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Document:	RL01/RL02 User Guide
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Revision:	005
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EK-RL012-UG -005

RL01/Rl02
User Guide

EK-Rl012-UG-005

Rl01/Rl02
User Guide

Prepared by Educational Services
Digital Equipment Corporation

1st Edition, December ]l978
2nd Printing (Rev), September ]l979
3rd Printing (Rev), June ]1980
4th Printing (Rev), October 1980
5th Printing (Rev), September 1981

Copyright @ 1981 by Digital Equipment Corporation
All Rights Reserved
The material in this manual is for informational purposes and is subject to change
without notice.
Digital Equipment Corporation assumes no responsibility for any errors which
may appear in this manual.

Printed in U.S.A.

This document was set on DIGITAL's DECset-8000 computeriized typesetting system.
•

Class A Computing Devices:

Notice: This equipment generates, uses, and may emit radio frequency energy.
The equipment has been type tested and found to comply with the limits for a
Class A computing device pursuant to Subpart J of Part 15 of FCC Rules, which
are designed to provide reasonable protection against such radio frequency interference when operated in a commercial environment. Operation of this equipment in a residential area may cause interference in which case the user at his
own expense may be required to take measures to correct the interference.
The following are trademarks of Digital Equipment Corporation, Maynard, Massachusetts:
DEC
DECUS
DIGITAL
Digital Logo
PDP
UNIBUS
VAX

DECnet
DECsystem-10
DECSYSTEM-20
DECwriter
DIBOL
EduSystem
lAS
MASSBUS

OMNIBUS
OS/8
PDT
RSTS
RSX
VMS
VT

CONTENTS

Page
CHAPTER 1

INTRODUCTION

1.1
1.2
1.3
1.3.1
1.3.2
1.3.2.1
1.3.2.2
1.3.2.3
1.3.2.4
1.3.3
1.3.3.1
1.3.3.2
1.4
1.5
1.6

PURPOSE AND SCOPE ........ ............. ......... ........................................................ 1-1
REFERENCE DOCUMENTS ............................................................................. 1-1
SUBSYSTEM DESCRIPTION ............................................................................ 1-1
RLO 1/RL02 Disk Drive.... ......... ......... ....... ...... ............ ...... ............................ 1-2
RLControllers ............. ;.................................................................................. 1-2
RLII Controller Description.................................................................. 1-2
RLVII Controller Description............................................................... 1-3
RLSA Controller Description................................................................. 1-3
RLV12 Controller Description............................................................... 1-3
RLOIK/RL02K Disk Cartridge..................................................................... 1-4
Interchangability ..... ................................................ ............ ................... 1-4
Sector Format......................................................................................... 1-4
SECTOR LOCATION .......................................................................................... 1-7
BAD SECTOR FILE ............................................................................................. 1-8
RLOI/RL02 SPECIFICATIONS ......................................................................... 1-10

CHAPTER 2

INSTALLATION

2.1
2.1.1
2.1.1.1
2.1.1.2
2.1.1.3
2.1.1.4
2.1.1.5
2.1.1.6
2.1.1.7
2.1.1.S
2.1.1.9
2.1.1.10
2.1.1.11
2.1.2
2.1.3
2.1.3.1
2.1.3.2
2.1.4
2.1.5
2.2
2.3

SITE PREPARATION AND PLANNING ......................................................... 2-1
Environmental Considerations........................................................................ 2-1
Cleanliness.............................................................................................. 2-1
Space Requirements............................................................................... 2-1
Floor Loading......................................................................................... 2-1
Heat Dissipation ..................................................................................... 2-1
Acoustics... ............... ......... ......................................... ............................ 2-2
Temperature ........................................................................................... 2-2
Relative Humidity .................................................................................. 2-2
Altitude..... ......... ........... ................. ............. ................... ...... ........ ........ ... 2-2
Power and Safety Precautions ..................... ......... .............. .................... 2-2
Radiated Emissions ................................................................................ 2-2
Attitude/Mechanical Shock................................................................... 2-3
Options............................................................................................................ 2-3
AC Power Requirements. ............................................................................... 2-5
Standard Applications ...................................................... ..... ....... .......... 2-5
Optional Applications............................................................................. 2-5
Installation Constraints................................................................................... 2-7
Grounding Requirements ......... ....... ................................................ ....... ........ 2-7
AC CABLING ....................................................................................................... 2-8
INSTALLATION - GENERAL .......................................................................... 2-10

111

Page
CHAPTER 2

INSTALLATION (Cont)

2.4
2.5
2.5.1
2.5.2
2.5.3
2.5.4
2.6
2.6.1
2.6.2
2.6.3
2.6.4
2.6.5
2.6.6
2.6.7
2.6.8
2.6.9
2.7
2.7.1
2.7.2
2.7.3
2.8
2.8.1
2.8.2
2.8.3
2.8.4
2.9
2.9.1
2.9.2
2.9.3
2.10

RLII CONTROLLER INSTALLATION ........................................................... 2-11
RLV11 CONTROLLER INSTALLATION ........................................................ 2-16
Bus Interface Module ..................................................................................... 2-16
Drive
..................................................................... '............................. 2-18
Module Slot Location..................................................................................... 2-19
Module Installation.................................................................................. ....... 2-20
RLV12 CONTROLLER INSTALLATION ........................................................ 2-21
Introduction .................................................................................................... 2-21
Device Address Selection ............................................................................... 2-21
Bus Selection...................... .................................................................... ........ 2-26
Interrupt Vector.......................................................... .................................... 2-26
Interrupt Request Level ................................................................................. 2-26
Memory Parity Error Abort Feature ...................................... ,................. ,. ..... 2-26
Other Jumpers ................................................................................................ 2-27
Installation..... ....... .............. ...................................................... ...................... 2-27
Acceptance Testing........................................................................................ 2-27
RL8A CONTROLLER INSTALLATION ................................................... ,. ..... 2-28
Introduction............ ........................................................................................ 2-28
Module Slot Location ..................................................................................... 2-28
Module Installation. ........................................................................................ 2-28
RLOI/RL02 DISK DRIVE INSTALLATION .................................................... 2-30
Unpacking and Inspection ....................................................................... ,. ..... 2-30
RL01/RL02 Disk Drive Unit Mounting ........................................................ 2-32
Drive Prestartup Inspection ............................................................................ 2-37
Drive Startup Operation Check ...................................................................... 2-39
CONFIDENCE TESTING ................................................................................... 2-39
RLI1-Based Diagnostics ................................................................................. 2-40
RLVI1-/RLVI2-Based Diagnostics ............................................................... 2-43
RL8A-Based Diagnostics ................................................................................ 2-43
USE OF THE M9312 BOOTSTRAP WITH AN RLII SUBSySTEM .............. 2-46

CHAPTER 3

OPERATOR'S GUIDE

3.1
3.2
3.2.1
3.2.2
3.2.3
3.2.4
3.2.5
3.3
3.3.1
3.3.2
3.4
3.4.1
3.4.2
3.4.3
3.4.4
3.5

INTRODUCTION.................................................................................................
CONTROLS AND INDICATIONS ....................................................................
Power ON /OFF Circuit Breaker....................................................................
Run/Stop Switch with LOAD Indicator ........................................................
UNIT SELECT Switch with READY Indicator ...........................................
FAULT Indicator .............................................................. .............................
WRITE PROTECT Switch and Indicator .....................................................
OPERATING PROCEDURES.............................................................................
Cartridge Loading and Drive Startup Procedure ...........................................
Cartridge Unloading Procedure......................................................................
OPERATOR MAINTENANCE...........................................................................
Introduction....................................................................................................
Professional Cartridge Cleaning.....................................................................
User Cartridge Cleaning.................................................................................
Spindle Assembly Cleaning ............................................................................
CARTRIDIGE CARE SUMMARy.....................................................................

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

Page
CHAPTER 4

II-FAMILY PROGRAMMING INFORMATION

4.1
4.1.1
4.1.2
4.1.3
4.2
4.2.1
4.2.2
4.2.3
4.2.3.1
4.2.3.2
4.2.3.3
4.2.4
4.2.4.1
4.2.4.2
4.2.4.3
4.2.4.4
4.2.5
4.3
4.3.1
4.3.2
4.3.3
4.3.4
4.3.5
4.3.6
4.3.7
4.3.8
4.4
4.4.1
4.4.2
4.4.3
4.4.4
4.4.5
4.4.6
4.4.7
4.5
4.5.1
4.5.2
4.5.3
4.5.4
4.5.5
4.5.6
4.6
4.7
4.7.1
4.7.2
4.7.3
4.7.4
4.7.5
4.7.6

GENERAL DESCRIPTION ................................................................................ 4-1
RL 11 Controller Description.. .................................... .............. ..... ................. 4-1
RLVII Controller Description ....................................................................... 4-1
RL V 12 Controller Description ...................................... ...... ............... ............ 4-1
ADDRESSABLE REGISTERS............................................................................ 4-1
Control Status Register .................................................................................. 4-2
Bus Address Register...................................................................................... 4-5
Disk Address Register .................................................................................... 4-5
DA Register During a Seek Command .................................................. 4-5
DA Register During Read or Write Data Command............................. 4-6
DA Register During A Get Status Command........................................ 4-7
Multipurpose Register .................................................................................... 4-8
MP Register After a Get Status Command ........................................... 4-8
MP Register After a Read Header Command ....................................... 4-10
MP Register During Read/Write Data Commands .............................. 4-11
Bus Address Extension Register............................................................. 4-11
Register Summary ........................................................................................... 4-12
CONTROLLER COMMANDS ........................................................................... 4-14
No-Op (RLll) or Maintenance (RLVll) - Function Code 0 ........................ 4-14
Write Check - Function Code 1 ..................................................................... 4-15
Get Status - Function Code 2 ......................................................................... 4-16
Seek - Function Code 3 ................................. .................................................. 4-16
Read Header - Function Code 4 .................................................................... 4-16
Write Data - Function Code 5 ........................................................................ 4-16
Read Data - Function Code 6 ........................................................................ 4-1 7
Read Data Without Header Check - Function Code 7 .................................. 4-17
CSR ERROR CODE DEFINITIONS .................................................................. 4-17
Operation Incomplete (OPI) ........................................................................... 4-17
Data CRC (DCRC) or Write Check (WCE) ................................................. 4-17
Header CRC (HCRC) .................................................................................... 4-17
Data Late (DLT) ............................................................................................ 4-17
Header Not Found (HNF) .............................................................................. 4-18
Non-Existant Memory (NXM) ....................................................................... 4-18
Memory Parity Error (MPE) .......................................................................... 4-18
OPERATIONAL CONSIDERATIONS .............................................................. 4-18
Interrupt ......................................................................................................... 4-18
Seek Operation.............. ......... ........ ................ ................................................ 4-18
Overlapped Seeks ........................................................................................... 4-18
Data Transfer .................................................................................................. 4-19
Recovery of Data with Bad Headers .............................................................. 4-19
Non-Interchangability of RLOIK/RL02K Disk Cartridges .......................... 4-19
ERROR RECOVERY ........................................................................................... 4-19
DIFFERENCE SUMMARY (RK05 AND RLOI /RL02) .................................... 4-21
Spiral Read/Write or Mid-Transfer Seeks ..................................................... 4-21
Implicit Seeks Versus Explicit Seeks ............................................................. 4-21
Recalibrate ..................................................................................................... 4-22
Bad Sector File............................................................................................... 4-22
Reformatting .................................................................................................. 4-22
Seek Interrupt ................................................................................................. 4-22

Page
CHAPTER 5

RL8A PROGRAMMING INFORMATION

5.1
5.2
5.2.1
5.2.1.1
5.2.1.2
5.2.2
5.2.3
5.2.4
5.2.5
5.2.6
5.2.7
5.2.7.1
5.2.7.2
5.2.8
5.3
5.3.1
5.3.2
5.3.3
5.3.4
5.3.5
5.3.6
5.3.7
5.3.8
5.3.9
5.4
5.4.1
5.4.2
5.4.3
5.4.4
5.4.5
5.4 . 6
5.4 . 6.1
5.4.6.2
5.4 . 7
5.5
5.6
5.6 . 1
5.6 . 2
5.6 . 3
5.6.4
5.6.5
5.6.6

GENERAL DESCRIPTION ................................................................................ 5-1
ADDRESSABLE REGISTERS............................................................................ 5-2
Command Register A ..................................................................................... 5-2
Command Register A During a Seek Command ................................... 5-2
Command Register A During Read or Write Data Command .............. 5-3
Command Register B...................................................................................... 5-4
Break Memory Address Register................................................................... 5-6
Word Count Register...................................................................................... 5-6
Sector Address Register................................................................................. 5-6
Error Register................................................................................................. 5-7
Silo Data Buffer.............................................................................................. 5-8
Data Buffer Contents Following a Get Status Command ...................... 5-9
Silo Data Buffer Contents Following a Read Header
Command ...... ...... ....... ...... ...... .................. ..... ............. ......... ........... ......... 5-9
Register Summary.......................................................................................... 5-9
CONTROLLER COMM.ANDS ........................................................................... 5-9
Maintenance Command ................................................................................... 5-16
Reset Command ............................................................................................. 5-16
Get Status Command ..................................................................................... 5-16
Seek Command................................................................................................ 5-1 7
Read Header Command................................................................................. 5-17
Write Data Command .................................................................................... 5-17
Read Data Command ..................................................................................... 5-18
Read Data without Header Check Command ................................................ 5-18
Maintenance Bit ....... ........... .................................... ........................ ............... 5-18
OPERATIONAL CONSIDERATIONS .............................................................. 5-20
8-Bit Mode Versus 12-Bit Mode ..................................................................... 5-20
Interrupt ......................................................................................................... 5-20
Seek Operation ............................................................................................... 5-20
Overlapped Seeks ........................................................................................... 5-20
Recovery of Data with Bad Headers .............................................................. 5-20
Non-Interchangability of Disk Cartridges .................................................... :. 5-21
RLOIK/RL02K ..................................................................................... 5-21
RL8A/RL11/RLV11/RLV12 .............................................................. 5-21
Use of Two RL8A Controllers....... ................ ....... .............. .......... .................. 5-21
ERROR RECOVERY ............................................................................................ 5-21
DIFFERENCE SUMMARY (RK05 AND RLOI /RL02) .................................... 5-22
Spiral Read/Write or Mid-Transfer Seeks ...................................................... 5-23
Implicit Seeks Versus Explicit Seeks .............................................................. 5-23
Recalibrate ... .................... ............................. ......... ..... .............................. ..... 5-23
Bad Sector File.................................................. ........ ..................................... 5-23
Reformatting... .................................................... ..... ............................. ......... 5-23
Seek Interrupt ................................................................................................. 5-23

APPENDIX A

RLll CONFIGURATION AND INSTALLATION CONSIDERATIONS

A.1
A.2

SPC CONSIDERATIONS ..................................................................................... A-I
CONFIGURATIONS CONSIDERATIONS ...................................................... A-I

Page
FIGURES

1-1
1-2
1-3
1-4
1-5
1-6
2-1
2-2
2-3
2-4
2-5
2-6
2-7
2-8
2-9
2-10
2-11
2-12
2-13
2-14
2-15
2-16
2-17
2-18
2-19
2-20
2-21
2-22
2-23a
2-23b
2-24
2-25
2-26
2-27
3-1
3-2
3-3
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
4-10
5-1
5-2

Typical RLOI/RL02 Mass Storage Subsystem Configuration .............................. 1-2
RLO 1/RL02 Disk Drive......... ............ .......... ....... ..... .......... .................... ................ 1-3
RLOIK/RL02K Disk Cartridge Format ................................................................ 1-5
Access Method for Sequential Transfers ................................................................ 1-7
Sector Relocation. .............. ..................................................................................... 1-8
Bad Sector File Format........................................................................................... 1-9
RLOI/RL02 Disk Drive - Rear View..................................................................... 2-5
Approved Electrical Plugs and Receptacles........................................... ........ ........ 2-6
Power Panel Grounded Building Frame.................................... .............. ......... ...... 2-7
Power Panel Grounded To Metal Plate .................................................................. 2-8
Typical 60 Hz Power System....... .......................................... ..................... ............ 2-9
Typical 50 Hz Power System.................. ................................................................. 2-10
Split Phase (2-phase) Power System ....................................................................... 2-10
Three Phase Y Power System................................................................................. 2-10
RL 11 Component Layout ........ ............ ......... ........ ..... ............. ................................ 2-11
RLll Base and Vector Address Jumper Configuration .......................................... 2-13
RLll Priority Jumper Assembly Connections ........................................................ 2-14
RL 11 Controller Installation.. ........... ......... ........ .................. ................................... 2-15
RLVll Bus Interface Module (M8014) (Component Side) ................................... 2-17
RL V 11 Base Address Switch Settings .................................................................... 2-18
RL V 11 Vector Address Switch Settings ................................................................. 2-18
RLVll Drive Module (M8013) .............................................................................. 2-19
H9273 Backplane Grant Priority Structure ............................................................ 2-20
RL V 12 J urn per Locations....................................................................................... 2-24
RLV12 Device Address Format. ............................................................................. 2-25
RLV12 Format Interrupt Vector ............................................................................ 2-26
RL8A Jumpers........................................................................................................ 2-29
H950 Shipping Package .......................................................................................... 2-31
RLOI/RL02 Cabinet Installation ........................................................................... 2-32
RLOI/RL02 Cabinet Installation ........................................................................... 2-33
RLO 1/RL02 Disk Drive - Exposed Drive Logic Module ....................................... 2-34
RLOI /RL02 - Covers Removed ............................................................................. 2-35
RLO 1/RL02 Disk Drive - Rear View................ ...... .................. .............. ............... 2-36
RLOI/RL02 Disk Drive - Front View .................................................................... 2-37
RLOI/RL02 Disk Drive - Front View.................................................................... 3-1
RLOI/02 Disk Drive - Rear View.......................................................................... 3-2
Cartridge Loading Procedure..... .................. ................... ...... ................................. 3-5
CS Register ............................................................................................................. 4-2
BA Register............................................................................................................. 4-5
DAR Contents to Execute a Seek Command ......................................................... 4-5
DAR Contents During a Read/Write Data Command .......................................... 4-6
DAR Contents to Execute a Get Status Command................................................ 4-7
MPR - Following a Get Status Command........ ...... ......... ....................................... 4-8
MPR - Following a Read Header Command ......................................................... 4-10
MPR - Used as a Word Counter ............................................................................ 4-11
BAE Register .......................................................................................................... 4-12
Register Summary.................................................................................................. 4-12
Command Register A During a Seek Command....... ......... .................. ...... ............ 5-3
Command Register A During a Read/Write Data Command ............................... 5-4

Vll

Page
FIGURES (Coot)

5-3
5-4
5-5
5-6
5-7
5-8
5-9
5-10
5-11

5-12

Command Register B.............................................................................................. 5-4
Break Memory Address Register............................................................................ 5-6
Word Count Register.............................................................................................. 5-6
Sector Address Register... ....................................................................................... 5-7
Error Register......................................................................................................... 5-7
Silo Buffer for Status Word I ......................................................... '........................ 5-9
Silo Buffer for Status Word 2 ................................................................................. 5-9
Silo Buffer for Header Words ................................................................................. 5-12
Register Summary.................................................................................................. 5-13
Maintenance Mode Bit................................. ..... ............. ... ........... ...... ...... ..... ......... 5-19

TABLES
I-I
1-2
1-3
1-4
2-1
2-2
2-3
2-4
2-5
2-6
2-7
2-8
2-9
2-10
2-11
2-12

2-13
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
4-10
5-1
5-2
5-3

Reference Documents ............................................................................................. I-I
RLO I /RL02 Disk Drive Physical and Environmental
Specification ........................................................................................................... 1-10
RLO I /RL02 Disk Drive Operational Specifications...... ........... .... ................... ...... 1-13
RLO I K/RL02K Disk Cartridge Specifications ....... .......... ...... ......... ............ ......... 1-14
Saleable RLOI /RL02 Subsystem Options ............................................................. 2-3
Saleable Cabinet Options: (Includes Skins, Doors, Covers,
Trim, and Power Controllers) ......................................................... '........................ 2-4
Address Selection............ ....... ........... ....... ................................ ............................... 2-22
Diagnostic Catalogs and Indexes ..... ...................... ...................... ..................... ...... 2-40
RLII-Based Diagnostics ......................................................................................... 2-40
RLII Diagnostic Kit Numbers ............................................................................... 2-41
RL II Diagnostic Components.................. ................. ..... .......... ..... ............ .... ......... 2-41
User Documents...................................................................................................... 2-42
RLVII /RLVI2 Diagnostic Kit Designations ......................................................... 2-43
RL8/RLOI Diagnostic Kits .................................................................................... 2-43
RL8/RLOI Diagnostic Components ....................................................................... 2-44
RL8A Diagnostic Kits. ....... ....................... ................. ............................................ 2-45
RL8/RL02 Diagnostic Components ....................................................................... 2-45
Controller Addressable Registers................... ........... ......... ................ ....... .... ......... 4-2
Control Status Register Bit Description ................................................................. 4-3
Disk Address Register Bit Description for Seek Commands.................................. 4-6
Disk Address Register Bit Description for Data Transfer
Commands....... ........ ....... ....... ..... ...... ..... ... ..... ......... ...... ..... ..... .... ..... ...... ..... ....... ..... 4-7
Disk Address Register Bit Description for Get Status
Commands............. ....... ......... ...... ..... ...... ...... ...... ..... ..... .... ............... ..... ...... ....... ..... 4-7
MP Register Bit Description for Get Status Commands........................................ 4-8
MP Register Bit Description for Read Header Commands .................................... 4-10
MP Register Bit Description for Data Transfer Commands .................................. 4-11
RLII /RLVII /RLVI2 Controller Commands ....................................................... 4-14
Errors. ... ........ ....... ............. ........ ..... ..... ...... ...... .... ..... .......... ...... .... ..... ........... ..... ...... 4-20
RL8A Instruction Set............................................................................................. 5-1
RL8A Controller Commands .......................................................... ,........................ 5-2
Command Register A Bit Description for Seek Commands................................... 5-3

viii

Page
TABLES

5-4
5-5
5-6
5-7
5-8
5-9

(Cont)

Command Register A Bit Description for Data Transfer
Commands............ ..... ........ ......... ................. ........ ........... ............... ................. ........ 5-4
Command Register B Bit Description..................................................................... 5-5
Error Register Bit Description........... .............................................................. ....... 5-7
Silo Data Buffer Word 1 of Get Status Command .... ............................................. 5-10
Silo Data Buffer Word 2 of Get Status Command ................................................. 5-11
Errors ...................................................................................................................... 5-22

CHAPTER 1
INTRODUCTION

1.1 PURPOSE AND SCOPE
This manual provides information on the capabilities, installation, operation, and programming of the
RLOI/RL02 disk subsystem. A basic subsystem is comprised of one RLll, RLVll, RLVI2, or RLSA
controller and up to four RLOI or RL02 disk drives.
This manual is intended primarily for operating and programming personnel. Service should be performed only by qualified Digital field engineering and maintenance personnel. A prerequisite for understanding this manual is a basic knowledge of PDP-S and/or PDP-II processors and peripherals.

1.2 REFERENCE DOCUMENTS
Table 1-1 lists the documents that provide the information necessary for a complete understanding of
the function, theory, and maintenance of the RLO 1/RL02 disk drives and the controllers. The
UNIBUS and LSI-II Bus are described in the PDP-II Bus Handbook (EB-17525). The OMNIBUS is
described in the PDP-8A Miniprocessor User's Manual (EK-SA002-MM).
Table 1-1

Reference Documents

Title

Document No.

RLOI/RL02 Disk Drive Technical Manual
RLOI Disk Drive Illustrated Parts Breakdown
RL02 Disk Drive Illustrated Parts Breakdown
RLOI/RL02 Disk Subsystem Preventive
Maintenance Manual *
RLO 1/RL02 Disk Drive Pocket Service Guide
RLII Controller Technical Description Manual
RLVII Controller Technical Description Manual
RLSA OMNIBUS Controller Technical Manual
RLV12 Disk Controller User's Guide
RL V 12 Controller Technical Description Manual

EK-RLOI2-TM
EP-OOO 16-IP
EP-OOO 16-IP
EP-OOOOS-PM

•

EK-RLOI2-PG
EK-ORLII-TD
EK-RLVI1-TD
EK-ORLSA-TD
EK-RLVI2-UG
EK-RLVI2-TD

This document is only available to Digital Equipment Corporation Service personnel.

