....

ei0151 R 742011!! A
i"0152 R 740i'll0 A
0111153 R 640603 A
2H'll154 R 742010 /I.
J0155 R 74001i!I A
~0156 R 640603 A

~0157

.,.,
69

71
72
75
76
71
'18

79
80

f 777

L.l.S

RTL
RAI.
L.L.S

AfllD
XOR
OAC
JMP
'ISC1

(070787
(606~60

NAME•2
WRJTt

'ISG2•MSCil~•1000

c
I

ASCII ""1L.E ALREADY "

ASCJI "PRESENT 11 11 <15>

;~1"17 ':: R 2426~2 A
r0171 R 422624 A

C0172
81

ere1rnei A

'.~0173
~11l174

R 502470 A
~ 551612 A

·~11J175

~10176

4125?4 A

r.; 1U432

/l'UT BACK IN AC
/STRJP or HIGH ORDER PART or REHAIN
/SlXBT coor ,OR LAST [XT CHAR
/INCREMENT TO HAKE NEW [XT
/REVERSE PROCESS TO r1x UP EXT lN
/PROPER SIXBT

RTI,.
RAI.

R 5ZZ311 R
;il016Cl R 2403t2 R

t'l0161 R ~403~3 R
130162
R 6'HH~36 R
"'1!1163 R 006000 /I.
R ?0'1000 A
"'" 16 4 R 432231 A
~0165
110166 R 44250~ A
::1"167 ~ 4e6312 A

/INPUT, CREATE N(W OUT~UT
/LOOP TO R£AO KEYBOARD
/CMANCE EXT
/1.[4ST SJGNlrJCANT DIGIT or
/SJXBT VAl,.UE or I.AST C~AR IN EXT
/STRIP orr HIGM PART or CODE
/l.t4ST SIGNtrJCANT DIGIT or
/SJXBT VALUE O' "JDDLE CMAR IN EXT
/STRIP orr HIGM PART or SlXBT COO[

RTR

6 !5
66
67
68

LAC
L.RS

uosw

;;iE:AOKB
1,;AM[•2
3

/TO CREATE NEW OUTPUT
/~PC roR HEADER WORO •

Programming ·Example - Assembly Listing (Cont.)

PAGE
83
84
8 !5

86
tn
.1

.c.
N

87
88
89

90
91

OKECMO ., i:'\ 1
:~e1

Ol<ECMO

n R eincrz A

1iH!l20t> R e0000~
Vlri'.12~1 R 422364
054636
00202
00203 R 525012
00204 R 744646
111~205 R 441012
.!!0206 R 447500
l~0207 R 456130
21021e R 550100
ei0211 R 446504
00212 R 031400
00213 R 242624
00214 R 047644
"'0215 R 202344
e121216 R ~40634
"10217 R 421010
!"02U R 351122
'110221 R 21111037
~~0222 R 676400
>H''.1223 ;:; e'020~2!

MSC2

MSGJ•MSG212•,rzei

UC l l "DO YOU wrsH TO 1<£EP

,..

A
A
A
A
A
A

A
A
A
A
A
A
A
A
A
A
A

R 2~0000 A
1"0225 R 373720 A
•1'1'226 ;.; ;:"'1'0000 A
A
l'J0227 R
A
'~0237 R
00301 R e50310 A

,UCll "IY OR N lf~D CR>

MSG3

C0M"'t-iSG312•1fH
0

:~k'224

,ASCII ">"<175)
COM
8Uf'F'ER
r..JAl1E

,Bl,.OCK
,BL,OCK
,SJXBT

uosw

R 1702100 A
;;•'11303 R 6'1'6061 A
~0304 R ~212'000 A
02'001',0 R
:.:ieJl1'5 ~ 774/,00 A *L
"'"'306 ~ 544030 A *L
t.' k: 30 7 ;;; 0~0777 A •L
c1e'31" ~ er>'0e-1 A *L
,10311 R ne1n A •L
"~312 R 61"6i60 A *L
NO
SI ?E•e'l1!313

10
42
••ECMC•ll01Z'1"

~C302

lioiPC

,ENO

[RROR LINES

R[Glill

)"(179>

;oR MEADER wORO ~

Program Example - Assembly Listing (Cont.)

PAGE
BEGIN
9UH'ER

eOM

36
23

12!11J221

911•

9
29

e7
12
JS
26

9•

2•
28

J r-J
JOPS

0011000
Hll!ll2
l'l0163

5•
7•

~SG3
I

0Hiltl
1110237

0e!0007

M$G2

DKECMO CROSS RtrERCNC[

')lSK

'45Gl
en

\&~E

110171
e0223
30301

~0136
''[WF'JL
'lUT
000001
q[AQDT
00es1
Q[AOt<B
021021

Q(STIH

1'121074

SHIH

TTJ

0!2'11l14
"111!0006

TTCl

2'2111'1'!05

37
41:
15

••

87
53

92e

33•

43
31

.58

cfil

15
18•

78
83

83•
ah

22
53•

6•
26•

15•

12
21

12•
3•
4•

93•

41
Ui:>Sw
JPIHTE
"''llH

YES

?r'l~~

19
14

~0036

22•

48
37•
77

~"'13~

50•

~0304

91•

42
33

6.8.6

File Integrity Considerations

In a system such as DOS-15, which offers a flexible I/O command repertoire, I/O programming requires care ••• otherwise, numerous IOPS errors
may result. Further, there are I/O sequences which the system allows •••
which, if carelessly used, can result in the destruction of the user's
files or those of others. The paragraphs below describe some important
considerations.
a.

Extreme care must be exercised when using the .TRAN macro to
output to the DECdisk, Disk Pack, DECtape or Magtape. The user
must know the disk and. DECtape file ~tructures completely, because .TRAN operates completely outs~d~ these file structures,
and ignores the existence of all directories and bit maps. The
entire contents of the disk or :DECtape or Magtape, tl:lerefore,
are vulnerable to the use:i:: of .TRAN.

Caution should be used when rea6ing a file from the disk sequentially (.READ) from one DAT slo~, while modifying the
same file via another .DAT slotusinq random access ( .RTRAN).

Generally speaking, output files are not recognized by the
system until they are .CLOSEd. Under most circumstances,
termination of program control and return to the Monitor
will cause the Monitor to delete any unclosed output files.
Occasionally, a system crash or other unusual phenomenon
will cause a disk output file t~ be truncated. Truncated
files are the remains of output files that the system did
not get a chance to deiete. Directory listings from PIP
that contain an asterisk l*l after a file name indicate a
truncated file. They take up disk space and should be
deleted via commands to PIP.
1

6-44

CHAPTER·7

SYSTEM INITIALIZATION
7.1

INTRODUCTION

This chapter describes the procedur•s to be followed when loading,
sta~ting, and tailoring the DOS-15 $oftware System. Under normal circumstances, these procedures shouldjrarely need to be used. Occasionally, however, a program may enter *runaway condition which could result in the inadvertent destructionjof a part of the DOS-15 software
residing on the system device or in: core. In addition, it may be necessary to change the DOS-15 software tonfiguration from time to time to
permit the use of a new 1/0 device or system program. These alterations
to the system are Only permitted to: be performed by those who have
access to the system's Monitor Identification Code (MIC). Thus, the
average user need not be concerned with the contents of this chapter
except as regards the loading and use of the DOS-15 Bootstrap (Paraqraph 7.3.2).
'
Chapter 10 contains the operating ptocedures
to be used once the system
is loaded and running.

7.2

HOW THE SYSTEM SOFTWARE IS SUPrLIED

The DOS-15 Monitor and System Prog~ams are supplied to users on
either DECtape or Magtape, depending upon the particular hardware configuration. The software system r~sides on the DECtape or Magtape
medium in a special form which is cleaningful only to those programs
which can transfer the system to thie disk. Thus, these tapes are often
called "disk restore tapes" as the~ may only be used for this purpose.
The DOS-15 Software System occupies· two reels of DECtape or one 7- or
9-track reel of Magtape which are i dentified as follows 1 :
1

DECtape
Tape U
Tape #2
Mag tape

RF Disk

RP Disk

DEC-15-MKDA-UC
DEC-15-MKDA-UC
DEC-15-MPMA-M7
(7 channel)
DEC-15-MPMA-M9
(9-channel)

DEC-15-MI<AA-UC
DEC-15-MKAA-UC
DEC-15-MPZA-M7
(7-channel)
DEC-15-MPZA-M9
(9-channel)

1 An additional DECtape (DEC-15-FFDA-UB) or Magtape (DEC-15-FFDA-M7, 7channel; DEC-15-FFDA-M9, 9-channel) is required for systems with the
optional FP-15 Floating Point Processor. The installation and loading
of software contained on these tapes is described in the SGEN-DOS Manual
(DEC-15-YWZB-DN12).

J-l

TWO paper tape programs are- also-p~i~a- eo assist the user 1-n loading and starting the DOS-15 system;:namely the Disk Save/Restore program DOSSAV (DEC-15-YIDA-PB) and DOS-15 Bootstrap (RFBOOT - RF15
Multicore Bootstrap, DEC-15-LWDA-PHJ RPBOOT - RP~2 Multicore Bootstrap,
DEC-15-LWAA-PH).
7.3

SYSTEM STARTUP PROCEDURES

The following paragraphs describe t~e procedure for loading and starting the DOS-15 Software System usin' the DOSSAV and DOS-15 Bootstrap
!
programs.
7.3.l

Disk Restoration {DOSSAV

The DOS-15 Software-System is transferred from the Disk Restore DECtapes or Magtapes supplied by Digital Equipment Corporation to the
appropriate disk device using the DOSSAV utility program. This program
provides users with the ability to ~ave and subsequently restore all
occupied blocks on the disk using either DECtape, Magtape, DECdisk, or
Disk Packs as the storage medium. though the program is most often
used to install the DOS-15 System, lt can also make additional copies
of the system currently on the disk• of a newly tailored system (i.e.,
after System Ge.nerati.on), ___oi:__of tbe~ntents _Qf_J~isk l'a__ok units l - 7
{in the case of multiple Disk Pack ~ystems).
DOSSAV operates interactively via tlte console teleprinter and asks the
user a series of questions to detexliine which devices and unit numbers
are to be used and, for Magtape, pafity, density and track count information. When all necessary infot:m.&tion has been obtained, DOSSAV
automatically begins the specified bperation. If a save or restore
operation requires more than one tape, the program stops and outputs
a message on the teleprinter to that effect. The user can then mount
I

--.i~:f-:..:µ'3lna.n p-:;_z .. G~rno

U4ZO..,

vuccn:"'u"31

detect both hardware and cnmmi'tnt'I <1rri nn prrnr" ;>nil n11 i-n11 t- <>
messages on the teleprinter.

,.,...,... .. ,.,,..,,..; "+-~

In addition, the program permits DECdisk users to restore systems
created in a small DECdisk configuration to an environment with a
larger DECdisk configuration. The reverse situation, however, is not
possible. The DOS-15 Disk Restore tapes supplied by Digital for a
one-platter system configuration, therefore, can be restored to any size
DECdisk system configuration 1 • DOS~AV is a stand-alone program supplied
1 This type of operation ahouid only' be done with master tapes (or copies
of them) since block 1775 8 must not be occupied when performing a restoration to a system with 5 or more platters.

i:n paper tape form {identification ·ntiJnber-DEC-15-YIDA-PB) and is loaded
via the high speed paper tape reader using the PDP-15's Hardware Readin
Mode {load address - 3772,, restart address 345~~).
7.3.l.l Operating Procedures - The following procedures should be
used when restoring or saving the DOS-15 System Software (or other usercreated data on Disk Pack units 1-7):
a.

Place the DOSSAV paper tape in the Paper Tape Reader.

Set the console ADDRESS switches to 37720.

To restore the disk:
ll

Mount the DOS-15 Disk Restore DECtape or Magtape
for the appropriate hai::dware configuration (i.e.,
DECdisk, Disk Pack, Floating Point or non-Floating
Point hai::dware) on the applicable tape drive.

Set the DECtape drive:WRITE ENABLE/LOCK switches
to LOCK.
{Magtape us~rs should remove the Write
Enable ring from the ~ape reel.)

Set the disk READ/WRI~E PROTECT switches to ENABLE.

To save the contents of the disk:
ll

Mount a fresh tape on:the appropriate tape drive.

Set the DECtape WRITE ENABLE/LOCK switch to ENABLE.
{Magtape users should install the Write Enable ring
on the tape reeL )

Set the tape drive unit number switches as desired. Set
the Disk Pack unit number switches as desired (DOS-15
Disk Pack Systems must be restored to unit~).

Set all ON LINE/OFF LINE switches of the devices being
used to ON LINE.

Press the Console Switches STOP and RESET simultaneously,
then press the READIN switch. {The DOSSAV tape should
pass through the reader.)

7.3.1.2 Commands - Once the paper tape has been read in, DOSSAV will
identify itself on the teleprinter and begin to ask the user a series
of questions about the devices to be used, as shown in Table 7-1.
Each user response must be terminated by a Carriage RETURN. It should

7-3

also be noted that-some- .of. the.-ques.ticiiiii -Sh.Ow:ri are ty!;)ed .out -0n1y
when applicable (i.e., no questions are asked about Disk Pack unit
numbers or ~agtape parity, density, or number of channels if these
devices are not to be used).

Legal input and output device combina-

tions are shown in Table 7-2.

Tablel 7-1
DOSSAV Commands
Query

User Responses

INPUT DEVICE?

DT = DECtapb, MT = Magtape, DK = DECdisk,
DP = Disk Pitek

UNIT NO?

Legal unit humbers are 0 - 7

TRACK (7 OR 9)?

Magtape track or channel number.
(If 9 is
specified, density is assumed to be 800 BPI.)

DENSITY (2,5,8)?

Magtape recprding density: 2=200 Bits Per
Inch (BPI),: 5=556 BPI, 8=800 BPI.

PARITY (E OR 0)?

Mag tape parity scheme: E = even parity,
O = odd parity.

OUTPUT DEVICE?

(See INPUT DEVICE above.}

UNIT NO?

(See UNIT NO. above.)

;

TRACK (7 OR 9) ?.

_ (See TRACK above.)

DENSITY (2,5,8)?

(See DENSITY above.)

PARITY (E ORO)?

(See PARITY above.)

DATE CREATED:

The date that the restore tape was created
is typed out by DOSSAV.
Table 7-2
Legal DOSSAV I/O Device Combinations

DECdisk

Disk
Pack

DECtape

Magtape 1

(DK}

(DP)

(DT)

(MT)

Illegal

Mag tape (MT)

Illegal

DECdisk (DK)

Illegal
OK

OK
Illegal

Disk Pack (DP)

OK
Illegal 2

DECtape (DT)

Illegal

1 All DOS-15 System Restore Magtapes distributed by DEC are 800 bpi, Odd
Parity.
2 Use PIP Utility program with no switch options for this operation
(refer to DEC-15-YWZB-DN13}.

7-4

Once the last- question has been answered,- DOSSAV proceeds with the
specified operation. If additional tapes are required to complete
tne restore or save operation, the·following message is output:
TAPE DONE.

MOUNT ANOTHER

At this point, the user should eitlper mount a fresh tape, if a save
operation is being performed, or mdunt the next tape in the sequence
established at tape creation, if a:restore operation. Then type any
character followed by a Carriaqe R.TURN to proceed with the operation.
When the requested operation is en~irely complete, DOSSAV restarts
and identifies itself as before:
DOSSAV Vnn
INPUT DEVICE?
At this point the current restore or save operation is complete. If
the DOS-15 Software was being restored, it is now ready to be started
as specified in 7.3.2. If other DOSSAV operations are desired, the
user should proceed again as specified in 7. 3 .1.1.
7.3.1.3 Examples of DOSSAV Commands - The following examples illustrate
typical DOSSAV commands when restoring and saving the DOS-15 Software
System. User responses are underlined.
loisk Restoration!
ll

Restore DECdisk system fr~m DECtape unit 1:

DOSSAV V3A
I NPUT DEVI Ct? JU _
UNIT I? J..
OUTPUT DEVICE? DK

DATE CREATEDt TT-oct-71

TAPE DONE. ~OUNT ANOTHER!

DOSSAV V3A

INPUT DEVICE?

7-5

(The user mounted the next tape,
then typed a G) to continue.)
(Operation complete DOSSAV
restarts.)

Restore DECdisR. system from Mag tape unit 0:

DOSSAV V3A
INPUT DEVI CE? MT
UNIT I? e
TRACKC7 OR 9)? 7
DENSITY <2,5,8>7 ~
PARITY CE OR 0)? 0
OUTPUT DEVICE? .rurDATE CREATED:l2 NOV 71

(Operation complete)

DOSSAV V3A
INPUT DEVICE:?
3)

(All DOS-15 System Disk Restore
magtapes are 800 BPI, Odd Parity.)

Restore Disk Pack System ~rom DECtape unit 1:

DOSSAV V3A
INPUT DEVICE? DT
UNIT #7 I
~
OUTPUT D!°VICE? DP
UNIT I? ..l
DATE CREATED 12•NOV-71
TAPE DONE, MOUNT ANOTHER

(The user mounted the next
tape, then typed a P) to continue.)
(Operation complete.)

DOSSAV V3A
INPUT DEVICE'2
41

Restore Disk Pack system ~rom Magtape unit 1:

DOSSAV V3A
INPUT DEVICE? MT
UNIT I? 1

TRACK<? OR 9>? 1
DENSITY <2,5,8)? J.
PARITY CE M O>? 0
OUTPUT DEVICE? DPUNIT 17

DATE CREATED: 12•NOV-71
DOSSAV V3A
INPUT DEVICE?

