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EK-0RA60-SV-1

May 1983

166 pages

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Document:	RA60 Disk Drive Service Manual
Order Number:	EK-0RA60-SV
Revision:	1
Pages:	166
Original Filename:

OCR Text

EK-ORA60-5V-OOl

RA60 Disk Drive
Service Manua I

EK-ORA60-5V-OOl

RA60 Disk Drive
Service Manua I

Prepared by Educational Services
of
Digital Equipment Corporation

First Edition, May 1983

Copyright© 1983 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 computerized 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-l0
DECSYSTEM-20
DECwriter
DIBOL
EduSystem
lAS
MASSBUS

OMNIBUS
OS/8
PDT
RSTS
RSX
VMS
VT

CONTENTS
Page
PREFACE .............................................................. .

CHAPTER 1 INTRODUCTION
1.1
1.2
1.3
1.4
1.5
1.6

INTRODUCTION. . . . .. . . . .. . . .. . . . . .. . .. . . . . . . . . . . . . . .. .. . . . . .. . . ..
GENERAL INFORMATION..........................................
RA60 BLOCK DIAGRAM............................................
RA60 MAINTENANCE FEATURES..................................
RA60 MAINTENANCE PHILOSOPHY.. .. . .. . . . . .. . . . . .. .. . . . . .. . .. ..
RA60 RELATED DOCUMENTATION................................

1-1
1-1
1-1
1-4
1-4
1-4

CHAPTER 2 REMOVAL AND REPLACEMENT PROCEDURES
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
2.23
2.24
2.25
2.26
2.27
2.28
2.29
2.30
2.31

INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .... .. ..
POWER PRECAUTIONS............................................
POWER SUPPLY LOCATION AND CONTROLS......................
REMOVING POWER FROM THE DISK DRIVE.......................
RA60 FRU LIST AND PART NUMBERS..............................
SPECIAL TOOLS...................................................
RA60 FRU LOCATION..............................................
REPLACEMENT SEQUENCE........................................
REMOVING THE REAR CABINET DOOR AND SIDE PANELS........
REMOVING THE SWITCH CAPS AND LIGHTS......................
ACCESS TO THE INSIDE OF THE DRIVE.. . .. . . . .. . . . .. . .. .. .. .. .. .
REMOVING THE POST/AMP DATA SEPARATOR MODULE.........
REMOVING THE SDI MODULE.....................................
REMOVING THE DRIVE LOGIC MODULE. . . . . . . . . . . . . . . . . . . . . . ... .
REMOVING THE BACKPLANE MODULE...........................
REMOVING THE PREAMP MODULE...............................
REMOVING THE POWER MODULE ASSEMBLy.....................
REMOVING THE TRANSFORMER ASSEMBLy.......................
REMOVING THE CAP/RECTIFIER ASSEMBLy......................
REMOVING THE READ/WRITE HEADS.............................
REPLACING THE READ/WRITE HEADS............................
REMOVING THE BEZEL............................................
REMOVING THE CONTROL PANEL................................
REMOVING THE AIR FILTER ASSEMBLy...........................
REMOVING THE DISKWELL ASSEMBLY. . . . . . . . . . . . . . . . . . . . . . . . . . . .
REMOVING THE SPINDLE ASSEMBLy.............................
REMOVING THE POSITIONER ASSEMBLY. . . . . . . . . . . . . . . . . . . . . . . . . .
REMOVING THE DECK ASSEMBLy.................................
REMOVING THE REAR FANS......................................
REMOVING THE SWITCH PLATE ASSEMBLy.......................
REMOVING THE HOME SWITCH ASSEMBLy.......................
iii

2-1
2-1
2-1
2-1
2-2
2-4
2-4
2-5
2-7
2-8
2-9
2-11
2-12
2-12
2-12
2-13
2-15
2-16
2-18
2-19
2-21
2-22
2-23
2-24
2-24
2-27
2-29
2-31
2-32
2-33
2-34