1.3 SUBSYSTEM DESCRIPTION
The RLOI/RL02 mass storage subsystem is based on the RLOIK/RL02K disk cartridges, the
RLOI/RL02 drive unit(s), and an appropriate controller such as the RLII (PDP-II), RLVII or
RLV12 (LSI-II), or RL8A (PDP-S). The basic subsystem is illustrated in Figure 1-1.
1-1

CONTROLLER
RL11

CU/DRIVE INTERFACE

RLV11
RLV12
RL8A

(DRIVE 0)

•
•
•

READ DATA
STATUS

•

SECTOR PULSES
(DRIVE 1)

•
•
•

UNIBUS
OMNIBUS
Q-BUS

•

GET STATUS

•
•

SEEK
WRITE DATA

(DRIVE 2)

(DRIVE 3)

01
01

0]
CZ-1007

Figure 1-1

1.3.1

Typical RLO] /RL02 Mass
Storage Subsystem
Configura tion

RLOljRL02 Disk Drive

The RLOI /RL02 drive unit is built into a chassis that slides out of the cabinet to allow operator access
to the top cover for loading and unloading of the disk cartridge. If the stops on the slide are manually
released, the chassis can be pulled farther out so that the rear top cover can be removed for servicing.
The front panel contains. operator controls and indicators.
The chassis contains a spindle, two read/write heads mounted on a positioner, logic modules, a power
supply with an ac power cord and circuit breaker, a closed-loop clean air system, a cooling air syste:m,
appropriate safety interlocks, and connectors for the I/O cable(s).
The drive unit is shown in Figure 1-2.
The RL02 drive unit has a label reading "RL02" on the front panel. The RLOI drive currently does not
have a label identifying it as an RLO 1.

1.3.2

RL Controllers

There are four controllers available for the RLO 1/RL02 subsystem. All can handle up to four drives
and all feature Direct Memory Access (DMA) operation.

1.3.2.1 RLl1 Controller Description - The RLII controller consists of a single, hex-height Small Peripheral Controller (SPC) module designated M7762. It is used to interface the drive with the PDP-II
UNIBUS. The data is formatted in 16-bit words.
1-2

Figure 1-2

RLOI/RL02 Disk Drive

1.3.2.2 RLVII Controller Description - The RLVII controller consists of two quad-height modules
designated M8013 and M8014. This controller interfaces the drive with the LSI-II Bus. The data is
formatted in 16-bit words. The controller can handle any combination of up to four RLOI /RL02 drives.
1.3.2.3 RL8A Controller Description - The RL8A controller consists of a single, hex-height module
designated M8433. It is used to interface the drive with the PDP-8 OMNIBUS. The data can be formatted in either 8-bit bytes or 12-bit words. This controller has a jumper-determined choice of handling
RLOI or RL02 drives. However, in the RL02-jumpered configuration, it can handle any combination of
up to four RLO 1/RL02 drives.
1.3.2.4 RLV12 Controller Description - The RLV12 controller consists of a single, quad-height module designated M8061. It is used to interface the drive with either the extended LSI-II Bus or the
standard LSI-II Bus. A jumper designates the 22-bit or 18-bit addressing scheme. The data is formatted in 16-bit words. This controller can handle any combination of up to four RLO 1/RL02 drives.

1-3

1.3.3 RLOIK/RL02K Disk Cartridge
The RLO 1K or RL02K is a removable, top-loading 5440-type disk cartridge that is formatted in a manner unique to the RL01/RL02 subsystem. Both cartridges contain a single platter. The RL01K cartridge has a capacity of 5.2 megabytes of user data, and the RL02K cartridge holds 10.4 megabytes of
data. Both sides of the platter are used for data. There are 256 tracks on each RL01K platter surface
and 512 tracks on each RL02K platter surface. Each track is divided into 40 sectors. Each sector contains 256 bytes of data. The last track of the last surface is reserved for the cartridge serial number and
bad sector information. Head positioning servo information and header information are prerecorded at
the factory and cannot be reformatted in the field. This information, along with the data, is read by the:
read/write heads but the internal logic of the drive unit protects the servo and header information from.
being overwritten.
1.3.3.1 Interchangability - The RL01K and RL02K disk cartridges are not functionally inter··
changable although they are physically interchangable. It is possible to mount an RL01K cartridge Ont
an RL02 drive, for example, but proper operation will not occur. An RL01K cartridge written on an.
RL01 unit can be read on any other RLOI unit even if that unit is controlled by a different type of
controller. The limitation to this interchangeability is that if an RL8A controller is used to write data.
and the cartridge is to be used by an II-Family controller, the RL8A must use the 8-bit byte mode of
operation.
An RL02K cartridge written on an RL02 unit can be read on any other RL02 unit (assuming the
conditions mentioned above).

1.3.3.2 Sector Format - As shown in Figure 1-3, each sector contains:
•

Servo information for head positioning,

•

Header (address) information,

•

Data (128 words of 16 bits or 256 bytes of 8 bits or 170 words of 12 bits).

Only the data portion of a sector can be written by the user. The servo and header information is pro.tected by the drive logic and controller to ensure disk integrity and cannot be written in the field.
Each sector starts with a sector pulse that is produced by a sector transducer mounted on the

unit.

It senses the sector notches that are machined into the hub of the disk cartridge.

During the time that the sector notch passes by the sector transducer, the heads detect two servo pulse
bursts (Sl and S2) that are prerecorded on the platter. These servo bursts are used by the drive logic
for head positioning.
The header follows the servo pulse bursts. It consists of:
•

A preamble of three words - 47 "0" bits and one "1" bit,

•

A word that contains the address - sector, head, and cylinder,

•

A word of all zeros,

•

A word containing information created by the Cyclic Redundancy Check (CRC) logic,

•

A one-word postamble of all zeros.

]-4

....- - - - - - - - - - - - - - - - 6251£5

---------------.-.11

.-62.51£5....

J
I

SECTOR
PULSE

•

>0--

__'

--------

.;"/

ZEROES

CRC

16 ZERO BITS

16 BITS

ADDRESS

PREAMBLE
47 ZERO BITS

16 BITS

POSTAMBlE

SECTOR

HEAD

SIX BITS

ONE
BIT

NINE BITS

16 BITIWORD
MODE

16 BITS

lSB
S BIT/BYTE

BYTE BYTE
1
0

MODE

SBITS SBITS

POSTAMBlE

2048 BITS

16 ZERO BITS

12 BITS

•

WORD 127

16 BITS

Figure 1-3

RLOIK/RL02K Disk Cartridge Format

"'- ......

WORD 126

BYTE

254

255

8 BITS 8 BITS

WORD 168 WORD 169

12 BITS

t L

-......

.IL.

·.If

MODE

....

CRC

12 BITIWORD WORD 0 WORD 1

......

16 BITS

DATA

WORD 1

WORD 0

......

PREAMBLE

16 ZERO BITS

CYLINDER

- --- -- ---

47 ZERO BITS

.......

.....

__________________

-----------------,
l

12 BITS

UNUSED
8 BITS

MSB

lSB

CZ·2C127

The user writeable data area follows the header. It consists of:
•

A preamble of three words - 47 "0" bits and one "1" bit,

•

Data (128 words of 16 bits or 256 bytes of 8 bits or 170 words of 12 bits),

•

A word containing CRC-generated information,

•

A one-word postamble of all zero bits.

Following each sector is a period of idle tirne that is simply a wait for the next sector pulse.
In addition to the data tracks, there are tracks both inside and outside of the data area that contain
unique servo signals that define those areas as guard bands. If the read/write heads attempt to enter a.
guard band, the drive logic causes the positioner to retreat from the guard band and return to
data
are:a.
The disk has a nominal rotational speed of 2400 rev/min. Therefore, the time for one revolution is 25
milliseconds. Since the revolution is divided into 40 sectors, the duration of each sector is 625 nlicro·,
seconds. This 625 microsecond period is divided into non-data (sector pulse, headel!", idle time) time and.
data time. The data time period is 500 microseconds. Thus, the data is transferred in 500
bursts that occur every 625 microseconds.
For 16-bit word mode there are 128 words of data in a sector so the peak transfer rate is 3.9 n(licro··
seconds per word and the average transfer rate is 4.9 microseconds per word.
For 8-bit bytes (256 bytes per sector), the peak transfer rate is 1.9 microseconds per byte and the aver..
age transfer rate is 2.4 microseconds per byte.
For 12-bit word mode (170 words per sector), the peak transfer rate is 2.9 microseconds per word and
the average transfer rate is 3.7 microseconds per word.

1-6

1.4 SECTOR LOCATION
The RLOIK/RL02K disk cartridges do not have a physical index notch (occurring once per revolution)
machined into the hub as some cartridges do. The controller determines the rotational position of the
disk cartridge by reading, from the header, the sector address as well as the head (surface) and cylinder
(track) addresses. Thus, the cartridge does not need a physical index. The sectors are relocated to optimize the data transfer rate when it becomes necessary to perform a seek during a data transfer.
A head switch to the other surface is considered a seek because the RLOI/RL02 subsystem uses servo
information that is recorded on each track. The newly selected head will position itself over the center
of the track. There is no hardware-controlled implicit seek on the RLOI/RL02 subsystem. All seeks,
including spiral (mid-transfer) seeks, must be programmed into the software. The correct head must be
selected and positioned over the correct track by a seek operation before the software can initiate a data
transfer.
When the end of a track is reached and the data transfer has not been completed, the software must do
one of two things. It must switch to the head that is over the corresponding track on the other surface
(6.5 milliseconds average, 8 milliseconds maximum) or the software must issue a seek to the next cylinder (15 milliseconds). If the head is to be switched also, the seek and the head switching are normally
combined. Once the unit has completed the seek operation, the software can continue the data transfer.
To reduce the rotational latency following a head switch seek, surface one is offset by 17 sectors from
surface zero. The eight milliseconds head switch corresponds to 13 sectors of this offset and the additional four sectors allow for software overhead.
To reduce the rotational latency following a one cylinder seek (with head switch), surface 0 of a cylinder is offset by 29 sectors from surface 1 of the previous cylinder. The 15 millisecond seek time takes
24 sectors of this offset and five more sector times are allowed for software overhead.
These two offset patterns are illustrated in Figures 1-4 and 1-5.

CYL =0
SURFACE "0"
(HDS = 0)

SPINDLE

SURFACE "1"
(HDS -1)

MA-0567

Figure 1-4

Access Method for Sequential
Transfers

1-7

Sp· 3
(PHYSICAL
SECTOR)

INDEX
NOTE:
NUMBERS IN BLOCKS REFER TO HEAD 1.
MA-0579

Figure 1-5

Sector Relocation

1.5 BAD SECTOR FILE
The Bad Sector File is a list of all bad sectors found on an RLO 1K/RL02K disk cartridge. It also contains the cartridge serial number. The operating system uses this information to avoid allocating bad
sectors to a user's files.
If there is an error in a header, or if there are 16 consecutive read/write errors within one sector, that
sector is defined as a bad sector.
This file is recorded on surface 1, track 255 (decimal) of an RLOIK cartridge, and surface 1, tra(!k 511
(decimal) of an RL02K cartridge. The file consists of 40 sectors of 128 words each. Figure 1-6 shows
the format of the Bad Sector File.
There is room in the file for 128 entries written by the factory and for 128 entries that can be written in
the field if bad sectors develop during field use.

1-8

BAD SECTOR FILE
SEC
TOR

LAST
CYLINDER
LAST
SURFACE
I

-.0

Figure 1-6

0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39

TWO
FACTORY WRITTEN BAD SECTOR INFO
ALL ONES
DUPLICATE OF SECTORS 0, 1
ALL ONES

16 BIT WORD

MSB

CONTENTS

SECTORS

25616 BIT
WORDS

125
ENTRIES

14 113 112 1 11

LSB

ALL ONES
DUPLICATE OF SECTORS 0,1

1 4

2
1

ZERO

5 MOST SIGNIFICANT OCTAL DIGITS OF CARTRIDGE SERIAL NUMBER

ZERO

5 LEAST SIGNIFICANT OCTAL DIGITS OF CARTRIDGE SERIAL NUMBER

ZEROES

ENTRY

ZEROES

SECOND
BAD
SECTOR
ENTRY

f--

0
1

CYLINDER ADDRESS

SECTOR
DUPLICATE OF SECTORS 0,1

ZEROES

ALL ONES

DUPLICATE OF SECTORS 0,1

HEADl

ZEROES

SECTOR ADDRESS

6
SAME FORMAT AS "'IRST BAD SECTOR ENTRY

ALL ONES

FIELD WRITTEN BAD SECTOR INFO

, r'

ALL ONES
DUPLICATE OF SECTORS 20, 21
ALL ONES

125th BAD {

252

SECTOR

f--

ENTRY

253

SAME FORMAT AS FIRST BAD SECTOR ENTRY

DUPLICATE OF SECTORS 20, 21

254

ALL ONES

255

ALL ONES

DUPLICATE OF SECTORS 20, 21
ALL ONES

NOTE: UNUSED BAD SECTOR ENTRIES ARE ALL ONES

DUPLICATE OF SECTORS 20, 21
ALL ONES
CZ-2028

Bad Sector File Format

1.6 RLOI jRL02 SPECIFICATIONS
The following tables list the specifications of the RL01jRL02 drives and the RL01KjRL02K cartridges.
1.

Table 1-2 RL01jRL02 Disk Drive Physical and Environmental Specifications

Table 1-3 RLO 1KjRL02K Disk Drive Operational Specifications

Table 1-4 RL01K/RL02K Disk Cartridge Specifications

Table 1-2

RLOljRL02 Disk Drive
Physical and Environmental
Specifications

Characteristics

Specifications

Width

Compatible with 19 inch RETMA rack

Depth

63.5 cm (25 in) behind bezel

Height

26.52 cm (10.44 in)

Weight

34 kg (75 lb)

Mounting

The drive mounts on chassis slides

Power Source

90-127 Vac (47.5-63 Hz)
180-256 Vac (47.5-63 Hz)
(Manually selectable)

Input Power

160W max at 115 Vac, 60 Hz

Power Factor

Greater than 0.85

Starting Current

3.5A (rms) max @ 90 Vacj47.5-63 Hz
5.0A (rms) max @ 127 Vac/47.5-63 Hz
1.75A (rms) max @ 180 Vac/47.5-63 Hz
2.5A (rms) max @ 254 Vac/47.5-63 Hz

Heat Dissipation

546 Btu/hr max

Power Cord and
Connector

A molded line cord compatible with the drive operating voltage and the 861 power control for 120
Vac is attached to the drive. The power cord is
2.74 m (9 ft) long and the plug is NEMA 5-15P.
The 230 Vac plug to be attached to high voltage
drives is NEMA 6-15P.

1-10

Table 1-2

RLOl/RL02 Disk Drive
Physical and Environmental
Specifications (Cont)

Characteristics

Specifications

Safety

The RL01 /RL02 disk drive is UL listed and CSA
certified.

Interlocks

Interlocks are used where potential exists for
damage to drive, media, operators, or service
personnel.

Temperature /
Humidity

Operating:
Temperature: 10 0 C (50 0 F) to 40 0 C (104 0 F)
Note: Maximum allowable operating temperatures are
reduced by a factor of 1.8 0 C/1000 meters (10 F /1000
feet) for operation above sea level.
Relative Humidity: 10 to 90 percent with maximum wet
bulb temperature 28 0 C (82 0 F) and minimum dew point
2 0 C (36 0 F)
Nonoperating:
Temperature: -40 0 C (-40 0 F) to 66 0 C (151 0 F)
Relative Humidity: 10 to 95 percent, non condensing

Altitude

Operating: 2440 m (8,000 ft) max
Nonoperating: 9144 m (30,000 ft) max

Shock

Operating:
Half sine shock pulse of gravity peak and 10 ± 3 ms
duration applied once in either direction of three
orthogonal axes (3 pulses total)
Nonoperating:
Half sine shock pulses of 40 gravity peak and 30 ±
10 ms duration perpendicular to each of six package
surfaces.

Vibration

Operating:
Sinusoidal vibration (sweep rate 1 octave/min)
5-50 Hz, 0.002 in displacement amplitude
50-500 Hz, 0.25 gravity peak
500-50 Hz, 0.25 gravity peak
50-5 Hz, 0.002 in displacement amplitude

I-I I

Table 1-2

RLOI/RL02 Disk Drive
Physical and Environmental
Specifications (Cont)

Characteristics

Specifications

Vibration

Nonoperating:
Vertical Axis Excitation - 1.40 gravity (rms) overall from 10 to 300 Hz; power spectral density of
0.029 g2/Hz from 10 to 50 Hz, with 8 dB/octave rolloff from 50 to 300 Hz
Longitudinal and Lateral Axis Excitation - 0.68
gravity (rms) overall from 10 to 200 Hz; power
spectral density of 0.007 g2/Hz from 10 to 50 Hz,
with 8 dB/octave rolloff from 50 to 200 Hz

EMI

Meets DEC Standard 102, Section 7.

Dust

The drive will operate in an ambient atmosphere of
less than 5 million particles 0.5 microns or larger
per cubic foot of air. The drive is intended to run
in a light industry or cleaner environment.

Attitude

Maximum pitch: ± 15 degrees
Maximum roll: ± 15 degrees

1-12

Table 1-3

RLOI/RL02 Disk Drive
Operational Specifications

Characteristics

Specifications

General

Linear bit density: 147 bits/mm (3725 bits/in) at
innermost track
16-bit words per sector: 128
Number of sectors per track: 40
Track density: 4.9/mm (125/in) for RL01K, 9.8/mm
(250/in) for RL02K
Number of tracks per surface: 256 for RL01K, 512 for
RL02K
Number of surfaces: 2
Formatted capacity (megabytes): 5.2 for RL01K, lOA
for RL02K
Encoding method: Modified Frequency Modulation (MFM)

Transfer Rate
(Unbuffered
Values)

Bit rate: 4.1 megabits/second ± 1 percent
Bit cell width: 244 ns ± 1 percent
Word transfer rate (16-bit words): 256 kilowords/
second ± 1 percent

Latency

Rotational frequency: 2400 rev/min ± 0.25%
Average latency: 12.5 ms ± 0.25%
Maximum latency: 25.0 ms ± 0.25%

Seek Time

Average seek time: 55 ms max (85 tracks for RL01,
170 tracks for RL02)
One cylinder/track seek time: 15 ms max
Maximum seek time: 100 ms max (256 tracks for RL01,
512 tracks for RL02)

Start/Stop Time

Start time: 45 seconds
Stop time: 30 seconds

Data Format

Refer to Figure 1-3

1-13

Table 1-4

RLOIKjRL02K Disk Cartridge
Specifications

Characteristics

Specifications

Operating
Environment

The cartridge will operate over a temperature range
of 4° C to 48° C (40° F to 120° F), at a relative
humidity of 8 to 80 percent. The wet bulb reading
must be less than 25° C (78° F). Before a cartridge
is placed in operation, it should be conditioned
within its cover for a minimum of 2 hours in the
same environment as that in which the disk drive is
operating. (The above specified ranges do not
necessarily apply to the disk drive.)

Storage
Environment

The cartridge should be stored at a temperature between -40 0 C to 65 0 C (-40 0 F to 150° F), with a wet
bulb reading not exceeding 29° C (85° F). For wet
bulb. temperatures between 0.56° C and 29 0 C (33 0 F
and 85° F) the disk cartridge will withstand a relative humidity of 8 to 80 percent. The stray magnetic field intensity shall not exceed 50 Oersteds.

Dirnensions
(Cartridge)

The external diameter of the top cover is 38.35 cm
(15.1 in).
The external diameter of the protection cover is
37.03 cm (14.58 in).
The external height of the cartridge is 6.19 cm
(2.44 in).

Maximum Speed

The rotating parts of the disk cartridge are capable
of withstanding the effect of stress created while
rotating at 2,500 rev Imin.

Track Geometry

There are 256 discrete concentric tracks per data
surface for the RLO 1K, 512 tracks per data surface
for the RL02K.

Identification
of Data
Location

Data Track Identification - Data tracks are numbered
by consecutive decimal numbers (000 - 255, RLOIK;
000 - 511, RL02K) starting at the outermost data
track of each data surface.
Data Surface Identification - The upper data surface is numbered 0 and the lower surface is numbered
1, to correspond with the head numbers.

1-14

Table 1-4

RLOIKjRL02K Disk Cartridge
Specifications (Cont)

Characteristics

Specifications
Cylinder Address - A cylinder is defined as both
data tracks (on either surface) with a common data
track identification.
Data Track Address - A 16-bit word defines the data
track address. Bits 0 - 5 define the sector, bit 6
defines the surface, and bits 7 - 15 define the
cylinder address. This information is in word 1 of
each sector's header.

1-15

CHAPTER 2
INSTALLATION

2.1 SITE PREPARATION AND PLANNING
This chapter describes power, space, environmental, cabling, and safety requirements that must be considered before installation of the RLOl/RL02 disk subsystem.
2.1.1 Environmental Considerations
The RLOl/RL02 disk subsystem is designed to operate in a business or light industry environment.
Although cleanliness is an important consideration in the installation of any computer system, it is particularly crucial for proper operation of a disk drive. The RLO 1K/RL02K disk cartridge is not sealed
while being loaded and is therefore vulnerable to dust or smoke particles suspended in the air, as well as
to fingerprints, hair, lint, etc. These minute obstructions can cause head crashes, resulting in severe
damage to the read/write heads and disk surfaces.
2.1.1.1 Cleanliness - The RLOl/RL02 disk drives can operate in an ambient with less than five million particles per cubic foot of air which are 0.5 micron or larger in diameter. The drive contains a filter
system which, under these conditions, maintains the particle count within the cartridge below 100 particles per cubic foot.
2.1.1.2 Space Requirements - Provision should be made for service clearances of 1 m (39 in) at the
front and rear of the rack or cabinet in which the drive is mounted and 1 m (39 in) at either side.
Storage space for the RLOIK/RL02K cartridges should also be made available. Each cartridge has a
diameter of approximately 38 cm (15 in) and a height of approximately 6 cm (2.5 in).
CAUTION
RL01K/RL02K disk cartridges must never be
stacked on top of each other. A designated shelf area
or specially designed disk cartridge storage unit is
recommended (see the DIGITAL Supplies and Accessories Catalog).
2.1.1.3 Floor Loading - The weight of the RLOl/RL02 disk drive alone is 34 kg (75 lb), which will
not place undue stress on most floors. However, the added weight of the rack or cabinet as well as the·
number of drives to be installed should be considered in relation to the weight of existing computer
systems. Possible future expansion should also be a consideration.
2.1.1.4 Heat Dissipation - The heat dissipation of each RLOl/RL02 disk drive is 546 Btu/hour maximum. The approximate cooling requirements for the entire system can be calculated by multiplying
this figure by the number of drives, adding the result to the total heat dissipation of the other system
components, and then adjusting the total figure to compensate for personnel, cooling system efficiency,
etc. It is advisable to allow a safety margin of at least 25 percent above the maximum estimated requirements.

2-1

2.1.1.5 Acoustics - Most computer sites require at least some degree of acoustical treatment. However, the RLOl/RL02 disk subsystem should not contribute unduly to the overall system
leve:1.
Ensure that acoustical materials used do not produce or harbor dust.
2..1.1.6 Temperature - The RLOl/RL02 disk subsystem operates over a temperature range of 10 0 C
(50 0 F) to 40 0 C (104 0 F). The maximum temperature gradient is 16.6 0 C (30 0 F) per hour. The nonoperating temperature range is from -40 0 C (-40 0 F) to 66 0 C (151 0 F).
2..1.1.7 Relative Humidity - Humidity control is important for proper operation of any computer system since static electricity may cause memory errors or even permanent danlage to logic components.
The RLOI/RL02 disk subsystem is designed to operate within a relative humidity range of 10 to 90
percent with a maximum wet bulb temperature of 28 0 C (82 0 F) and a minimum dew point of 2 0 C
(36 0 F). The nonoperating relative humidity range is from 10 to 95 percent, with a maximum wet bullb
temperature of 46 0 C (115 0 F).
2.1.1.8 Altitude - Computer systems operating at high altitudes may have heat dissipation problems.
Altitude also affects the flying height of read/write heads in disk drives. The maximum altitude specified for operating the RLOI/RL02 disk subsystem is 2440 m (8000 ft). Also, the maximum allowable
operating temperature is reduced by a factor of 1.8 0 C per 1000m (l0 F per 1000 ft) above sea level
Thus, the maximum allowable operating temperature at 2440 m (8000 ft) would be reduced to 36 0 C
(96 0 F).
2.1.1.9 Power and Safety Precautions - The RLOI/RL02 disk subsystem presents no unusual fire or
safety hazards to an existing cOlnputer system. AC power wiring should be checked carefully, however,
to ensure that its capacity is adequate for the added load as well as for any possible expansion. The
RLO 1/RL02 disk drive is UL listed and CSA certified.
2.1.1.10 Radiated Emissions - Any source of electromagnetic interference (EMI) that is near the
computer system may affect the operation of the processor and its related peripheral equipment . Conlm.on EMI sources that are known causes of failures include:

•
•
•
•
•
•
•
•
•

Thunderstorms,
Broadcast stations,
Radar,
Mobile communications,
High-voltage power lines,
Power tools,
Arc welders,
Vehicle ignition systems,
Static electricity.