(Operation complete.)

(saving the Contents of the Disk!
The single example below should suffice in illustrating this type of
operation, since save operations are simply the reverse of restore
operations.

DOSSAV V3A
INPUT DEVI CE? !UL
OUTPUT DEVICE? DT
UNIT#? I
~
TAPE DONE. ~OUNT ANOTHER
A
DOSSAV V3A
INPUT DEVICE?

(DOSSAV allows for as many
DECtapes or Magtapes as are
necessary to contain the entire contents of the specified disk.)
(Operation complete.)

7.l.1.4
Error Messages and Meanin~s - DOSSAV attempts to detect all
Reyboard and run-time errors and t~ recover if possible. The three
types of errors which can occur ar~ shown below along with their
meaning and recove~ procedures wh'n applicable.

Comnand StriI!l Errors - These errors occur when a
question is answered inco~rectly. DOSSAV r~peats
the question.
Message

Meaning

ILLEGAL DEVICE

Either an illegal device mnemonic (one
other than DT, MT, DK, or DP) or an illegal ··combination of devices (DT for
input and MT for output) was typed.

BAD TRACK

A track number other than 7 or 9 was
typed.

BAD DENSITY

A density ¢ther than 2(200 BPI), 5(556
BPI) or 8(800 BPI) was typed.

BAD PARITY

A parity other than E (even) or 0 (odd)
was typed.

Recoverable Operating Errors - These errors occur when
one of the I/O devices is not properly set up. When
the condition has been corrected, operation can be resumed by typing any character followed by a Carriage
RETURN.
Message

Meaning

TAPE NOT READY

The DECtape or Magtape unf t is not
switched to ON LINE, is not set to
WRITE ENABLE, or is not set to the
unit number specified in the UNIT
NO? question.

DISK NOT READY

The DECdisk is not set to WRITE ENABLE.

DISK PACK NOT
READY

The Disk Pack unit is not switched to
ON LINE, is not set to WRITE ENABLE or
is not set to the unit number specified
in the UNIT NO? question.
1-1

Unrecoverable Errors - E~rors associated with these
messages are primarily ha~dware errors from which
DOSSAV cannot recover. A~ter the message is typed,
DOSSAV restarts itself.
Meaning

Message

DECTAPE ERROR
MAGTAPE ERROR
DECDISK ERROR
DISK PACK ERROR

}

H~rdware error detected

ATTEMPT TO RESTORE SYSTEM
TO WRONG DISK

Tne user tried to restore a
DECdisk system using a Disk
Pack restore tape or vice
versa.

BLK 1775 OCCUPIED. NO
2ND SAT CREATED.

The user did not use a master
restore tape (i.e., block 1775
occupied) when restoring a system created for 4 or fewer
platters to a system having 5
or more platters.

7.3.1.5 Restart Procedures - The testart procedures below should be
used either to terminate prematurefy the current operation or to reinitialize DOSSAV if it fails to start up automatically after an error.
a.
b.
c.

Press "the Console Switches STOP and RESET simultaneously.
Set the ADDRESS switches to 34500.
Press the START Console Switch.

DOSSAV should then identify itself as when originally loaded, otherwise it must be reloaded as described in Paragraph 7.3.l.1.
7.3.2

Loading and Starting the Monitor

The DOS-15 Monitor is loaded into core from either the DECdisk or Disk
Pack and is automatically started with the DOS-15 Bootstrap Loader
program. Once loaded, the bootstrap remains in the upper 1419 locations
of the core bank into which it was loaded during all normal system
operation. The bootstrap not only aids in initializing the Monitor,
but also acts as an integral part of the Monitor as it operates. It
is supplied on paper tape in two versions. One version, RFBOOT,
(identified as DEC-15-LWDA-PH) is for use with DECdisk systems, and
the other version,RPBOOT, (identified as DEC-15-LWAA-PH) is for use
with Disk Pack Systems.
7-R

Each time that the DOS•l5 System·--software is restored using DOSSAV,
the bootstrap must be loaded into qore. Occasionally, a runaway program or hardware malfunction may cause the destruction of the Monitor
as it resides in core, and prevent !the user from restarting it by
keyboard conmand. In this circwnstance, it is often possible to restart the bootstrap (unless it, too, has been destroyed) and avoid
reloading the bootstrap. The paragraphs which follow describe the
initial loading and restart procedures for the DOS-15 Bootstrap
Loader.
7.3.2.l

Loading the Bootstrap ·

Select the appropriate version of the bootstrap (either
DECdisk or Disk Pack) and place it in the paper tape
reader.

Set the console ADDRESS s~itches to one of the addresses
shown below in accordance with the maximwn core size
of the system.

Address

!Maximum Core Size

37637
57637
1163--1--

16K or 20K
24K or 28K
-32K

Press the console switche$ STOP and RESET~ then press
READIN.

Once the bootstrap is loaded, it starts automatically and loads the
Monitor from the disk. When loaditlg is complete, the Monitor gets
control and identifies itself on t~e console teleprinter as follows:
DOS-15 Vnn
ENTER DATE MM/DD/YY
The system is now loaded and operabte and is ready to accept the keyboard commands (Chapter 8) in accor ance with the operating procedures
described in Chapter 10. Users wit new systems, that is, systems
which have not previously been tail~red, should refer to Paragraph
7.4.2.
7.3.2.2 Bootstrap Restart Procedures - As mentioned above, situations
occasionally arise in which the Monitor must be reloaded by the bootstrap. If the bootstrap is intact! in core, it may be restarted by
the procedures which follow.

7!-9

7.4

Set ·the console ADDRESS swU-:ches to· one of the addresses shown below in acqordance with the maximum
core size ofthe system.
Address

Maximum Core Size

37646
57646
77646

16K or 20K
24K or 28K
32K

Press the console switches STOP and RESET: then
press START.

The Monitor should then identify itself as shown
in 7 .3. 2 .1.

If the Monitor does not identify itself, the bootstrap has been destroyed and must be reloaded as described in 7.3.2.1.
I

SYSTEM MODIFICATION (TAILORING) fROCEDURES

The software package supplied to e•ch user is a qeneral purpose version of the DOS-15 Software Systemi This means that the system contains all of the standard DOS-15 1 nguaqe programs, utility programs,
I
library routines, and I/O device h•ndlinq routines supported by
Digital Equipment Corporation. In~luded as a part of this general
package is a utility prC>grmn-caiief the- syst~ Generator (or SGEN).
SGEN enables the user to tailor thelDOS-15 software to suit the
particular hardware configuration and operating requirements of his
installation.
Specifically, SGEN provides the user with the ability to: (1) delete
system programs or add his own 1 : (2) add and delete I/O device handlers; (3} add and delete system library routines: (4) alter system
load-time parameters ~uch as: I/O device assignments, teleprinter
model currently being used, availability of an extra memory page,
number of buffers to be allocated, file and directory protection
codes, etc.; (5) change system operating parameters including: the
Priority Interrupt Skip Chain, number of positive .DAT slots, the
presence of 7- or 9-channel Magtape drives, the Monitor Identification
Code (MIC).

in the DOS-15 pystem Manual (DEC-15-NRDA-D) and
the System Generator Utility Program Manual (DEC-15-YWZB-DN12).
1 Described

7.-10

CHAPTER 8
KEYBOARD COMMANDS
8.1

INTRODUCTION

This chapter describes the commands which can be issued from the console keyboard to direct the operations of the DOS-15 system software.
In conununicating with the Monitor, the keyboard of the console teleprinter is used as the system's control device. The operator at the
keyboard types commands to allocate system resources, load and start
system and user-created programs, terminate program operation, and exchange information ~ith the Monitor. Most of the Monitor's keyboard
commands are issued prior to loading system or user programs and are
interpreted by the Nonresident Monitor.
During program execution, a small set of keyboard commands is available for general program control. These commands are interpreted by
the teleprinter's I/O device handler (which is part of the Resident
Monitor), and are used to control program start and restart, dumping
of core, and the reloading of the NOnresident Monitor. Paragraph 8.11
describes commands used during program execution.
The console teleprinteristhe communications interface between the
user-operator and the Monitor. The interaction between the operator
and the Nonresident Monitor is completely conversational. Each command issued causes the Monitor to type out an appropriate reply.
Monitor responses may vary from a single character to several pages
of information.
In the context of this manual, the term "console keyboard" designates
any one of several keyboard/printer/display I/O devices which could be
used by the Monitor as the system command console device.
(That is,
it is associated with .DAT slots -2 and -3). Generally, a Model 33
or 35 teleprinter is used.
The keyboard comnands are, however, not strictly limited to input from
the keyboard. The Monitor can be operated in a Command Batching Mode
(see 8.12) in which keyboard commands can be issued from either punched
cards or paper tape with minimum operator intervention. Similarly,
the Monitor's responses to commands are not strictly limited to a keyboard device's printer or display, but may also be output to other
devices including the VT15 Display or a line printer, when available.
8-1

KEYBOARD COMMAND FORMATS AND CHARACTERS

H.1

8.2.1

Keyboard Command Elements

All keyboard commands, except those using the keyboard CTRL key, consist
of at least two elements, a command name and a terminator.

Some com-

mands require an additional third element consisting of one or more
arguments inserted between the command name and the terminator.

Each

command name is separated from its argwnent (or argument string) by one
or more spaces.

Delimiters between multiple arguments vary, and are

specified in the dest:riptions for the individual conunands.

Except as

otherwise specified, each conunand string can be terminated by either a
Carriage RETURN or an ALT MODE.

CTRL commands are formed by simultane-

ously depressing the keyboard's CTRL key and letter key, and are interpreted by the ~esident Monitor.

These commands need no terminators,

such as Carriage RETURN or ALT ~ODE.
after they have been typed.

They are interpreted immediately

Once typed, the command is echoed in the

form of an up-arrow (t) followed by the letter which identifies the command.

Thus, CTRL c is echoed

+c.

The symbols defined in the introduction to Chapter 5 are used in illus•
trating the command formats described in the succeeding paragraphs of
this chapter.

DOS-15 system programs accept ASC1I characters shown in

Appendix A.
8.2.2

Editing Features

The teleprinter's device handler provides two keyboard editing functions
which can be used to change the line currently being typed (prior to
typing Carriage RETURN or ALT ~ODE}.
RUBOUT

The RUBOUT key permits successive deletion of characters,
st~rting with the last character typed.
Each RUBOUT
deletes one char'icter and causes a backslash (\} to be
echoed in response. RUBOUT does not delete characters
past the previous line terminator. Once all characters
in a line have been deleted, additional RUBOUTs are
ignored. For example, if the command INSTRUCT were mistyped as INSTRUTC, it could be corrected by typing two
RUBOUTs followed by CT, as shown below:
Example:
$INSTRUTC \\CT

C'l'RL U

Formed by depressing the CTRL key and striking the u key,
this command during input eliminates all characters typed
up to the last Carriage RETURN or ALT MODE and echoes
a @.
Thus an irretrievably bollixed input line may be
eliminated (before typing Carriage RETURN or ALT MODE)
by typing CTRL u. This feature can also be used during
output to abort the current line.

8-2

8.2.3

When to Issue Keyboard Conunands

All keyboard commands, except for the CTRL conunands (see 8.11) are
only recognized and accepted when the Nonresident Monitor is in core,
as evidenced by the appearance of either of the following identifiers
on the teleprinter:
DOS-15 Vnn

where:

vnn

version nwnber

or
$

The operator can obtain the Nonresident Monitor by typing CTRL C, (described in 8.11.1). When the Monitor is initialized using the Bootstrap, or by typing CTRL C, the full identification is typed. At all
other times it indicates its readiness to accept keyboard conunands by
simply typing the dollar sign ($) • Once the $ is typed, the Monitor
idles until the operator types a conunand.
8.3

COMMANDS TO REQUEST SYSTEM INFORMATION

The conunands in this paragraph provide the user with various lists
of system information. The lists include:
(1) general system information, (2) keyboard commands, (3) error messages, and (4) .DAT
slot assignments. Since these lists tendto be lengthy, users who
have either a line printer or a VT-15 Display can speed up the output
of this information by using the special line printer and VT-15 commands (described in paragraphs 8.9 and 8.8, respectively).
8.3.1

SCOM

The SCOM command causes the typeout of DOS-15 system information.
The information includes (l) available I/O device handlers, (2) system default parameters, (3) important core addresses, and (4) the
Priority Interrupt Skip Chain order.
Form:

S[COM])

8-3

Example:

SY~TEM

INFO - DOS-15 -

11/02/71

77646 - BOOTSTRAP RESTART ADDR
77636 - IST FJ?EE CELL BEL.OW BOOTSTRAP

2722- ADDP OF .DAT

2760- ADDP OF .UFD

20 - NO. OF POS •• DAT SLOTS
SYSTEM HAS API
SYSTEM HAS FAE
PAGE MODE OPERATION
7 CHANNEL MAGTAPE.ASSUMED BY HANDLERS
80-CHARACTER LINE PRINTER ASSUMED BY HANDLERS
2 - DEFAULT FILE PROTECTION CODE
03 - DEFAULT BUFFS SETTING
1274- 1'Q ADDRESS FOP. MANUAL DUMP
l/J HANDLERS AVAILABLE
TTA
TELETYPE: IIO, ASCII MODES, ALL FUNCTIONS
PR A TAPE READER: INPUT, ALL MODES, ALL FUNCTIONS
PPB
TAPE READER: INPUT, IOPS ASCII MODE, ALL FUNCTIONS
PPA
l'UNCH1 OUTPUT, ALL MODES, ALL FUNCTIONS
PPB
PUNCH: OUTPUT,ALL MODES LESS IOPS ASCII, ALL FUNCTIONS
PPC
PUNCH1 OUTPUT, IOPS BINARY MODE, ALL FUNCTIONS
DTA
DECTAPE: 3 FILES, 110, ALL MODES, ALL FUNCTIONS
OTC
DECTAPE: I FILE, INPUT, IOPS MODES, LIM FUNCTIONS
DTD
DECTAPE: I FIU:, 110, ALL MODES, ALL FUNCTIONS
DTE
DECTAPE: I FILE, I/O, ALL PIODES, NO .MTAPE
DTF
DECTAPE: NON-FILE ORIENTED FOR F4 .ors
DKA
DECDISK1 N FILES, IIO, ALL MODES, ALL FUNCTIONS
mrn DECDISK: N FILES, 110, ALL MODES, LIM FUNCTIONS
DKC
DECDISK: N FILES, INPUT, ALL MODES, LIM FUNCTIONS
DPA
DISKPACK: N FILES, IIO, ALL MODES, ALL FUNCTIONS
DPB
DISKPACK: N FILES, 110, ALL MODES, LIM FUNCTIONS
DPC
DISKPACK: H FILES, INPUT, ALL MODES, LIM FUNCTIONS
LPA
LINE T'rtINTER: OUTPUT, ASCII MODES, ALL FUNCTIONS
CDB
CARD READER: INPUT, IOPS ASCII_ MO_DE, Al,.L _FU~CTJON_S
VTA
VT-15: I/O
LKA
LK-35 KEYf.OARD: INPUT, ASCII MODES, ALL FUNCTIONS
SKIP CHAIN ORDER
SPFAL
DTDF
DSSF
VPSJ
SPDI
WTSK
RCSF
RCSD

CLSF
LSDF
RSF
PSF
KSF
SPKF
TSF
DTU
DPSE
MPS NE
MPSK
SPE

8-4

8.3.2

INSTRUCT

The INSTRUCT command causes a typeout of either the keyboard commands
or system errors, depending upon which form of the command is used.
Form 1:

I[NSTRUCT))

Example:

nos-is coMMANns:

LOGCL>: USEP COMMENTS TERMINATED RY ALTMODE
LOGW: U~F.R COMMENTS TERMINATED IW ALTMODF, WAIT F'OR tP TO CONTINUE
DATF.CD>: ECHO DATF.
DATECD> i"tl/DD/YY: ENTER DATE
TIME<T>: ECHO TIME
TIMECT) HHMM: ENTER TIMF.
PPOTF.CTCP> N: CHANGE DEFAULT PROTECTION CODE TO N
KF.F.PCK> ON/OFF': KEEP .DAT SLOTS UNALTERED ON .F.XIT
LOGIN UIC: DEFINE NEW CURRENT UIC
LOGOUT: SIGN OFF UIC
ROSSl5: ENTER ROSSIS RATCH MODF.
SCOMCS): SYSTEM INFO
INSTRUCT<!>: LIST OF MONITOR COMMANDS
INSTRUCT<!> ~RORS: DESCRIPTION OF ERROR CODES
REQUESTCR>, REQUESTCR> PRGNAM: .DAT SLOT USAGE
REQUESTCR) USER: POSITIVE .DAT SLOT USAGE
ASSIGNCA) DEVN <UIC> A,B, ••• IETC.: .DAT SLOT MODS
QDUMP(Q): SET TO SAVE CORE CtQ) ON .IOPS ERROR
HALT<H>: SET TO HALT ON .IOPS ERROR
tQN: SAVE CORE ON UNIT N
GET<G> : RESTORE CORE FROM tQ AREA
GETP : RESTORE CORE FROM tQ AREA AND RESTART WITH tP
GETT : RESTORE CORE FROM tQ AREA AND RESTART WITH tT
GETS : RESTORE CORE !=HOM tQ AREA AND RESTART WITH tS
GETCG) N FILE : RESTORE CORE FROM F'ILF. ON UNIT N AND RESTART
GETP N F'ILE : RESTORE CORE FROM FILE <UNIT N) AND RESTART WITH tP
GETT N FILE s RESTORE CORE FROM FILE ON UNIT N AND RESTART WITH tT
GETS N fILF. : RESTORE CORE FROM FILE ON UNIT N AND RESTART WITH tS
PUT N FILENM : PUT tQ AREA INTO FILENM ON UNIT N
API ON/OF'F': CHANGE STATE OF API
VT ON/OFF': TURN GRAPHIC DISPLAY ON/OFF'
~ALF' ON/OFF': TURN HALF' RUFFER MODE FOR GRAP~IC DISPLAY ON/OFF
33TTY ON/OFF: CHANGE STATE OF TELETYPE
LP ON/OF'F': TURN ON/OFF' LINE PRINTER FOR OUTPUT OF' SOME NRM COMMAND~
X4K ON/OFF': CHANGE STATE OF' EXTPA 4~ CORE CONFIGURATIONS
RANK ON/OFF': CHANGE STATUS OF' RANK MODE
PAGE ON/OF'F': CHANGE STATUS OF' PAGE MODE
BUFFS N: CHANGE DEFAULT BUFFER ALLOCATION
C~ANNEL 7/9: SETUP DEFAULT ASSUMPTION FOR MAGTAPE
tC: RESTORE DOS-J5
tP: USER RESTART
tT: RESTART DDT
tX: TURN VT ON OR OFF