Page
CHAPTER 3 DRIVE-RESIDENT DIAGNOSTICS

3.1
3.2
3.3
3.4
3.5
3.6
3.7
3.8
3.9
3.10
3.11
3.12
3.13
3.14
3.15
3.15.1
3.15.2
3.15.3
3.15.4
3.15.5
3.15.6
3.16

INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FUNCTIONAL AND DIAGNOSTIC FIRMWARE......................
THE DIAGNOSTIC TERMINAL.....................................
SHIFT KEYS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CONTROL CHARACTERS..........................................
CONTINUE (CONT) AND CLEAR (CLR) KEyS.......................
X-ON, X-OFF KEYS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DELETE KEY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DISPLAY SCROLL SWITCH. . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . .
BREAK KEY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CR KEY (CARRIAGE RETURN).....................................
ESCAPE KEY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
POWERING UP THE DRIVE........................................
INSTALLING THE TERMINAL......................................
DIAGNOSTIC COMMAND SELECTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Get Status Command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recalibrate (Recal) Command.......................................
Incremental Seek Command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Random Seek Command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Seek Command (with Parameters)............. . . . . . . . . . . . . . . . . . . . . . . . .
Toggle Seek (with Parameters). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TERMINATING THE TEST. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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

CHAPTER 4 THEORY OF OPERATION

4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.7.1
4.7.2
4.7.3
4.7.4
4.7.5
4.7.6
4.7.7
4.7.8
4.8
4.8.1
4.8.2
4.8.3
4.8.4
4.8.5
4.9
4.9.1
4.9.2

INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RA60 GENERAL DESCRIPTION.....................................
RA60 DISK DRIVE FEATURES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RA60 PERFORMANCE SPECIFICATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . .
RA60 POWER SPECIFICATIONS....................................
RA60 OPTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RA60 TECHNICAL DESCRIPTION...................................
SDI Interface Module..............................................
Drive Logic Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Post Amp/Data Separator Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preamp Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Panel Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Motor Control Module.............................................
Positioner Motor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Spindle Motor.....................................................
POWER SUPPLY ASSEMBLIES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Switchplate Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transformer Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cap/Rectifier Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Regulator Module....... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Heat Sink Module.................................................
RA60 FUNCTIONAL DESCRIPTION................................ .
RA60 Physical Disk Layout.........................................
RA60 Physical Sector Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

4-1
4-1
4-1
4-2
4-2
4-3
4-4
4-4
4-5
4-6
4-7
4-7
4-7
4-7
4-8
4-8
4-9
4-9
4-11
4-11
4-12
4-13
4-13
4-13

Page

CHAPTER 4 THEORY OF OPERATION (cont.)
4.9.3
4.9.4
4.9.5
4.9.6
4.10
4.10.1
4.10.2
4.11
4.11.1
4.11.2
4.12
4.13
4.14

Servo Data Interval................................................
Head/Disk/Preamp Configuration...................................
Sector Header And Data Field. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Logical Disk Format...............................................
RA60 SERVO SySTEM..............................................
Servo Linear Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Servo Seek Mode..................................................
RA60 READ/WRITE OPERATION...................................
The Rate ¥3 Modulation Code. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RA60 Write Commands............................................
RA60 READ COMMANDS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
POWER SUPPLY FUNCTIONS......................................
POWER SHUTDOWN...............................................

4-14
4-14
4-15
4-16
4-18
4-20
4-20
4-20
4-21
4-22
4-22
4-22
4-25

CHAPTER 5 FAULT ISOLATION
5.1
5.2
5.2.1
5.2.2
5.3
5.4
5.4.1
5.4.2
5.4.3
5.4.4
5.4.5
5.4.6
5.4.7
5.4.8
5.4.9
5.4.10
5.4.11
5.4.12
5.4.13
5.4.14
5.4.15
5.4.16
5.4.17
5.4.18
5.4.19
5.4.20
5.4.21
5.4.22
5.4.23
5.4.24
5.4.25
5.5
5.5.1

INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RA60 TROUBLESHOOTING AIDS...................................
Front Panel Codes............ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RA60 Error Messages..............................................
POWER REGULATOR MODULE LEDS..............................
RA60 FAULT ISOLATION FLOWCHART ............................
Block 1 - Type Problem. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Block 2 - Is The Fault Light On? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Block 3 - Push The Fault Button. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Block 4 - Look Up The Fault Code..................................
Block 5 - Replace The Failing FRU..................................
Block 6 - Check Power Supply LEDs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Block 7 - Run The Drive-Resident Diagnostics. . . . . . . . . . . . . . . . . . . . . . . ..
Block 8 - Did The HHT Invoked Diagnostic Tests Fail? . . . . . . . . . . . . . ..
Block 9 - Look Up HHT Error Code. . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . .
Block 10- Run The Subsystem Diagnostic Tests. . . . . . . . . . . . . . . . . . . . . . ..
Block 11 - Did Test 1 Fail?........................................
Block 12 - Look Up UDA50 Error Code. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Block 13 - Run Subsystem Tests 2, 3, 4, 5. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Block 14 - Is The Fault Light On? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Block 15 - Push The Fault Button. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Block 16 - Is Status Byte 15 Available?.. .. . .. .. .. .. . .. .. .. . .. .. .. . .. .
Block ] 7 - Decode Status Byte 15..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Block 18 - Look Up Subsystem Error Messages. . . . . . . . . . . . . . . . . . . . . . . .
Block 19 - Examine Error Log. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Block 20 - Are Statue Words Available? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Block 21 - Decode Status Words. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Block 22 - Run SPEAR, If Available. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Block 23 - Did SPEAR Pick Out A Bad FRU? . . . . . . . . . . . . . . . . . . . . . . . .
Block 24 - Replace The FRU Suggested By SPEAR. . . . . . . . .. . . . . . . . . . .
Block 25 - Obtain System Manager Approval. . . . . . . . . . . . . . . . . . . . . . . . . .
THE STATUS MESSAGE............................................
Layout of the Status Message. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5-1
5-1
5-1
5-4
5-8
5-11
5-11
5-12
5-12
5-12
5-12
5-14
5-14
5-14
4-1
5-15
5-15
5-15
5-15
5-15
5-16
5-16
5-16
5-16
5-16
5-16
5-17
5-17
5-17
5-17
5-17
5-18
5-18

Page
CHAPTER 6 INSTALLATION
6.1
6.2
6.2.1
6.2.2
6.2.3
6.2.4
6.3
6.4
6.5
6.6
6.7
6.7.1
6.7.2
6.8
6.8.1
6.9
6.10
6.11
6.12
6.13
6.14
6.14.1
6.14.2
6.14.3
6.14.4
6.14.5
6.14.6
6.14.7
6.15
6.15.1
6.15.2
6.15.3
6.15.4

INTRODUCTION...................................................
SITE PREPARATION AND PLANNING..............................
Cleanliness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Floor Loading.....................................................
Heat Dissipation...................................................
Temperature And Humidity... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EQUIPMENT UNPACKING AND EXTERNAL INSPECTION..........
RA60 INSTALLATION CHECKLIST..................................
JOINING CABINETS................................................
INSTALLING LEVELER FEET.......................................
INSTALLING SDI CABLES..........................................
Installing The External SD I Cables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Internal SDI Cable Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RA60 SAFETY LABELS.............................................
Safety Label Information...........................................
SETTING THE VOLTAGE AND FREQUENCy........................
REMOVING THE HEAD LOCKING PIN. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PROGRAMMING THE UNIT ADDRESS PLUG. . . . . . . . . . . . . . . . . . . . . . .
REMOVING THE RETAINING BRACKET SCREW. . . . . . . . . . . . . . . . . . . .
PLUGGING IN THE POWER CABLE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
INSTALLING ADD-ON DRIVES.....................................
Removing The Front Filler Panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installing The Slide Assembly.... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mounting The RA60 Drive On The Slides. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Extending The Drive On The Slide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Set Drive AC Voltage And Frequency. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Remove The Head Locking Pin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Program The Drive Unit Address Plug. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RA60 CHECKOUT PROCEDURE....................................
Applying Power...................................................
Drive Checkout Procedures.........................................
Internal Diagnostics................................................
Subsystem Diagnostics..............................................