The effect of radiated EMI emissions on a computer system is unpredictable. Thus, grounding plays an
inlportant role in protecting the circuits used in disk drive subsystems.
To help reduce the effects of known high-intensity EMI emissions, perform the following actions:
•

Ground window screens and other large metal surfaces,

•

Ensure that the overall computer system is grounded properly (refer to Paragraph 2.1.5,
Grounding Requirements),

•

Provide proper storage (metal cabinets with doors) for disk cartridges.

2-2

2.1.1.11 Attitude/Mechanical Shock - Performance of the RL01/RL02 disk subsystem will not be
affected by an attitude where maximum pitch and roll do not exceed 15 degrees.
The subsystem is designed to operate while a half-sine shock pulse of 10 gravity peak and 10 ± 3 ms
duration is applied once in either direction of three orthogonal axes (three pulses total).
2.1.2 Options
The RL01/RL02 disk drive can be shipped with various controllers (for UNIBUS, OMMIBUS and
LSI-II Bus computer systems), and can be configured for 115 Vac or 230 Vac operation.
Table 2-1 shows saleable RL01/RL02 subsystem options. Table 2-2 shows RL01/RL02 cabinet components.
Table 2-1

Saleable RLOI/RL02 Subsystem Options

Option
Number

Description

RL01A

RL01 unit, BC20J I/O cable, chassis slide and mounting hardware

RL02A

RL02 unit, BC20J I/O cable, chassis slide and mounting hardware

RL01-AK

RL01-A (drive), RL01K-DC (cartridge)

RL02-AK

RL02-A (drive), RL02K-DC (cartridge)

RL01K-DC

RL01 data cartridge

RL02-DC

RL02 data cartridge

RL11-AK

RL01-AK, RL11 controller, BC06R, terminator

RL211-AK

RL02-AK, RL11 controller, BC06R, terminator

RLV11-AK

RL01-AK, RLV11 controller, BC06R, terminator

RLV12-AK

RL02-AK, RLV11 controller, BC06R, terminator

RL8A-AK

RL01-AK, RL8A controller, BC80J, terminator

RL28A-AK

RL02-AK, RL8A controller, BC80J, terminator

RLV21-AK

RL01-AK, RLV12 controller, BC80M, terminator

RLV22-AK

RL02-AK, RLV12 controller, BC80M, terminator

2-3

NOTE
BC20J cables come in lengths of 20, 40 or 60 feet. If
10 foot cables are desired, then the cable designation
becomes 70-12122-10. Total length of cables from
this controller to the last drive must not exceed 30
M (100 ft.).
Table 2-2 Saleable Cabinet Options:
(Includes Skins, Doors,
Covers, Trim, and Power
Controllers)
Type

Volts

Dwg.

Remarks

H 950

110
220

H960-BC
H960-BD

Includes five 26.67 cm {l0.5 in)
high panels

H 967

110
220

H967-BA
H967-BB

26.67 cm (10.5 in) cover panels
(H950-QA) must be ordered if
required

H 9500

110

H9603-ED

SWLB with H9514-B top covers

220
110

H9603-EE
H9601-ED

DWLB with H9514-A top covers

220
110

H9601-EE
H9602-EA

SWHB complete hiboy cabinet

220
110

H9602-EB
H9600-EA

DWHB complete hiboy cabinet

220

H9600-EB
H9602-B-O

SWHB option arrangement dwg.
Order as required

H9600-A-O

DWHB option arrangement dwg.
Order as required

H9603-B-O

SWLB option arrangement dwg.
Order as required

H9601-A-O

DWHB option arrangement dwg.
Order as required

H 9500

2-4

2.1.3 AC Power Requirements
The RLOI or RL02 drive can operate within one of four voltage ranges that are manually selected by
means of two terminal blocks located at the rear of the device (Figure 2-1). These voltage ranges are:

NOM
LO

110

220

105-128
90-110

210-256
180-220

The drive will operate when the line frequency is between 47.5 and 63 Hz.

NORMAULOW
LINE VOLTAGE
TERMINAL BLOCK - - - - - : : : . . COVER-

11 0/220 VOLTS
TERMINAL
BLOCK COVER

CZ-1056

Figure 2-1

RLOI/RL02 Disk Drive - Rear View

2.1.3.1 Standard Applications - The drive can be shipped from the factory as a free-standing unit or
mounted in various racks and cabinets (refer to Paragraph 2.1.2, Options).
If shipped as a free-standing unit, the 2.74 m (9 ft) ac power cord is terminated with a NEMA type 515P plug (DIGITAL Part No. 90-08938). This plug requires a NEMA type 5-15P receptacle (Figure 22).

2.1.3.2 Optional Applications - Operation in the high voltage range (180-256 Vac) will require reconfiguring the terminal block at the rear of the drive and changing the line cord plug (Figure 2-1).
In 50 Hz applications, the line cord plug must be changed (Figure 2-2).

2-5

SOURCE
120V
15A
l-PHASE

120/208V
30A
3-PHASE Y

120/208-240V
20A
2-PHASE
or
120/208V
20A
3-PHASE Y

PLUG

tiJ)

HUBBEL
1II6266-C
NEMA III 6-16P
DEC III 90-08938

HUBBEL
"
1112611
NEMA III L6-30P
DEC III 12-11193

240V
16A
1-PHASE

@
f

HUBBEL
1112411
W
NEMA # L14-20P
DEC III 12-11046

240/416V
20A
3-PHASE Y

ALL 120V STANDARD
CABINET MOUNTED [OPT

POWER
CONTROLLER
861-C

120V PDP-ll/46 PROCESSOR CABINET OIlILY.

POWER
CONTROLLER
861-A

#2410
L14-20R
12-11046

Y
X

'"!t

#2610
L21-20R
12-11210

D'c:::::>
b\J

Y
60 Hz RM 10 DRUM
60 Hz RP02lRP03/
RP04. RP06. RP06

-- g
rd

ALL 240V TABLE-TOP
COMPUTERS.
STANDARD LOW-CURRENT
240V DISTRIBUTION.
MOST 240V
DEVICES.
240VTU10.

c:::J c:::::J

6-16R
12-11204

HUBBEL
"
1112321
Y
NEMA III L6-20P
DEC III 12-11192

#2320
L6-20R
12-11191

_
W
HUBBEL
V@)
1112811
NEMA
Z
L21-30P
DEC 12-12314

@
@)

ALL 240V STANDARD
CABINET MOUNTED
EQUIPMENT.

POWER
CONTROLLER
861-B

Wt'
X
NEMA III -- NOT NEMA
DEC III 12-09010

120V
30A
1-PHASE

',_

HUBBEL
#2611
NEMA III L21-20P
DEC # 12-11209

POWER
CONTROLLER
861-F

ALL 120 V TABLE-TOP
COMPUTERS. STANDARD
120V LOW-CURRENT
DISTRIBUTION. 120V
TU10 UNITS. MOST
120V TERMINAL DEVtCES.

NEMA # 6-16P
DEC # 90-08863

240V
20A
1-PHASE

1116262
6-16R
12-06361

1112610
L6-30R
12-11194

USED ON

G
120!208V
20A
3-PHASE Y

RECEPTACLE

NOTNEMA V
12-11269

t:::::),
1112810
L21-30R
12-12316

60 Hz RM10 DRUM
60 Hz RP02lRP03/
RP04

PDPll/70
PROCESSOR
PDP 11/70 MEM.
VAX-ll/780
PROCESSOR

POWER
CONTROLLER
861-0

CP-1968

Figure 2-2

Approved Electrical Plugs
and Receptacles

2-6

2.1.4 Installation Constraints
The route from the receiving area to the installation site that the equipment will travel should be studied in advance to ensure problem-free delivery. Among the considerations are:

•
•
•
•

Height and location of loading doors,
Size, capacity, and availability of elevators,
Number and size of aisles and doors en route,
Bends or obstructions in hallways.

2.1.5 Grounding Requirements
Each cabinet of a DIGITAL computer system is equipped with ground lug terminals that should be
connected to a low-impedance earth ground by No.4 AWG (5 mm/O.20 in) copper wire or stranded
No.4 A WG welding cable. A Burndy QA4C-B solderless lug (or equivalent) is recommended for terminating the cable. DIGITAL supplies a standard grounding conductor with each I/0 and memory cabinet.

A steel building beam is an adequate ground in many instances. However, some disk-oriented systems
may require additional connections to earth ground, in addition to the ground leads carried through
various signal buses and ground connectors contained within the power cables. The green grounding
wire in the power cable must also be returned to ground, usually through the conduit of the electrical
distribution system. Note that the green wire is a not a current-carrying conductor, nor a neutral conductor.
Whenever possible, the system power panel must be either mounted in contact with bare building steel
by bonded joints (Figure 2-3) or connected to the steel by a short length of cable.

POWER PANEL

08-0717

Figure 2-3

Power Panel Grounded Building Frame

2-7

Where neither scheme is possible, a metal area (comprising the power panel, the conduit, and a Inetal
plate) of at least 1 m 2 (10 ft 2) that is in contact with masonry must be connected to the green ground
a
wire (Figure 2-4). The connecting wire must not exceed 1.5 m (5 ft) in length and should be at
No. 12 AWG (2mm).

POWER PANEL

PLATE

08-0718

Figure 2-4

Power Panel Grounded To Metal Plate

When two cabinets are bolted together, DIGITAL bonds them electrically with a No.4 AWG conductor (5 mmjO.20 in) or by several copper mesh straps connected between the cabinet frames.
After the grounding system is installed, it is advisable to take a voltage reading between the cabinet
frame and the nearest grounded object. NBFU No. 70 (published by the National Bureau of Underwriters) provides further details regarding preferred grounding procedures.
2.2 AC CABLING
Computer equipment requires a power source with a minimum number of voltage and frequen<!y disturbances. Line voltage disturbances greater than 1 j 4 cycle (measured at the receptacle during systenl
operation) are undesirable.
DIGITAL power wiring conforms to Underwriters Laboratories, Inc., Handbook UL No. 478, National
Electrical Code standards, and the type II requirements of the National Fire Protection Association
(NFPA 70). This means that in the United States the wire used as equipment ground is green, or green
with a yellow stripe; it carries no load current (except in emergency), but does carry leakage cu.rrent.
No equipment is permitted to leave DIGITAL that does not have a grounding connection to its frame.
The grounded conductor is light grey or white. It must not be used to ground equipment. Its purpose is
to conduct current.

2-8

Lines 1, 2, and 3 in a typical 60 Hz power system (Figure 2-5) are represented by black, red, and blue
wires, respectively, and phase rotation is in that order.
CAUTION
Where no grounded wire can be guaranteed, it must
not be assumed. There are some 115 V/60 Hz systems within the United States where neither side of
the line is grounded (115 V 3-phase delta).

PHASE A

J
(
MAIN SUPPLY
TRANSFORMER - (ONLY SECONDARY SHOW

(

MAIN CIRCU IT
rBREAKER OR
CUT-OFF CONTACTOR

/7"'..'
I
I
I
I
I
I
I

120V

PHASE B

208V

I
I
I
I
I
I

120V

1 1

PHASE C

lfV

-=-=-

-+-A

NEUTRAL

FRAME GROUND

1
NOTES
A THE NEUTRAL CONDUCTOR SHOULD BE GROUNDED AT THE MAINS
SUPPLY TRANSFORMER
AND IF REQUIRED BY LOCAl. AUTHORITIES AT THE DISTRIBUTION
PANEL AND ELSEWHERE.
B

'--.,--J

TO SINGLE PHASE
(TYPICAL)

,) ,) I)

'--.,--J

'----...--I

LOADS

TO THREE
PHASE LOADS
(TYPICAL)

THE FRAME GROUND CONDUCTOR MAY CONSIST OF ELECTRICAL
METALLIC CONDUIT OR
RACEWAY IF APPROVED BY LOCAL AUTHORITIES

Figure 2-5

Typical 60 Hz Power System

Figure 2-6 shows a typical 50 Hz power system.
Two types of power systems can be used to provide power to the NEMA type L14-20R receptacle. The
type shown in Figure 2-7 is referred to as split-phase (or 2-phase 180 0 displaced) 120/240 Vac. It comprises a center-tapped transformer with 120 Vac between the center tap and either of the two legs. 240
Vac exists between the two outside legs.
The second type (Figure 2-8) is referred to as 3-phase Y (120 0 displaced) 120/280 Vac. The 120 Vac
exists between neutral and any of the three other legs (X, Y, or Z), and 208 Vac exists between any two
of the outer legs (i.e., between X and Y, X and Z, or Y and Z). Although Figure 2-8 shows the X and Y
connections as the two phases used for the receptacle, any two of the three phases shown can be used.
The ground terminal on the LI4-Z0R receptacle will normally have a green screw, the neutral terminal
will be white or silver, and the "hot" terminal will be brass covered.

2-9

MAIN CIRCUIT
rBREAKER OR
CUT-OFF CONTACTOR

PHASE A

I
I

220/240V

38 0/416V
MAIN SUPPLY
TRANSFORMER - - - - - - . . . .
(ONLY SECONDARY SHOWN)

I
I

PHASE B

3801

416V

I
I
I

220/240V

I
I
PHASE C

I
,---....

220 1240V
NEUTRAL

1--

SAFETY EARTH GROUND

-1

1 I) 1 1)[

NOTES
A THE NEUTRAL CONDUCTOR SHOULD BE CONNECTED TO EARTH
GROUND AT THE MAINS SUPPLY
TRANSFORMER IF REQUIRED BY LOCAL AUTHORITIES IT MAY ALSO BE
EARTHED AT THE
DISTRIBUTION PANELISI AND ELSEWHERE
B

'---...r---J

TO SINGLE PHASE
(TYPICAL)

LOADS

,) ,) ,)

'----'
TO THREE
PHASE LOADS
( TYPICAL)

THE SAfETY EARTH GROUND CONDUCTOR MAY CONSIST OF
ELECTRICAL METALLIC CONDUIT OR
RACEWAY IF APPROVED BY LOCAL AUTHORITIES

Figure 2-6

Typical 50 Hz Power System

POWER LINE

I TRANSFORMER
Iz

I
I

D
I

I) 1

'---...r---J

-LG

I
___ ____

I
I
I

L_ -=-_ _ -.J

I
I
IL

GREEN
SAFETY GROUND

(A) 120/240V SPLlT:PHASE (TWO PHASE)

L--_ _ _

Split Phase (2-phase) Power System

_ _ _ .--J

(B) 120!20SV THREE PHASE

Figure 2-7

_ __+-/Y
GREEN
SAFETY GROUND

WHITE
OR
GREY

Figure 2-8

11-2294

Three Phase Y Power Systeln

2.3 INSTALLATION - GENERAL
The controller should be installed first, followed by the drive(s). Next, the diagnostics should be run to
denlonstrate that the subsystem is functioning properly or to diagnose any problems. ParagrapJh 2.4
explains the installation of the RLll controller, Paragraph 2.5 deals with the RLVll, Paragraph 2.6
describes RL V12 installation and Paragraph 2.7 describes RL8A installation.
Paragraph 2.8 contains instructions to install the untt and Paragraph 2.9 explains acceptance testing
and contains separate paragraphs for each of the three co'ntrollers. Paragraph 2.10 describes the use of
the M9312 bootstrap module that may be used on RLll-based systems.

2-10

2.4 RLll CONTROLLER INSTALLATION
The RLII controller (M7762) is a single hex-height module that is installed in a hex-height Small Peripheral Controller (SPC) slot. Connector J 1 connects the controller to the drive bus (Figure 2-9).
Of the 21 jumpers on the RLII controller, five are used for factory test purposes. The remaining 16 are
for address selection:
WI-W6
W7-W16

VECTOR ADDRESS (160)
BASE ADDRESS (774400)
NOTE
A logical one is represented by the presence of a
jumper wire.

OLDER VERSION

Figure 2-9

RL 11 Component Layout (Sheet 1 of 2)

2-11

W16

Wl0

W15

Wll

W14

W13

W12

W7-W16

Figure 2-9

ITEM NO.1

Wl-W6

RL 11 Component Layout (Sheet 2 of 2)

The UNIBUS priority plug sets the priority for bus requests. For the RL 11 subsystem, bus requests are
at priority level 5 (BR5/BG5). (See Figures 2-10 and 2-11.)
To install the controller:
1.

Remove the M7762 module from its shipping container and examine it for any physical dalllage.

If a priority level other than 5 is required, obtain an appropriate priority jumper assembly or
set up the priority jumper assembly (Item 1, Figure 2-9) using Figure 2-11 as a guide. The
vector and base address jumpers WI-WI6 are for 160 and 774400, respectively. If the subsystem configuration requires other than standard addresses, set the jumpers up as shown in
Figure 2-10. Physical location of these jumpers is shown on Figure 2-9.

Install the ribbon cable (BC06R-XX) with the red indicator stripe to the right and the
smooth side facing the viewer when viewing the component side of the controller as shown in
Figure 2-12. Dress the cable as necessary.

Insert the controller into its appropriate slot in the SPC backplane as shown in Figure 2-12
after ensuring that the slot does not contain a grant continuity module in row D. Do not chafe
the ribbon cable. Route the cable up and out to the rear of the cabinet, allowing for cable
strain relief.

2-12

NOTE
Adjustments on the RLll are preset at the factory
and are not to be changed in the field.
VECTOR ADDRESS SCHEME

I
I 0
0
I
I
217 2 16 2 16 214 2 13 2121 211 2'0
0

X 1X
I,

FOR VECTOR ADDRESS

I
I
I 8
2 I 2
o I 0
9

•

1
27

II 22

1
1
W 31 W 4

1 2

W61
, W2

160 - W3, W4, W5 JUMPERS IN
WI, W-z, We JUMPERS OUT
BASE ADDRESS SCHEME

2181 217

2 16

215 1 214

2'3

2'21 2"

2'0

I 25

29 I 28

I 1

o I 0

XI X

Wgl W"

W'O W'31

W'21 W'6 W'5 W,41 W 7

3
2 1 22
01 0

FOR BASE ADDRESS 774400 - W'2, W'6, W 7 JUMPERS IN
WI, W 9 , W'O, WI', W'3, W'4, W'5. JUMPERS OUT
NOTE:
X'S DENOTE DON'T CARE (NOT SELECTABLE)
1 'S DENOTE JUMPER IN
O'S DENOTE JUMPER OUT

Figure 2-10

Cl-2004

RL 11 Base and Vector Address
Jumper Configuration

2-13

16151413121110

o <:)

<:>-<:)

12345678
PRIORITY JUMPER PLUG FOR
BUS REQUEST LEVEL FIVE (5)
PLUG PIN NUMBER

SIGNAL NAME

UNIBUS PIN

1
2

BGIN

BG OUT

UB BG 4

DT2

UB BG 41N

DS2

UB BG 5

DR2

UB BG 51N

DP2

UB BG 6

DN2

UB BG 61N

DM2

UB BG 7

DL2

UB BG 7 IN

DK2

UB BR 4

002

UB BR 5

DE2

UB BR 6

DF2

UB BR 7

DH2
MA-0560

Figure 2-11

RLII Priority Jumper
Assembly Connections

2-14

NOTES:
1.

WHEN INSTALLED IN BAllK OR BAllL
EXPANSION BOX. BC06R CABLE (ITEM #3)
SHOULD BE FOLDED 90° AND ROUTED UP
OUT OF THE BOX AS SHOWN.

WHEN ALTERNATE MOUNTING POSITION
IS USED CONNECTOR IN TRANSITION
BRACKET MUST BE INVERTED SO THAT
I/O CABLE FROM DRIVE WILL HANG
IN A DOWNWARD POSITION AS SHOWN.

ITEM #3 THRU ITEM #8 ARE NOT
ASSEMBLED AT THIS POINT BUT ARE
SHIPPED WITH UNIT FOR ASSEMBLY
AT INSTALLATION TIME.

PRIORITY JUMPER ASSY (ITEM #1) TO
BE PLUGGED INTO M7762 AT FINAL ASSY.

THE RLll MODULE (M7762) WILL
OCCUpy ONE HEX SPC SLOT.

JUMPER WIRE FROM CAl TO CBl ON
THE SPC BACKPLANE MUST BE
REMOVED AT INSTALLATION.

16
____ 3

REF. STRIPE
N

M7762

SMOOTH

DESCRIPTION

DWG PART NO.

ITEM NO.

2 SCREW. PHL TRS HD. #10-32 X .50 LG

9006073-03

2 NUT. SPRING #10-32

9007786-00

1 SCREW. TAP-TLTE. #8 X .38 LG

9006418-01

1 CLAMP. CABLE

9007083-00

1 TRANSITION BRACKET ASSY

C-AD-70 1241 5-0-0

1 CABLE ASSY

D-UA-BC06R-06

1 RLll CONTROLLER

D-UA-M7762-0-0

1 PRIORITY JUMPER ASSY

5408778

CZ-2005

Figure 2-12

RL 11 Controller Installation

NOTE
See Appendix A for configuration rules and SPC
slot selection considerations.
5.

Remove the jumper between CAl and CB1 (NPR Grant) on the backplane if the
exists.

Install the transition bracket at the rear of the cabinet shown in Figure 2-12. Assemble and
install transition connector.

Connect the other end of the ribbon cable (BC06R-XX) with the red indicator stripe on the
top. Use Figure 2-12 as a guide.

Apply system power and, using a suitable measuring device (Le., digital voltmeter or e:quivalent), verify that the voltages are within the ranges specified below.
Voltage

Range

Test
Point

Ground
+5 Vdc
+ 15 Vdc
-15 Vdc

+4.75 to +5.25 Vdc
+ 14.25 to + 15.75 Vdc
-15.75 to -14.25 Vdc

AC2
AA2
CUI
CB2

Backplane
Location

Measure all· voltages between the ground test point and the appropriate voltage test point. If
any adjustments to the power supply are necessary,
to the appropriate power supplly
manual.
2.5 RLVll CONTROLLER INSTALLATION
An RLVII controller is comprised of a bus interface module (M8014) and the drive bus module
(M8013). Each module has switches, jumpers, trimpots, and connectors that are explained in the following paragraphs.
2.5.1 Bus Interface Module
The bus interface module (M8014) contains the logic circuits that perform the following major functions:
•
•
•

LSI-II bus interface functions,
Programmable registers,
Silo data storage and control circuits.

·An illustration of the component side of M8014 is shown in Figure 2-13. The location of the bus address
switches, the vector address switches, and the connector finger assignments are shown in this figure.

2-16

RLV11 BUS INTERFACE MODULE (M8014)
COMPONENT SIDE 1

MSBI

BUS ADDRESS SWITCH

LSB
VECTOR SWITCH
LSB

...
D

P"'"

B
V

A
CZ-2006

Figure 2-13

RLV11 Bus Interface Module
(M80 14) (Component Side)

The bus address switch is used to set up the device base address. It is normally factory preset to 7440.
This means the device CS register has an address of 174400 and the MP register has an address of
174406. The switches have the ON and OFF positions labeled. The ON position is the logical 1 or true
state (Figure 2-14).

2-17

E23...- - - - - - - - - L . O G I C ELEMENT

,..-----------I

I 2 15
HARDWIRED---....