...B-5

·DOS-15 PROG LOADING COMMANDS ~ND PROGNAM FOR REQUEST COMMAND
LOAD: LINK LOAD AND WAIT FOR tS
GLOAD: LINK LOAD AND GO
DDT: LINK LOAD WITH SYfllBOLS AND GO TO DDT
DDTNS: LINK LOAD W/O SYfllBOLS AND GO TO DDT
MACRO: SYM~OLIC MACRO ASSEMBLER
F4: FOPTRAN IV COMPILER
EDIT: TEXT EDITOR
PIP: PERIPHERAL INTERCHANGE PROG
SGEN: SYSTEM GENERATOR
DUMP: BULK STOR DEV DUMP
UPDATE: LIRR FILE UPDATE
SRCCOM: SOURCE COMPARE
EDITVP: STORAGE SCOPE EDITOR
EDITVT: GRAPHIC DISPLAY <VT> Pl>ITOR
PATCH: ~YSTEM TAPE PATCH ROUTINE
EXECUTE<E> FILE: LOAD AND RUN FILE XCT
CHAIN: XCT CHAIN BUILDER
BTRAN: PDP-8 TO PDP-15 TRANSLATOR
891RAN: PDP-8 TO PDP-9 TRANSLATOR
MTDUMP: MAG-TAPE UTILITY PROGRAM
DTCOPY: DECTAPE COPY PROGRAM
D0~-15: f'ATCH
BATCHCR> DV: ENTER RATCH MODE WITH DV AS RATCH DEV
DV: PR : PAPER TAPE READER
CD : CARD READER
$JOR: CONTROL COMMAND WHICH SEPARATES JOBS
$DATA: REGINNING OF DATA
$END: END OF DATA
$PAUSE: WAIT FOR tR ON TTY
$EXIT: LEAVE BATCH MODE
tT: SKIP TO NEXT JOB
tC: LEAVE BATCH MODE
tRt CONTINUE F'ROll! $PAUSE

Form 2:

I[NSTRUCT]

ERROR[SJ}'

Example:

SI ERRORS

DOS-15 • .IOPS
0 ILL FUNCTION CAL - CAL ADDR
I CAL* ILL - CAL ADDR
2 .DAT SLOT ERROR - CAL ADDR
3 ILL INTERRUPT - I/O STATUS REGISTER
4 DEV NOT READY • TYPE tR WHEN READY *
5 ILL .SETUP CAL • CAL ADDR
6 ILL HANDLER FUNCTION - CAL ADDR *
7 ILL DATA MODE - CAL ADDR *
10 FILE STILL ACTIVE - CAL ADDR **
11 SEEK/ENTER NOT EXECUTED - CAL ADDR *
12 llNPECOVERARLE DEVICE ERROR - STATUS REG B AND UNIT NO.

8-6

13 FILE NOT F'OUND - CAL ADDR **

14 DIP EC TORY F'ULL - CAL ADDR

DEVICE F'ULL - CAL ADDR **
OUTPUT RUF'F'ER OVERFLOW - CAL ADDR
17 TOO MANY F'ILES F'OR HANDLER - CAL ADDR *
20 DISK FAILURE CCTRLR TO RETRY> - DISK STATUS,BLK #,DEVICE/UNIT 1,u1c
21 ILL DISK ADDR - BLOCK NO,DEVICE/UNIT NO,CAL F'UNCTION,UIC
22 TWO OUTPUT F'ILES ON ONE DECTAPE UNIT - CAL ADDR
23 ILL WORD PAIR COUNT - CAL ADDR **
3A API SOFTWARE LEVEL ERROR - API STATUS REG
31 NON-EXISTENT MEMORY REF - PC
32 MEMORY PROTECT VIOLATION - PC
33 MEMOPY PARITY ERROR • PC
34 POWER F'AIL SKIP NOT SETUP - PC
37 LINE OVFLO - CAL ADDR
40 HEADER LAREL ERROR - CAL ADDR
41 DIPECTORY FORMAT ERROR - CAL ADDR
4?. ACCESSIRILITY MAP OVF'lO - CAL ADDR
43 DIRECTORY RECORDING ERROR • CAL ADDR
44 LOGICAL EOT F'OUND - CAL ADDR
45 LONG INPUT RECORD - CAL ADDR
46 ATTEMPT TO DELETE SYSTEM F'ILE - CAL ADDR
47 ILL HORIZONTAL TAR - CAL ADDR
51 ILLEGAL USER F'ILE DIRECTORY - CAL ADDR **
55 NO BUFFERS AVAILABLE - CAL ADDR *
61 PAP ITY ERROR IN DIRECTORY OR FILE BIT lllAP - CAL ADDR *
63 PPOTECTED USER FILE DIRECTORY - CAL ADDR *
64 PROTECTED F'ILE - CAL ADDR **
65 UNRECOVERABLE MAGTAPE ERROR - MT STATUS
66 RELATIVE BLOCK rs 0 OR NOT WITHIN F'ILE SCOPE c.RTRAN> **
67 .RTRAN ARGUMENTS CAUSE DATA BLOCK OVERFLOW - CAL ADDR **
70 RUFFER SIZE TOO SMALL - CAL ADDR *
71 EMPTY UIC **
72 INPUT PARITY OR WRITE CHECK ERROR CfR TO RETRY>
- CALADDR,BLOCK NO,DEVICE/UNIT NO,CAL F'UNCTION,UIC
73 NULL FILE NAME GIVEN ON SEEK/ENTER/DLETE/FSTAT/RAND *
74 F'ILF. STRUCTURE DEGRADATION - ATTEMPT TO CLEAR SUBMAP
BIT THAT WAS ALREADY OFF **
75 FILE STRUCTURE DEGRADATION - ILLF.GAL SUBMAP WORD!
71l FILE STRUCTURE DEGRADATION - ILLF.GAL BACKWARD POINTER FOR F'IRST
MF'D OR UFO BLOCK C'TR TO RETRY>
77 ATTEMPTED USE OF' NON•EXISTANT tQ AREA
15
I~

DISK ONLYt
CAL ADDR,DEVICE AND UNIT N0 0 ,CAL F'UNCTION,UIC
**
DISK ONLY:
CAL ADDR,DEVICE AND UNIT NO.,CAL FUNCTION,UIC,F'ILF. NAME
LOADER EPRORS • .LOAD OR .SYSLD
MEMORY OVERFLOW
2 DATA F.RROR
3 SUFIR NOT FOUND
4 .DAT SLOT ASSIGNMENT ERROR
5 PROG SEGMENT GREATER THAN 4K CPAGE lllODE>
OBJECT TIME SYSTEM ERRORS - .OTS
5 ILL REAL SQUARE ROOT ARG
ll ILL DOUBLE SQUARE ROOT ARG
7 ILL INDEX IN COMPUTED GOTO
10 ILL I/0 DEV #
II ILL INPUT DATA
12 ILL FORMAT STATEMENT
I,~ !L.L RF.AL LOG ARG

8-7

14 Ill OOUALE LOG ARG
15 7ERO RAISED TO ZEflO

21 IJNDEFI NED FILE

OR NEGATIVE POWER

22 ILLEGAL RECORD SI1E
23 SIZE DISCREPANCY
24 ILLr.GAL RECORD NUMRER
25 MODE DISCREPANCY
2ti; TOO MANY OPEN FILES
30 SINGLE INTEGER OVEPFl.OW
31 f.)(TENDF.O <DOUALE> INTEGER OVERFLOW
;rn n Nr.tF. Fl. T. OVERFLOW
33 DOURLF. Fl.T. OVEPFLOW
34 Sitlr.LE Fl. T. UNDERFLOW
35 DOURLF. Fl.T. UNDERFLOW
3..; Fl T• nt VIDF. CHECK
37 INTF.GER DIVIDE CHECK
4~ ILLEGAL CHARACTER COUNT
41 ARRAY EXCEEDED
42 BAD INPUT DATA
5~ F'PP ME~ORY PROTECT/NON-EXISTANT MEMORY VIOLATION
51 ILLEOAL I/O DIRECTION CHANGE TO DISK

8 .3. 3

REQUES~

The REQUEST command causes a typeout of the I/O Device Handlers currently associated with the slots of the Monitor's Device Assignment
Table (.DAT) • Since this command is closely related to the commands
which affect I/O device assigrunents, it is described in paragraph
8.5.1.
8.4
8.4.1

COMMANDS RELATED TO FILE PROTECTION
LOGIN

This command permits the operator to enter his User Identification
Code (UICl into the system in order to do directoried disk I/O.
After a LOGIN, the Nonresident Monitor sets the slots of the User File
Directory Table (UFD~ to the three-character code entered. All input/
output operations to the disk are directed to the UFO associated with
the last UIC entered by this command, unless a program has subsequently
executed a .USER I/O Macro, or the operator has issued an ASSIGN
conunand (see 8.5.2).

8-8

Each LOGIN command issued enters a new UIC into the system and automatically deletes the one entered previously. Each LOGIN is an implicit LOGOUT (see LOGOUT, in paragraph 8.4.4). A UIC must consist
of exactly three alphanumeric characters in any combination except
"@@@", "???", "PAG", "BNK", "SYS", "IOS" and "CTP".
Form:

where:

uic = User Identification Code

8.4.2

MICLOG

This command permits the Monitor Identification Code (MIC) to be
-tov. rvt,.; ~
entered into the !\¥Stem. This provides the operator with unrestricted
access to all files contained in the various directories on the disk
and permits the system programs SGEN and PATCH to be used to modify
the system. The MIC of each system, as initially supplied to the user,
is "SYS". As with LOGIN, a MICLOG entry is deleted from the system
by the LOGOUT or LOGIN commands. The MIC is usually known only by
the system owner, and the code is easily changed at system generation.
Form:

MICLOG'-"1\iC)

where:

mic = Monitor Ident:.ification Code

8.4.3

PROTECT

The PROTECT command is used to alter the default value of the file
protection code, set when the system was generated (by the SGEN
program). The default file protection codes set by this command
remain in effect until another PROTECT conunand is given or until the
user issues a LOGIN or LOGOUT (which resets the protection code to
the system's default value). Refer to 4.7.3 for a list of these codes.
form:

P [ROTECT].._,n)

where:

8.4.4

LOGOUT

Protection Code

This command deletes the current UIC or MIC entry from the system.
LOGOUT also resets all system parameters affected by keyboard commands
to their default status. These parameters include:
8-9

.DAT and .UFDT assignments (ASSIGN command)

Commands which take an "O"/OFF" argument, such as:
KEEP, X4K, 33TTY, HALF, LP, PAGE/BANK, API, and VT.

Commands which take a numeric argument, including:
CHANNEL, PROTECT, and BUFFS.

Form:
8.5

LOGOUT)
COMMANDS DEALING WITH I/O DEVICE ASSIGNMENTS

8.5.1

REQUEST

This comm.and causes a typeout of the I/O devices currently associated
with the slots of the Monitor's Device Assignment Table (.DAT) and
the UIC's associated with the User File Directory Table (.UFDT). The
command can be issued using various arguments which result in a complete
printout of the assignments or selected portions thereof. If REQUEST
is issued with no argument, the entire .DAT/.UFDT
list of assignments is output. If the argument USER is inserted, only the positive
(user) .DAT and associated .UFDT assignments are output. If an argument which is a legal systemproqram name is used (e.g., MACRO, PIP,
etc.), only the assignments for that program are output.
Form:

R[EQUESTL,,~~
"prog" may be any of the following:
MACRO
F4
FOCAL
PATCH
DTCOPY
GLOAD
LOAD
DUMP
MTDUMP
UPDATE
PIP

EDIT
EDITVP
EDITVT
SGEN
SRCCOM
CHAilf

EXEcdTE
8TR~

89TiqN
DDT I
DDTNS

Examples:

.DAT
·15
-14
-13
-12

DEVICE UIC
DKA
DKA
DKA

LPA

SCR
SCR
SCR
SCR

9-10

-1 J
-10

-7
-6

-4

-3

-2
-I

+I
+2
+3
+4
+5
+6
+7
+10
+11
+12
+13
+14
+15
+16
+17
+20

OKA
TTA
OKL
DKA
NON
DKA
TTA
TTA
DKA
OKA
OKA
DKA
TTA
PRA
PPA
DTAI
VTA
NON
DTA2
NON
NON
NON
NON
NON
NON

SCR
SCR
SYS

SCR
SCR
SCR
SCR
SCR
SYS
SCR
SCR
SCR

SCR
SCR
SCR
SCR
SCR
SCR
SCR
SCR
SCR
SCR
SCR
SCR
SCR

Example 2:

SR USD
.DAT
+I
+2
+3
+4
+5
+6

+7
+1111
+ 11
+12
+13
+14
+15
+16
+17
+2111

DEVICE
DKA
DKA
DKA
TTA
PRA

PPA
DTA I
VTA
NON

DTA2

NON
NON
NON
NON
NON
NON

UIC
SCR
SCR
SCR
SCR
SCR
SCR
SCR
SCR
SCR

SCR
SCR
SCR
SCR
SCR
SCR
SCR

Example 3:

5R MACRO

.DAT
.. 14
-1.3
-12
-1 l

-·Ill

DEVICE
DKA
OKA
LPA
DKA
TTA

UIC
SCR
SCR
SCR
SCF

SCR

USE
INPUT
OUTPUT
LISTING
INPUT
SECONDARY INPUT

8-11

8.5.2

1'SSIGN

This corrunand permits the temporary reassignment of the various slots
of the Monitor's Device Assignment Table (.DAT) to I/O device handlers
other than those permanently assigned at system generation.

In addi-

tion, the corresponding slots of the User File Directory Table (.UFDT)
can also be reassigned to UIC's other than the UIC which is currently
in effect.

Unless the KEEP command' is issued, the change of assign-

ment is effective only for the current job (i.e., the program about to
be run}, since the permanent assigninents are restored when the Nonresident Monitor regains control (i.e., after the current job has terminated).
The KEEP command (described below) can be used to retain assignments
from job to job.
Prior to using ASSIGN, the user should be familiar with the various
handlers which can be used with the program for which the assignments
are to be made.

Chapter 9 describes the handlers in the system.

list of the handlers available on any given system can be obtained in
the printout obtained with the SCOM conunand.

The following rules should

he observed when typing ASSIGN commands:
a.

Device handler names consist of three characters which
can be abbreviated to two c~racters if the last character is an "A". Thus, "D " becomes "DK". In addition, a number can be typ
as a fourth character to
specify the device unit number (in octal). The
unit number is applicable tor devices which can have
more than one unit: Disk Pack, DECtape, and Magtape.
If the unit number :is zero, it need not be specified.
Thus, "DTA.S" becomes simplir "DT", similarly, "DPB.S"
can be typed as "DPB".
"D'rAl" may be typed as "DTl" •

.DAT/.UFDT slot numbers (octal) must be within the legal
range for the particular system being used. Since the
number of negative slots does not change (-15 is the
lowest negative slot) , the user need only be concerned
with the number of positive slots available. This ~an
be determined either from a SCOM or a REQUEST USER command.

A series of assiqnments can be typed on the same line,
using a single ASSIGN corrrnand, by separating the assignments with a slash (/)" The user can then type
another device name, UIC, and slot number(s).
(See
examples below.)

Assigning NON instead of a device handler name will
assign a null handler to .DAT slots that are not
needed. This will save core since no handler will
be loaded at run time.

8-12

A[SSIGN)

Form:

<I.lier a{,b,c,eto.J)
ev <uio
ev
ON

where:
uic = legal User Identification Code
dev = Device Handler name and unit (if applicable)
a,b,c,etc. = Legal slot numbers
NON = No device handler
Examples:
1.

To assign the teleprinter to .DAT slot -11 and the
paper reader (version A) to .DAT slot 14, type:

,1"..,.TT...,-11 I EtRa..114)

To assign UFO "ABC" to .UFDT slot -14, and the Disk Pack and
UFO "TRE" to .UFDT slot 1., type:

To assign the Disk Pack to several .DAT slots, type:
At...illPa...l,2,3,lSJ

8.5.3

KEEP ON/OFF

This command instructs the Monitor either to retain or reset .DAT/.UFDT
slot assignments after the current program (for which the assignments
were made) terminates execution and control returns to the Monitor.
"ON" retains assignments and "OFF" allows them to be reset. When a
LOGOUT command is issued, the "OFF" parameter is automatically set.