6-1
6-1
6-1
6-1
6-1
6-1
6-1
6-3
6-4
6-11
6-13
6-13
6-15
6-16
6-16
6-16
6-20
6-21
6-22
6-23
6-24
6-24
6-25
6-26
6-28
6-29
6-29
6-29
6-29
6-29
6-29
6-30
6-30

Simplified RA60 Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RA60 Power Controls................................................
RA60 External FRU Location. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RA60 Internal FRU Location. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sequential Part Removal and Replacement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Door Removal... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Side Panel Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Switch Cap and Light Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Access to the Inside of the Drive .................................... "
Removing the Logic Modules. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing the Backplane Module .................................... "
Removing the Preamplifier Module....................................
Removing the Power Module Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

1-3
2-2
2-4
2-5
2-6
2-7
2-8
2-9
2-10
2-11
2-13
2-14
2-15

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

Page
FIGURES (cont.)
2-13
2-14
2-15
2-16
2-17
2-18
2-19
2-20
2-21
2-22
2-23
2-24
2-25
2-26
2-27
3-1
3-2
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
4-10
4-11
4-12
4-13
4-14
4-15
4-16
4-17
4-18
4-19
4-20
4-21
5-1
5-2
5-3
5-4
5-5

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

Removing the Transformer Assembly .................................. .
Removing the Cap/Rectifier Assembly ................................. .
The Read/Write Heads .............................................. .
Position of Insertion Tool for Down Data Head ........................ .
Position of Insertion Tool for Up Data Head .......................... .
Removing the Bezel ................................................. .
Removing the Control Panel ......................................... .
Removing the Air Filter Assembly .................................... .
Removing the Diskwell Assembly ..................................... .
Removing the Spindle Assembly ...................................... .
Removing the Positioner Assembly .................................... .
Removing the Deck Assembly ........................................ .
Removing the Rear Fans ............................................. .
Removing the Switch Plate Assembly .................................. .
Removing the Home Switch Assembly ................................. .
Field Service Diagnostic Terminal ..................................... .
Diagnostic Terminal Connections ..................................... .
Simplified RA60 Block Diagram ...................................... .
SDI Module Block Diagram .......................................... .
Drive Logic Module Block Diagram ................................... .
Post Amp/Data Separator Module Block Diagram ......................... .
Preamplifier Module Block Diagram .................................. .
Motor Control Module Block Diagram ................................ .
Power Supply Block Diagram ........................................ :
Voltage Range Switch and Frequency Plugs ............................ .
Location of Circuit Breakers (Old Style Transformer) ................... .
Location of Circuit Breakers (New Style Transformer) ................... .
Regulator Module Block Diagram ..................................... .
Heatsink Module Block Diagram ..................................... .
Servo Data Interval Format. ......................................... .
Head/Disk/Preamp Configuration .................................... .
RA60 Overview of the 16 Bit Logical Disk Format. ..................... .
RA60 Physical to Logical Cylinder Translation ......................... .
RA60 Physical Location of Block Numbers ............................ .
Servo Control System Block Diagram ................................. .
RA60 Simplified Write Command Diagram ............................ .
RA60 Simplified Read Command Diagram ............................. .
Detailed Power Distribution Diagram .................................. .
Front Panel Fault Codes ............................................. .
Regulator Modules LEDs ............................................ .
RA60 Fault Isolation Flowchart ...................................... .
Location of Circuit Breakers (Old Style Transformer) ................... .
Location of Circuit Breakers (New Style Transformer) ................... .
Separating the Status Message Bytes ................................... .
Bit Map of the Drive Status Message Bytes ............................ .
Unpacking the Disk Subsystem ........ '............................... .
Ramp Construction ................................................. .
Side Pane~ and Joiner Pane~ ........................................ .
Opening the Rear Door .............................................. .