BASE ADDBESS

214 2 13

212
1

1 0 0

I
I ____ L _____ _
L

BINARY VALUE

987

654

3 2 1

SWITCH NUMBER

21121029

2 5 24 2 3

MSB

LSB

FOR EACH "0" SET THE CORRESPONDING SWITCH "OFF"
FOR EACH "'" SET THE CORRESPONDING SWITCH "ON"
USE THIS SCHEME TO SELECT THE APPROPRIATE BASE
ADDRESS IF A DIFFERENT BASE ADDRESS IS REQUIRED
C;Z-2034

Figure 2-14

RLV11 Base Address Switch Settings

The vector address switch is used to select the address of the vector for this device when it interrupts. It
is factory preset for an address of 160 (Figure 2-15).
E22:....- - - - - - - L O G I C ELEMENT

VECTOR ADDRE SS

--------,

2 8 27 2 6

2 5 24 2 3

0
2

BINARY VALUE

, ,

SWITCH NUMB ER

21 2 0

IHARDWIRED
I

______ JI

LSB

MSB

FOR EACH "0" SET THE CORRESPONDING SWITCH "OFF"
FOR EACH "'" SET THE CORRESPONDING SWITCH "ON"
USE THIS SCHEME TO SELECT THE APPROPRIATE
VECTOR ADDRESS IF A DIFFERENT VECTOR
ADDRESS IS REQUIRED

Figure 2-15

CZ-2007

RLVII Vector Address Switch
Settings

2.,5.2 Drive Module
The drive module (M8013) contains the circuitry that performs the following major functions:
•
•
•

Data formatting and error-detecting circuits,
Control microsequencer and timing circuits,
Drive bus interface.
2-)8

An illustration of the component side of M8013 is shown in Figure 2-16.

NOTE
Adjustments to the RL VII are preset at the factory
and are not to be adjusted in the field.

r-J1-/]

CABLE CONNECTOR TO DRIVE

veo POT

RLV11 DRIVE MODULE (M8013)
COMPONENT SIDE 1
JUMPERS W2 AND W4 IN PLACE FOR EPROM USE (PART #05887)
JUMPERS W1 AND W3 IN PLACE FOR MASKED ROM USE (PART #23017E2)

Q¢

W4W3

EPROM

V
A
V
A
V
NOTE:
JUMPERS ARE ZERO OHM COMPOSITION RESISTORS

Figure 2-16

-I

I"""'

B
A

A
CZ-2008

RLVII Drive Module (M8013)

2.5.3 . Module Slot Location
Modules M8013 and M8014 must be inserted into the H9273 backplane (Figure 2-17) such that the
M8013 module is in the slot closest to the processor. Outside of this one restriction, the two modules
can be inserted in any two unused slots. The controller priority level is based solely on its electrical
distance from the microprocessor module in slot 1.

2-19

PROCESSOR MODU LE

HIGHEST 'PRIORITY

•

I
I

LOWEST PRIORITY

..'-

I
I

•

(MODULE SIDE VIEW OF 9 SLOT BACKPLANE)
MA-0566

Figure 2-17

2.5.4

H9273 Backplane Grant Priority
Structure

Module Installation
1.

Using the normal configuration rules, select two adjacent slots in the backplane for the two
controller modules.

Insert the ribbon cable (BC06R-XX) into Jl on the M8013 with the red stripe edge toward
the top (Row A) of the module.

Insert the M8013 module into the selected slot that is closest to the processor.

Examine the M8014 to insure that the base address switches and the vector address
are set correctly. Check jumpers WI thru W4 for correctness. See Figures 2-14, 2-15, and 216.

Insert the M8014 module next to the M8013.

Install the transition bracket at the rear of the cabinet as shown in Figure 2-12. Assemble and
install the transition connector.

Connect the other end of the ribbon cable with the red stripe up.

Apply system power and, using a suitable measuring device (Le., digital voltmeter or equivalent), verify that the voltages are within the ranges specified below.

2-20

Voltage

Range

Test
Point

Ground
+5 Vdc
+ 12 Vdc
-5 Vdc

AC2
+4.75 Vdc to +5.25 Vdc
+ 11.5 Vdc to -\- 12.5 Vdc
-5.25 Vdc to -4.75 Vdc

AA2
AD2
ALI (M8013 only)

NOTE
The -5 Vdc is generated on the M8013 module. It is
not adjustable but must be within specifications for
proper operation. Module replacement is the only
corrective procedure.
Measure all voltages between the ground test point and the appropriate voltage test point. If
any adjustments to the power supply are necessary, refer to the appropriate power supply
manual.
2.6

RLV12 CONTROLLER INSTALLATION

2.6.1 Introduction
The following paragraphs provide the user or installer with information to correctly configure and install the RLV12 in a 16-, 18-, or 22-bit LSI-II bus. The user can change the device address, interrupt
vector, and memory parity error abort feature.
2.6.2 Device Address Selection
Software control of the RLV12 is by means of four or five device registers - CSR, BAR, DAR, MPR,
and BAE. Four registers are used for 16- or 18-bit addressing; five registers are used for 22-bit addressing. The bus address extension (BAE) register is added for upper address bit selection for 22-bit addressing. The usual device starting address is as follows.
Addressing
Mode

Starting
Address

16-bit
18-bit
22-bit

174400
774400
17774400

The first register, the CSR, is assigned the starting address and the other registers are assigned the next
sequential addresses as shown in Table 2-3.

2-21

Table 2-3

Address Selection
16-bit
Addressing

18-bit
Addressing

22-bit
Addressing

Starting
Address
Range:

160000177770

760000777770

1776000017777760

Starting
Address:

174400

774400

17774400

8 (5 are used;
3 are not)

CSR (174400)
BAR (174402)
DAR (174404)
MPR (174406)

CSR (774400)
BAR (774402)
DAR (774404)
MPR (774406)

CSR (17774400)
BAR (17774402)
DAR (17774404)
MPR (17774406)
BAE (17774410)

Tie M22 ("I")
to: M17, M20,
and M21

Tie M22 ("1")
to: M17, M20,
and M21

Tie :M22 ("1")
to: M17, M20,
and M21;

Device
Address

No. of
Registers:

Registers
Used:

Jumpers
Used:

Tie MIl ("X")
to: M12
Interrupt
V1ector

Vector
Range:

0-774

Standard
Vector:

160

Jumpers
Used:

Tie M3 ("I")
to: M6, M7,
andM8

TieM3 ("I")
to: M6, M7,
andM8

2-22

The device starting address is selected by jumpers for bits 3 through 12. These jumpers are shown in
Figure 2-18. A jumper from the selected bit to ground (M22) decodes a 1; no jumper decodes a 0; and a
jumper to +5 V (MIl) decodes an X (don't care) condition. Figure 2-19 shows the RLV12 device starting address format.

NOTE
For 22-bit addressing, bit A3 is not decoded in the
starting address.

2-23

ENABLE CRYSTAL
_%M29
IZ4-M28
ENABLE
VCO CLK
M27 M26

tv
I
tv

NOTE:
THE MEMORY PARITY ERROR ABORT
FEATURE IS AVAILABLE FOR USE
WITH MEMORIES THAT HAVE PARITY
ERROR CHECKING.
THIS FEATURE DOES NOT HAVE TO
BE DISABLED FOR MEMORIES THAT
DO NOT HAVE PARiTY ERROR
CHECKING. THE PINS ARE CONNECTED AS FOLLOWS:
CONNECTION

FUNCTION

M23 - M24
M24 - M25

NO PARITY
PARITY ERROR ABORT

TEST POINT
M30

MEMORY PARITY ERROR
ABORT SELECTION M23

Mll-+5V
M12 - A3
M13 - A4
M14 - A5

M15 - A6
DEVICE
ADDRESS M16 - A7
M17 - A8
PINS
M18 - A9
M19 - AW
M20 - All
M2l - A12
M22-- GND
Wi

-c::::J-

PASS CD PRIORITIES
(CDMG, CIAK)

M24
M25

SEE NOTE

M10 M9 M8 M7 M6 M5 M4 M3
V8 V7 V6 V5 V4 V3 V2 VEC TO BUS H
\
I
:
:

•

JUMPER
ASSEMBLY

M2
Ml
ENABLE
22-BIT ADDRESSING
MR-5748

Figure 2-18

RLV12 Jumper Locations

BANK SELECT 7
FOR 18-BIT
ADDRESSING

IV
I
IV
VI

FACTORY
CONFIGURATION
CSR
BAR
DAR
MPR
BAE

BANK SELECT 7 FOR
22-BIT ADDRESSING
(CONNECT Ml TO M2)

M21

M20

M19

l, l l I l I I. I I 1.
M18

M17

M16

M15

M14

M13

M12

BUS ADDRESS PINS
CONNECT TO GROUND (PIN M22)
TO DECODE A 1. CONNECT TO +5 V (PIN Mll)
FOR A DON'T CARE (X) CONDITION.
NO CONNECTION DECODES A O.

774400
774402
774404
774406
774410

MR·5749

Figure 2-19

RLV12 Device Address Format

2.6.3 Bus Selection
The RLV12 module can be used on 16-, 18-, or 22-bit LSI-II buses. When sent from the factory.) the
module operates on 16- or 18-bit buses. To enable the module to operate on a 22-bit extended LSI-II
bus, install jumper Ml to M2, shown in Figure 2-18. When installed, the jumper enables bank sele:ct 7
(BBS7) to be determined by the upper address bits (13-21). When the jumper is removed, the RLV12
has an I8-bit mode bank select 7 and can replace an existing RL V 11 or RL V21 as the disk controller
for RLOI and RL02 disk drives.
2.6.4 Interrupt Vector
The interrupt vector has a range of 0 to 774. The interrupt vector is preset at the factory to 160. The
user may select another vector by changing the jumpers for bits V2-V8, as shown in Figure 2-20. A
connection to VEC TO BUS H (M3, shown in Figure 2-18) generates a 1 for that bit; no connec:tion
generates a O.

[0 I 0 I I
FACTORY
CONFIGURATION
160

(

II t

I I 1 1y________
1 I I

_ _ _ _M9
_____
_ _ _ _M7
_
M10
M8

- -M4
-J

INTERRUPT VECTOR PINS
CONNECT TO PIN M3
TO DECODE A 1.
NO CONNECTION DECODES A O.
MR-5750

Figure 2-20

RLV12 Format Interrupt Vector

2.6.5 Interrupt Request Level
The RL VI2 interrupts at priority level 4 determined by the interrupt chip E23, a DC003.
2.6.6 Memory Parity Error Abort Feature
When reading the system's optional memory with parity error detection, a parity error will set OP] and
NXM of the CSR. This is a unique error condition that aborts the current command to the RLVI2.
This error abort feature is possible only with memories that have parity data bits.
The RLV12 is sent from the factory with the memory parity error abort feature enabled. To disable
parity error abort, remove the jumper between pins M24 and M25 and install a jumper between pins
M23 and M24 (see Figure 2-18). This feature does not have to be disabled for non-parity memori<!s, as
parity errors are not generated. Parity error abort uses data bits 16 and 17.

2-26

2.6.7 Other Jumpers
The module has two jumpers, WI and W2, that enable priority signals to pass on the CD side of the
module. The module has these jumpers installed and they should be left in when this controller is installed on the normal LSI-II bus. If the RLVI2 is installed in a C-D interconnect backplane with another module already in place, then these jumpers are removed. If the other module does not use the CD interconnect scheme, then the status of jumpers WI and W2 is not important.
Jumper

Signal

WI
W2

CIAKI to CIAKO
CDMGI to CDMGO

One jumper, W3, enables the word count register to automatically increment during a DMA operation.
This jumper is used for factory testing and should be left in.
Two jumpers on the module disable the crystal oscillator and the voltage-controlled oscillator during
factory testing. These jumpers should be left in.
Jumper

Oscillator

M26-M27
M28-M29

VCO
Crystal

2.6.8 Installation
The RLVI2 can be installed in any quad LSI-II bus slot. The controller's priority level is based on its
electrical distance from the processor module. Use the following procedure to install the module.
1.

Examine the module to make sure that the base address jumpers and vector address jumpers
are set correctly. (See Paragraphs 2.6.2 and 2.6.4.)

Check jumpers MI and M2 for enabling the correct bank select 7 (BBS7) for the 18- or 22bit LSI-II bus.

If desired, disable the memory parity error abort feature. This feature can only be used with
system memories that have parity options, but this feature does not have to be disabled for
non-parity memories. (See Paragraph 2.6.6.)

Insert the BC80M controller cable into JI on the M8061.

Insert the M806I in the selected slot in the LSI-II bus.

Connect the other end of the BC80M cable to the drive.

Continue with the disk installation. (Refer to Paragraph 2.8.)

2.6.9 Acceptance Testing
The RL V 12 controller is tested by running the RL V 12 diskless diagnostic test and, if a drive is attached, by running the diagnostics that exercise the RLOI and RL02 disk drive. The diskless diagnostic
should be run first. The RLVI2 diagnostics are available on different media. Contact your local
DIGITAL sales office for the types of media available and their part numbers.

2-27

Run the XXDP+ diagnostics in the following order.
1.

CVRLB RL V 12 Diskless Diagnostic (16-, IS-, or 22-bit mode)
NOTE
When the RLV12 is configured for 16- or IS-bit addressing, the RLVll diskless diagnostic (CVRLA)
is compatible with the RLV12 diskless diagnostic
and checks the same logic.

2.
3.
4.
5.
6.
7.
S.
9.

CZRLG Controller Test Part 1
CZRLH Controller Test Part 2
CXRLI Drive Test Part 1
CZRLJ Drive Test Part 2
CZRLN Drive Test Part 3
CZRLK Performance Exerciser
CZRLL Compatibility Test
CZRLM Bad Sector File Utility
NOTE
The Bad Sector File Utility is not a diagnostic test.
It is used by Field Service personnel to examine the
bad sector file on the disk and to write entries into
that file.

2.7 RLSA CONTROLLER INSTALLATION
2.7.1 Introduction
The RLSA OMNIBUS controller module (MS433) contains the following logic functions:
•
•
•
•
•
•

Interface logic,
Programmable registers,
Silo data storage and control,
Data formatting and error detection,
Control microsequencer and timing logic,
Drive bus interface logic.
NOTE
Adjustments on the RLSA are preset at the factory
and are not to be changed in the field.

2.7.2 Module Slot Location
The module can be inserted into any unused OMNIBUS hex-height slot between the CPU and
first
memory element. The controller is connected to the first drive via a BCSOJ-20 interface cable. Connections between drives are made using a BC20J-XX (70-12122-10) cable.
2.7.3 Module Installation
1.

Remove the MS433 module (see Figure 2-21) and interface cable (BC80J-20) from the shipping container and inspect them for physical damage.

2-28

Wl0
1-3_...",..,....,.."...--,
2 - 4 1 E133
W11 . ROM

M8433
RL8A
DISK CONTROLLER

W6
W7

---W4

L-J'-J
c

A
CZ·2030

Figure 2-21
2.

RL8A Jumpers

Verify the proper jumper configuration for device codes and priority (Figure 2-21).

Device
Code

60,61
62,63

IN
IN

OUT
IN

Break
Priority

IN
OUT

OUT
IN

IN
OUT

o
1

NOTE
The RL8A is shipped from the factory with a priority of O.
Device
Type

RLOI
RL02

OUT
IN

IN
OUT

2-29

ROM Type
(EI33)

WI0

Wll

012E2

OUT

8708 or
2708

OUT

Position the BC80J-20 interface-to-drive cable in the PDP-8 chassis and connect the Berg
connector to the M8344 module.

Install the M8344 module into selected slot in the OMNIBUS backplane.

Route the cable out to where the first drive will be installed.

2.8 RLOI/RL02 DISK DRIVE INSTALLATION
2.8.1

Unpacking and Inspection
1.

When delivered, each drive and its associated cabinetry is enclosed by a heavy cardboard
carton. If the drive is shipped with a system and mounted in a cabinet, then the carton is
attached to a shipping skid (Figure 2-22). Remove the plastic straps that secure the shippin.g
carton to the skid.

2-30

FULL TELESCOPE CAP

(9905446)

5-PANEL FOLDER

(9905975)

CRATING SLAT

(7606858)

CUSHIONED

11 4979

Figure 2-22

H950 Shipping Package

Remove the lid from the top of the carton.

Remove the staples that fasten the wooden crating slats and carton flanges to the skid.

Remove the shipping carton.

Inspect the cabinet and drive for signs of damage. Retain all packing material and receipts in
the event that any claims for shipping damage must be filed. All claims should be filed
promptly with the transportation company.

2-31

2.8.2 RLOljRL02 Disk Drive Unit Mounting

NOTE
If the RLOljRL02 is to be mounted in an H9S0 cabinet, the shipping brackets must be retained and refitted after installation. This is the only way to prevent the drive from sliding while repositioning or
moving the H9S0 cabinet.
The drive may be shipped in a rack or cabinet as an integral part of a system or may be shipped in a
separate container for addition to an existing system.
If the drive is to be installed in an existing rack or cabinet, install the chassis slides first as described in
Steps 1 through 6 below (Figure 2-23). The procedure for installing the drive itself begins with Ste:p 7.
1.

Install cabinet stabilizers before mounting the drive.

Remove the slides from the carton. (Retain the hardware for reassembly.)

Install slides into the rack or cabinet using enclosed hardware. Be sure the slides are at the
correct height to permit installation of pop panels (dress panels) upon completion of installation. Also verify that the slides do not bind on any hardware used to mount the slide.

Extend slides to lock position.

OPERATOR'S CONTROL PANEL
CZ·0502

Figure 2-23a

RLOI jRL02 Cabinet Installation
2-32

RIVETS

SLIDE EXTENSION RELEASE
CATCH

BUMPER
CZ-0503.

Figure 2-23 b
5.

RLO 1/RL02 Cabinet Installation

Place drive onto chassis slides and reinstall mounting hardware.
a.

Figure 2-23 shows the relationship between the drive, slide mounting rails, and slides.
Note first the position of the slide mounting rails. These rails are currently rIveted to the
sides of the drive.

The cabinet slides fit under the edge of the mounting rails. The forward edge of the
mounting rails are curved to grip the curled edge of the slides (see Figure 2-23a, 2-23b,
and detailed view A).

At the rear of each slide is a locking tab that grips the top rear edge of the rail (Figure
2-23b).

The drive should be carefully placed on top of the slides hooking the front and rear of
each slide as previously described.

When properly placed, the locking latch (Figure 2-23b) on each mounting rail drops into
a groove on each slide. This holds the drive securely so that the screws may be inserted
to bolt the front of each slide to the drive (Figure 2-23b).

After bolting the front of each slide, adjust the length of the slide (using the slide extension release catch) so that the rear slide screw may be inserted (Figure 2-23b).

Ensure that the disk drive moves easily on the slides, that there is no binding in the cabinet,
and that the proper height has been maintained for dress panels.

2-33

Open the drive access cover by loosening the four captive fasteners holding the module access cover. When the screws are sufficiently loosened to raise the cover, the drive access cover may then be lifted off the drive. The module access cover may be rested on the rear lip of
the drive (Figure 2-24).

DRIVE LO G I C _ _
MODULE

...

D.C.SERVO MODU LE
AND TEMPLATE
MA-O!)64

Figure 2-24

RLOI/RL02 Disk Drive Exposed Drive Logic Module

Loosen the head restraining bracket screw located on the positioner. Turn the bracket '90
degrees and retighten the screw (Figure 2-25).

2-34

POSITIONER
FRONT VIEW:

ACCESS COVER

CZ-2003

Figure 2-25

RL01/RL02 - Covers Removed

On newer drives there are two shipping screws on the bottom of the unit that secure the
spindle /blower motor. Remove the screws.

10.

If the drive is being installed in a dual-drive cabinet that has an interlock system to prevent
more than one drive being extended at a time, ensure that the interlock is connected.

2-35

11.

Inspect the terminal block covers at the rear of the drive. Ensure that they are
properly for the input power available (Figure 2-26).
CAUTION
Connection to the wrong power source will result in
serious damage to the disk drive.

NORMAULOW
LINE VOLTAGE
TERMINAL BLOCK ------:..-1
COVER

11 0/220 VOLTS
TERMINAL
BLOCK COVER

C:Z-1056

Figure 2-26

RLOI/RL02 Disk Drive - Rear View
NOTE
On newer-drives, a shielded cable is used. Its part
number is BC21Z-XX.

12.

If there is only one disk drive in the system, or if this is the last drive of the daisy chain,
install a terminator assembly (DIGITAL part no. 70-12293) in the "cable out" location at
the rear of the drive (Figure 2-26).

13.

If this is an RLll- or an RLVl1-based system, route the I/O cable BC20J-XX (DIGITAL
part no. 70-12122-10) between the first drive and the transition connector. If this is an
RL8A-based system, route the BC80J-20 cable from the RL8A to the first drive. If this is an
RLVl2-based system, route the BC80M-6 between the RLV12 and the first drive.

14.

If this is a multidrive installation, connect an I/O cable from "cable in" of this drive to the:
"cable out" connector of the previous drive. Repeat for each drive.

2-36

NOTE
The total length of cable from controller to the last
drive must not exceed 30 m (100 ft).
15.

Install the proper unit-select plug at the front of the drive (Figure 2-27).

LOAD SWITCH
AND INDICATOR
UNIT SELECT PLUG
AND READY INDICATOR

WRITE PROTECT SWITCH
AND INDICATOR
CZ-1005

Figure 2-27

RLO 1/RL02 Disk Drive - Front View

2.8.3 Drive Prestartup Inspection
With the drive power off, follow these steps.

NOTE
If a problem occurs, consult the RLOI/RL02 Technical Manual.

2-37

Ensure that the positioner restraining bracket is secured out of position to prevent interference with the positioner (Figure 2-25).

Ensure that the positioner is home.

Ensure that the read/write head gimbals are not bent or dirty. (If they are dirty, clean with a
solution of 91 percent alcohol and 9 percent water and a lint-free wiper.

Ensure that the spindle rotates freely and its top surfaces are not dirty. (Clean as described
above.)

Ensure that the brush assembly is home (not exposed).
NOTE
An engineering change has eliminated the need for
brushes on the drive. On newer RLOI and RL02
drives, the brush assembly has been replaced with a
unit containing only the cartridge-in-place and top
cover interlock. The Drive Logic Module also contains some logic changes to accommodate the brush
cycle removal.

Ensure that the logic modules and connectors are seated firmly.

Turn CBl ON.

Ensure that the spindle rotates slowly counterclockwise for approximately 15 second.s and
stops. At this time, the LOAD light will come on.
NOTE
On the newer drives (without brushes), the spindle
will NOT rotate until both the top cover and the cartridge-in-place interlocks are depressed.

Ensure that the FAULT light is not on.

10.

Ensure that the cooling fan at the rear of the drive is operating.

11.

On the newer drives, release the top cover and cartridge-in-place interlocks, noting that
spindle stops rotating.

12.

Using a suitable measuring device (Le., digital voltmeter or equivalent), ensure the following
drive voltages are within the specified tolerances.
Voltage

Range

Test
Point

+15 UNREG
-15 UNREG
+5 REG
+8 REG
-8 REG

(+ 15.0 to + 18.0 Vdc)
(-15.0 to -18.0 Vdc)
(+4.48 to +5.1 Vdc)
(+ 7.7 to +8.3 Vdc)
(-7.7 to -8.3 Vdc)

+VUNREG
-V UN REG
TP8
TP4
TP5

2-38

See Figure 2-24 for dc servo module location. Test points are located on the mask covering
the dc servo module.
13.

Verify that the WRITE PROTect switch cycles in and out and the indicator lights up when
the switch is pressed.

14.

Verify that the LOAD switch cycles in and out and the indicator light goes out when the
switch is pressed. Return switch to the "out" position.

15.

Turn off CBl.

16.

Reinstall the top cover and secure with the captive screws.

17.

Ensure that the drive access cover cannot be opened.

18.

Turn CB 1 on and ensure the drive access cover will open.

2.8.4 Drive Startup Operation Check
1.

With the drive power ON, install a scratch cartridge as described in Paragraph 3.3.

Close the cover, press the LOAD switch and note the following.
•

The LOAD light will go out.

•

When the cartridge reaches nominal speed (after approximately 30 seconds), a brush
cycle commences on those drives that have brushes. When the brushes have returned
home, the read/write heads will load and approach cylinder o. When the heads have
locked onto cylinder 0, the READY light will illuminate. The total time for this process
is approximately 45 seconds.

Press the LOAD switch again. The READY light should go off and the read/write heads
should retract to their home position. The spindle should slow down and then come to a complete stop after about 30 seconds. The LOAD light should illuminate when the spindle has
stopped.

If the drive startup operation check detailed above is successfully completed (i.e., the
READY indicator illuminates), run the subsystem confidence tests described in Paragraph
2.9. If there is a problem, consult the RL01/RL02 Technical Manual.