8.6
8.6.1

CORE ALLOCATION COMMANDS
BUFFS

This command temporarily changes the parameter which specifies the
default value for the number of buffers available in the Monitor's
buffer pool for disk I/O and for the .GVBUF and .GTBUF Monitor Commands. The default value is restored whenever the Nonresident Monitor

8-13

returns. This value ]s set during system generation along with the
actiual size of the bu.ffers to be allocated (the default values for
systems as initially distributed are: Number of Buffers
3, Buffer
Size= 5~- 8 ).

The user should exercise care when issuing this command, since the DEC~
disk and Disk Pack device handlers and the DECtape "A" handler obtain
the buffers required for their operation from this pool. One of these
buffers is required for each opened file. Terminal errors result
when an insufficient number of buffers is available. Alternatively,
program loading errors occur when the number of buffers allocated
results in an insufficient amount of core for program loading. When
requesting system programs, the user need not be concerned about buffer availability since each system program has its own default parameter for the maximum number of buffers required (e.g., MACRO has 3,
EDIT has 2.).
BUFFS~n)

Form:
where:

n = number of buffers (decimal radix) desired.

8.6.2

X4K ON/OFF.

This command informs the Monitor of the availability of a page (4K)
of memory in systems which have an odd number of memory pages (i.e.,
20K and 28K systems). The additional oore space, when specified as
available, is used for loading system and user programs.

8.7

CORE IMAGE SAVE/RESTORE COMMANDS

The commands described.in this section provide facilities for.saving
and restoring the entire image of core. These conanands can be used to
advantage not only for obtaining "snapshots" of core for debugging
purposes, but also for rapid loading of commonly used programs, particularly user-created programs which use many library routines •
These connnands work in conjunction with a reserved area on the DECdisk
and each Disk Pack called the Save Area, or QAREA. The QAREA is a
temporary storage area into which a core image may be dumped and from
which core images are restored. This is considered a temporary storage

8-14

area since each time a command to dump core is given, the previous
contents of this area are lost. Additional commands are therefore
supplied, to permit users to create named files of core
images in the QAREA. Such files can be used for permanent storage
and can be restored to core via Keyboard commands. The DUMP
program can be used to obtain listings of core dumped into the QAREA.
B.7.1

CTRL Q

This conunand interrupts the program currently running, dumps the entire contents of core into the QAREA of the system device and returns
control to the Nonresident Monitor. Users with Disk Packs
must specify on which unit the dump is to take place. The
command is typed by simultaneously depressing the CTRL and Q keys
on the keyboard. Upon receipt of the conunand, the Monitor echoes an
tQ.
(If no echo occurs, no QAREA exists on the device, or the sys~em
has crashed.} If the system device is -Disk Pack, the Monitor waits
for the user to type a unit number before processing, otherwise processing continues automatically, core is dumped into the QAREA and the
Monitor regains control as shown below.
Form:

CTRL Q

Response:

tQn

DOS-15

Vnn

where:

n = Disk Pack Unit Number

8.7.2

ODUMP

l--7)

This co11111and instructs the Monitor ·_to automatically execute a CTRL O
command (see above) when a terminal !OPS error is detected. IOPS
errors are listed in Appendix o.
Form:

Q [DUMP]

8.7.3

PUT

This command instructs the Nonresident Monitor to create a file,
which is a copy of the current contents of the specified QAREA, on
the device associated with .DA'l' slot -14. If the system device is
Disk Pack, a unit number can be specified, otherwise - is assumed.
The user must type a file name whidh may consist of up to six characters and a three character extension.
8-15

Form:

PUT [L...lh]~ filnam..._.ext)

where:
n = Disk Pack Unit Number (~-7}, ~ assumed if not specified
filnam = File Name (1-6 characters)
ext = Required filename extension (1-3 char;cters)
8.7.4

GET

This command instructs the Monitor to restore (to core) a core image
residing either in the QAREA of the system device, or on the device
associated with .DAT- slot -14 as a named file (i.e., created by a PUT
command). No name with the command gives the first option. If the
user supplies a name, the second option (.DAT -14) will be taken.
Execution of the restored core image is resumed by one of the Program
Start/F~start Commands described in Paragraph 8.11 (CTRL P, CTRL T,
or CTRL S). These commands can be issued either manually from the
keyboard or automatically by argument in the GET command string.
When a restored core image is to be restarted
manually (i.e., by typing CTRL P, CTRL T, or
CTRL L) , the user should wait at least 8 seconds after issui~ the GET to ensure the complete transfer of the core image before typing
the command.
When restoring a core image file from .DAT -14, the Monitor also
places the core image in the QARF.A of the system device. Disk Pack
unit numbers other than zero must be specified in the command string.
This permits the user to conveniently use the DUMP program to obtain
listings of core image files.

Po=•

GET{i} ] i._.nJ

[~filnam ext])

where:
P,T,S = Perform automatic proqram start
P

T
S

CTRL.P start address
CTRL T start address
CTRL S start address

Note that there must be no space between GET or G
and P, T, or s.
If not specified, appropriate CTRL character must
be issued from the keyboard.
n = System device unit number (~-7) of Disk Pack QAREA to
be u~ed. I f no~ -sp&Gi..fied, ,e_is assumed.
8-16
r.

filnam ext

Note:

Name and extension of core image to be retrieved from .DAT -14. If not specified,
the contents of the QAREA are restored.

Since GET corrunands cause an entire core image
to be brought in, all system conditions and
parameters extant when cor_e was dumped ~re
restored. This includes the DATE and TIME
.SCOM registers.

Examples:
1.

Restore the QAREA of the DECdisk or Disk Pack unit ,0:
type:

GET)

Restore a core image file called DMPFIL ~~l and automatically start at the CTRL P address:

typ.e:
Restore a core image file called DMPFIL -~2, placing
the core image in the QAREA of Disk Pack unit 3:

type:
Notice that a manual start must be perfor.med, since
P, T or S was not specified with the GET.

8.8.

VT15 DISPLAY COMMANDS

The commands described in this section provide users who have conf igurations which include a VT15 Display Processor and a

VT~4

Display Con-

sole with the ability to display any text normally directed to the
teleprinter on the screen of the VT~4 Display Console.

The control

commands are issued from the teleprinter keyboard and permit rapid
switching between hard and soft copy output when operating with either
the Monitor, system programs, or
character lines can be displayed.

us~r

programs.

Up to fifty-six 72-

Keyboard input is echoed both on

the display (when ON) and the teleprinter.

When operated in this

manner, the VT15/VT~4 Display System functions as an extension of the
teleprinter and communicates directly with its device handler. 1
8.8.1

Operating Features

8.8.1.l

Display Modes - Two modes of display are provided which are

controlled by the two rightmost pushbuttons (#5 and #6) on the
VT,04 console.

1 To operate the display as a separate I/O device, the user must use the
software package described in GRAPHIClS Programming Manual, DEC-15-ZFSA-D.

8-17

Continuous (Scroll) Mgd,e - In this mode of operation,
pushbutton #5 must be in the OFF position (i.e., not
illuminated). Each text line is displayed on the
screen starting at the top and progressing to the
bottom. When 56 lines have been displayed, or the
display buffer is full (as with HALF ON), each additional line causes all displayed lines to move up
one line position and the top line to be deleted.

Paging Mode - This mode of operation causes the display to stop after 56 lines have been output, or
the display buffer is full. The display will then
wait for the user's signal. Paging Mode is entered
by setting pushbutton ts to the ON position (i.e.,
button #5 is illuminated) • The next display page is
obtained by depressing pushbutton #6 once.

8.8.1.2 Clearing the Display Screen - The display screen can be
erased at any time by depressing pushbutton #6 once and typing a
Carriage RETURN.
8.8.1.3 Editing - Both single characters and entire lines can be
deleted during input from the teleprinter keyboard using the standard
keyboard editing commands RUBOUT and CTRL u. The only difference on
the VT is that, when using RUBOUT, no backslash ( \ ) is echoed on
the display; the unwanted character is simply deleted.
8.8.2

Display Command Descriptions

The following paragraphs describe the three keyboard commands required
for operating the display.
B.8.2.l VT ON/OFF - The ON argumen!t of this command instructs the
Monitor to load the routines which ~nterface the VT15 to the teleprinter's device handler and set up, the display buffer to the size
specified by the HALF ON/OFF command (or its default setting). After
this command has been typed, the user can switch at will between
teleprinter and VT15 output using the CTRL x command described below.
The routines and buffer space for display operation occupy either
1234 1 ~ locations (when HALF is on) or 1923 1 e locations (when HALF is
off). The OFF argument of this cominand erases the display screen and
releases the core area occupied by the display routines and display
buffer.

8.8.2.2 HALF ON/OFF - This command: is used to set the size of the
display buffer. This, in turn, limits the maximum number of characters which can be displayed on the VT~4 screen. The OFF argument
permits a full size buffer to be created. The full size buffer allows
4~32 1 ~ characters to be displayed (i.e., fifty-six 72-character lines).
The ON argument allows only a half size display buffer to be loaded.
A half size buffer allows 2016 characters to be displayed (e.g., 28
72-character lines). Since most lines are not 72 characters long,
more than 28 lines can usually be displayed with HALF ON. This feature
is particularly useful during assembly or compiling operations when
additional symbol table space is required.
ON
HALF'-'{OFF})

Form:

8.8.2.3 CTRL X - This command, formed by typing CTRL and X simultaneously, alternately switches text output either to the teleprinter
or to the VT~4 screen. Once VT ON· has been issued, CTRL X can be
typed at any time (i.e., with the Monitor, a system program, or a
user program) to change output control. An up-arrow (+) is echoed on
the device to whioh control-is- .tran&fen.'eG•·
8.8.2.4 Command Default Settings - The commands VT ON/OFF and
HALF ON/OFF can be initially set during system generation to meet
user requirements. The default settings for the DOS-15 system as
initially supplied are: VT OFF and HALF OFF.
8.9

MISCELLANEOUS COMMANDS

8.9.l

API ON/OFF

This command controls the status of the Automatic Priority Interrupt
System for machine configurations having this option. The ON
argument enables the API and the OFF argument disables the API.
Form:

8-19

B.9.2

33TTY ON/OFF

This command instructs the teleprinter device handler to operate with
hardware configurations having either a Model 33 or Model 35 terminal
as the system teleprinter. The ON argument specifies a Model 33 terminal and the OFF argument specifies a Model 35 terminal.
Form:
8.9.3

CHANNEL 7/9

This command sets a constant in the Monitor which is used by the Magtape device handlers as the default operation parameter for 7- or 9channel operation. Refer to the description of the Magtape handlers
in Chapter 9 for further information.
Form:

C[HANNEL].._,{~})

8.9.4

LP ON/OFF

This command p~rrnits the text output resulting from the System Information Commands REQUEST, REQUEST USER, INSTRUCT, INSTRUCT ERRORS, and
INSTRUCT SCOM to be output to a line printer, if one is available·
The ON argument directs output to the line printer and the OFF argument restores output to the teleprinter.

8.9.5

BANK ON/OFF

PAGE ON/OFF

These commands permit the user to select either Bank or Page Mode
In Page Mode, relocatable system and user programs (inoperation.
eluding device handlers) are loaded within 4K memory pages, and Index
Register usage is permitted. Library routines are loaded from the
library residing in the PAG UFO. In Bank Mode, Index Register usage
is not permitted, and user programs (including device handlers}
are loaded within SK memory banks, and system library routines
are loaded from the library contained in the BNK UFO. Either BANK
OFF or PAGE ON sets the system to operate in Page Mode. Conversely,
8-20

BANK ON or PAGE OFF sets the system to operate in Bank
Mode.
Form:

ON
BANK '--' {OFF} )

8.9.6

DATE

ON }
PAGE'--' {OFF )

This conunand is used either to enter a calendar date or to examine
the calendar date currently stored in the Monitor.

This information

is used by· the system to indicate the date of creation of mass storage
files.

If no date has been entered into the system, each time con-

trol is returned to the Monitor it outputs a message requesting that
a date be entered.

When a date is to be entered, the entire date

(month, day and the last two digits of the year) must be typed.

The

DATE conunand with no argument causes the date currently stored in the
Monitor to be typed out.
Form:

D[ATE)[ ._.mm[/)dd[/]yy) )

where:
mm • Month

{~1-12)

Day of Month

Year

(~1-31)

('7~-'99)

If the slash delimiters (/) aie used, leading zeroes can
be omitted; otherwise all six digits must be typed.
8.9.7

TIME

This command is used either to enter or to examine the time of day
currently stored in the Monitor.
Monitor every second.
as a 4-digit number

This information is updated by the

When time is to be entered, it must be typed

(~~~~-2359)

in 24-hour clock notation.

The TIME

command with no argument causes the current time of day (as kept in
the Monitor) to be typed out.
Form:

T[IME] [._,hhrnm) )

where:
(~~-23)

Hours

Minutes

(~~-59)

8-21

8.9.8

TIMEST

This coll1111and instructs the Monitor to terminate the current operation
and restart itself after a specified time interval has elapsed.

The

command is particularly applicable when operating in Command Batching
Mode (discussed in 8.12 ), since i t permits users to unconditionally
terminate a program's operation if its execution time exceeds that
value expected for normal operation.

The time interval can be speci-

fied in minutes, seconds, or a combination of both.

The maximum time

interval (total minutes and seconds) can not exceed 131,071 seconds.
Once executed, a TIMEST command can only be nullified by a subsequent
LOGIN or LOGOUT command.

Form:

mm
TIMEST ~ mm~~

Example:

)

TIMEST :5281 (5281 seconds)

where:

or
TIMEST 88:1 (88 minutes, 1 second)
8.9.9

Minutes

Seconds

LOG

This command instructs the Monitor to ignore subsequent keyboard input
and is used primarily for making operator comments.

Typing ALT MODE

restores the keyboard for normal command input.
Fonn:

L[OG]

) .

comment
corrunent ALT MODE
8.9.10

HALT

This command will cause the Monitor to halt computer operation. after terminal IOPS errors. Press CONTINUE, followed by CTRL P or CTRL c to continue system operation.
Form:

H[ALT] )

8.9.11

CTRL D

This command, formed by simultaneously striking the CTRL and D keys on
the teleprinter keyboard, is used to indicate an end-of-file condition
when the keyboard is used as an ordinary input device (as opposed to its
being used as a command input device).

CTRL D signals the teleprinter's

device handler, or other keyboard device handler, if available, to
8-22

transmit a header word pair to the t:equesting program's I/O buffer in
which bits 14-17 are set to the end•of-file code /U~l 2 • Any information currently in the buffer is lost. In !OPS ASCII mode, therefore,
a carriage RETURN should always precede a CTRL D in order to assure
output of the last line.
8.10

SYSTEM PROGRAM LOADI~ COMMANDS

The commands described in Table 8-1, System Program Loading Commands,
are used to instruct the system loader within the Monitor to load the
various language and utility programs which are part of the DOS-15
Software System. Each command must be typed as shown, terminated by
either a Carriage RETURN or ALT MODE.
8.11

PROGRAM START/RESTART/CONTINUE COMMANDS

The commands described below are used to provide keyboard control
during system and user program operation. The format of these commands has been previously described in paragraph 8.2.1.

8.11.l

CTRL C

This command returns control to the Nonresident Monitor. It can be
typed at any time, signaling the Monitor that the user wishes to abort
a program, or enter a keyboard command. In returning control to the
Nonresident Monitor from a previously executing program, all device
and UFD assignments are returned to their default settings unless the
KEEP ON command is in effect (see 8.5.2 and 8.5.3). CTRL c can also
be used to terminate the Monitor's processing of all keyboard commands
except for TIMEST (see 8.9.8). In this case, device and UFD assignments are not affected.
8.11. 2

CTRL P

This command restarts system programs, terminating current operation.
Upon execution of this co11U11and, control is transferred to the
start address specified in the last .INIT I/O Macro to the teleprinter.
User programs may use this restart facility by issuing a .INIT_macro

8-23

Table '8-1
SYSTEM PROGRAM LOADING COMMANDS
Program Loaded

Command

FORTRAN IV compiler.

M1\.CRO

MACR0-15 Assembler.

EDIT

Symbolic Text Editor.

EDITVP

Symbolic Text Editor for the VP15A Display.

EDITVT

Symbolic Text Editor for the VT15/VT.IJ4 Display System.

LOAD

LinkiIVJ Loader (manual program start)

GLQAD

Linking Loader (load and go program start)

PIP

Peripheral Interchange Program.

DDT

Dynamic Debugging Tedhnique Program

DDTNS

DDT program with no user symbol table loaded (i.e.,
octal number debugging) •

DUMP

Program to create listiIVJS of the contents of the
QAREA (see 8.7).

CHAIN

Program to create a system of core overlays.

E[XECUTE]

Control program which supervises core residency during
execution of a CHAIN•built overlay system.

SRCCOM

Source Compare Progr~m (for comparing two ASCII files).

MTDUMP

Magtape user's utili~y program.

DTCOP'l

High-speed DECtape ctjpy program.

SGEN 1

System Generator Program.

PATCH 1

Mass Storage Patching Program.

UPDATE

Program to create and update library files.

8TRAN

Program to translate PDP-8 code to PDP-15 code.

89TRAN

Program to translate PDP-8 code to PDP-9 code.