2.9 CONFIDENCE TESTING
Confidence testing consists of running the diagnostic programs. Each diagnostic has a listing that contains operating instructions. Each listing explains system hardware requirements, software environment, which features are tested and how they are tested, program options and how to select them, how
to interpret printouts, error handling, device information tables, dialogue with the Diagnostic Supervisor, and complete operating instructions. The listings are available as hard copy printouts or on microfiche.
The binary form of the diagnostic programs are available on various media. It is always advisable to
keep a copy of the RLOI/RL02 diagnostics on a media other than the RLOIK or RL02K cartridge so
that the diagnostics can be loaded through another device if the RL subsystem is down.

2-39

The old MAINDEC naming system is replaced with a new naming system. Manual and microfiche
designations are also converted. In addition, part numbers are assigned that conform to DIGITAL's
standard twelve character part numbering system.
When ordering diagnostic media, listings, manuals, or microfiche, check the current catalog or index
for the latest revision level. The applicable catalogs and indexes are listed in Table 2-4. Unless otherwise specified when ordering, the latest revision will be shipped.
Table 2-4

Diagnostic Catalogs and Indexes

Name

Part Number

PDP-II Diagnostic Software Components Catalogue*
PDP-8 Software Components Catalogue*
PDP-II Maindec Index (microfiche)
PDP-8 Maindec Index (microfiche)

AV-B02 1E-TC
AV-0872B-TA
AH-9026P-MC
AH-6572G-MA

Both of these catalogs are available on microfiche (EP-08/ 11)

2.9.1 RLII-Based Diagnostics
The diagnostic package used for an RLII/RLOI subsystem before the release of the RL02 consisted of
the six free-standing programs listed in Table 2-5. There were two revisions, Revision A and Revision B.
These programs handled only RLOI drives (not RL02 units).
Table 2-5

RLII-Based Diagnostics

Part Number

Description

CZRLAAO
CZRLBAO
CZRLCAO
CZRLDAO
CZRLEAO
CZRLFAO

Controller Test Part I
Controller Test Part 2
Drive Test Part 1
Drive Test Part 2
Performance Exerciser
Drive Compatibility Test

These diagnostics can be run free-standing under the Diagnostic Supervisor, manually under XXDP,
chainable under XXDP (except CZRLFAO which requires manual intervention), or under manufacturing checkout environments such as SLIDE or ACT-II.
A new diagnostic package is available to test either an RLOI or an RL02 unit. The kit numbers are
listed in Table 2-6 and the contents of the tests are shown in Table 2-7.

2-40

Table 2-6

RLll Diagnostic Kit Numbers

Part Number

Description

ZJ283-RB
ZJ283-RZ
ZJ283-PB
ZJ283-FR

Documentation and paper tape
Documentation only
Paper tape only
Microfiche only

Table 2-7

RLll Diagnostic Components

Part Number

Name

Item

AC-FIIIA-MC
AH-FII0A-MC
AK-FI08A-MC
AK-FI09A-MC
AF-FIIIA-MO

CZRLGAO Controller Test #1

Documentation
Fiche
Paper tape #1
Paper tape #2
DECO

AC-F115A-MC
AH-F114A-MC
AK-FI12A-MC
AK-FI13A-MC
AF-FI15A-MO

CZRLHAO Controller Test #2

Documentation
Fiche
Paper tape #1
Paper tape #2
DECO

AC-FI19A-MC
AH-FI18A-MC
AK-FI16A-MC
AK-F117 A-MC
AF-FI19A-MO

CZRLIAO Drive Test # 1

Documentation
Fiche
Paper tape # 1
Paper tape #2
DECO

AC-FI23A-MC
AH-F122A-MC
AK-F120A-MC
AK-FI21A-MC
AF-FI23A-MO

CZRLJAO Drive Test #2

Documentation
Fiche
Paper tape #1
Paper tape #2
DECO

AC-F127A-MC
AH-F126A-MC
AK-FI24A-MC
AK-FI25A-MC
AF-FI27 A-MO

CZRLKAO Performance Exerciser

Documentation
Fiche
Paper tape # 1
Paper tape #2
DECO

2-41

Table 2-7

RLll Diagnostic Components (Cont)

Part Number

Name

Item

AC-F131A-MC
AH-F130A-MC
AK-F128A-MC
AK-F129A-MC
AF-F131A-MO

CZRLLAO Drive Compatibility Test

Documentation
Fiche
Paper tape # 1
Paper tape #2
DECO

AC-F13SA-MC
AH-F134A-MC

CZRLMAO Bad Sector File Utility

Documentation
Fiche
Paper tape # 1
Paper tape #2
DECO

AF-F13SA-MO

There is a new program added to the package named CZRLMAO. It is used to read the Bad Sector File:
and can be used to write entries into the field writable portion of the Bad Sector File. This program is
not a diagnostic and should not be used as one. It assumes that the system is functioning properly.
In addition to the free-standing diagnostics, there is a DECXll module for use with the DECXll Sys··
tern Exerciser. Revision A (RLAA) will operate an RLOI drive only. Revision B or later (RLAB) will
operate either an RLOI or an RL02.
There is also an RL subsystem driver for the Maintenance Program Generator (MPG).
The binary form of the diagnostics are included as part of XXDP. This makes them available on Jnedia
for the RKOS, RK06, RK07, RLOl, RXOl, DECtape, magnetic tape, and DECassette.
The use of XXDP, DECXll, and MPG is explained in the manuals listed in Table 2-8.
Table 2-8

User Documents

Part Number
HardCopy

Part Number
Microfiche

Name

AC-9093I-MC
AC-8240Z-MC
AC-816JC-MC

EP-DZQXA-J-D
AH-8242Z-MC
EP-DTUMA-C-D

CZQXAIO XXDP User Guide
CXQBAZO DECXll User Document
CTUMACO M.P.G. User Manual

2-42

2.9.2 RLVll-/RLVI2-Based Diagnostics
With one exception, the RLVI1/RLVI2 controller-based subsystem is tested with the same set of diagnostics as the RLII controller subsystem. The RLVII and RLV12 each has an internal maintenance
feature that is not tested by the RLII diagnostics. Therefore, for the RLVII subsystem, there is an
additional diagnostic program called the CVRLAAO Diskless Test. RLV12 subsystems use the
CVRLBA Diskless Test. {At some point in time, this test (CVRLBA) will replace CVRLAA.}
The diagnostic kit includes the same items as the RLII diagnostic kit plus the CVRLAAO test. The
RLVI1/RLVI2 kit designations are shown in Table 2-9.
Table 2-9

RLVll/RLVI2'Diagnostic Kit
Designations

Designation

Contents

ZJ285-RB
ZJ285-RZ
ZJ285-PB
ZJ285-FR

Documentation and paper tape
Documentation only
Paper tape only
Microfiche only

The DECXll module is the same one used for the RLll.
2.9.3 RL8A-Based Diagnostics
There are six free-standing diagnostic programs for the RL8/RLOI system. There is also a DECX8
module for use with the DECX8 System Exerciser. These diagnostics are available in a kit (see Table
2-10) or as individual components (see Table 2-11) and are for use with the RLOI only.
Table 2-10

RL8/RLOI Diagnostic Kits

Part Number

Contents

ZB233-RB
ZB233-RZ
ZB233-PB
ZB233-FR

Documentation and paper tape
Documentation only
Paper tape only
Microfiche only

2-43

Table 2-11

RL8jRLOl Diagnostic Components

Part Number

Designation

AC·-C656A-MA
AH-C657 A-MA
AK-C658A-MA
AL-C659A-NA
AC-C660A-MA

AJRLAAO, RL8A Diskless Control Test (Document)
AJRLAAO, RL8A Diskless Control Test (Fiche)
AJRLAAO, RL8A Diskless Control Test (Paper tape)
AJRLAAO, RL8A Diskless Control Test (DECtape)
AJRLBAO, RL8AjRLOl Drive Test 1 (Document)

AH-C661A-MA
AK-C662A-MA
AL-C663A-NA
AC-C664A-MA
AH-C665A-MA

AJRLBAO, RL8AjRLOl Drive Test 1 (Fiche)
AJRLBAO, RL8A/RLO 1 Drive Test 1 (Paper tape)
AJRLBAO, RL8A/RLOI Drive Test 1 (DECtape)
AJRLCAO, RL8A/RLOI Drive Test 2 (Document)
AJRLCAO, RL8A/RLO 1 Drive Test 2 (Fiche)

AK-C666A-MA
AL-C667A-NA
AC-C668A-MA
AH-C669A-MA
AK-C670A-MA

AJRLCAO, RL8A/RLO 1 Drive Test 2 (Paper tape)
AJRLCAO, RL8A/RLOI Drive Test 2 (DECtape)
AJRLDAO, RL8A/RLOI Compat. Verify (Document)
AJRLDAO, RL8A/RLOI Compat. Verify (Fiche)
AJRLDAO, RL8A/RLOI Compat. Verify (Paper tape)

AL-C671A-NA
AC-C672A-MA
AH-C673A-MA
AK-C674A-MA
AL-C675A-NA

AJRLDAO, RL8A/RLOI Compat. Verify (DECtape)
AJRLEAO, RL8A/RLOI Perf. Exer. (Document)
AJRLEAO, RL8A/RLOI Perf. Exer. (Fiche)
AJRLEAO, RL8A/RLOI Perf. Exer. (Paper tape)
AJRLEAO, RL8A/RLOI Perf. Exer. (DECtape)

AC-C676A-MA
AH-C677A-MA
AK-C678A-MA
AC-C682A-MA
AH-C683A-MA

AXRLAAO, RL8A DECX8 Module (Document)
AXRLAAO, RL8A DECX8 Module (Fiche)
AXRLAAO, RL8A DECX8 Module (Paper tape)
AJRLGAO, RL8A/RLOI Pack Verify (Document)
AJRLGAO, RL8A/RLOI Pack Verify (Fiche)

AK-C684A-MA
AL-C685A-NA

AJRLGAO, RL8A/RLOI Pack Verify (Paper tape)
AJRLGAO, RL8A/RLOI Pack Verify (DECtape)

There are six free-standing diagnostic programs for the RL8/RL02 subsystem, plus a module for use
with the DECX8 System Exerciser. They are available in kit form (Table 2-12) or as individual components (Table 2-13). The Diskless Controller Test (AJRLACO) is simply Revision C of the RLO L test
and can test a subsystem with either RLO 1 or RL02 units. The other diagnostics test RL02-based sys··
tenlS only.

2-44

Table 2-12

RL8A Diagnostic Kits

Part Number

Contents

ZF241-RB
ZF241-RZ
ZF241-PB
ZF241-FR
ZF241-PH
ZF241-RH

Documentation and paper tape
Documentation only
Paper tape only
Microfiche
RL02
RL02 and documentation

Table 2-13

RL8/RL02 Diagnostic Components

Part Number

Name

Item

AC-C656C-MA
AH-C657C-MA
AK-C658C-MA
AL-C659C-NA

AJRLACO RL8A Diskless Control Test

Documenta tion
Fiche
Paper tape
DECtape

AK-F362A-MA
AH-F363A-MA
AH-F364A-MA
AL-F365A-MA
AF-F362A-MO

AJRLHAO RL8/RL02 Seek/Function

Documentation
Paper tape
Fiche
DECtape
DECO/DEPO

AC-F366A-MA
AK-F367A-MA
AH-F368A-MA
AL-F369A-MA
AF-F366A-MO

AJRIAO RL8/RL02 Read/Write

Documentation
Paper tape
Fiche
DECtape
DECO/DEPO

AC-F370A-MA
AK-F371A-MA
AH-F372A-MA
AL-F373A-MA
AF-F370A-MO

AJRLJAO RL8/RL02 Drive Compat.

Documentation
Paper tape
Fiche
DECtape
DECO/DEPO

AC-F374A-MA
AK-F375A-MA
AH-F376A-MA
AL-F377A-MA
AF-F374A-MO

AJRLKAO RL8/RL02 Perf. Exer.

Documentation
Paper tape
Fiche
DECtape
DEPO/DECO

2-45

Table 2-13

RL8/RL02 Diagnostic Components (Cont)

Part Number

Name

Item

AC-F378A-MA
AK-F379A-MA
AH-F380A-MA
AL-F381A-MA
AF-F378A-MO

AJRLLAO RL8/RL02 Pack Verify

Documentation
Paper tape
Fiche
DECtape
DECO/DEPO

AC-F382A-MA
AK-F383A-MA
AH-F384A-MA
AF-F38SA-MO

AXRLBAO DEC/X8 MOD RL8/RL02

Documentation
Paper tape
Fiche
DECO/DEPO

2.10 'USE OF THE M9312 BOOTSTRAP WITH AN RLll SUBSYSTEM
The M9312 module is used on many PDP-II UNIBUS systems to provide bootstrap capability as well
as other functions. The module has five Ie sockets for ROM chips, four of which are reserved for peripheral bootstrap programs. There are several ROM chips available for the different peripheral devices, and an M9312 is configured by selecting the appropriate chips for the particular system on which
it is used.
The RL subsystem bootstrap program is contained in ROM chip number 23-751A9. This chip can
ordered individually and is also available in kit MRII-EA, which consists of an M9312 module plus all
the available ROM chips.
An RL system disk can be booted by a command to the console emulator (a program that is a feature of
the M9312). The device mnemonic for the RLII is DL or DLn, where n is the unit number (0 through
3).
More information on the M9312 is available in the M9312 Technical Manual. It is available in printed
form (EK-M9312-TM) or on microfiche (EP-M9312-TM).

2-46

CHAPTER 3
OPERATOR'S GUIDE

3.1 INTRODUCTION
This chapter describes the function of all external controls on the RLOI/RL02 disk drive and explains
how to operate the subsystem.
3.2 CONTROLS AND INDICATORS
Figures 3-1 and 3-2 show all the drive controls and indicators.

LOAD SWITCH
AND INDICATOR
UNIT SELECT PLUG
AND READY INDICATOR

WRITE PROTECT SWITCH
AND INDICATOR
CZ-1006

Figure 3-1

RLOI/02 Disk Drive - Front View
3-1

NORMAULOW
LINE VOLTAGE
TERMINAL BLOCK - - - - - . : : : : - , .
COVER

11 0/220 VOLTS
TERMINAL
BLOCK COVER

CZ-105€i

Figure 3-2

RLOI/02 Disk Drive - Rear View

3.2.1 Power ON/OFF Circuit Breaker
When the power plug is inserted into the proper ac outlet, ac power is applied to the rear panel circuitt
breaker on the drive. When the circuit breaker is switched ON, ac power is applied to the drive and the
blower motor is energized.
3.2.2 Run/Stop Switch with LOAD Indicator
This push on/push off switch, when pressed in, energizes the spindle motor providing the folllowing
conditions have been met.
•

The RLOIK/RL02K cartridge has been installed.

•

The cartridge protective cover is in place and the cartridge access door is closed.

•

All ac and dc voltages are within specifications.

•

The read/write heads are home (retracted).

•

The brushes are home (newer drives have no brush assembly).

When this switch is released, the spindle drive motor is deenergized if the read/write heads are not
loaded. If the heads are loaded, they are immediately retracted and the spindle drive motor is then
deenergized. In the event of a main power interrupt and subsequent power restoration, the drive will
cycle up if the switch is ON since it contains mechanical memory.

3-2

The LOAD indicator is illuminated whenever:
•
•
•
•

The spindle is stopped,
The read/write heads are home,
The brushes are home (on drives so equipped),
The spindle drive motor is not energized.

3.2.3 UNIT SELECT Switch with READY Indicator
The UNIT SELECT switch is a cam-operated switch that is actuated by inserting a numbered, cammed button. The switch contacts are binary encoded so the drive interface logic recognizes the UNIT
SELECT number (0, 1,2 or 3).
The UNIT SELECT indicator, when lit, indicates a drive READY condition. This condition exists
when:
•
•

The read/write heads are loaded,
The heads are detented on a specific track.

3.2.4 FAULT Indicator
The FAULT indicator is lit whenever the following fault or error conditions develop in the disk drive:
•

Drive-select error,

•

Seek time-out error,

•

Write current in heads (during sector time) error,

•

Loss of system clock (this condition is not latched and not represented in status word),

•

Write-protect error,

•

Write data error,

•

Spin error.
NOTE
Volume Check does not light the FAULT indicator
but does cause DRIVE ERROR.

3.2.5 WRITE PROTECT Switch and Indicator
This push on/push off switch is used either to set the WRITE PROTECT condition if it has been reset
or to reset the WRITE PROTECT condition if it has been set. The switch unit contains a light that is
on when the WRITE PROTECT condition is set.
3.3 OPERATING PROCEDURES
This paragraph explains how to load a cartridge into a disk drive and how to cycle up the drive to put
the subsystem on-line. The cycle-up procedure assumes that ac power is available, the drive ac circuit
breaker is on (cooling fan is energized), system power is on, and the LOAD indicator on the drive control panel is on.

3-3

3.3.1

Cartridge Loading and Drive Startup Procedure
1.

Raise the drive access cover.

Prepare a cartridge (Figure 3-3) for loading as follows.
a.

Lift the cartridge by grasping the top cover handle with the right hand.

Support the cartridge with the left hand holding the protection cover.

Lower the top cover handle and push the handle slide to the left with the thumb of the
right hand. Again, raise the handle to its full upright position to release the protection
cover.

Lift the cartridge from the protection cover and carefully seat the cartridge on the
spindle with the top cover handle recess facing the rear of the machine.

Carefully rotate the top cover handle back and forth to ensure that the spindle locating
arms are seated properly within the cartridge housing detent slots.
CAUTION
Use care when seating the cartridge on the drive
spindle. Rough handling of the cartridge may cause
damage to the spindle/cartridge interface which, in
turn, can cause excessive cartridge runout and positioning errors.

Gently lower the top cover handle to a horizontal position to engage the cartridge on the
drive spindle.

Place the protection cover on top of the cartridge.

Close the drive access cover.

Start the drive as follows.
a.

Press the run/stop switch (LOAD indicator).

When the drive has completed the drive startup sequence and the read/write heads are
detented on cylinder 0, the READY indicator on the numbered UNIT SELECT switch
will be illuminated.

If write protection is desired, press the WRITE PROTect switch.

3-4

TO READY DRIVE:
RAISE CARTRIDGE ACCESS DOOR
LOAD CARTRIDGE
VI

DEPRESS RUN/STOP SWITCH (LOAD INDICATOR)
•

NOTE THAT SPINDLE MOTOR STARTS TURNING
AFTER 30 SECONDS. UNIT SELECT INDICATOR
SHOULD LIGHT INDICATING DRIVE IS READY
TO READ OR WRITE
IF WRITE PROTECTION IS DESIRED. DEPRESS
WRITE PROTECT SWITCH (PROTECT INDICATOR)

DRIVE INDICATORS:
LOAD:
LIGHTS TO INDICATE THAT CARTRIDGE
MAY BE LOADED OR THAT SPINDLE IS
STOPPED.
UNIT
SELECT:
INDICATES LOGICAL DRIVE ADDRESS.
WHEN LIT. INDICATES DRIVE IS
READY TO READ. WRITE OR RECEIVE
CONTROLLER COMMANDS.
FAULT:
WHEN LIT. INDICATES A DRIVE
ERROR CONDITION IF THIS
CONDITION PERSISTS. SEEK
ASSISTANCE.
WRITE
PROTECT:
WHEN LIT. INDICATES THAT
CARTRIDGE CURRENTLY MOUNTED
IS WRITE PROTECTED.

TO LOAD CARTRIDGE:
SUPPORT CARTRIDGE "A" WITH LEFT HAND
HOLDING PROTECTION COVER "B".
PUSH HANDLE SLIDE "C" TO LEFT WITH
THUMB OF RIGHT HAND.
RAISE COVER HANDLE "D" TO FULL UPRIGHT
POSITION. RELEASING PROTECTION COVER "B".
LIFT CARTRIDGE "A" FROM PROTECTION COVER
"8" AND CAREFULLY SEAT IT ON DRIVE SPINDLE
WITH HANDLE RECESS FACING REAR OF DRIVE.
CAREFULLY ROTATE TOP COVER HANDLE "D"
A FEW DEGREES CLOCKWISE AND COUNTERCLOCKWISE TO ENSURE FIRM SEATING.
GENTLY LOWER TOP COVER HANDLE "D" TO
HORIZONTAL POSITION TO ENGAGE CARTRIDGE
ON DRIVE SPINDLE.
PLACE PROTECTION COVER "B" ON TOP OF
CARTRIDGE.

CZ-2032

Figure 3-3

Cartridge Loading Procedure

3.3.2 Cartridge Unloading Procedure
1.

Power down the drive as follows.
a.

Press the run/stop switch and wait approximately 30 seconds for the LOAD indicator lto
illuminate.

Raise the drive access cover.

Remove the cartridge as follows.
a.

Remove the cartridge protection cover and hold the cover in the left hand.

Push the top cover handle slide to the left with the thumb before raising the handle.

Raise the top cover handle to a full upright position to release the cartridge from the
drive spindle.

Carefully lift the cartridge up and out of the drive and place it in the protection cover

Lower the top cover handle to the horizontal position to lock the protection cover in
place.

3.4 OPERATOR MAINTENANCE
3.4.1 Introduction
User maintenance procedures are limited to the care and cleaning (external) of the disk cartridge and
the cleaning of the drive spindle assemblies.
3.4.2 Professional Cartridge Cleaning
Cartridges should be professionally cleaned every six months or whenever practical. Complete cartridge
cleaning procedures must be performed by a professional cleaning service. Application of cleaning procedures to the recording surfaces by unqualified personnel may void not only the warranty on the serviced cartridge, but the warranty for any drive on which the cartridge is operated.
3.4.3 User Cartridge Cleaning
The user should clean the outer sides of a completely assembled cartridge by using a lint-free, wiper
dampened with a solution of 9 percent water and 91 percent isopropyl alcohol. However, the cartridge
must not be saturated and all excess solvent must be removed with a dry wiper. This procedure is necessary to prevent solvent from entering the seams of the assembly and contaminating the platter.
CAUTION
For cleaning purposes, use only a solution of 9 percent water with 91 percent isopropyl alcohol. Water,
trichloroethylene, or other solvents are not permit·,
ted.

3-6

3.4.4 Spindle Assembly Cleaning
Using a lint-free wiper dampened with. the isopropyl alcohol solution, clean the spindle cone prior to
loading the cartridge. However, do not saturate the assembly; remove all excess solvent with a dry wiper. This procedure is necessary to prevent solvent from entering a loaded cartridge and contaminating
the platter. In addition, ensure that the shroud is as free of lint and dust as possible before loading a
cartridge. Dry lint and dust may be blown from the spindle area using filtered dry air. However, do not
use manufacturing environment air that may contain water or oil; canned air is an acceptable substitute.
3.5 CARTRIDGE CARE SUMMARY
The following list summarizes care and cleaning considerations for an RLO 1K/RL02K disk cartridge.
•

Keep cartridges clean.

•

Use cartridges at computer room temperature only.

•

Manipulate cartridges by the top cover handle only.

•

When the protection cover is removed (for loading), do not touch disk surfaces, hub center
cone, or surfaces.

•

When the protection cover is removed (for loading), interior metal hub surfaces must be
clean.

•

When the protection cover is removed (for loading), ensure that the disks are not moved or
rotated, since improper disk motion may generate plastic particles which can result in disk
damage.

•

When loading or unloading a drive, insert and remove cartridges gently. In addition, do not
use excessive force when manipulating the top cover handle.

•

If, during operation, a cartridge makes rumbling or continuous tinging sounds, discontinue
use of the cartridge. Use of a damaged cartridge on other drives may damage the drives,
resulting in additional damage to all other cartridges used in those drives.

•

Each cartridge should be cleaned professionally every six months and/or whenever a specific
cartridge is not operating properly.

•

Cartridges are factory-repairable only. Disassembly in the field is not permitted, and such
action may void the warranty on a cartridge, as well as any drive on which the cartridge may
be opera ted.