TKB

RSX15 Task building program. 3
'

1 This program can only be run when the user is logged-in to the system
with the MICLOG command.

zWhen this program is used with the system device, the user must be
logged-in under the MIC.
3 ~ to RSXlS Reference Manual (DEC-15-GRQA-D).
8-24

to .DAT-2 (which is permanently assigned to the teleprinter handler).
See 6.7.6 and the description of the teleprinter handler in Chapter 9.
CTRL P is ignored until the teleprinter handler receives the proper
.INIT.
8.11.3

CTRL S

This command is used to start a program loaded by the Linking Loader
via the LOAD command.
8.11.4

CTRL T

This command is used only with the DDT program and the Monitor's
Command Batching Mode (see BATCH described below).

When used with

DDT, CTRL T terminates execution of the program being debugged and
causes DDT to enter command mode.
When used with the Monitor's
Command Batching Mode, it causes the current job to be terminated
and a skip to the next job.
8.11.5

CTRL R

This cormnand permits the user to c¢ntinue program operation either
after an IOPS4 (I/O device not ready) error occurs, or after the
execution of a $PAUSE (see 8.12.3.4).

Prior to typing this command,

the user must first correct the condition which caused the error
(e.g., DECtape unit incorrect, OFF LINE, etc.).
8.12

BATCHING KEYBOARD COMMANDS

Most of the Monitor's keyboard commands, as well as the keyboard commands for most system programs, can be issued from either the card
reader or the paper tape reader.

This is possible when the system is

in the Monitor's Command Batching Mode.

Batching Mode allows many

programs to be run in sequence with minimum operator intervention.

A typical sequence of operations might include file editing, assembly
and program execution.

All commands input from the batch device arc

echoed on the console teleprinter.
8.12.1

Preparation

For Command Batching Mode, the progranuner must prepare a paper tape
or a deck of punched cards which contains the keyboard commands for

~-25

the operations to be performed.

These commands should be in

the same order and form as they would normally be issued from the
teleprinter keyboard.

The only exception to this is that certain job

rqntrol commands must be inserted in the command sequence.

When pre-

paring paper tapes, the user will find it convenient to use the system's
Teo:t Editor Program EDIT.

When preparing commands for input from cards,

the user can prepare his cards using a card punch which punches either
02J or 026 Hollerith codes (see Appendix F).
8 .12. 2

Opera tor Commands

The following
~

conman~s

~ -

l?..2.1

are provided for operator control:

This command is used to enter Command Batching Mode.

Once this command is jssued, the Monitor begins to read from the batch
device specifi?d (PR= paper tape reader, CD= card reader).
PR

Form:

B[ATCH] l..J {CD}

8.12.2.2

)

CTRL T - This command causes the Monitor to skip to the next

job (i.e., skip to·the next $-JOB job separator.

See 8.12.3.1).

CTRL C - This cOl'l'llland is ~sed to terminate Command Batching

8.12.2.3

Mode operation.

It operates in al~ other respects as it does with

normal keyboard operation (see 8.1~.l).
8.12.2.4

CTRL R -

This command is'. used to recover from either the

exec 11tion of a $PAUSE (see 8 .12. 3. 4) or an IOPS4 (see 8 .11. 5) .
8.12.3

Job Control Commands

The following conmands are inserted into the normal

keyboar~

command

sequences on the batch device mediumto provide job control.
B.12.3.1

$JOB - This command separates one job from the next.

loading of any system or user program constitutes a job.)

(The

The command

operates, within the context of Command Batching ~ode, in a manner similar to the CTRL C command since it causes the Batching Mode Nonresident
Monitor to be reloaded, and all .DAT/.UFDT slot assignments to be reset
to their default settings, if KEEP is OFF.

$JOB must occur as the first

command on the batch medium and can be used thereafter each time the

8-26

user wishes to exit from 11ie-cu.:trent pro·gram and issue another command
to the Monitor.
Form:

$J"OB.._.comment )

where:

comment = User comments

8.12.3.2 $DATA - When the batch device is to be used for data input
(as it might be in non-batch mode), this command marks the beginning
of the data. Unlike BATCH commands, data is not printed on the teleprinter.
Form:
where:

$DATA~omment)

comment = User comments

8.12.3.3 $END - This command follows the $DATA command and data to
signify the end of the data.
Form:

$END._,comment )

where:

commeJlt = user collllllents.

8.12.3.4 $PAUSE - This command terminates input from the batch device
until the operator types a CTRL R. It has particular application when
the user wishes to signal the operator to mount a DECtape, reload the
batch device, or perform some other manual operation.

Form:

$PAUSE.._.comrnent )

where:

comment = User comments

$EXIT - This command signals the Monitor to leave Command
Batching Mode and resume operation using commands from the teleprinter
keyboard.
8.12.3.5

Form:

$EXIT....,comment )

where:

comment - User comments

8.12.4

Restrictions

When operating in Command Batching Mode, the following restrictions
apply:
8-27

8.13

The following comnands are illegal: QDUMP, HALT,
GET (all forms), PUT, BATCH, BOSS 15, LOAD, DDT, DDTNS.

Any ASSIGN command which references either batch device will automatically obtain the services of the
current batch device handler. This is because the
card and paper tape devices are mutually exclusive
when in Batching Mode. Thus, if the card reader is
the batch device, an ASSIGN PR -4 will result in the
card reader assigned to .DAT -4. Functions provided
by these handlers are equivalent to those provided
in the PRA or COB handlers as described in Chapter 9.

When using the REQUEST canmand, .DAT slots assigned
to the batch device are printed as either PR* {paper
tape reader) or CD* {card reader) .

KEYBOARD ERROR DETECTION AND HANDLING

The Monitor performs comprehensive error checking on all keyboard commands typed.

Upon detection of an error, an appropriate message is

output to the teleprinter indicating the nature of the error, and the
remainder of the line from the error is ignored.

The dollar sign ($)

prompting symbol is then output to indicate the Monitor's readiness
to accept another command.

Keyboard errors which result during opera-

tion of system programs are explained in the appropriate reference
manual for the particular program {see Preface).

Error messages which

are prefixed by "IOPS", ".SYSLD" or", LOAD" are listed and explained in
Appendices D and E. respectively.

CHAPTER 9
I/O DEVICE HANDLERS

9.1

INTRODUCTION

This chapter describes the I/O device handling routines which are supplied as a part of the DOS-15 system software.

Included in this chap-

ter are their operating characteristics and their applicability for
use with the various language and utility programs in the DOS-15 system.
Each I/O device handler has a unique three-character name which is used
when assigning it to a .DAT slot via the ASSIGN keyboard conunand (see
8.5.2).

The first two characters of the name designate the device with

which the handler operates.
TT = Teleprinter, etc.

For example:

DK= DECdisk; DP = Disk Pack;

The third character specifies a particular ver-

sion of a handler, since some I/O devices have several handlers.
OK~

designates the "A" version of the DECdisk device handler.

DT£ is the "C" version of the DECtape handler.

Thus,

Similarly,

Table 9-1 lists the

standard DOS-15 I/O device handlers.
-·· -Table: 9.:1
DOS-15 I/O DEVICE HANDLERS 1
'

Device Name
DK (OECdisk
DP (Disk Pack)
OT (DECtape)
TT (Teleprinter)
PR (Paper Tape Reader)
PP (Paper Tape Punch)

~---

LP (Line Printer)

./
I
I

./
./

./
./
I

I
I
I
I

./
./

(VPl SA Display)

r-.tT (Mag tape)

CD (Card Reader)
VP

Version

t--- t------

1 Users having a VT15 Graphic Display System should refer to the
GRAPHIC15 Progranuning ~anual (DEC-lS~ZFSA-D) for descriptions of the
associated device handlers VTA, LKA, and VWA.

9-1

The availability of several handler versions allows the user who is
concerned with core utilization to select a particular version with the
size and capabilities most nearly suited to his needs. Device handler
versions differ from one another in the number of I/O functions (Macros)
and Data Modes allowed, and in the number of files which can be accessed
concurrently. The fewer capabilities allowed, the smaller the handler.
"A" version handlers are the largest, but also provide the greatest
capabilities. Other versions are more limited, and consequently are
smaller.

In selecting a handler, the user must consider all I/O requirements
for the program with which it is to run. What I/O Macros and Data Modes
are used? Is output required? How many files may be concurrently open?
To assist the user in selecting handlers, paragraph 9.2 lists all
versions of the handlers which can be assigned to the various .DAT
slots used by the various DOS-15 System programs, and paragraph 9.3
describes the specific functional characteristics of the handlers.
9.2

DEVICE HANDLERS ACCEPTABLE TO SYSTEM PROGRAMS

The following paragraphs provide listings of .DAT Slot assigrunents
for the various system programs and the I/O device handlers which
may be assigned to each. Standard assignments for the system
initially supplied are indicated by an asterisk (*).

9-2

NOTE: Only one I/O handler for a particular device may be in core
at the same time, since there is no colllllunication between the interrupt
handling routines.

9.2.1

FORTRAN IV (F4)

.DAT Slot

-13

-12

Handler

Output

Listing

PPA
PPB
PPC
*DK.A,
DKB,

*TTA
LPA
VPA
PPA
DK.A,
DKB,

*DPA,
DPB,

DPA,
DPB,

OTA,

MTA

OTO,
DTE
DTF,

MTF

DTA,

MTA

DTD
DTE
DTF,

MTF

OTA,

MTA

OTC,
OTO,
DTE,
DTF,

MTC

t--·

-11

Input

TTA
J.>RA

PRB
*DK.A,
DKB,
DKC,

9-3

*DPA,
DPB,
DPC,

MTF

9.2.2

MACR0-15
.DAT Slot

-14

Handler

Macro
Definitions
File

·TTA
PRA
PRB
CDB
*OKA,
DKB,
DKC,

*DPA,
DPB,
DPC,

PPA
PPB
*OKA,
DKB,

*DPA
DPB

*TTA
LPA
VPA
PPA,
DKB,
TTA
PRA
PRB
CDB
*OKA,
OKB,
DKC,

OTA,
DTD
DTE

MTA

DPA,
DPB,

OTA,
DTD
DTE

MTA

*DPA,
DPB,
DPC,

OTA,
DTD
DTE

MTA

i------·

-13

-12

-11

Output

Listing
Output

Input

·---

1-----·--

....10

Parameter
File
Input

*TTA
PRA
PRB
CDB
OKA,
OKB,
DKC,

9-4

DPA,
DPB,
DPC,

OTA,
DTD
DTE

MTA

9.2.3

FOCAL
.DAT Slot

1----··----

Library
Input

--I- TTA
PRA
PRB
COB
*DKA,
DKB,
DKC,

TTA
PPA
OKA,
DKB,
LPA,
VPA

Library
Output

Handler

---

_________,

*DPA,
DPB,
DPC,

OTA,
OTC,
DTD,
DTE

MTA
MTC

DPA,
DPB,

OTA,
OTO
DTE

MTA

DPA, *DTA,
DPB, OTC,
DPC, OTO
DTE

MTA
MTC

DPA, *OTA,
DPB, DTD
DTE

MTA

1---·

··-·

Data File
Input

TTA
PRA
PRB
COB
OKA,
DKB,
DKC,
DKE,

-·--- ---- --- - ---10

Data File
Output

TTA
PPA
OKA,

DKB,
LPA
VPA

1 Prior

to loadill9 FOCAL, this .DAT slot must be reassigned to one
of the devices listed, if library output is desired.

9•5

9.2.4

EDIT, EDITVP, and EDITVT
.DAT Slot
-15

t-----·- -

Scratch/
Output

Handler

TTA
VPA
LPA
PPA
*OKA,
DKB,

*DPA,
DPB,

DTA,
DTD
DTE

MTA

·-- ·-------+--

-14

Input

TTA
PRA
PRB
COB
*DKA,
DKB,
DKC,

*DPA,
DPB,
DPC,

OTA,
DTD
DTE

MTA

*TTA
PRA
PRB
COB
DKA,
DKB,
DKC,

DPA,
DPB,
DPC,

OTA,
DTD
DTE

MTA

r--10

9.2.5

Secondary
Input

Display
Output
(EDITVP only)

VPA

Linking Loader and DDT
.DAT Slot
-5

-4

-1

Handler

External
User
Library
Input
user
Program
Input

System
Library
Input

*NON

PRA
*DKA,
DKB,
DKC,

*DPA,
DPB,
DPC,

OTA

PRA
*DKA,
DKB,
DKC,

*DPA,
DPB,
DPC,

OTA

9-6

DTC
DTD
DTE

OTC
OTO
DTE

9.2.6

PIP (Peripheral Interchange Program)

PIP uses all positive .DAT slots and -2 and -3 for TTY I/O.

Prior to

use, any non-standard device assignments should be made via the ASSIGN
command to the Monitor.

If several functions are to be used with a

variety of peripherals, assignment of these devices all at the same
time avoids the necessity for returning to the Monitor to reassign
devices and for repeatedly reloading PIP after each operation that
requires a new device.
NOTE
The device handlers used with PIP should normally
be those having the greatest capability (i.e., PRA,
PPA, DTA, DKA, etc.).
If both input and output are
to occur on the same device (e.g., DECtape), separate
.DAT Slots must be assigned. Both .DAT Slots must
be assigned to the same handler.
Positive .DAT Slot assignments for the system, as initially supplied,
are as follows:

9. 2. 7

Handler

.DAT Slot

Use

I/O

*DKA

*DPA

I/O

*DKA

*DPA

I/O

*OKA

*DPA

I/O

*TTA

5
6
7

Input

*PRA

Output

*PPA

I/O

*DTA

lfiJ
11

I/O

*DTA

I/O

*NON

I/O

*NON

l./O

*NON

I/O

*NON

15
16

I/O

*NON

I/O

*NON

1/0

*NON

2fi'

I/O

*NON

SGEN

(System Generator)

.DAT Slot

Use

-14

Input/Output

Handler

I------

*DKA

9-7

*DPA

9.2.8

PATCH
.DAT Slot

9 , 2 •9

Use

-14

I/O

*DKA,

*DPA,

OTA
DTD
DTE

-1~

Secondary
Input

*TTA
PRA
DKA,

DPA,

DTA

UPDATE
.DAT Slot

-15

-14

-12

-1,

Handler

PPA
PPB
PPC
DKA,
DKB,

DPA,
DPB

DTA,

MTA

PRA
*DKA,
DKB,
DKC,

*DPA,
DPB
DPC

DTA,

MTA

DPA,
DPB

DTA,

MTA

DKB,
*TTA
PRA
DKA,
DKB,
DKC,

DPA,
DPB
DPC

DTA,

MTA

Output

Input

Listing

-·

9.2.10

Handler

LPA
*TTA
VPA
PPA
~--··---

Secondary
Input

- -·DJCA;

DUMP
.DAT Slot

use
--

-14

Input

*DKA,
DKB,
DKC,

-12

Listing

*TTA
LPA
VPA
PPA
DKA,
DKB,

Handler

9-8

MTA
*DPA, *DTA,
DTD
DPB,
DPC,
DTE
-·· -------- - ·-·-----

DPA,
DPB,

DTA,
DTD
DTE

MTA

9.2.11

CHAIN
.DAT Sloj;j

Handler

(same as .DAT slot -4 when used)

-5

User
Library

*NON

-4

Input

PRA
*DKA,
DKB,
DKC,

-1

System
Library

DPA,
DPB
DPC,

DTA,

MTA

DTC,
DTD
DTE

MTC

r·

if nonly
other
DT, DK, or
MT is assigned.

Same as for .DAT -4

-NOTE
use the smallest handlers possible since they are not
recoverable as user handlers in the overlay system.
9.2.12

EXECUTE
.DAT Slo_!
-4

9.2.13

Use

Handler

jcHAIN-Built
PRA '
*Dl?A, DTA,
joverlay Sys- *DKA,;
tern Input
DKB,
DPB
(i.e., ~... - _nxc,, ___ .DP.C,_ .DTC,.
XCU Files)
OTO
DTE

MTA~·· only if
MTC nc;it shared
with overlay
system

SRCCOM (Source Compare)
1

.DAT Sloj

Handler

Use

-15

jold File
Input

TTA

not assigned to -14)
PRA
(if not assigned to -14)
COB (if not assigned to -14)
MTA
*OKA,
*DPA, OTA,
DKB,•
DPB, DTD
DKC,
DPC, DTE

-14

New File
Input

TTA (if not assigned to -15)
PRA (if not assigned to -15)
CDB (if not assigned to -15)
*OKA,
*DPA, DTA,
MTA
DPB, DTD
DKB,
DTE

-12

Listing

*TTA
PPA
LPA
VPA
OKA,
DKB,

(if

-·

·-~·-

--·- ..

--'

9-9

DPA,
DPB,

OTA,
DTD,
DTE

MTA

9.2.14

DTCOPY (DECtape Copy)
Use

....15

output

DTA
DTD
DTE

-14

Input

OTA
DTD
DTE

9.2.15

BTRAN (PDP-8 to PDP-15 Translator)
89TRAN (PDP-8 to PDP-9 Translator)

.DAT Slot

-15

Input

-14

9.2.16

Output

Handler
PRA
COB
TTA
*OKA,
, DKB,
, DKC,

*DPA,
DPB,
DPC,

OTA,
DTD
DTE

MTA

PPA
LPA
TTA
VPA
OKA,
DKB,

DPA,
DPB,

DTA,
DTD
DTE

MTA

MTDUMP (Maqtape User's Utility Program)

.DAT Slot 2
!---·

9.3

Handler 1

.DAT Slot

Handler

Input

MTA,

MTF

Output

MTA,

MTF,

TTA

I/O HANDLER DESCRIPTIONS

The following paragraphs describe the operating features of .the standard
DOS-15 I/O Device Handlers. The DOS-15 System Manual (DEC-15-NRDA-D)
describes functions which are internal to the handlers and provides
instructions to assist users in creating their own special device handlers. users having a VT15 Graphics Display System should refer to
the GRAPHIC15 Programming Manual (DEC-15-ZFSA-D) for descriptions of
the associated device handlers VTA, LKA, and VWA.
1 Prior to program loading, one of these handlers must be assigned to
both .DAT slots.
2 Prior to loading this program, the .DAT slots must be reassigned to
one of the handlers listed here.

9-10

9.3.1

Teleprinter Handler (TTA)

9.3.1.l General Description : The teleprinter handler is embedded in '
the Resident Monitor and provides all functions necessary for teleprinter input/output. The handler performs I/ O using either !OPS ASCII
(Mode 2) or Image Alphanumeric (Mode 3) data. Table 9-2 lists the
handler's responses to the various I/O Macros.
Table 9-2
TELEPRINTER 1/0 FUNCTIONS

Macro

Response

.INIT
.FSTAT
.REN.AM
.DLETE
.RAND
.RTRAN
.SEEK

Accept
Ignore
Ignore
Ignore
Illegal
Illegal
Ignore
l;gnore
Ignore
Accept
Ignore
Accept
Accept
Accept
Accept
Illegal

. EN'l'_~-.CLEAR
.CLOSE
.MTAPE
.READ
.WRITE
.WAIT
.WAITR
.TRAN
Illegal =

Illegal Function (IOPS6)

9.3.l.2 Device Dependent Characte!istics - The following paragraphs
describe the characteristics which are unique to the teleprinter
handler in its response to certain I/O Macros and characters:
a.

.INIT

l) Maximwn I/O buffer size returned: 42 8 (34 10 >

Set up CTRL P restart address from address
specified in .!NIT argument "restrt". Refer
to the DOS-15 System Manual (DEC-15-NRDA-D)
for setup of the restart addresses for CTRL c •
and CTRL T.

Output Carriaqe RETURN/LINE FEED
9-ll

.CLOSE - Output Carriage RETURN/LINE FEED.

.WRITE - When in IOPS ASCII Mode a LINE FEim is normally
output automatically before the line (logical
record) is output unless an Overprint (2,0) is
the first character (see Table 9-3).

Non~Printing

Function Characters - The non-printing
function characters contained in Table 9-3
have special significance when input and output in IOPS ASCII mode.
Table 9-3

- SPECIAL NON-PRINTING FUNCTION CHARACTERS FOR IOPS ASCII TELEPRINTER I/O
FUNCTION
(ASCII in parentheses)
Carriage RETURN

TRANSFER
DIRECTION
Input

Insert all characters typed, including this Carriage RETURN, since the
last Carriage RETURN or ALT MODE,
into the requesting program's I/O
Buffer. Echo a LINE FEED on the
printer.

Output

Terminate output of the contents
of the requesting program's I/O
buffer. Output Carriage RETURN.

Input

Terminate the current line and insert all characters typed since the
last Carriage RETURN or ALT MODE into
the requesting program's I/O buffer.
Map into the I/O Buffer as 175.

output

Terminate output of the contents of
the requesting program's I/O buffer.

(,015)

ALT MODE

ACTION

(33, 175, 176)

1--------------~------..._

LINE FEED

______________ -- -- -

Input

Insert in requesting program's I/O
buffer.

Output

Ignore if this is the first character in the I/O buffer1 otherwise,
output.

(fll2)

--------------+-------+----------------------·-· -- VT (Vertical Tab)

Input

Insert in requesting program's I/O
buffer.

Output

Model 35 teleprinters output FORM
Feed.
Model 33 teleprinters ignore.

(fll3)

or
FORM Feed
(,014)

9-12

Table 9-3
FUNCTION
(ASCII in parentheses)
----··· ------ -

...

TRANSFER
DIRECTION

(Cont.)
ACTION

--------- -- --·---

-------------- --···------ -

Input

Insert in requesting program's I/O
buffer.

Output

Model 35 teleprinters output TAB
(.fill}.
Model 33 teleprinters output suff icient number of SPACES (,04,0) to
position printer at columns 9, 17,
25, .•• etc.

Skip One Line
(,021)

Output
Only

I f this is the first character- in the
requesting program's I/O buffer, skip
1 line. Otherwise, ignore.

Overprint
(,02,0)

Output
Only

If this is the first character in the

Horizontal TAB
C,IHl)

-·-·

requesting program's I/O buffer,
suppress the LINE FEED normally output.
Otherwise, ignore.
---

t-----

RUBOUT

Input
(177)

Delete the last character typed
previous to this and echo a backslash
(

1--------

CTRL U
{,02 5)

Null
(,0,0,0}
CTRL D
(,0,0~}

9.3.1.3

---

\ ).

-----·-·- --

·-···-··

Input

Delete all characters typed since
tile last Carriage RETURN or ALT
MODE, and echo an "at" sign ( @ )

Output

If typed while output is under way,
ttuncate the remainder of the logical
record being input and output an "at"
sign ( @ } plus Carriage RETURN.

Input/
Output

Ignore

Input

T:tansmi t to the requesting program's
I/O buffer a logical record which
consists of a header word pair only,
with the I/O Mode Bits (14-17) set
to ,01,01 to indicate end-of-file.
(See paragraph 6.3.1.1.)

------ -- .
-

----

Program Control Characters - The teleprinter retains its role

as control device during all I/O operations.
(CTRL C, CTRL P, CTRL

The CTRL characters

s, and CTRL Tl are recognized when typed, regard-

less of Data Mode or transfer direction.

These characters perform

specific system functions as described in 8.1 •

Experienced users who

wish to alter their meaning may do so using procedures described in
the DOS-15 System Manual fDEC-15-NRDA-D).

9-]3

9.3.2

Paper Tape Punch Handlers (PPA, PPB, and PPC)

9.3.2.1 General Description - There are three paper tape punch
handlers: PPA (571 8 registers), PPB (416 8 registers), and PPC (322 8
registers). All three handlers respond identically to the I/O
Macros, but differ as to the various data modes which are acceptable
to them. Table 9-4 lists the data modes which are acceptable and
Table 9-5 shows the handlers' responses to the I/O ~acros.
Table 9-4
PAPER TAPE PUNCH DATA MODES
Handler
PPA
PPB

_Data Mode
IOPS ASCII
IOPS Binary
Image
Alphanumeric
Image Binary
Dump

PPC

x
x
x

x
x

Table 9-5
PAPER TAPE PUNCH I/O FUNCTIONS
Macro

Response

.INIT
.FSTAT
.RENAM
.DLETE
.RAND
.RTRAN
.SEEK
.ENTER
.CLEAR
.CLOSE
.MTAPE
.READ
.WRITE
.WAIT
.WAITR
.TRAN

Accept
Ignore
Ignore
Ignore
Illegal
Illegal
Illegal
Ignore
Ignore
Accept
Ignore
Illegal
Accept
Accept
Accept
Illegal

Illegal

Illegal Function (IOPS6 Error)

9-14

9.3.2.2

Device Dependent Characteristics - The following paragraphs

describe the characteristics which are unique to the Paper Tape Punch
Handlers in their response to certain I/O Macros and characters.
a.

.INIT - 1)
2)

.CLOSE- 1)

2)
c.

Maximum I/O buffer size returned: 648 (5210).
Punches two fanf olds of leader.
Output EOF (end-of-file) header word pair
(see 6.3.1.l) as last record on the tape.
Punches two fanfolds of leader.

Special Characters - The characters listed in Table 9-6
have special significance to the handlers
when output in IOPS ASCII Mode. These characters, except TAB, are ignored if they do
not appear as the first character in a logical record (line).
If a LINE FEED, VT (Vertical Tab) , or FORM Feed does not appear as the
first character in a logical record, a LINE
FEED is supplied by the handlers.
Table

9-6

SPECIAL FUNCTION CHARACTERS FOR FIRST CHARACTER IN LINE
FUNCTION

ACTION 1

LINE FEED

Output.

(IJ12)

VT (Vertical TAB)
(l<Jl3)

Output, followed by four RUBOUTs 1

FORM Feed
(IJ 14)

Output, followed by 40 Nulls 1 (lrJl<JlrJ) •

Horizontal TAB
(IJll)

output, followed by one RUBOUT 1

9.3.3

(177).

Paper Tape Reader Handlers (PRA and PRB)

There are two paper tape handlers:
registers).

PRA (673 8 registers) and PRB (446 8
Both handlers respond identically to the I/O Macros, but

differ as to the data modes which are acceptable.

Table 9-7 lists the

data modes which are acceptable, and Table 9-8 shows the handlers' response to the I/O Macros.
1 The RUBOUT and NULL functions which follow output of the desired characters are used for hardware timing purposes when the paper tape is
to be transmitted to a printer in an off-line environment.

9-15

Table

9-7

PAPER TAPE READER DATA MODES
Handler
Data Mode

PRA

PRB

IOPS Ascii
IOPS Binary
Image
Alphanumeric
Image Binary
~Dump

x
x

x
x
x

Table 9-8
PAPER TAPE READER I/O FUNCTION
Response

Macro
.INIT
.FSTAT

Accept 1
Ignore
Ignore
Ignore
Illegal
Illegal
Ignore
Illegal
Illegal
Accept
Ignore
Accept
Illegal
Accept
Accept
Illegal

.RENAM

.DLETE
.RAND
.RTRAN
.SEEK
.ENTER
.CLEAR
.CWSE
.MTAPE
.RF.AD
.WRITE
.WAIT
.WAITR
.TRAN
Illegal

Illegal Function (IOPS6 Error)

Maximum I/O buffer size returned:

64 8 (52 10 1.

9-16

9.3.4

DECtape Handlers (O'l'A, DTC, O'l'D, DTE, and DTF)

9.3.4.l General Description - There are five DECtape handlers for
TU55/TU56 DECtape operation:
o

OTA (2761 8 locations) is the most general DECtape
handler provided. It has a simultaneous threefile capacity, either input or output. Input files
can be referenced on the same or different DECtape
unitsi however, not more than one output file can
exist on the same unit.
(I.e., file creation on
the same unit must occur sequentially.)

DTC (1261 8 locations) is the most limited and also
the most conservative of core (for IOPS data mode
operations) of the handlers. It is an input only
handler with a one-file capacity.

DTD (307i 8 locations) provides single file operation,
either input or output.

DTE (2674 8 locations) is simi1ar to DTD, differing
only in
its I/O function capabilities as shown in
Table 9-10.

DTF (11519 locations) is a handler which simulates
the non-directoried, sequential access file structure
of Magtape. It accommodates (serially) up to eight
DECtape units, both input and output. When the last
block of a tape on a particular unit has been accessed,
DTF oauses the Monitor to output an IOPS4 message
(Device Not Ready) to permit the operator to remove
the current tape from the DECtape drive and mount
another. The operator can then type a CTRL R to continue processi~.

·rable 9-9 illustrates the data modes which are acceptable to these
handlers, while Table 9-10 shows the handlers' responses to the various I/O Macros.
Table 9-9
DECTAPE DATA MODES
Data Mode

DTA

Handler
OTC
DTD

!OPS ASCII
!OPS Binary
Image
Alphanumeric
Image Binary
Dump

x
x

DTE

DTF

x .
x

x
x

x
x
··-- 1 - - - - -x
x

9-17

x
x

--·-···--t--·.

9.3.4.2

Device Dependent Characteristics - The following character-

istics are unique to the DECtape Handlers in their responses to certain
r/O Macros.
a . . !NIT - Maximum I/O buffer size returned: 377 8 (255 10 >.
b.

.MTAPE

DTD accepts REWIND and BACKSPACE RECORD
subfunctions only.

DTF accepts REWIND, BACKSPACE RECORD and
SKIP RECORD subfunctions only.
Table 9-10
DECTAPE I/O FUNCTIONS
Handler

Macro
.INIT
.FSTAT
.RENAM
.DLETE
.RAND
.RTRAN
.SEEK
.ENTER
.CLEAR
.CLOSE
.MTAPE
.READ
.WRITE
.WAIT
.WAITR
.TRAN

9.3.S

OTA

OTC

DTD

DTE

DTF

Actept

Att t

Illegal

r11Igal Illegal Illegal

II::
Illr Illr
Illr Acrl "T'
Accept

Illegal

•

Illegal

Accept Illegal

Ignore

Illegal

Ignore

+ Illegal

Ig~ore

Aclept

Illegal

Illlal

DE.Cdisk and Disk Pack Handlers (DKA/DPA, DKB/DPB, and DKC/DPC)

9.3.5.1

General Description - Three handlers are provided for RV-15

DECdisk and RP-02 Disk Pack operations.

Version for version, these

handlers are identical in their functions with these two exceptions:

While both the DECdisk and Disk Pack are block addressable for direct access operations (.TRAN and .RTRAN
Macros) the DECdisk in addition provides word addressability.
9-18

The Disk Pack has a unit structure while the DECdisk
does not.
This means that each DECdisk is treated as
a single addressable unit regardless of the actual
number of platters incorporated (up to 8).

All versions of these handlers support the disk file structures described in Chapter3.

There is no fixed limit as to the number of input

or output files which can be simultaneously accessed, except as determined by the amount of available buffers.

To this end, the handlers

perform dynamic buffer allocation from the Monitor's buffer pool, using
the .GTBUF and .GVBUF Monitor Macros described in Chapter 5.

At run

time, the operator need only be concerned that the number of files concurrently accessed is not greater than the number of buffers allocated
by the BUFFS Keyboard command (see 8.6.1).
The following colllllands obtain buffers from the pool, and return them
immediately upon completion of the operation:
.DLETE
.RENAM
.CLEAR

The following commands obtain a buffer from the pool and do not return
it until a subsequent .CLOSE, .INIT or Rewind (.MTAPE) is performed:
.FSTAT
.ENTER
.SEEK
.RAND
The following conunands return a buffer to the pool, if any·was taken:
.INIT
.CLOSE
.MTAPE (Rewind subfunction)
The handlers operate in all data modes (i.e., IOPS, Image, and DUllip).
Table 9-11 lists the I/O Macros which are acceptable to the various
handler versions.

9.0.19

Table 9-11
DECDISK AND DISK PACK I/O FUNCTIONS
Handler
DKB(3631 8 )
DPB(4007 8 )

DKA(4274 )

Macro

DPA(4561~)

.INIT
.FSTAT
.DLETE
.RENAM
.RAND
. RTRAN
.SEEK
.ENTER
.CLEAR
.CLOSE
.MTAPE
.READ

.WRITE
.WAIT
.WAITR
.TRAN

•

Accept
Accept

Illegal

Accept
Accept
Illegal
Accept
Illegal

DKC (21638)
DPC (22758)

Illegal

•

Accept
Illegal
Illegal
Accept
Illegal
Accept
Illegal
Accept
Accept
Illegal

9.3.5.2 Device Dependent Characteristics - The following characteristics are unique to these handlers in responding to certain I/O Macros:
a.

. !NIT
ll Maximum I/O buffer size returned: 376 8 (254 10 ).
2) The disk handlers allow write verification on output files.
If the file is defined as an output file, the user has the
opportunity of guaranteeing the integrity of his data by
using 11 8 as the "dd" argument to the .!NIT macro. The
handler will then check every block of data it writes
out, to ensure that the transfer occurred without error.
A second .!NIT command must be executed to remove or add
the write checking feature.
31 An output file already opened on a .DAT slot referenced by
.INIT will be deleted. If a .!NIT references a .DAT slot
with an opened input file, the handlers will close it,
and give back the buffer it was using.
4) Control is retained until all necessary I/O is complete.
5)
The .INIT macro uses the relationship between the User
File Directory Table and the Device Assignment Table to
get the correct UIC from the User File Directory Table.
If the user is changing UIC's under program control (via
.USER macros), the operation must be accomplished before
a .!NIT in order to obtain the desired UFD.
9•20

.DLETE
1)

Control is not returl,ned until all necessary Disk I/O is
complete.
If the UIC associated with this .DAT slot
does not exist in the MFD, or if the named file can not
be found, the disk handlers ignore this macro.
If the
name is found, the h andlers return the first block number of the file in the AC. The buffer used by the handlers to delete the named file is given back to the buffer pool upon completion of the .DLETE.
1

The .DLETE macro follows the protection rules for directory modification. That is, .DLETE will not work on
a protected directory, but returns an !OPS 63 error.

.RENAM
1)

The first block number of the renamed file is returned
in the AC after a successful operation.
If the file or
UFO does not exist, the handlers return to LOC+3 with
, in the AC.
.RENAM changes the renamed file's date to
the current date (maintained by the DATE keyboard corrunand
described in Chapter 8).

At completion of the .RENAM function, the handlers return the buffer to the buffer pool.

The .RENAM macros must follow the protection rules for
directory modification. That is, .RENAM will not work
on a protected directory (IOPS 63).

.ENTER
1)

The handlers check for directory protection. If any of
the following conditions is satisfied, the handlers will
allow successful operation.
If none is satisfied, the
handlers will terminlate with an IOPS 63.
Conditions for gaining UFO access:
Entry in .UFDT equals the logged-in UIC
Logged-in UIC equals MIC
Directory protection code equals ,

Once the entry in the UFO has been made via the .ENTER,
the file is defined as being opened and truncated.
Upon
a subsequent .CLOSE, the file will exist as a closed
file, but not truncated.