3-7

CHAPTER 4
II-FAMILY PROGRAMMING INFORMATION

4.1 GENERAL DESCRIPTION
This chapter describes the RLll, RLVll, and RLV12 controllers and points out the differences among
them.
4.1.1 RLll Controller Description
The RLII controller consists of a single hex-height M7762 module. It can be installed in any hex-height
small peripheral controller (SPC) slot. This controller provides a programmable interface between the
PDP-II UNIBUS and the RLOI/RL02 disk drive(s). The controller has four addressable registers that
are detailed in Paragraph 4.2. The controller can respond to one of seven commands from the software.
These controller commands are explained in detail in Paragraph 4.3.
The RLII buffers the data flow between drive and memory with a 16- x 16-bit IC buffer. This buffer
has the designation of SILO as it is a first-in, first-out device.
4.1.2 RLVll Controller Description
The RLVII controller consists of 2 quad-height modules designated M8013 and M8014. This controller provides a programmable interface between the LSI-II Q-Bus and the drive(s). Like the RLll,
the RLVII has four addressable registers that are explained in detail in Paragraph 4.2. The RLVII can
respond to one of eight commands from the software. These commands are explained in Paragraph 4.3.
The RL V 11 buffers the data flow between drive and memory with a 256- x 16-bit RAM. This RAM
has the designation of FIFO (first-in, first··out).
4.1.3 RLV12 Controller Description
The RL V 12 controller consists of one quad-height module designated M8061. This is a fine-line etch,
multi-layered module with an extremely high IC chip density. The controller may be used on the standard LSI-II Q-Bus or the Q-22 Bus. The use of 22-bit addressing (Q-22 Bus) is selected via a jumper.
This controller functionally replaces the RLVl1 as the programmable interface between the drive(s)
and the LSI-II Q-Bus. The program accessible registers are explained in detail in Paragraph 4.2. Like
the RLVll, the RLV12 has a maintenance command that the RLII does not have. All eight commands
are described in Paragraph 4.3. The RLV12 also has a 256- x 16-bit RAM used as a FIFO buffer.
4.2 ADDRESSABLE REGISTERS
There are four addressable registers in the RLII and RLVII controllers that are used to control and
monitor the operation within the controller itself and within the disk drive unit(s). These are described
briefly in Table 4-1 and described in detail in the following text. The RLV12 controller contains these
four plus an additional register to hold the balance of the 22-bit memory address.

4-1

Table 4-1

Controller Addressable Registers

Address
(Octal)

Description

774400

Control Status (CS) - Indicates drive ready condition; decodes drive commands and
provides overall control functions and error indications.

774402

Bus Address (BA) - Contains the memory location involved in a data transfer during
a normal read or write operation.

774404

Disk Address (DA) - Stores information for: (1) seeking to desired track; or (2) selecting sectors to be transferred during read/write operations; or (3) used wh,en requesting a drive status message.

774406

Multipurpose (MP) - (1) Functions as word counter when transferring read/writ,:!
data between UNIBUS and drives; or (2) acts as storage buffer when reading drivl:!
status; or (3) stores header information from controller silo when executing a read
header command.

17774410

Bus Address Extension (BAE) - Contains the upper six bits of 22-bit memory ad.dress.ing. This register is used only with the RL V 12 controller and then only when 22-bit
addressing mode is enabled.

4.2.1 Control Status Register
The Control Status (CS) register (Figure 4-1) is a 16-bit register with a base address of 774400. Bits 1
through 9 can be read or written; the other bits can only be read. Table 4-2 describes the bit fonnat of
the Control Status register.
When the controller is initialized, bits 1-6 and 8-13 are cleared and bit 7 is set. Bit 0 is set whenever the
selected drive is in the ready condition; otherwise, the bit is cleared. Bit 14 is set whenever there is :a
drive error; it is cleared when the drive error is corrected or the drive error is cleared by a Get Status
command. Bit 15 is set when there is a drive or controller error (indicated in bits 10-14).
CONTROL STATUS REGISTER (CSR)
15

ERR

DSl

DSO

CRDY

SA17

BA16

READIWRITE

READ ONLY

::J

A--..-/
flEAD
ONLY
C:Z-2009

Figure 4-1

CS Register

4-2

Table 4-2

Control Status Register Bit
Description

Bit(s)

Description

Drive Ready (DRDY) - When set, this bit indicates that the selected drive is ready to receive a command. The bit is cleared when a seek or head select operation is initiated and set
when the operation is completed.

1-3

Function Code - These bits are set by software to indicate the command to be executed.
Command

F2-FO

No Op (RL11) or
Maintenance Mode
(RLV11jRLV12)

000

Write Check

001

Get Status

010

Seek

011

Read Header

100

Write Data

101

Read Data

110

Read Data without
Header Check

111

4-5

Bus Address Extension Bits (BAI6, BAI7) - These are the two most significant bus address
bits when operating in 18-bit addressing modes. They are read and written as data bits 4
and 5 of the cs register but considered as address bits 16 and 17 of the bus address register
(see Paragraph 4.2.2).

Interrupt Enable (IE) - When this bit is set by software, the controller is allowed to interrupt the processor at the normal command or error termination.

Controller Ready (CRDY) - When cleared by software, this bit indicates that the command
code in bits 1-3 is to be executed (negative GO bit). The hardware sets this bit to indicate
the controller is ready to accept another command.

4-3

Table 4-2

Control Status Register Bit
Description (Cont)

Bit(s)

Description

8-9

Drive Select (DSO, DSl) - These bits determine which drive will communicate with the
controller via the drive bus.

10-13

Error Code

Error Name

E3-EO

Operation Incomplete
(OPI)

0001

Read Data CRC
(DCRC or Write Check
Error (WCE)

0010

Header CRC (HCRC)

0011

Data Late (DLT)

0100

Header Not Found
(HNF)

0101

Non-Existant Memory
(NXM)

1000

Memory Parity Error
(MPE) RLV12 only

1001

Drive Error (DE) - This bit is tied directly to the DE interface line. When set, it ind:icates
that the selected drive has flagged an error. (The source of the error can be determined by
executing a Get Status command and then executing an MPR read.)
DE can be cleared by executing a Get Status command with bit 3 of the DA registe:r set.

Composite Error (ERR) - When set, this bit indicates that one or nlOre of the error bits (bits
10-14) is set. If the IE bit (bit 6 of CS) is set and an error occurs (which sets bit 7), an
interrupt will be initiated.

4-4

4.2.2 Bus Address Register
The Bus Address (BA) register (Figure 4-2) is a 16-bit register with an address of 774402. Bits 1
through 15 can be read or written; bit 0 is always zero. Bus address bits 1'6 and 17 are contained in bits
4 and 5 of the CS register.
The BA register indicates the memory location involved in the data transfer during a normal read or
write operation. The contents of the BA register are automatically incremented by two as each word is
transferred between the bus and the I/O buffer. This register overflows bits BA16 and BA71 into CS
register bits 4 and 5. If the controller is an RLV12 and if 22-bit addressing mode is enabled, then bits
BA16 through BA21 are found in the BAE register.
The BA register is cleared by initializing the drive or by loading the register with zeros.
15

BA15 BA14 BA13 BA12 BA 11 BA10

BA9

BA8

BA7'

BA6

BA5

BA4

BA3

BA2

BA1

____________________________•______, ,_________________________________--J/

REAOIWRITE

Figure 4-2

CZ-2035

BA Register

4.2.3 Disk Address Register
The Disk Address (DA) register is a 16-bit register with an address of 774404. Its contents can have
one of three meanings depending on the function being performed. This register is cleared by initializing the device or loading the register with zeros. All 16 bits can be read or written by the processor. The following three paragraphs describe the uses of the Disk Address register.
4.2.3.1 DA Register During a Seek Command - To perform a Seek function, it is necessary to provide
cylinder address difference, head-select, and head-directional information to the selected drive. Figure
shows the bit layout of the Disk Address register during seek commands, while Table 4,,:,3 describes
the bit format.
15

DF8

OF7

OF6

OF5

OF4

OF3

DF2

OF1

DFO

DIR

CZ-2010

Figure 4-3

DAR Contents to Execute
a Seek Command

4-5

Table 4-3

Disk Address Register Bit
Description for Seek Commands

Bit(s)

Description

Marker Bit - Must be a one.

Seek - Must be a zero, indicating to the drive that a seek is being requested. With this bit
cleared, the drive uses the remaining contents of the register as seek parameters.

Direction (DIR) - This bit indicates the direction in which a seek is to take place. When the
bit is set, the heads move toward the spindle (to a higher cylinder address). When the bit is
cleared, the heads move away from the spindle (to a lower cylinder address). The actual
distance moved depends on the cylinder address difference (bits 7··15).

Must be a zero.

Head Select (HS) - Indicates which head (disk surface) is to be selected. A one select.s the
lower head; a zero, the upper head.

5-6

Reserved.

7-15

Cylinder Address Difference DF 08:00 - Indicates the number of cylinders the heads are to
move on a seek.

4.2.3.2 DA Register During Read or Write Data Command - For a read or write operation, the DA
register is loaded with the address of the first sector to be transferred. As each successive sector is
transferred, the DA register is automatically incremented. The contents of this register are used by the
header comparison logic to locate the desired sector. The header read from the disk is compared against
the contents of this register. Figure 4-4 shows the bit format of the Disk Address register during data
transfer commands, while Table 4-4 describes the bit format.

I I I

EA 81 CA 71 CAS CA 51 CA41 CA31 CA21 CA 1 CAO HS SA51 SA41 SA3! SA2! SAl! SAO

CZ-2011

Figure 4-4

DA'R Contents During a
Read/Write Data Command

4-6

Table 4-4

Disk Address Register Bit
Description for Data Transfer
Commands

Bit( s)

Description

0-5

Sector Address SA 05:00 - Desired address of one of the 40 sectors on a track as supplied
by the software (range is 0 through 47, octal).

Head Select (HS) - Desired head address of one of the two drive heads. A one indicates the
lower head; a zero, the upper head.

7-15

Cylinder Address CA 08:00 - Desired address of one of the cylinders on the disk (range is 0
through 777, octal). The RLOI has 256 cylinders and the RLV12 has 512 cylinders.

4.2.3.3 DA Register During a Get Status Command - For a Get Status command, the DA register bits
must be programmed as shown by Figure 4-5 and described in Table 4-5.

RST

I I I I I I I I IoI I I I

CZ-2037

Figure 4-5

DAR Contents to Execute
a Get Status Command

Table 4-5

Disk Address Register Bit
Description for Get Status
Commands

Bit(s)

Description

Marker Bit - Must be a one.

Get Status (GS) - Must be a one, indicating to the drive that the status word is being requested. At the completion of the Get Status command, the drive status word is read into
the controller Multipurpose (MP) register. With this bit set, the drive ignores bits 8-15.

Must be a zero.

Reset (RST) - When this bit is set, the drive clears its error register (resets all drive faults)
before sending the status word to the controller.

4-7

Table 4-5

Disk Address Register Bit
Description for Get Status
Commands (Cont)

Bit( s)

Description

4-7

Must be a zero.

8-15

Not used during a Get Status.

4.2.4 Multipurpose Register
The Multipurpose (MP) register is a 16-bit register with an address of 774406. This register can have
one of three meanings, depending on the function being performed. The following three paragraphs
describe the uses of the Multipurpose register.
4.2.4.1 MP Register After a Get Status Command - When a Get Status command is executed, the
status word is returned to the controller and transferred to the MP register. Figure 4-6 shows the bit
layout, while Table 4-6 describes the bit format.
15

WOE

CHE

SKTO SPE

WGE

OSE

STC

STB

[

CZ-:W12

Figure 4-6

MPR - Following a Get Status Command

Table 4-6

MP Register Bit Description
for Get Status Commands

Bit( s)

Description

0-2

Major State Code (ST C:A) - These bits define the state of the drive.
STC

STB

STA

0
0
0
0
1
1
1
1

0
0
1
1
0
0
1
1

0
1
0
1
0
1
0
1

Load cartridge
Spin-up
Brush cycle
Load heads
Seek
Lock on
Unload heads
Spin-down

4-8

Table 4-6

MP Register Bit Description
for Get Status Commands (Cont)

Bit(s)

Description

Brush Home (BH) - Set when the brushes are home.

Heads Out (HO) - Set when the heads are over the disk.

Cover Open (CO) - Set when the drive access cover is open or the dust cover is not in place.

Head Select (HS) - Indicates the currently selected head. A zero indicates the upper head;
a one, the lower head.

Drive Type (DT) - A zero indicates an RLOl; a one, an RL02.

Drive-Select Error (DSE) - Set when a multiple drive selection is detected.

Volume Check (VC) - Set during transition from a head load state to a head-on-track state.
Cleared by execution of a Get Status command with Bit 3 asserted.

Write Gate Error (WGE) - Sets when Write Gate is asserted and one or more of the following conditions exist.
•
•
•
•

Drive is not "ready to read/write"
Drive is write-protected
Sector pulse is occurring
Drive has another error

Spin Error (SPE) - Set when spindle has not reached speed in the required time during
spin-up or when spindle speed is too high.

Seek Time Out (SKTO) - Set when the heads do not come on-track in the required time
during a Seek command or when "ready to read/write" is lost while the drive is in position
(lock-on) mode.

Write Lock (WL) - Set when the drive is write protected.

114

Current Head Error (CHE) - Set if write current is detected in the heads when Write Gate
is not asserted (reading).

Write Data Error (WDE) - Set if Write Gate is asserted but no transitions are being detected on the Write Data line.

4-9

4.2.4.2 MP Register After a Read Header Command - When a Read Header command is executed"
the next header is read and its three words are transferred to the MP register. The first word
sector address, head-select, and cylinder address information. The second word contains zeros. The:
third word contains header CRC information. All three words can be read sequentially by the prograrrl
by reading the contents of the MPR. Figure 4-7 shows the bit layout of the MP register for Read Head··
er commands, while Table 4-7 describes the bit format.

[ CAS

[

]

ZEROES

[

]

CRC

C:Z-2013

Figure 4-7
Table 4-7

MPR - Following a Read Header Command
MP Register Bit Description
for Read Header Commands

Bit(s)

Description

0-5

SA 0:5 - Sector Address

HS - Head Select

7-15

CA 0:8 - Cylinder Address

4-10

4.2.4.3 MP Register During Read/Write Data Commands - Before the reading or writing data, the
program loads the word count into the MP register in two's complement form. The counter is incremented as each word is transferred. Usually, the reading or writing operation is terminated when the
word counter reaches zero (overflows). The word counter can keep track of from one to the full 40sector count of 5120 data words (decimal). Figure 4-8 shows the bit format of the MP register for data
transfer commands, while Table 4-8 describes the bit format.

NOTE
The RLOI/RL02 disk drive will not do spiral
read/writes. If data is to be transferred past the end
of the last sector of a track, it is necessary to break
up the operation into the following steps.
1. Program the data transfer to terminate at the
end of the last sector of the track.
2. Program a seek to the next track. This can be
either a head switch to the other surface but
same cylinder or a head switch and move to the
next cylinder.
3. Program the data transfer to continue at the
start of the first sector at the next track.

WC12 WC11 WC10 WC9

WC8

WC7

WC6

WC5

WC4

WC3

WC2

WC1

WCO

CZ-2036

Figure 4-8

MPR - Used as a Word Counter

Table 4-8

MP Register Bit Description
for Data Transfer Commands

Bit(s)

Description

0-12

Word Count WC 12:00 - Contains the two's complement of total number of words to be
transferred.

13-15

Must be ones.

4.2.4.4 Bus Address Extension Register - The Bus Address Extension (BAE) register (Figure 4-9) is a
six-bit register with an address of 17774410. It is used only with the RLV12 controller, and then only
when the 22-bit addressing mode is enabled. Bits 0 through 5 can be read or written. Bits 0 and 1 contain the same information found in the CSR bits 4 and 5.
4-11

NOTE
If 22-bit addressing is to be used, the software must
correctly load the CSR bits 4 and 5 with the contents of BA17 and 16. Upon command initiation,
these two bits are loaded into BAE bits 0 and 1. Figure 4-9 shows the bit format of the Bus Address Extension register.
15

[ I

I I I I I I I I I
0

BA21 BA20 BA19 BA18 BA17 I3A16

READ/WRITE

Figure 4-9

CZ-048B

BAE Register

4.2.5 Register Summary
Figure 4-10 is a bit and function summary of the CS, BA, BAE, DA, and MP registers.
CONTROL STATUS REGISTER (CSR)

ERR

NXM

DS1

DSO CRDY

[

BA17 BA16

DRDyl
READ
ONLY

READIWRITE

READ ONLY

CZ-200SI

BUS ADDRESS REGISTER (BAR)

BA 15 BA14 BA13 BA12 BA 11 BA10

BA9

BA8

BA7

BA6

BA5

BA4

BA3

BA2

BA1

o ]

READIWRITE

Figure 4-10

4-12

CZ-2035

BA21 BA20 BA19 BA18 BA17 BA16

READ/WRITE

CZ-0488

DAR DURING READING OR WRITING DATA COMMANDS
15

CA8

CA7

CA6

CA5

CA4

CA3

CA2

CAl

CAO

SA5

SA4

SA31 SA2

SAl

I I
SAO

CZ-2011

DAR DURING GET STATUS COMMAND
15

14
X

I I I
0

RST

00
1

CZ-2037

WDE

CHE

SKTO

SPE

MPR AFTER GET STATUS COMMAND
04
05
07
06
10
09
08

WGE

STC

STB

STA

DSE

CZ-2012

CA8

CA7

CA6

CA5

MPR AFTER READ HEADER COMMAND
10
09
08
07
06
04
05

ZEROES

08
CRC

CZ-2013

Figure 4-10

MPR DURING READIWRITE COMMANDS FOR WORD COUNT
15

WC12 WC11 WC10 WC9

WC8

WC7

WC6

WC5

WC4

WC3! WC2! WC1 I

CZ-20:J6

Figure 4-10

4.3 CONTROLLER COMMANDS
The RLII controller responds to one of seven commands from the software, while the RL VII jRLV12
can respond to one of eight commands. Table 4-9 lists the commands. Each command is explained in
the following paragraphs.

Table 4-9
I'unction
Code

RLll/RLVll/RLVI2 Controller Commands

Command
No Op (RLll) or Maint. (RLVII jRLVI2)
Write Check
Get Status
Seek
Read Header
Write Data
Read Data
Read Data Without Header Check

1
2
3

4
5
6
7

4.3.1 No-Op (RLll) or Maintenance (RLVll) - Function Code 0
The RLII performs no operation aside from clearing errors (all except DE), setting CRDY and
rupting if IE is set.
The RLVlljRLV12 maintenance command is used during a diskless diagnostic routine to detect controller malfunctions or to establish a level of confidence in controller operation. Prior to issuing the
nlaintenance command, a buffer area in memory must be set aside for writing and reading of test patterns. The controller registers must be loaded by program with the following information.
•

BAR with address of first memory buffer location

•

we register with a count of 511 (177001 octal)

•
•

DAR with test word
CSR with a function code 0, reset bit 7

4-14

When the maintenance command is issued (MAINT) and the CRDY bit is cleared, the OPI timer
starts. The microsequencer decodes the command and starts a maintenance routine. Two internal tests
are performed and the DAR is incremented after each. DMA transfers take place between memory and
the controller FIFO, transferring 256 words from the memory write test buffer into the FIFO. Once the
FIFO is full, 255 words are transferred into the memory read test buffer previously prepared. The DAR
is now incremented a third time. Throughout MAINT, error checks are made; if an error occurs, the
function sets ERR. The DAR is incremented as the test proceeds. This incrementing serves as a trace
to determine the failing internal test.
Next, the test word + 3 that was initially loaded into the DAR is channeled through the data multiplexer and into the CRC circuit. A CRC word is generated from this test word and sent through the
data multiplexer again. This CRC of the test word then passes through the write precompensation circuit and the data separator circuit to eventually end up in the FIFO.
The contents of the DAR are then incremented and become test word +4. This new test word follows
the same path as the preceding test word and ends up as the second word in the FIFO. At this point, the
FIFO holds:
WORD

FIFO

1st
2nd

CRC of test word + 3
CRC of test word + 4

The contents of the DAR are now incremented once again and become test word + 5.
Next, the second word in the FIFO (CRC of test word +4) is removed from the FIFO and serialized. It
is sent through the data multiplexer the CRC, and data multiplexer again, and so on. It follows the
same data path as the two previous words and ends up back in the FIFO as the new second FIFO word.
At this point, the FIFO holds the following.
WORD

FIFO

1st
2nd

CRC of test word + 3
CRC of CRC of test word + 4

The contents of the DAR is then incremented for the sixth time to become test word + 6. The controller
ready bit is then set and the CPU receives an interrupt request. This completes the maintenance command operation.
As a result of this maintenance test, the following circuits are tested: the FIFO, the registers, the data
multiplexer, the CRC circuit, the match circuit, the write precompensation circuit, the data separator
circuit and the FIFO input and output serializer. Also, many of the microsequencer functions are exercised.
4.3.2 Write Check - Function Code 1
The write check command is used to verify that data was written on the disk correctly. It is used after
writing a block of data onto the disk by the write command function. The write check command reads
this same block of data from the disk and compares it with the contents of its source data buffer area in
main memory. Because this comparison is performed in the controller, this source data must be transferred out of memory and into the controller buffer.

4-15

Prior to issuing this command, the BA register must be loaded with the address of the first location of
the data block in the main memory. The word counter register must be loaded with the data blo(;k
length. The DA register is then loaded with the starting disk address location. At this point, th,e write
check command can be loaded into the CS register.
Once the header is found, and the header CRC validates the match, 128 words of data are read fro:m
the disk. The disk data is then compared serially with the serial data coming out of the silo (SER
DATA OUT). Either a compare error or a data CRC error will set bit 11 in the CS register.
4.3.3 Get Status - Function Code 2
The Get Status command causes the status word from a drive to be transferred to the controller where
the software can access it through the MPR. The software should first verify that the controller is ready
DAR
to perform an operation (the drive does not have to be ready). Then, the software should load
with ones in bits 01 and 00, and zeros in the other locations. Next, the software should load the CSR
with drive-select bits, a negative GO bit, IE bit (if desired) and a code of 2 in the function bits. The
controller will then command the selected drive to transfer its status word to the MPR in the controller.
If the "reset" bit (03) in the DAR is also set, the drive resets its status
before transferring it 1to
the controller. This is the manner in which Volume Check is cleared or to check for hard errors.
4.3.4 Seek - Function Code 3
The Seek operation causes the positioner to move (either forward or reverse) some number of cylinders.
The software should first verify that the drive is ready to accept a command, then load the DAR wi1th
the difference word (difference between the present position and desired position). This word contains
the number of cylinders to move (bits 15 through 07), the head-select bit (04) and the direction :bit (bit
02, 1 = forward, 0 = reverse). Bits 06, 05 and 01 must be reset and bit 00 must be set. After the DAR is
loaded, the software should load the CSR with the command word. This word should contain the: driveselect bits, the negative GO bit, the IE bit (if desired), and a code of 3 in the function bits. The controller sends the Seek command to the selected drive, causing the drive to start its Seek operation. At
this time, the controller becomes ready and interrupts if IE is set. The controller is now ready to accept
another command to perform another operation on another drive while the Seek is occurring.
If the difference word is large enough that the heads attempt to move past the innermost or outermost
limits, the head will stop at the guard band and retreat to the first even-numbered data track.
4.3.5 Read Header - Function Code 4
When a Read Header function is decoded, the controller will read the first header encountered on the
selected drive and place the three header words in the buffer. They pass through the buffer and stop
with the first word in the MP register. The software can then access the first word to determine the
current sector, head, and cylinder address. When the software extracts the first word from the M:P
register, the second word automatically moves into the MP register. If the software extracts the second
word, the third word automatically moves into the MP. This is the CRC word. The software can now
access it for checking purposes.
4.3.6 Write Data - Function Code 5
When this function is decoded with CRDY cleared, the controller reads successive header words and
compares them to the DA register. When a match is found, the header CRC is checked and, if c:orrec:t,
that sector is written with the words from memory designated by the BA and/or BAE register(s). The
BA and MP registers are incremented for each word that is transferred. For partial sector writes, the
remaining sector area is filled with zeros. At the end of the sector, the sector portion of the DA
is incremented. The next sector is written if all the words have not been written. At the end of the
transfer, CRDY is set and an interrupt made if IE is set.