When. a .ENTER is done with a file name that already
exists, the old file is deleted only after the new
file (just .ENTERed) is .CLOSEd, i f the old file is not
truncated. If the old file is a truncated file, it is
deleted immediately, before the new file is listed in
the UFO. The process of deletion of identically named
truncated files continues until a non-truncated file
with the same name is found. At this point, the new
directory entry is made. Truncated files which follow
are not deleted. In all cases, UFO searches are
sequential starting at the beginning.

9-21

.CLEAR
1) The disk handlers will not hono:r .CLEAR unless the user
has logged in under the MIC. The .CLEAR function deletes
all files and directories on the entire disk. All bit maps
are closed and indicate only the space which they occupy.
The MFD will have no UFD's, SYSBLK or BAT. An I/O buffer
is obtained from the pool for this operation and is subsequently returned on its completion.
.CLOSE

.READ

All .READ commands executed after an end-of-file
(EOF) header has been reached will return an EOF
in header word .0 (.0.01.0.05).

.MTAPE
1)

On input, the handlers give the buffer back (if
one was acquired) and make the .DAT slot available
for subsequent .INITs. On output, the handlers
write an end-of-file record (if the user did not
already write one), and then proceed as on input.

OKA and DPA accept the REWIND and BACKSPACE subfunctions during input only. REWIND is effectively
a .CLOSE.

.TRAN
l}

The .TRAN is not included as part of the disk file
structure. That is, all blocks read or written are
done so at the user's discretion. MFD's, UFD's,
Bit Maps, and RIB's are not considered, and are not
protected from the .TRAN macro. The .TRAN macro is
allowed to any .DAT slot that has been .INITed, and
not .CLOSEd or rewound (via a .MTAPE).

For the RF DECdisk, the user can reference a specific
platter just by identifying the block number he
wants. The block numbers and platter relationships
are shown below:
Platter Number

.0-1777

2rJn-3111

4.0J'l.0-5777
6,0,0,0-7777
1.0.0.0.0-11777
12J'l.0.0-13777

4
5
6

14.0.0~-15777

16f".0J'l-17777

Block Number

.FSTAT
1)

Normal operations, except that a subsequent .SEEK
to a file found via .FSTAT will not require redundant ·
disk access. That is, both .FSTAT and .SEEK ordinarily
require a minimum of three disk accesses -- one to the
MFD, one to the UFD, and one to the file. If the user
does a .FSTAT to an existing file, and then a .SEEK,
the disk handlers "remember" the successful .FSTAT,
and do not do an extra disk access.
9-22

.RAND

.RAND commands to a nonexistent file cause an IOPS13.
Those to a nonexistent UFD cause an IOPSSl. Those to
an empty UFD cause an IOPS71.

.RTRAN
ll

The disk pack handler ignores the word number argument
(assumed to be ~) and returns the whole block. If the
word number plus the word count exceeds 254 10 , the
disk handlers will return IOPS67.
output .RTRAN to the RP disk requires 25610-word buffers to allow the handlers to supply the ~Orrect
links in the last two words,
(Otherwise, random
files would require two buffers from the pool,)
If the block humber argument requested by the .RTRAN
is less than one, or greater than the number of blocks
in the file, an IOPS66 will result.

9.3.6

Magtape Handlers (MTA, MTC, and MTF)

9.3.6.l General Description - Three handlers are provided for operation
of Magtape drives TUlO, TU20A, TU20B, TU30A, and TU30B. These handlers
permit control of up to eight transports.
0

MTA (4600A locations) is[ the most general and permits
either industry-standard ~agtape file structuring,
using the .MTAPE Macro, or DECtape file structuring
using .SEEK and .ENTER Macros (refer to Chapter 4).
When treated as DE~~. Up ~o- three files can be
concurrently referenced, each on a different transport, either input or output.

MTC (1253A locations) is a read-only handler designed
for operation using DECt~pe file structuring only.
It has a single file capacity; sequential file references are, of course, allowed.

M'l'F

(1307 8 locations) is designed for Magtape file
structuring only. It acex>mmodates up to eight concurrently referenced transports, both input and output.

The track count (either 7- or 9-channel) can be set at System Generation, or by using the CHANNEL Keyboard Command. IR addition, it can
also be set dynamically, along with parity and recording density parameters, using the .MTAPE I/O Macro (see paragraph 6.7.7) when using
Magtape file structuring. When using DECtape file structuring, parity
and density are fixed at odd parity and 800 BPI recording density.
Table 9-12 lists the Data Modes acceptable to the handlers and Table
9-13 lists the I/O Macros and their responses.
9-23

Table 9-12
MAGTAPE DATA MODES
Data Modes

MTA

Handler
MTC

MTF

IOPS ASCII
IOPS Binary
Image
Alphanumeric
Image Binary
Dump

x
x

x
x
x

Table 9-13
MAGTAPE I/O FUNCTIONS
Maero
.INIT
.FSTAT
.RENAM
.DLETE

.RAND
.RTRAN
.SEEK
.ENTER
.CLEAR
.CLOSE
.MTAPE
.READ
.WRITE
.WAIT
.WAITR
.TRAN
Illegal

MTA

+--

-"j~!

Illr
Illegal

Accept
I

Handler
MTC

Ilrl
-

Accept
Illegal
Illegal
Accept
Illegal
Accept
Illegal
Accept
Accept
Illegal

MTF

Acr
Illegal

•

Illegal Function (IOPS6 Error)

9-24

9.3.6.2 Deviee Q~e'1den\>.gnqracterist;\c;!il,,- The filist .INIT to a Magtape
unit causes the system default parameters for track count, recording
density, and parity to be assigned as follows:
Parity odd
Density 800 BPI
Track Count - System Generated Default unless otherwise specified in the CHANNEL Keyboard Command.
(See Paragraph 8.9.3.)
The following characteristics are unique to the operation of the A and
C handlers in responding to the I/O Macros below:
a . . INIT - Maximum I/O buffer size returned: 376 8 (254 10 ).
b.
.MTAPE - MTA accepts REWIND and BACKSPACE RECORD subfunctions only.
The following characteristics are unique to the operation of the MTF
handler:
a.
b.

c.
d.

.!NIT - Returns standard buffer size of 377 8 •
.MTAPE - On functions 05, 06, and 07 (skip record, skip
file, and skip to logical end-of-tape), if the handler
senses phycical end-of-tape, !OPS 65 is issued.
.READ - Bad Tape and Data Late errors are considered unrecoverable and MTR issues IOPS 65 for them.
.TRAN - Permits either the PDP-15 standard 18-bit transfer
(both 7 and 9 track look like 7 track) or the industry standard 9-track transfer. In true 9-track operation, entered
by setting bit 6 of the CAL to 1, each lB-bit word is interpreted as two 8 bit bytes of data plus associated parity
bits (which are set on output and checked on input by the
hardware). Tpus:
A parity

Byte A

Byte B

2 .... 9

Ul - 17

1..1-..-1------..--------.
~

9.3.7

B parity-"'
Line Printer Handler

9.3.7.l General Description - LPA (541 8 locations) is designed to
operate both the BO column and 132 column LP15 Line Printers. The
handler accepts data in either !OPS ASCII or Image Alphanumeric data
modes.

Table 9-14 lists the various I/O Macros and the handler's

response to them.
Table 9-14
RESPONSES TO LINE PRINTER I/O FUNCTIONS
Accept
.INIT
.CLOSE
.WRITE
.WAIT
.WAITR

Illegal
(!OPS 6)
.RAND
.RTRAN
.SEEi\
.READ
.TRAN

9-25

Ignore
.FSTAT
.RENAM
.DLETE
.ENTER
.CLEAR
."I.TAPE

9.3.7.2 Device Dependent Characteristics - The following paraqraphs
describe characteristics which are unique to the Line Printer Handler
in its response to certain I/O Macros and characters.
a.

.INIT - 1) Maximum I/O buffer size returned: 66 8 (54 10 >
for 132 column printers;
44 8 (36 10 > for 80 column printers.
2) Output FORM· Feed.
3) Test Bit 6 of the .INIT CAL (see 6.7.6).
If set, inhibit FORM Feed each 57 10 lines.
(This bit is set by using a 5 rather than a 1
•in the "dd" argument of the .INIT.)

b . • CLOSE - Output a FORM Feed (if not inhibited in the .!NIT)·
c.

.WRITE - 1)

Examine header word 1' in the user's I/O
buffer as follows:
Meaning
1' = Enter Single Line Mode

1 = Enter Multiple Line Mode

1-8

Contains Line Count for
Mµltiple Line Mode

14-17

Data Mode
2 = !OPS ASCII
3 = Image Alphanumeric

Check the first character of the user's I/O
buffer for the following vertical form control characters, all of which are output
by the FORTRAN IV Object Time System:
/114
/121'
/121
/112

FORM Feed
Overprint
Print every second line
Line Feed

To effect the Overprint function for FORTRAN
users, it is necessary to simulate certain
vertical form control characters. If the
first character of a line is /112, /114, or /121,
the handler automatically enters Multiple Line
Mode (by setting bit 1' of the first word in
the user's I/O buffer to l) and prints two
lines, the first line being the vertical control character, and the second line being the
actual data. If the first character is /121'
(overprint), it is replaced in the user's
I/O buffer by /115 (Carriage Return) which
does not affect the page position and both
lines are printed. All other characters cause
a Line Feed to be output from the handler's
internal buffer followed by the line from the
user's buffer. After output, any data in the
user's I/O buffer which was changed (i.e., header
word 1' or the first data word) is restored.
9-26

If the user intends to output to another device
from the same I/O buffer (e.g., two sequential
.WRITEs), a .WAIT should be used after the .WRITE
referencing the Line Printer to permit the restoration of any data which may have been replaced
in the user's I/O buffer by LPA.

Output in either Single Line Mode or Multiple
Line Mode as applicable.

Restore modified portions of the user's I/O
buffer (if changed).

carriage Control Characters - The control characters in Table
9-15, except horizontal TAB, cause line termination, in both !OPS and Image Modes, except for
sp~cial cases described under .WRITE above.
Table 9-15
LINE PRINTER CARRIAGE CONTROL CHARACTERS

Character

Action

Line Feed (,012)

Space one line

VT (Vertical Tab)
Form Feed

(,013)

(~14)

Space 20 lines
Move to top of form

Carriage Return (015)

Reset column count to zero (no
implicit LINE FEED function)

DLE (,02,0) "I

Space 30 lines

DCl (,021}
DC2 (.022)
DC3 (,023)

)

Refer to Appendix

S~ace 2

A for alternate

Space 3 lines

designations

Space 1 line

lines

DC4 (,02 4)

Space 10 lines

ALT MODE (175)

Reset column count to zero (no
implicit LINE FEED function)

Horizontal Tab

9.3.8
9.3.B.l

(~11)

Output sufficient number of spaces
to position printer at column 9,
17, 25, ••• ,etc. This is not a
line terminator and may occur anywhere in the line.

Card Reader Handler (CDB)
General Description - COB (770 8 locations) is designed to

operate the CR03B card reader.
ASCII mode only.

The handler transmits data in IOPS

As initially supplied, it interprets Hollerith code

as punched in DEC 029 Card Code.

CDB is also supplied in source form

which can be assembled to produce a version of the handler which interprets Hollerith punched in DEC 026 Card Code 1 •

Appendix F contains a

1 Refer to the §GEN manual Tor procedures for assembling and installtng
the 026 code version of COB.

.9-27

table of 029 and 026 Hollerith codes and the corresponding !OPS ASCII
codes.

Table 9-16 lists the handler's response to the various I/0 Macros.
Table 9-16
CARD READER I/O FUNCTIONS

Macro

Response

.INIT

.FSTAT

Ignore

.~ENAM

Ignore

.DLETE

Ignore

.RAND

Illegal

.RTRAN

Illegal

.SEEK

Ignore

.ENTER

Illegal

.CLEAR

Illegal

.CLOSE

.MTAPE

Ignore

.READ

.WRITE

Illegal

.WAIT

.WAITR

.TRAN

Illegal

Illegal - Illegal Function (IOPS6 Error)

9.3.8.2

Device Dependent Characteristics - The following paragraphs

describe the characteristics which are unique to the Card Reader Handler
in its response to certain I/O Macros.
a.

.INIT - Maximum I/O buffer size returned: 44 8 (36 10 )

.READ

Eighty card columns are read and interpreted
as 029 or 026 Hollerith data, mapped into the
corresponding 64-graphic subset of ASCII, and
stored in the user's I/O buffer in 5/7 format
(36 10 locations are required to store an 80
colilirln card). Compression of internal blanks
to tabs and truncation of trailing blanks is
performed (all 80 characters appearing on the
card are delivered to the user's buffer).
In
addition, a carriage RETURN (~15) character is
appended to the input line; thus, a total of 81
characters are returned to the user.

9-28

Illegal punch configurations ~ all illegal punch configurations (i.e., those not appearing in the 029 or
026 character set shown in Appendix F) are interpreted as validity errors and will cause an
IOPS 4 error condition. The card containing
the error must be repunched.

Special Codes - In addition to the Hollerith character set,
the handler recognizes the ALT MODE terminator
which is necessary for some system programs.
ALT MODE, reaognized as a 12-8-1 code (multiplepunched AS) ~s mapped in to the standard ALT
MODE character (175) in the user's buffer.
Each file must be terminated with an EOF card
punched in either of two ways: a) multiple
punch the characters +-0123456789 which punches
all positions in card colwnn 1, or b) multiple
punch characters A~- which produces a 12-11-9-1
punch in card column l.
NOTE
The card reader handLer used when the system is
operated in Command Batching Mode (described in
paragraph 8.12) is a separate handler similar to
COB, but resident in the Monitor itself. As initially supplied, it :interprets cards punched in
DEC 029 Hollerith Code. Another version, which
recognizes DEC 026 Hollerith Code can be installed into the system using procedures
contained in the SGEN Manual.

9.3.9

VP15A Storage Tube Display (VPA)

VPA (1213 8 locations) operates the VP15A Storage Tube Display. It
accepts data in IOPS ASCII, Image Alphanumeric and Dump Modes. In
IOPS ASCII and Image Alphanumeric Modes, up to 70 8 (56 10 > 72-character
lines can be displayed. In Dump Mode, the handler interprets each
18-bit data word as a coordinate for point plotting operations.
Two versions of VPA are provided. The version installed in the system
as initially supplied (1144 8 locations) automatically erases the screen
when an attempt is made to display the 57th ASCII line and· that line
is placed at the top of the screen.; The other version of VPA, which
has a file name VPA.S, is slightly larger (1211 8 locations). It permits the user to operate the display in a "paging" mode by settinq AC
switch ~ (when set to 1) to inhibit further output once the 56th ASCII
line is displayed. Operation is resumed by pressing the ERASE pushbutton, Paging is stopped by resettinq AC switch~ to ~. 1
1 Refer to the SGEN' Manual for procedures for installing the VPA.S version of VPA.

9-29

Table 9-17 lists the handler's response to the various I/O Macros.
The user should refer to the VPlSA Graphics Software Manual (DEC-15UXSB-D) for a detailed description of the handler's capabilities and
programming considerations.
Table 9-17
VPlSA DISPLAY I/O FUNCTIONS
Macro

Response

.INIT
.FS'!IAT
.RENAM
.DLETE
.RAND
.RTRAN
.SEEK
.ENTER
.CLEAR
.CLOSE
.MTAPE
.READ
.WRITE
.WAIT
.WAITR
.TRAN

Accept
Ignore
Ignore
Ignore
Illegal
Illegal
Illegal
Ignore
Ignore
Accept
Ignore
Illegal
Accept
Accept
Accept
Illegal

Illegal

= Illegal Function (IOPS6 Error)

9-30

l.:HAPTER 10
OPERATING PROCEDURES
10.1

INTRODUCTION

This chapter provides general operating procedures and considerations
to assist novice users in operating in the DOS-15 Monitor environment.
Procedures for system startup and system generation are the subject
of Chapter 7 and are not included here. The discussions and examples
in this chapter assume a properly configured and running system. It
is assumed that the reader is familiar with the keyboard commands, as
defined in Chapter B. Further, the user should be aware of the different types of I/P device handlers and their versions, as described
in Chapter 9, and in particular, the tables which list those handlers
which can Qe used with the DOS-15 $ystem programs.
Specific operating procedures for the system programs (i.e., command
strings, options, functions, error messages, and so on) are provided
in the various language and utility program manuals listed in the
Preface. Once a user gains some understanding of the use of the system programs and their commands from these manuals, he will find that
the DOS-15 Keyboard Command Guide (DEC-15-NGKA-D) provides most of
the information normally required for day-to-day user reference.
Since most procedures involved with keyboard operation are specific
to particular programs, very little will be said here about them.
In general, keyboard operations at the Monitor level consist of
issuing commands to set up system operation, prior to calling system
and user programs. This usually involves at least the LOGIN and
LOGOUT commands, and quite often requires the PIP program, as well.
This chapter consists primarily of two large examples of what might
be typical DOS-15 operations. Each example is the result of an
actual session at the PDP-15. On the left side of each page of the
examples is the actual teleprinter output. All commands typed by
the user are underlined. On the right is a running commentary on
all significant teleprinter lines.
10.2

EXAMPLE OF KEYBOARD OPERATIONS

Figure 10-1, Example of DOS-15 Keyboard Operating Procedures, demonstrates some typical keyboard procedures. The example consists of
a series of operations in which a simple FORTRAN program is trans10-1

ferred to the disk from DECtape, edited, compiled run, and transferred back to DECtape. Figure 10-2, Listing of Sample FORTRAN Program, shows the program.

The program simply prints the numbers 1

through 10 on the device associated with .DAT slot 4, and then returns
control to the Monitor.

Figure 10-3 shows the teleprinter output,

without comment.
The user types CTRL C to prepare
the Monitor for keyboard command
input.
If no response, the Monitor
must be reinitialized using the
bootstrap -- see Chapter 7.

DOS-15 VIA
ENTER DATE CMM/DD/YY) - 11/2/71

If the Monitor requests a date (indicating it has just been started
via the bootstrap) enter it as required. Otherwise check the date
(type D.J ) to make sure it is current ana correct it if it is not.

$LOGIN JOE

If the user wishes to use disk
storage, he must log-in to the
Monitor with a UIC of his creation.

At this point, the user might consider typing other commands such
as: VT ON, KEEP ON, X4K ON, PROTECT
etc.
(refer to Chapter 8) •

$J>IP

Call PIP

DOSPIP VfSA
Request a User File Directory
listing to see if there is enough
space available for the operations
to be performed.
(Since there
are 5323 blocks indicated, the
user can continue.
If enough
space were not available, however,
other files in the UFD would have
to be deleted.)

>L TT..DK

02-NOV-71

DIRECTORY LISTING
1EiEi0 FREE BLKS
13 USER FILES
3Ei2 USER BLKS
DKECHO 001
6

T
T

001
002

3
I
11116

LEF'

SRC

JOB

BIN

AL
AL

SRC
Fl! N

II
3

MAX

045

ACCT

~54

>T DK ..

CJOE>

02-NOV-71
02-NOV-71
02-NOV-71
02-NOV-71
02-NOV-71
02-NOV-71
02-NOV-71
02-NOV•71
02-NOV-71

If the user had no previous UFO]
on.the disk, he would create one
[ using the PIP command

N.JJK)
Transfer program (FTNTST SRC)
from user's DECtape to disk.

or F'TNTST SRC

Figure 10-1
Example of DOS-15 Keyboard Operating Procedures
10-2

Return to the Monitor

>tC
DOS-15 VIA
EDIT

.DAT
-15
-14

- !QI

OF.VICE
OKA
OKA
TTA

UIC
JOF.
JOE
JOE

USE
OUTPUT/SCRATCH

Examine the .DAT/.UFDT slots
for the EDITOR for proper
assignment (no change required
in this case).

I/O

SECONDARY INPUT

Call the EDITOR to correct any known
errors on the file program prior to
assembly or compilation.
(In this
case the FORTRAN comment line ·
descriptor "C" was missing and must
be inserted,

EDITOR VISA
>OPEN FTNTST

Open the file for editing.

EDIT

>P 4

Locate ertor (i.e.,print some lines)

EXAMPLE - SAMPLE FORTRAN TEST PROGRAM

Go back to the top of the file.
Point to the error line.

>T
>N ?.
~

>Ll!S:l.
c

>CLOSE

Error line (the comment descriptor "C"
is missing)

Print it out as added precaution.

EXAMPLE - SAMPLE FORTRAN TEST PROGRAM
EXAMPLE - SAMPLE FORTRAN TEST PROGRAM

Add the "C" to the
beginning.

Close the file

EDITOR Vl8A
>~

Return to the Monitor.

DOS-15 VIA

m F4
.DAT
-13
-12
-11

DEVICE
DKA
TTA
DKA

$A TT -12

UIC

JOE

JOE
JOE

USE
OUTPUT
LISTING
INPUT

Examine the .DAT/UFDT slots for the
FORTRAN compiler for proper assign.ment.
(In this case the user wished
to have his listing on the teleprinter, rather than the line
printer.)
Assign the teleprinter to .DAT-12.

Figure 10-1 (Cont.)
Example of DOS-15 Keyboard Operating Procedures
10-3

$,E!

Call FORTRAN Compiler.

F'4)(' V?.8A

Issue command string.

>L ,B .. FTNTST

END PASSI

c
c
c

001
002
003

004
005
006
007
008

l
100

F4X V28A

Program listing output begins.

EXAMPLE - SAMPLE FORTRAN TEST PROGRAM
DO I I : I , 11/J
WRITE <4, 100>1
FORMAT C6X,I3>
STOP 12345
END

>tC

Compilation complete.
Return to the Monitor.

DOS-15 VlA
$fl USER

DEVICE
DKA
DKA
DKA

.DAT
+l
+2
+3
+4
+5

TTA

PRA

Examine the .DAT/UFTD slots for
available user programs.
(This
program uses .DAT slot 4 as referenced in the FORTRAN WRITE statement in the listing above.)

UIC
JOE
JOE
JOE
JOE
J1f

CTRL P typed to abort remainder of
typeout.

TT 4

Assign the teleprinter to .DAT
slot 4.
Call the Linking Loader (load and
go command.
Give conunand string.

$GLOAD

BLOADER Vl2A
>t-FTNTST

Program is loaded and execution
begins.

2
3
4

5
fi

7
R
9
lQI

STOP

01?.345

DOS-15 VI A

End of program execution. The
Monitor is called automatically by
the FORTRAN STOP statement.

$PIP

Call PIP.

DOSP!P VfiA
Transfer edited source file from
disk to DECtape.
Device Not Ready error - the user
forgot to WRITE ENABLE the DECtape
unit.

>T DTl ..DK FTNTST SRC
IOPSL! tR
Figure

10-1 (Cont.)

Request User File Directory listing
to examine the contents after current series of operations.

>.1..__IJ~JUS.

02•NOV•71
DIRF.CTORY LISTING (JOE>
1656 FREE flLKS
15 USER FILES
.36 4 IJSER flLKS
DXECHO 00 l
6 02-NOV-71

T
T

001

3
I
1"6

002
LEF
SRC
JOB
fl IN
AL
SRC
AL
BIN
MA:X
fll45
FTNTST SP.C
FTNTST BIN

15
11
3
3

I
1

l/J2-NOV·7l
02-NOV-71
02·NOV•71
l/J2•NOV•71
02-NOV-71
l/J2•NOV•71
02-NOV-71
l/J2-NOV·71
l/J2•NOV•71

>D DK F"TNTST SRC

D0~-15

Delete source file (User decides to
keep only his binary file on the
disk)
Return to the Monitor.

VIA

$LOGOUT

Current sessfon at the computer is
completed. Oser logs-out.
Figure 10-1 (Cont.
Example of DOS-15jKeyboard Operating
ProcEfdure

I/Jiil l

l/Jl/J2

EXAMPLE - SAMPLE FORTRAN TEST PROGRAM

>1111 I c •--------(diagnostic)
t/HIJ3

004
005
006
01117

008

1
100

DO l I: I , 10

WRITE <4,11110)1
FORMAT CGX,I3>

STOP 12345

END

Figure 10-2
Listing of Sample FORTRAN Proqram

10-5

DOS-15 VlA
ENTER DATE CMM/DD/YY) • 11/2/71
SLOGIN JOE

$PIP
DOSPIP V6A
>L TT..DK
02•NOV•71
DIRECTORY LISTING CJOE)
1660 FR EE ALKS
13 USER FILES
362 USER BLKS
DKECHO ~11.11
6 82-NOV-71
T
001
3 02-NOV-71
T
0A2
I 11.12-NOV•71
LEF
SRC
lf1.16 11.12-NOV-71
JOB
BIN
15 11.12-NOV-71
AL
SRC
11 02-NOV-71
AL
BIN
3 02•NOV•71
MAX
11.145
3 11.12-NOV-71
ACCT
654
3 f212-NOV-71

>T DK ..or rTNTST SRC
>tC

DOS-15 VIA
$R EDIT

.DAT
-15
-14
-H'I

DEVICE UIC

USE

JOE
JOE
JOE

I/0

OKA
OKA
TTA

OUTPUT/SCRATCH

SECONDARY INPUT

$EDIT
EDITOR VISA
>OPEN FTNTST
EDIT

>P 4

c
c

EXAMPLE - SAMPLE FORTRAN TEST PROGRAM

Figure'l0-3
Uncommented Listing of Keyboard Operating Session

10-6

>T
>N 2
>P
>C I/Cl

>CLOSE

EXAl'IPU: • SAl'IPLE FORTRAN TEST PROGRAM
EXAMPLE - SAMPLE FORTRAN TEST PROGRAM

EDITOR VISA
>tC
DOS•l5 VIA
$F1 F 4

.DAT
-13

-12
-11
$A

DEVICE
DKA
LPA
DKA

UIC
JOE
JOE
JOE

USE
OUTPUT
LISTI NG
INPUT

TT -1"2

SF.II
F4X V28A
>L ,B ... FTNTST
END PASSI
001
002
llJ03
l/JflJ.4
llJ05

eJllJ5

c
c
c
I

I AA

0fl7

008

F4X V28A
>tC

EXAMPLE - SAMPLE FORTRAN TEST PROGRAM
DO I I : I, 11/J
WRITE C4,lfll0>I
FORMAT C5X ,I 3)
STOP 12345
END

DOS-15 VIA
$R USER
.DAT
+I
+2
+3
+4
+5

$A TT 4

DEVICE
DKA
DKA
DKA
LPA
PRA

UIC
JOE
JOE
JOE
JOE
..,.ztP

$GLOAD

Figure 10-3

(Cont.)

Uncommented Listing of Keyboard Operating Session

10-7

RLOADER Vl2A
>t-FTNTST
1
2
3

6
7
8
9

STOP

UJ
fll12345

DOS-15 VIA·
$PIP
DOSPIP V6A
>T DTt-DK FTNTST SRC
IOPS4 tR
>L TT..DK
l(;-NOV-71
DJPECTOPY LISTING <JOF.>
1525 FPF.:E RLKS
13 USER nu:s
161 IIBEP RLKS
r>KECHO 001
6 16-NOV-71
T
fllflll
3 16-NOV-71
T
002
1 16-NOV-71
LF:F
SR C
106 lt;-NOV-71
JOB
BIN
15 16-NOV-71
AL
SRC
11 16-NOV-71
AL
BIN
3 16-NOV-71
MAX
fll45
3 16-NOV-71
ACCT
(;54
3 16-NOV-71
FTNTST BIN
I 16-NOV-71
FTNTST SRC
I 16-NOV-71
>D DK FTNTST SRC
>tC
DOS-15 VIA
$LOGOUT
$

Figure 10~3

(Cont.}

Unconunented Listing of Keyboard Operating Session

10-8

10.3

EXAMPLE OF OPERATING PROCEDURES USING COMMAND BATCHING MODE

The example which is contained in Figure 10-4 demonstrates typical
operations using the Monitor's Command Batching Facility. Figure
10-5 contains just the console teleprinter output without comment.
Essentially the same types ·of operations which can be performed at
the keyboard can be accomplished using Command Batching Mode. There
are, of course, some operations which, although legal, are more difficult to accomplish, such as editing. To prepare a job for Command
Batching Mode, the Programmer creates a file of keyboard commands
in the sequence in which they would normally be issued from the teleprinter, interspersed with the special batching commands described in
paragraph 8-12 (as applicable). The file can exist either on punched
cards or paper tape. The programmer then submits the batch file and
other required data (DECtapes, Magtapes, etc. for use during the job
run) to the computer operator for qxecution along with appropriate
instructions. Users who prepare b~tching files on punched cards
should remember to place an end-of~f ile card at the end of the card
deck. This card is created by mul~iple punching all punch positions
in card column 1 (see 9.3.8.1 d).
The example below is basically similar to that in 10.2 except that
no editing is performed since it is more easily and accurately accomplished by the programmer directly. Similarly, requests for device assignments were also omitted since this information cannot be
utilized at runtime in a batching environment.

10-9

$tC

The operator types CTRL C to prepare the Monitor for keyboard command input.

$BATCH PR

Instruct the Monitor to enter Command Batching Mode with the paper
tape reader as the batching input
device (the batch tape has already
been loaded in the reader).

DOS-15 VIA

The Monitor reinitializes itself
indicating it has entered Command
Batching Mode.

$$JOB TEST COMMAND BATCHING MODE

$JOB must be the first command on
the batching medium.
(The programmer titles his batch run "TEST COMMAND BATCHING MODE".)

Log-in the UIC to be used.

$LOG

PLEASE MOUNT DECTAPE
CONTAINING "F"TNTST SRC" ON
DECTAPE UNIT 1 AND SET
TO WRITE ENABLE
THANKS

$$PAUSE
tP

The programmer uses the LOG command
to give instructions to the operator.

The $PAUSE stops the job to permit
the operator to comply with the
instructions. The operator types
CTRL R to continue operation.

Call PIP.

ill

DOSPIP Vl\A

>I DK~DTl FTNTST SRC

>hllm

Transfer the file to be compiled to
the user's disk file area (it is
assumed in this example that the
user has already created a UFO for
himself at some previous time).
Return to the Monitor.

DOS-15 VIA

Figure 10-4
Example of Conunand Batching Mode
10-10

$A IT •12

Assign teleprinter to .DAT slot -12
(user should know standard assignments for his system) to permit
PORTRAN listing to be output to it.
Call the FORTRAN Compiler.

F4X V28A
>L ,B , .. FTNTST
END
001

Issue command string.

PASSl

c
c
c

002

00.3
11H1J4
005
1
006
100
007
01?J8
F4X V28A

Program listing output begins.

EXAMPLE • SAMPLE FORTRAN TEST PROGRAM
DO 1 I= I, 10

WPITE C4,11110>I
FORMAT C6X,I 3)

STOP 12345

Compilation ends.

>$JOH
DOS-15 VIA

Return to the Monitor.

$A TT 4

Assign the teleprinter to .DAT
slot 4 (the user wants his program
to use the teleprinter rather than
device normally assigned to .DAT 4).
Call the Linking Loader (load and
go command) •
Issue command string.

$filJl.AQ
RLOADER Vl2A
> .. FTNTST
1

Program is loaded and execution
begins.

2
3
4
5
11)

7
8
9
10

ZTOP

012345

DOS-15

VIA

$$JOH

End of program execution. The
Monitor is called automatically by
the STOP FORTRAN statement.

m
DOSPIP V6A

Call PIP.

>T DTl...OK FTNTST BIN

Transfer the binary of the program
just compiled to the user's DECtape for permanent storage.
n.gure L0-4 (c;ont.)

Example of Commana Batching Mode

10-11

>D DK F'TNTST SRC

Delete the source file from the UFD.

>L TT+-DK

Request directory listing of user's
disk area.

02-NOV-71
DIRECTORY LISTING
CJOE>
1657 FFEE BLKS
14 USER F'ILES
363 USER BLKS
DK E:CHO 001
6 02-NOV-71
T
001
3 02-NOV-71
T
00~
1 02-NOV-71
LEF
SFC
106 02-NOV-71
JOR
RIN
15 02-NOV-71
FTNTST RIN
1 02-NOV•71

>L TT+-DT 1

Request directory listing of
DECtape the user supplied with
batch job.

02-NOV-71
DIRECTORY LISTING
101>6 FFEE BLKS
2 USER FILES

I 0 SYSTEM BU<S
1
FTNTST BIN
2
FTNTST SRC

>$JOB

DOS-15 VIA
$LOG01JT
$$EXIT

Batching run completed.
Command Batching Mode.

DOS-15 VIA
$

Figure 10-4 (Cont.)
Example of Command Batching Mode

BATCH PR
oo~-15

VI A

5$JOR TEST COMMAND RATCHYNG MODE
LOGIN JOE
$LOG

PLF:ASF. MOUNT DF.CTAPF.
CONTATNTNG "FTNTST !WC" ON
DF.CTAPF. UNIT I AND SET
TO WP ITF' F.NARU:
THANKS
$$PAUSE

PIP
DOSPIP VSA

>T DK+-DTI FTNTST SRC
>$JOB
DOS-15 VIA
$A TT ·12

Figure 10-5
Uncommented Listing of Command Batching Mode
10-12

Exit from

$F'4
F'4X V?.6A
>L ,B , ... FTNTST
END PASSI

c
001
1111112
c
c
1111113
11104
005
l
006
I fll111
011J7
00R
F 4X \l'UA
>$JOfl
DOS-15 VIA
$A TT 4

tXAMPLE -

SAMPLE FORTRAN TEST PROGRAM

DO I I:J,10
WRITE C4, 100>!
FORMAT C6X,I3)
STOP 123-45
END

$GLOAD
LOADF.P VI 2A
,.. ... FTNT!'T

2
3
4
5
6
7
8
9
Je
STOP

111123-45

DOS-15 VIA
$$JOR
PIP
DOSPIP Vf\A
>T DTl~DK f'iNTST RIN
•D DK f'iNTST SRC
•L

TT... DK

l fl-NOV•'71
(JOE>
DIRECTORY LISTING
1526 F'PEE RLKS
12 USER FILES
I 6111 USER RLKS
6 16-NOV-71
Dl<'f.CHO 0fll I
3 16-NOV-11
£1101
T
eel2
1 l6-NOV•71
T
SRC
106 16-NOV-71
LEF'
15
16-NOV-71
JO'R
RIN
SPC
16-NOV-71
11
AL
3 16-NOV-71
AL
RIN
045
3 16-NOV-71
MAX
654
3
IE>·NOV-71
ACCT
l 6•NOV-71
l
f'iNTST RI N

li'igure 10-5 ·(Cont.)
Uncorninented Listing of Command Batching Mode
10-13

>L TT<-DT I
l~-NOV-71