4-16

4.3.7 Read Data - Function Code 6
When this function is decoded, the controller reads successive header words and compares them to the
contents of the DA register. When a match is found, the header CRC is checked and, if correct, that
sector is read and the words are placed in the memory location designated by the BA and/or BAE
register(s). Both the BA and MP registers are incremented for each word that is transferred. This operation continues until the contents of the MP register are all zeros. Data CRC is checked and the DA
register is incremented at the end of each sector. If the word count has not overflowed, the next sector
is read. Otherwise, CRDY is set and an interrupt is made if IE is set.
4.3.8 Read Data Without Header Check - Function Code 7
When this function is decoded, the data portion of the sector following the next sector pulse is read and
the words requested are placed in the memory locations designated by the BA register. The BA and MP
registers (word count in two's complement form) are incremented for each word transferred. The header is neither compared nor checked for CRC errors. Data CRC is checked at the end of a sector. If the
word count has not overflowed, the next sector is read. Otherwise, CRDY is set and an interrupt is
made if IE is set.
NOTE
The DA register is not incremented during multisector transfer.
4.4 CSR ERROR CODE DEFINITIONS
4.4.1 Operation Incomplete (OPI)
This error is flagged by the setting of bit 10 of the CSR. When bit 10 is set and 11 through 13 are clear,
the indication is that the current command being executed did not complete within the OPI timer period. For an RLll, this timer period is 200 ms. For the RLVII controller, the period is 490 ms. The
RLV12 controller timer is set for 550 ms.
4.4.2 Data CRC (DCRC) or Write Check (WCE)
This error is flagged by the setting of bit 11 of the CSR. When bit 11 is set and bit 10 is clear, the
indication is either that a CRC error has occurred when reading data or that a write check error has
occurred. If the function currently being executed is a write check command, then the probabilities are
that the error is a WCE. If the function being executed is a read data command, then the error is a
DCRC. A write data command cannot flag either of these errors.
4.4.3 Header CRC (HCRC)
This error is flagged by the setting of bit 11 of the CSR. When bit 11 is set and bit 10 is also set, the
indication is that a CRC error has occurred when reading a header. This error can set during write data
or read data commands.
4.4.4 Data Late (DLT)
This error is flagged by the setting of bit 12 of the CSR. When bit 12 is set and bit 10 is clear, the
indication depends upon the command being executed.
•

Write Data Command - The silo or FIFO buffer in the controller emptied before the word
counter overflowed. This means that the command is not finished but the buffer contains no
more words to write. When this happens the DMA cycles are too slow.

•

Read Data Command - The silo or FIFO buffer in the controller is full and there are more
words to read from the disk. When this happens, the DMA cycles are too slow causing data
being read to be lost.

4-17

4.4.5 Header Not Found (HNF)
This error is flagged by the setting of bit 12 of the CSR. When bit 12 is set and bit lOis also s,et, the
indication is that the desired header address could not be found before the OPI timer expired.
4.4.6 Non-Existant Memory (NXM)
This error is flagged by the setting of bit 13 of the CSR. When bit 13 is set and bit 10 is clear, the
indication is that the addressed memory did not respond to the DMA cycle request within 10 to 20
microseconds.
4.4.7 Memory Parity Error (MPE)
This error is flagged by the selting of bit 13 of the CSR. When bit 13 is set and bit lOis also set, the
indication is that a data parity error was detected on a DMA cycle to the controller. This error appli<::s
to RL V 12 controllers only.
4.:5

OPERATIONAL CONSIDERATIONS

4..5.1 Interrupt
The controller will request an interrupt if the IE bit and the CRDY bit are both set in the CS register.
The IE bit is set or reset by the software and reset with the initialize condition. The CRDY bit is set by
the hardware upon completion of a function or upon the setting of an error flag. It is also set by the
initialize condition. It is reset by the software to cause the controller to start a function (negative GO
bit). The interrupt vector address is 160. The normal priority level for the RLII is BUS REQUEST 5.
The RLVII and RLV12 controllers use the one priority level provided by the LSI-II processor.
4..5.2 Seek Operation
The following sequence is an example of performing a seek function.
1.

Issue read header function to drive and wait for interrupt or wait for CRDY.

Check error flag.

Read the header word from the MP register.

Calculate difference and direction for the seek.

Move difference word to the DA register.

Issue seek function to drive and wait for seek to be completed as indicated by drive ready bit.

Check error flag.

A software system that optimizes positional latency (see Paragraph 1.4) would keep current cylinde:r
and head-select information in core so that Steps 1, 2, and 3 would be unnecessary. Also, note that
reading the header gives rotational position as well so that some rotational optinlization is possible.
4.5.3 Overlapped Seeks
Since the controller comes ready and interrupts as soon as a seek is issued, it is possible to issue
to
additional drives while the first is seeking. However, no interrupt occurs when the seeks are completed,
so the transfer command should be issued to the drive requiring the shortest seek as soon as all seeks are
issued. In this way, the drive completing its seek first will immediately perform its transfer and interrupt when finished.

4-18

4.5.4 Data Transfer
Data transfer is via DMA facility. Sixteen words of silo buffering are provided for data by the RL11.
The RLV11 and RLV12 controllers provide 256 words of FIFO (RAM) buffering and will not start
transferring a sector unless the FIFO has enough space to hold the entire sector.
To do a data transfer, steps of the seek operation would be followed by:
•

Load BA and BAE registers with address of first memory location to be transferred,

•

Load DA register with address of first disk location to be transferred,

•

Load WC register with two's complement of number of words to be transferred,

•

Issue read data or write data and wait for interrupt or test for ready,

•

Check error flag.

Other drives could do seeks or data transfers between the issuing of seek and the issuing of the data
transfers.
4.5.5 Recovery of Data with Bad Headers
Function 7, read data without header check, is provided to allow the recovery of data should headers
become unreadable. If constant HNF of HCRC errors are encountered on a particular sector so that
the data is not recoverable by the standard read command, proceed as follows. Perform successive read
header commands until the sector preceding the bad sector is found. Then, within 300 microseconds,
issue the read data without header check command. The data portion of the next sector will be read
without either a header compare or a check of the header CRC. Data CRC errors will be reported.
4.5.6 Non-Interchangability of RLOIKjRL02K Disk Cartridges
These two types of cartridges are not functionally interchangeable but a cartridge will physically fit
into the "wrong" type of drive. If a cartridge is loaded into the wrong drive, no damage will occur to the
drive, media, or data, but the software will not run normally. If such symptoms are exhibited, the operator should check for the proper cartridge type.
4.6 ERROR RECOVERY
There are several errors that can be detected and flagged in the RL01/RL02 subsystem. Some of them
can be considered recoverable in the sense that if the operation is retried it is possible that the error will
not recur and successful use of the subsystem can continue. Some of the errors are considered fatal
because retries could damage the data, media, or equipment. The errors are listed with the recommended reaction in Table 4-10.
The nature of these errors should be considered when determining how many times to retry the operation before declaring that retrying has reached a practical limit. For instance, a DLT error could be
caused by a hardware system failure but it could also be the result of bus activity due to other I/O
devices exceeding the throughput capability for a short duration. In this latter case, it is likely that the
operation would be successful on the first retry. The rate of occurences is a good indicator of overall
system performance and an error logging routine should count that. A general increase in the rate of
DLT errors could indicate hardware system failures or it could indicate that the usage of the system is
approaching its throughput capacity in its present configuration.

4-19

Table 4-10

Errors

Controller
Error

Bit
in C.S.

Recommended
Reaction

OPI

Retry some practical number of tilnes,.

DCRC/HCRC/WCE

Retry some practical number of times.
Be sure to record contents of the DA
register.

DLT/HNF

Retry. If HNF, perform a read header,
and verify cylinder.

NXM

Retry once. Be sure to record the
contents of the BA register.

DRIVE ERROR

Perform a Get Status and check bits
listed below.

D"ive
Error

Bit in
Status
Word

DSE

Retry once before notifying operator
to verify UNIT SELECT plug.

WGE

Retry.

SPE

Retry.

SKTO

Retry, Wait for 1.5 sec after Reset.

CHE

Fatal. Do not retry.

WDE

Fatal. Do not retry.

Recommended
Reaction

4-20

Another example of applying practical reaction to an error is the handling of an HNF error. It should
be retried once; if it recurs, then possibly the head is not positioned over the correct track. If a read
header operation is performed and the address from the media is examined, the current cylinder and
head can be determined to see if it is a position problem. If it is not, then possibly there is a bad spot on
the media and another area should be tried. If there is a bad header, that sector address should be
entered into the Bad Sector File and the software should avoid using the the original sector.
As an additional example, consider an NXM error. It indicates that a memory unit is not responding to
a DMA request for data transfer to/from that memory unit. It is unlikely that the media or disk unit is
failing and only slightly more likely that the controller is failing (hardware problem). It is possible that
the program is trying to access a non-existant memory unit (software problem). A retry may be worthwhile for one time but more than likely it will re.cur. The most important piece of information needed
for diagnosis is the contents of the BA register.
Each of the errors should be given the same type of practical thought when programming error recovery routines. Whenever an error occurs, the program should log it (along with the symptoms such as the
contents of the registers), the status of the unit, and whether or not a retry was successful. The more
complete the error log, the more quickly and accurately the cause can be diagnosed.
4.7 DIFFERENCE SUMMARY (RKOS AND RLOI/RL02)
This section may be helpful to users who have formerly used DIGITAL's RK05 disk cartridge subsystem. It points out the differences between programming an RK05 subsystem and programming an
RLOI/RL02 subsystem.
In general,. the RK05 subsystem has a lot of its functionality built into the hardware while the
RLOI/RL02 subsystem requires the software to provide SOIne of the functionality. The major differences are explained below.
4.7.1 Spiral Read/Write or Mid-Transfer Seeks
A spiral read/write is a transfer of data that continues past the end of a track. The RK05 subsystem
provides hardware support for this by using the hardware to detect the end-of-track condition. The
hardware will then cause a mid-transfer seek to the next track and restart the react/write operation at
sector 0 of the next track. Note that this seek is either a Jhead switch from the upper surface to the
lower surface of the same cylinder with no head positioner nl0vement, or a switch from lower surface to
upper surface with a positioner movement to the next cylinder. The RLOI/RL02 subsystem hardware
cannot handle this. If a read/write operation continues past the 40th sector, the sector counter in the
DAR advances to 50 (octal), which is illegal, and the OPI error flag is set. It is necessary for the software to: 1) prevent this from occurring by calculating the remaining area left versus the amount of data
left before the operation, or, 2) detect that it has occurred. The software must initiate a separate seek
function as well as a continuance of the read/write function. Note that a head switch from upper to
cylinder is considered a seek in the
lower surface without a positioner movement to the
RLOI/RL02 subsystem. After a head switch, the positioner will seek the center of the new track.
4.7.2 Implicit Seeks Versus Explicit Seeks
The RK05 subsystem can perform either implicit or explicit seeks. An explicit seek is a software-directed seek operation. An implicit seek is a seek initiated by the hardware at the beginning of a
read/write operation if the desired cylinder address or head address does not coincide with the present
position. The RLOI/RL02 subsystem hardware does not have this capability. The software must ensure
that the positioner is over the desired cylinder and that tbe desired head is selected before starting a
read/write operation.

4-21

4.7.3 Recalibrate
The RK05 subsystem has a return-to-zero or recalibrate function which causes the positioner to move to
cylinder O. There is no similar function in the RLO 1/RL02 subsystem. An explicit seek to cylinder 0
must be performed. If the current cylinder address is not known then the drive is commanded to seek
into the outer guard band. The guard band will be detected and the head will retreat to cylinder O.
4.7.4 Bad Sector File
There is a bad sector file feature on each RLO 1/RL02 disk cartridge. Its use is explained in Paragraph
1.6. There is no standard Bad Sector File used with the RK05.
4."1.5 Reformatting
The RK05 cartridge can be reformatted in the field while the RLOIK/RL02K cartridges cannot. The
embedded servo information and Bad Sector File greatly reduce the need to reformat the cartridge in
the field.
4.7.6 Seek Interrupt
The RK05 will provide two interrupts as the result of a seek operation. The first interrupt occurs as
soon as the controller has caused the drive to start its movement, indicating that the controller is free to
handle another function. The second interrupt occurs when the drive finishes the seek movement
RLOl/RL02 subsystem does not provide the second interrupt. Thus, the software must perform
proper monitoring of the drive to determine when the seek has been completed.

4-22

CHAPTER 5
RL8A PROGRAMMING INFORMATION

5.1 GENERAL DESCRIPTION
The RL8A controller consists of a single hex-height M8433 module. It interfaces the PDP-8 OMNIBUS with the RLOI /RL02 disk drive bus and contains the control, monitor, and data handling logic
for disk operation. The RL8A can handle up to four drives via a daisy-chained I/O cable. A PDP-8 can
handle two RL8A controllers, providing control for up to eight drives.
The RL8A has six addressable registers that are detailed in Section 5.2. The PDP-8 computer communicates with the controller by accessing these registers using Input Output Transfer (lOT) instructions
which have a format of 6XXX. The device codes X60X and X61 X are assigned to the first controller. If
there is a second controller, it uses device codes X62X and X63X. The specific instructions that cause a
response in a controller are shown in Table 5-1. The instructions are used to monitor and control the
controller and are not used to transfer data. Data is transferred using Direct Memory Access (DMA)
operation via data break cycles on the OMNIBUS. The result is an exchange of data between the controller and memory directly, one 12-bit word at a time. The controller has a silo which can buffer up to
16 words. The controller can transfer 12-bit words to the disk as 12-bit words or can transform them
into 8-bit bytes by dropping the high order four bits in each word. The controller can transfer data
coming from the disk onto the OMNIBUS as 12-bit words or it can group the data as 8-bit bytes and fill
in the remaining four bits as zeros. The advantages and disadvantages of both the 8-bit and 12-bit mode
are covered in Paragraph 5.4.
Table 5-1

RL8A Instruction Set

OCTAL CODE *

MNEMONIC

FUNCTION

6600

RLDC

Clear controller, all registers, AC and flags. (Do not use to
terminate a disk function.)

6601

RLSD

Skip on function done. Then clear if set to a one.

6602

RLMA

Load break MA register from AC 0: 11

6603

RLCA

Load command register A from AC 0: 11

6604

RLCB

Load command register B from AC 0: 11 , execute command

6605

RLSA

Load sector address register from AC 0:5

6607

RLWC

Load word count register from AC 0: 11

6610

RRER

Read error register into AC 0, 1, 2, 10, 11

5-1

Table 5-1

RL8A Instruction Set (Cont)

OCTAL CODE *

MNEMONIC

FUNCTION

6611

RRWC

Read word count register into AC 0: 1 I

6612

RRCA

Read command register A into AC 0: II

6613

RRCB

Read command register B into AC 0: II

6614

RRSA

Read sector address register into AC 0:5

6615

RRSI

Read silo word into AC 0: I I

6617

RLSE

Skip on composite error, then clear if set to a one.

The RL8A controller is capable of perfonning eight operations. These are listed briefly in
and detailed in Paragraph 5.3.

5-2

Errors and error recovery are covered in Paragraph 5.5.

Table 5-2 RL8A Controller Commands
Function
Code

o
1
2
3
4
5
6
7

Operation
Maintenance
Reset
Get Status
Seek
Read Header
Write Data
Read Data
Read Data Without Header Check

5.2 ADDRESSABLE REGISTERS
5.2.1

Command Register A

Command Register A is a 12-bit register used during the Seek, Read Data, and Write Data commands.
The register is loaded by an RLCA (6603) command and may be read by an RRCA command (6612).
Initialize from the bus will clear this register and the other addressable registers.

5.2.1.1

Command Register A During a Seek Command - To perform a Seek function, it is necessary to
provide cylinder address difference, head select, and head direction information to the selected drive as
indicated. Figure 5-1 shows the bit layout and Table 5-3 describes the bit format.

5-2

DIR

I I

MSB

CYLINDER DIFFERENCE
CZ-2016

Figure 5-1

Table 5-3

Command Register A During
a Seek Command

Command Register A Bit
Description for Seek
Commands

Bit

Name

Function

ACO

Direction
(DIR)

This bit indicates the direction in which a
seek is to take place. When the bit is set,
the heads move toward the spindle (to a higher
cylinder address). When the bit is cleared,
the heads move away from the spindle (to a
lower cylinder address). The actual distance
moved depends on the cylinder address difference (bits 3-11).

ACI

Head Select
(HS)

Indicates which head (disk surface) is to be
selected. A one indicates the lower head; a
zero, the upper head.

AC2
AC3:11

Spare
Cylinder
Address
Difference

Indicates the number of cylinders the heads
are to move on a seek.

5.2.1.2 Command Register A During Read or Write Data Command - For a Read or Write operation,
the Command Register A is loaded with part of the address of the first sector to be transferred (cylinder address and head select). This information is transferred to the disk address register along with the
contents of the Sector Address register to make the complete address of the sector. Figure 5-2 shows
the bit layout and Table 5-4 describes the bit format.

5-3

I MSBI

I LSB I

)

CYLINDER ADDRESS
CZ-2017

Figure 5-2

Table 5-4

Command Register A During
a Read/Write Data Command

Command Register A Bit
Description For Data
Transfer Commands

Bit

Function

Name

Must be zero

ACO
AC1

Head-select bit - a one indicates the lower
head; a zero, the upper head

Head Select
(HS)

Must be zero

AC2

Cylinder address

Cylinder
Address

AC3:11

5.2.2 Command Register B
Command Register B is a 12-bit register that contains the mode, drive number, extended memoryaddress bits, interrupt enable, and the function code. The RLCB command (6604) is used to load the
register and the RRCB command (6613) reads the register. The RLCB command also executes the
function. Figure 5-3 shows the bit layout and Table 5-5 describes the bit format.

RES

MAIN MODE

MSB

LSB

EMAO EMA1 EMA2

09
FC

I I I

DRIVE SELECT
CZ-2018

Figure 5-3

Command Register B

5-4

Table 5-5
Bit

Command Register B Bit Description
Name

ACO

Function

Reserved.

ACI

Maintenance

The contents of the Disk Address (DA) register are looped back to the silo for maintenance purposes. Bit 2 of command register B
must also be set for this function to work
correctly. See Paragraph 5.3.9.

AC2

Mode

When set, this bit indicates that the data
field will be 256 8-bit bytes per sector.
When zero, the data field is truncated to
170 12-bit words per sector. This bit must
be set when a Maintenance, a Get Status or
a Read Header command is to be executed.

AC3

Interrupt
Enable
(IE)

When this bit is set, the controller is
allowed to interrupt the processor at the
conclusion of a normal command or error
termination.

AC4:5

Drive
Select
(DSO, DS1)

These bits determine which drive will communicate with the controller via the drive
bus.

AC6:8

Extended
Memory
Addressed
(EMA)

These three bits define the memory field
location. This allows up to 32K memory
locations to be addressed on processors
ha ving more than 4K of memory.

AC9:11

Function
Code

These bits indicate the command to be executed by the controller/disk subsystem.
Bit
9

Bit
10

Bit
11

Command

0
0
0
0
1
1
1
1

0
0
1
1
0
0
1
1

0
1
0
1
0
1
0
1

Maintenance
Reset
Get Status
Seek
Read Header
Write Data
Read Data
Read Data Without
Header Check

5-5

5.2.3 Break Memory Address Register
The Break Memory Address (BRK MA) register is a 12-bit register that points to the memory locatiolll
of the data to be transferred. It is loaded by the RLMA command (6602). The contents of the: BRK
MA register are automatically incremented as each word is transferred between memory and controller.
The register is cleared by initializing the controller or by loading the register with zeros (Figure: 5-4).
00

BMOO BM01

BM02 BM03 BM04 BM05 BM06 BM07 BM08 BM09 BM 10 BM11

CZ-2019

Figure 5-4

Break Memory Address Register

5.2.4 Word Count Register
The Word Count (WC) register is a 12-bit register loaded by the RLWC command (6607) and read by
the RRWC command (6611). Before reading or writing data, the word counter is loaded with the twO'!»
complement of the number of words to be transferred. As each Direct Memory Address (DMA) trans··
fer.takes place, the word counter is incremented and terminates the command on overflow. It can count
from 1 to 4096 data words. This corresponds to 24 sectors while operating in 12-bit word mode. In
8-bit byte mode the transfer is limited to one sector (170 bytes) (Figure 5-5).

NOTE
The disk drive will not do spiral Read/Writes. The
program must break up a data transfer if track-totrack Read/Writes are to be done. Between two
such data transfers, a seek to the next track or surface must be made.
00

we 00 we01 we 02 we 03 we 04 we OS we 06 we 07 we 08 we 09 we10 we11

CZ-2020

Figure 5-5

Word Count Register

5.2.5 Sector Address Register
The Sector Address (SA) register is a 6-bit register loaded by an RLSA command (6605) and read by
an RRSA command (6614). Before executing a Read or Write operation, the sector address is loaded
into the SA register (Figure 5-6).

5-6

SA 00

SA01

SA02 SA03 SA04 SA05

CZ-2021

Figure 5-6

Sector Address Register

5.2.6 Error Register
The Error register is a 5-bit register that is read by the RRER command (6610). Bits 0:2 are cleared by
initialize or when Command Register B is loaded. Figure 5-7 shows the bit layout and Table 5-6 describes the bit format.
00

DCRC

OPI

DLT

HCRC

NOT DEFINED

DRDY

HNF
CZ-2022

Figure 5-7

Error Register

Table 5-6 Error Register Bit Description

Bit

Name

Function

ACO

DataCRC
(DRCR) or
Header CRC
(HCRC)

If OPI is cleared and this bit is set, the
CRC error occurred in the data (DCRC). If
OPI is set and this bit is also set, the CRC
error occurred on the header (HCRe).

AC1

Operation
Incomplete
(OPI)

When set, this bit indicates that the current
command was not completed within 200 ms. It
is also used in conjunction with bits 0 and
2 of this register.

AC2

Data Late
(DLT) or
Header Not
Found (HNF)

This bit is set during a write if the silo is
empty and the word count is not yet zero
(meaning, that no word was available for writing). OPI will not be set.

5-7

Table 5-6
Bit

AC2

Error Register Bit Description (Cont)
Name

Function

Data Late

This bit is set during a write if the silo is
empty and the word count is not yet zero
(meaning that no word was available for writ·
ing). OPI will not be set.

(OLT) or
Header Not
Found (HNF)

This bit is set during a read if the silo is
full and the word count is not yet zero
(meaning that the word being read could not
enter the silo). OPI will not be set.
When this bit and OPI are both set, then a
200 ms timeout occurred while the controller
was searching for the correct sector to read
or write (no header compare - HNF).
ACO:2

Error Code

Summary

Error
00
DLT

OPI

0
0
1
1

HNF
DCRC
HCRC
ACI0

Drive Error
(DE)

Bits
01

0
1
1
0
1

1
0
1
0
0

This bit is tied directly to the Drive Error
interface line. When set, it indicates that
the selected drive has flagged an error.
The source of the error can be determined by
writing a Get Status command.
The DE bit is cleared with a Reset command
to the drive.

ACII

Drive Ready
(DRDY)

When set, this bit indicates that the
selected drive is ready to receive a command. The bit is cleared when a Seek operation is initiated and set again when the
Seek operation is completed.

5.2.7 Silo Data Buffer
The RRSI command (6615) is used to transfer the contents of the silo data buffer to the AC. The silo
data buffer contains four different types of information.
5-8

5.2.7.1 Data Buffer Contents Following a Get Status Command - When a Get Status command is executed and a status word is returned to the controller, the contents of the silo data buffer appear as
shown in Figures 5-8 and 5-9. Figure 5-8 shows the bit layout of the error/status bits for the first RRSI
command. Figure 5-9 shows the bit layout of the remaining error/status bits when a second RRSI command is executed. Table 5-7 describes the error/status bits for the first data buffer read, and Table 5-8
describes the error Istatus bits for the second data buffer read.
00

NOT DEFINED

I STC I STB I STA

WORD 1
CZ-2023

Figure 5-8
00

Silo Buffer for Status Word 1
02

NOT DEFINED

IWOE I CHE I WL I STO I SPE IWGEI VC lOSE
WORD 2

CZ-2024

Figure 5-9

Silo Buffer for Status Word 2

5.2.7.2 Silo Data Buffer Contents Following a Read Header Command - When a Read Header command is executed, six 8-bit bytes are stored in the silo as six 12-bit words. The first two are header
words and contain the sector address, head select, and cylinder address information. The second two
words are zeros. The last two words contain the header CRC information. All six words are read by the
RRSI command (6615) (Figure 5-10).
5.2.8 Register Summary
Figure 5-11 is a bit and function summary of the addressable registers.
5.3 CONTROLLER COMMANDS
The RL8A controller is capable of performing eight operations by responding to the function code in
the low order three bits of Command Register B. In many cases it is necessary to load other registers
prior to loading the function code into Command Register B. No registers should be loaded unless the
controller is ready. This condition can be checked by using the appropriate lOT instruction that checks
the function done status or by using the interrupt mode.

5-9

Table 5-7

Bit(s)

Silo Data Buffer Word 1
of Get Status Command
Name

ACO:3

Function
Undefined

AC4

Drive Type

A zero indicates an RLOl; a one, an RL02.

AC5

Head Select
(HS)

Indicates currently selected head. A zero
indicates the upper head; a one, the lower
head.

AC6

Cover Open
(CO)

Set when the drive access cover is open or
the dust cover is not in place.

AC7

Heads Out
(HO)

A one indicates that the heads are over the
disk; a zero indicates that the heads are
home.

AC8

Brush Home
(BH)

Set when the brushes are home.

AC9:11

State Bits

These bits define the state of the disk
drive.
State Bit Definitions
Bit

Bit
B

Bit
A

0
0
1
1
0

0
1
0
1
0

1
1

0
1

C
0

0
0
0

5-10

Definition
Load State
Spin-up
Load Heads
Brush Cycle
Seek (Track
Counting)
Lock-on (keeping
on track)
Unload Heads
Spin-down

Table 5-8 Silo Data Buffer Word 2
of Get Status Command
Bit(s)

Name

Function
Undefined

ACO:3
AC4

Write Data
Error (WDE)

This bit is set when the write gate is on
but no transitions were detected on the
write data line.

AC5

Current Head
Error (CHE)

This bit is set when write current is
detected in the heads but the write gate
has not been asserted.

AC6

Write Lock
(WL)

Set when the drive is write-protected.

AC7

Seek Time
Out Error
(SKTO)

Set when the heads do not come on track in
the required time during a seek operation,
or when the heads drift off track and do
not return within 1.5 seconds.

AC8

Spin Error
(SPE)

Set when the spindle does not come -up to
speed within 40 seconds or when the
spindle speed is too high.

AC9

Write Gate
Error (WGE)

Set if write gate is asserted and one or
more of the following conditions are true.
1.
2.
3.
4.

Drive is not "Ready to Read/Write"
Drive is write-protected
Drive is sensing a sector pulse
Drive has another error asserted

ACIO

Volume
Check (VC)

Set when a new cartridge has been loaded or
when the power has been cycled down, then
up. This bit is reset by a Reset command.

ACII

Drive Select
Error (DSE)

Set when one or more drives has/have the
same number (unit select plug) or have
responded to the same number.

5-11

LSB

WORD 1

"-y-J

MSB

)

'V"
SECTOR ADDRESS

CYLINDER
ADDRESS
01

I I I

NOT DEFINED

I I

NOT DEFINED

MSB

\..

WORD 2

NOT DEFINED

V'
CYLINDER ADDRESS

WORD 3

__
WORD 4

____

___
WORD 5

__ __ __ __=r I I
LSB

)

\....

V"
HEADER CRC

NOT DEFINED
WORD 6

V"
HEADER CRC

J
CZ-2025

Figure 5-10

Silo Buffer for Header Words

5-12

DIR

IMSB I

I LSB

)

V
CYLINDER DIFFERENCE

CZ-2016

I MSBI

I LSB

)

'V
CYLINDER ADDRESS

CZ-2017

RES

MAIN MODE

MSB

LSB

EMAO

EMA1

EMA2

DRIVE SELECT
CZ-2018

BMOO BM01

11 .

BM02 BM03 BM04 BM05 BM06 BM07 BM08 BM09 8M 10 BM11

CZ-2019

WCOO WC01 WC02 WC03 WC04 WC05 WC06 WC07 WC08 WC09 WC10 WC11

CZ-2020

Figure 5-11

5-13

SAOO

SA01

SA02 SA03 SA04 SA06

CZ-2021

DCRC

OPI

DLT

HeRC

NOT DEFINED

DRDY

HNF

CZ-2022

[

NOT DEFINED

STC

STB

STA

I I I I I I

WORD 1
CZ-2023

NOT DEFINED
WORD 2
CZ·2024

Figure 5-11

5-14

NOT DEFINED

NOT DEFINED
WORD 2

'-v-l
04

\..

I MSB

I I
'"V"
CYLINDER ADDRESS

)

V
SECTOR ADDRESS

NOT DEFINED

I LSB I

CYLINDER
ADDRESS
01

I LSB I HS I MSBI

WORD 1

--l

WORD 3

NOT DEFINED

WORD 4

NOT DEFINED
WORD 5

V"
HEADER CRC

NOT DEFINED
WORD 6

Figure 5-11

----------------)

'V"
HEADER CRC

5-15

5.3.1 Maintenance Command
This command tests the controller by causing it to perform the following tasks.
•

The controller requests a data word from memory via the OMNIBUS using the Break Memlory Address (BRK MA) register as an address. When the controller receives this word, th,e
BRK MA and the Word Count (WC) register are both incremented.

•

The data word is bubbled through the silo, serialized and transferred (in 8-bit mode) through
the CRC-generating logic where two more 8-bit bytes are appended. This 24-bit data strearl1
goes through the write data pre compensation logic and then is looped back and brought in as
if it were read data from the drive. The data passes through the phase-locked loop and data
separator logic and into the silo where it is converted back to parallel (eight bits per word),
and bubbles through the silo to be available to the OMNIBUS.

•

The controller requests three memory accesses and transfers the three words back to memory
using the BRK MA register as a pointer. The BRK MA register and WC register are incremented for each transfer. The words are now available for the program to check for diagnostic purposes.

•

The above processes repeat and the cycle continues until the WC register equals zero.

Prior to starting this command it is necessary to load the following registers.
•

The BRK MA register should be loaded with the address of the first word of data to be transferred to the controller. The next three words of memory will receive three words of data
frorn the controller.

•

The WC register should be loaded with the desired count (in two's complement form). A
cornplete cycle takes four counts.

•

The Command Register B should be loaded with 10XO or 14XO. This sets the mode bit to
indicate 8-bit mode. The maintenance bit is a zero. The function code is 000. The remaining
bits are irrelevant.

5.3.2 Reset Command
This command is used to reset all of the error bits in the selected drive unit. It does not reset any conditions in the controller nor does it cause any head movement in the drive. Prior to executing this COlTlmand, the Sector Address Register and Command Register A must be cleared by using appropriate
lOT instructions.
5.3.3 Get Status Command
The Get Status command reads the 16-bit status word from the selected drive and transfers it into two
8-bit bytes in two consecutive words in the silo. The computer can then extract them with two lOT
RRSI instructions. The format of the bits are shown in Paragraph 5.2.7.1. Prior to performing a Ge:t
Status command it is necessary to clear both the Sector Address Register and Command Register A.
When Command Register B is loaded with the function code, the appropriate drive-select bits should be
set, the interrupt enable bit should be set if desired, and the mode bit must be set for 8-bit mode. The
controller should be ready before performing any of these load register operations but the drive does not
. have to be ready.

5-16

5.3.4 Seek Command
The Seek command is used to move the heads or to select the other head on the selected drive. Prior to
executing the seek command, the Sector Address Register should be cleared and Command Register A
should be loaded with a direction bit, a head-select bit, and cylinder difference word. Command Register B is then loaded with the drive-select bits and the seek function code. The controller will send a
command to the selected drive to cause it to start a seek operation. The controller will become ready
and can then perform another command even though the drive is still seeking.
If the drive attempts to move the head past the innermost or outermost tracks, the head will retreat
from the guard band and stop at the first even-numbered track it encounters.
5.3.5 Read Header Command
The Read Header command will read the first header encountered on the selected drive and load the
header into six consecutive word locations in the silo, one 8-bit byte per word. The computer can then
extract this information with lOT RRSI instructions. The format of the information is shown in Paragraph 5.2.7.2. A check is performed on the header that is read.
5.3.6 Write Data Command
The Write Data command requests data from memory, one word at a time, via the OMNIBUS using
the DMA mode. It then transfers the data through the controller silo buffer to the selected drive. The
data is written at the specified sector data area. This operation continues, incrementing both the Break
Memory Address register and the Word Count register once for each OMNIBUS transfer until the
Word Count register reaches zero.
Prior to starting this command it is necessary to position the head over the desired track using a Seek
command. Then the registers should be loaded as follows:
•

The Break Memory Address register with the address of the first memory word to be transferred,

•

The Sector Address register with the address of the first sector to be written,

•

The Word Counter register with the two's complement of the number of words to be transferred,

•

The Command Register A with the head-select bit and the cylinder address word,

•

The Command Register B with a mode bit (8-bit or 12-bit mode), interrupt-enable bit (optional), drive-select bits, extended memory address bits, and the Write Data function code.

The Write Data command will then read headers and perform header checks until the desired header is
located. After the header is checked, the data is transferred. The header check includes a header CRC
check. There is no implicit seek performed, so if the selected head is not positioned over the desired
track, the desired header will not be found and an OPI error will occur. If only a partial sector is written, the remainder of the sector is written with all zeros. A CRC word (16 bits) is generated and written
for each sector automatically. Since the word count is limited to 4096, this means that the maximum
amount of data that can be written with one Write Data command is 16 sectors in 8-bit mode. If 12 bit
mode is used, a maximum of 170 words (one sector) can be transferred. The hardware will not perform
a spiral (mid-transfer) seek. Therefore, if data must be written that would overflow to the next track, it
is necessary to write the data to the end of the track, seek to the next track, and then continue to write
the remainder of the data.

5-17

5.3.7 Read Data Command
The Read Data Command will cause the controller to read data from the selected drive. It will read
from the track that is currently under the selected head, starting at the specified sector. The data is
transferred through the controller silo buffer. The controller requests DMA transfers to memory via the
OMNIBUS. The Break Memory Address and the Word Count registers are incremented once for each
12-bit word transferred over the OMNIBUS. When the Word Count register reaches zero, the Read
Data command is terminated. Prior to starting the Read Data command, the head should be positioned
over the desired track with a Seek command. Load the registers as follows:
•

The Break Memory Address register with the address of the first location in memory to
which the data is to be transferred,

•

The Sector Address register with the address of the first sector from which the data is to be
read,

•

The Word Counter register with the two's complement of the number of words of data to be
read,

•

The Command Register A with a head-select bit and a cylinder address word,

•

The Command Register B with a mode bit and interrupt-enable bit (optional) drive-select
bits, extended memory address bits, and the function code for Read Data.

The Read Data command then reads headers, comparing them to the desired disk address. Th,e data
transfer begins when the desired header is found. The header checks include header CRC checks.
There is no implicit seek, so if the selected head is not over the desired track, the desired header will not
be found and an OPI error will occur.
The RL8A cannot perform a spiral (mid-transfer) seek. If a block of data to be read passes the end of a
track and continues on the other surface or on the next cylinder, it is necessary to program a Read Data
just to the end of the track. The drive must then Seek to the next track and then continue reading data,
A CRC check is performed on each sector during a Read Data operation.
5.3.8 Read Data without Header Check Command
This command is the same as a Read Data command except that no header check is performed. The
next header read is considered a match so that sector is the first sector read. Since no header check
takes place, the header CRC is performed.
5.3.9 Maintenance Bit
The maintenance bit in Command Register B enables a path for the serial information leaving the DA
register. When this bit is set, the data that is going out to the drive is looped back and shifted into the
silo. The data bubbles through the silo and becomes accessible (as two 8-bit bytes) to lOT RRSI instructions. The program can then monitor the operation of the DA register which is not a directly adldressable register. This feature must be used only with Reset, Get Status, and Seek commands. Be:cause the DA register is a 16-bit register, the 8-bit mode bit should be set. This insures that the contents
of the DA register fit into two 8-bit bytes. The contents of the DA register and the two silo words ar,e
illustrated in Figure 5-12. During the loading of the DA register (which occurs on every command),
there is more than one input to some of the bit positions. These inputs are ORed together. Normally,
Status Register A is cleared before any Reset, Get Status, or Seek command and Control
A is
cleared before any Reset or Get Status command. It is possible to test all the bits in the DA register by
using selected patterns in Control Register A and Status Register A.

5-18

LOADING OF DAR

RESET
GET STATUS
SEEK

MARKER

GET STATUS
_DIRECTION

SEEK

RESET
SEEK

HEAD SELECT

_
1,. ,

l 0 1 2 3 4 5 6 7 8 9 10 1112 13 14 151 DAR
I

I 0 1 2 3 4 51 SAR

lO 1 2

567

10 11

I CA R

TRANSFER OF DAR TO SILO

SILO 1ST WORD

SILO 2ND WORD

o 1 2 3

012

12 13 14 15 DAR
CZ·2026

Figure 5-12 Maintenance Mode Bit

5-19

5.4

OPERATIONAL CONSIDERATIONS

5.4.1 8-Bit Mode Versus 12-Bit Mode
The disk cartridge is formatted in 8-bit bytes. For instance, the header contains a 16-bit word address,
another 16-bit word, then a 16-bit header. The data area is 256 8-bit bytes and the data area CRe is 16
bits. None of these areas are evenly divisible by 12, which is the PDP-8 word length. Therefore, the
RL8A controller has the capability of operating in either 8-bit mode or 12-bit mode.
When reading in 8-bit mode, the serial data from the disk is broken into 8-bit bytes and put into the silo
with eight bits per word. Since the silo is 12 bits wide, the data goes into the eight low order bit positions and zeros are put into the remaining four high order bit positions. That is the format used when
the computer transfers a 12-bit word fronl the silo to the CPU accumulator or to memory. The 8-b:it
mode is necessary when performing a Read Header, Get Status, or Maintenance command where 16
bits of data are read. Otherwise, information would be lost.
The 8-bit mode can be used for data on the disk. In such a case, 256 8-bit bytes are read froDl each
sector and transferred to memory as 8-bit words. In some cases, this may be an advantage. For
if 8-bit ASCII data is being handled, the 8-bit mode is preferable to the 12-bit mode. In most cases,
however, the 8-bit mode wastes 33% of the memory space. Because the 12-bit mode uses 12-bit words i.t
uses less memory. In the 12-bit mode, each sector contains 170 words with only 8 wasted bits at the end
of each sector.
In the 12-bit mode, the RL8A controller hardware blocks data into 170 words per sector. The operating
system for the PDP-8 uses only 128 words per sector, so that while memory is used more efficilently,
some disk space is wasted.
5.4.2 Interrupt
The RL8A will interrupt the processor if the Interrupt Enable bit is set and the controller is done. If an
error occurs during an operation, the done condition is set.
5.4.3 Seek Operation
If the program does not keep track of the current position of the head (cylinder and surface), and it is
desired to read or write from a particular area from the disk, it is necessary to:
•

Read Header to obtain the current position of the head,

•

Calculate the difference (if any) from the desired position,

•

Issue a Seek with the proper difference, direction and head-select information.

5.4.4 Overlapped Seeks
Since a Seek operation does not involve data transfer, it is possible to have one drive seeking
another is transferring data. Only one drive at a time can transfer data, but up to four drives can
seeking simultaneously.
5.4.5 Recovery of Data with Bad Headers
If
Function 7, Read Data Without Header Check, allows the recovery of data with unreadable
HNF or HCRC errors are repeatedly encountered on a particular sector, and the data is not recov··
erable by the standard Read command, proceed as follows. Read successive headers until the sector
preceding the bad sector is found. Then, within 300 microseconds, issue a Read Data Without Header
Check. The data portion of the next sector will be read without either header compare or header CRe
check. Data CRC errors will be reported.

5-20

5.4.6 Non-Interchangability of Disk Cartridges
5.4.6.1 RLOIK/RL02K - These two types of cartridges are physically interchangable but not functionally interchangeable. If a cartridge is installed on the incorrect type of drive, no physical damage
will take place and data will not be destroyed. However, the unit will not operate in a normal manner.
The symptoms exhibited depend upon the program running at the time. If the system is exhibiting abnormal characteristics, the operator should ensure each drive contains the correct type of cartridge.
5.4.6.2 RL8A/RLll/RLVll/RLV12 - RLOIK cartridges are interchangeable with other RLOIK
cartridges assuming that the RL8A has written the cartridges in 8-bit mode. RL02K cartridges are
interchangeable with other RL02K cartridges under the same condition.
5.4.7 Use of Two RL8A Controllers
A PDP-8 system can be configured with two RL8A controllers to increase the capacity of the system up
to eight drives. However, if both controllers are trying to perform data transfers at the same time, the
throughput capacity of the OMNIBUS may be exceeded. In this case, conflicts (DLTs) will occur.
5.5 ERROR RECOVERY
There are several errors that can be detected and flagged in the RLOl/RL02 subsystem. Some of them
are considered recoverable. In this case, if the operation is retried, it is possible that the error will not
recur and use of the subsystem can continue. Some of the errors are considered fatal, however, because
retries may cause damage to the data, media, or equipment. The errors are listed with the recommended reaction in Table 5-9.
The nature of these errors should be considered when determining how many times to retry the operation. For instance, a DLT error could be a hardware system failure but it could also be the result of
bus activity due to other I/0 devices exceeding the throughput capability. In the latter case, it is likely
that the operation will be successful on the first retry. The rate of occurences is a good indicator of
overall system performance and an error logging routine should count the rate at which errors occur. A
general increase in the rate of DLT errors could indicate that system usage is approaching its throughput capacity in its present configuration.
Another example of applying practical reaction to an error is the handling of an HNF error. It should
be retried once. If it recurs, then the head may not be positioned over the correct track. If a Read
Header operation is performed and the address from the media is examined, the current cylinder and
head can be determined to see if it is a position problem. If not, then possibly there is a bad spot on the
media. If there is a bad header, that sector address should be entered into the Bad Sector File and the
software should avoid using the original sector.
Whenever an error occurs, the program should log it, along with the contents of the registers, the status
of the unit, and whether or not a retry was successful. The more complete the error log, the easier it is
to diagnose the cause of errors.

5-21

Table 5-9 Errors
Controller
Errors

Recommended
Reaction

OPI

Retry some practical number of times.

DCRC/HCRC

Retry. Be sure to record the contents of the DA register.

DLT/HNF

Retry. If an HNF error, perform a Read Header and verify cylinder.

Drive Error

Perform a Get Status and check the bits listed below.

Drive
Errors

Recommended
Reaction

DSE

Retry once before notifying operator to verify UNIT SELECT plug.

WGE

Retry.

SPE

Retry.

SKTO

Retry. Wait for 1.5 sec after Reset.

CHE

Fatal. Do not retry.

WDE

Fatal. Do not retry.

5.6 DIFFERENCE SUMMARY (RK05 AND RLOI/RL02)
This section may be helpful to users who have used DIGITAL's RK05 disk cartridge
points out the differences between programming the RK05 subsystem and programming
RLOl/RL02 subsystem.

In general, the RK05 subsystem provides more hardware support of functions while the RLOl/RL02
subsystem requires that the software provide some of the functionality. The major differences are ex··
plained below.

5-22

5.6.1 Spiral Read/Write or Mid-Transfer Seeks
A spiral read/write is a transfer of data that continues past the end of a track. The RK05 subsystem
provides hardware support for this by using the hardware to detect the end-of-track condition. The
hardware will cause a mid-transfer seek to the next track and then restart the read/write operation at
sector 0 of the next track. Note that this seek is either a head switch from the upper surface to the
lower surface on the same cylinder with no head positioner movement, or a switch from lower surface to
upper surface with a positioner movement to the next cylinder. The RLOl/RL02 subsystem hardware
cannot handle this. If a read/write operation continues past the 40th sector, the sector counter in the
DA register advances to 50 (octal), which is illegal and therefore sets the OPI error flag. It is necessary
for the software to 1) prevent this from occurring by calculating the remaining area left versus the
amount of data left before the operation or 2) to detect that it has occurred. The software must initiate
a separate seek function and initiate a continuance of the read/write function. A head switch from the
upper to the lower surface without a positioner movement is considered a Seek in the RLOl/RL02
subsystem. After a head switch, the positioner will seek the center of the new track.
5.6.2 Implicit Seeks Versus Explicit Seeks
The RK05 subsystem can perform either implicit or explicit seeks. An explicit Seek is a software-directed seek operation. An implicit Seek is a seek initiated by the hardware at the beginning of a
read/write operation if the desired position is different from the present position. The RLOl/RL02
subsystem cannot do an implicit seek. The software must ensure that the positioner is over the desired
cylinder and that the desired head is selected before starting a read/write operation.
5.6.3 Recalibrate
The RK05 subsystem has a return-to-zero or recalibrate function which causes the positioner to move to
cylinder o. There is no similar function in the RLOI /RL02 subsystem. An explicit seek to cylinder zero
must be performed. If the current cylinder address is not known and the drive is commanded to seek
beyond the outer guard band, this guard band will be detected and the head will retreat to cylinder
zero.
5.6.4 Bad Sector File
There is a bad sector file feature on each RLOl/RL02 disk cartridge. Its use is explained in Paragraph
1.6. There is no standard Bad Sector File used with the RK05.
5.6.5 Reformatting
The RK05 cartridge can be reformatted in the field while the RLOIK/RL02K cartridges cannot. The
embedded servo information and Bad Sector File features greatly reduce the need to reformat in the
field.
5.6.6 Seek Interrupt
The RK05 will provide two interrupts as the result of a seek operation. The first interrupt occurs as
soon as the controller has caused the drive to start its movement, indicating that the controller is free to
handle another function. The second interrupt occurs when the drive finishes the seek movement. The
RLOl/RL02 subsystem does not provide the second interrupt. Thus, the software must perform the
proper monitoring of the drive to determine when the seek has been completed.

5-23

APPENDIX A
RLII CONFIGURATION AND INSTALLATION CONSIDERATIONS
A.I SPC CONSIDERATIONS
The RLII is a Small Peripheral Controller (SPC) but does not unconditionally fit into any SPC slot.
Early SPCs were always quad-height modules or combinations of smaller (single or dual) modules that
involved only four rows. Thus, the standard pin assignments applied only to rows C, D, E, and F on a
hex-height modules and therefore required that rows A and B be vacant since some SPC slots use rows
A and B for UNIBUS cables or power connectors. Some hex-height options require standard UNIBUS
pinning on rows A and B and some require Modified UNIBUS Device (MUD) pinning. In the case of
the RLII, the only connections used on rows A and B are the + 5v and ground. Thus, these rows can be
either standard UNIBUS or MUD pinning.
The early SPCs did not utilize Direct Memory Access (DMA) data transfers to/from memory and
therefore those signals were not part of the origianl SPC pin assignments. Some of the newer options,
such as the RLII, do utilize DMA transfers. There is a new pin assignment called SPC PRIME that
includes these signals. If the RLII is to be used in an older (non SPC-PRIME) slot, then it is necessary
to ensure that the following signals are wired on the backplane.
•
•
•
•
•

Pin CAl - NPG In
Pin CBI - NPG Out
Pin FJI - NPR
Pin CVI - AC LO
Pin CUI - +15v

If the slot has SPC PRIME pinning, then another precaution must be taken. NPG continuity is maintained across an empty SPC PRIME slot by a backplane jumper from pin CAl to pin CBl. This jumper must be removed whenever a DMA-type option is installed, such as an RLII, and the jumper must
be added if the module is removed. This consideration is in addition to the normal Bus Grant Continuity
card used in row D of all empty SPC slots.
A.2 CONFIGURATION CONSIDERATIONS
When configuring a UNIBUS system for the best priority assignments, two characteristics of a peripheral option must be taken into consideration. These are the peak word transfer rate and the TI time (Tl
time is a function of the peak transfer rate and the silo size). The RLII has a peak transfer rate of 256
kHz (3.9 microseconds/word) and a TI time of 62.4 microseconds. This dictates its position in the priority scheme. The recommended priority scheme is listed below.
CPU
Memory
RKll/RK05
TMll/TUI0
TCII/TU56
RL 11 /RLO l-RL02
RJS04
RM02
RJP04
RK611/RK06-RK07
RPI1C/RP03
RJS03
TJU16
RFII/RSII
DBll
A-I

Other general configuration rules are:
•

On a PDP-II UNIBUS, a combination of two disk subsystems and a tape or floppy disk subsystem is considered maximum.

•

On a PDP-II /70 system, on UNIBUS disk subsystem is considered maximum if thc;:re are
MASSBUS disks.

•

A disk subsystem should not be installed beyond a bus expander.

A-2

Reader's Comments

RLOI/UL02 DISK SUBSYSTEM
USER GUIDE
EK-RL012-UG-005

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