vii

2-17
2-18
2-19
2-20
2-21
2-22
2-23
2-25
2-26
2-28
2-30
2-31
2-32
2-33
2-34
3-2
3-4
4-4
4-5
4-5
4-6
4-7
4-8
4-8
4-9
4-10
4-11
4-12
4-13
4-14
4-14
4-17
4-17
4-18
4-19
4-21
4-23
4-24
5-2
5-9
5-11

5-13
5-14
5-18
5-19
6-2
6-3
6-4
6-5

Page

6-5
6-6
6-7
6-8
6-9
6-10
6-11
6-12
6-13
6-14
6-15
6-16
6-17
6-18A
6-18B
6-19
6-20
6-21
6-22
6-23
6-24
6-25
6-26
6-27
6-28

Rear Door and Side Panel Lock Removal .............................. .
Side Panel and Key Bottom Button Removal ........................... .
Joining the Cabinets ................................................. .
Bottom Trim Panel Removal ......................................... .
Installing the Front Locking Bracket .................................. .
Installing the Back Locking Brackets .................................. .
Shipping Bracket Removal ........................................... .
Leveler Feet Installation ............................................. .
Leveler Feet Adjustments ............................................ .
External SDI Cable Installation ....................................... .
Internal SD I Cable Installation ....................................... .
RA60 Safety Labels ................................................. .
Removing the Rear Covers ........................................... .
120V/60Hz Voltage/Frequency Configuration .......................... .
240V / 50Hz Voltage/Frequency Configuration .......................... .
Head Locking Pin Removal .......................................... .
Drive Ready Switch and Unit Address Plug ............................ .
Removing the Retaining Bracket Screws ............................... .
Power Controller Plugs and Receptacles ............................... .
Removing Cabinet Filler Panels ....................................... .
Mounting Chassis Slide to Front Upright .............................. .
Mounting Chassis Slide to Back Upright ............................... .
Extending Cabinet Stablizer Foot ..................................... .
Mounting the Chassis Slides .......................................... .
Extending the Drive ................................................. .

6-6
6-7
6-8
6-9
6-10
6-11
6-12
6-12
6-13
6-14
6-15
6-16
6-17
6-18
6-19
6-20
6-21
6-22
6-23
6-24
6-25
6-26
6-27
6-27
6-28

RA60 FRU List. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Special Tools........................................................
RA60 Diagnostic Codes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sector Byte Format..................................................
RA60 Front Panel Fault Codes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RA60 Error Messages................................................
Regulator LEDs Fault Codes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Bit Description of Status of Message Bytes. . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

2-3
2-4
3-5
4-15
5-3
5-5
5-10
5-20

TABLES

2-1
2-2
3-1
4-1
5-1
5-2
5-3

5-4

viii

PREFACE

This service manual provides the information needed to implement the RA60 Disk Drive corrective
maintenance procedures.
Chapter 1 describes the RA60 maintenance features, the RA60 maintenance philosophy, and a list of
related documentation used for the RA60 Disk Drive.
Chapter 2 describes the detailed removal and replacement procedure for each RA60 FRU. Chapter
2 also contains a list of all FRU's" and their part numbers.
Chapter 3 describes how to use the drive resident diagnostics. Following this, a description of each
utility routine and diagnostic test is presented.
Chapter 4 describes the theory of operation of the RA60 Disk Drive.
Chapter 5 describes the fault isolation procedures that Field Service engineers use to troubleshoot the
disk drive.
Chapter 6 describes the installation procedures necessary to install and check -out the RA60 Disk
Subsystem.

CHAPTER 1
INTRODUCTION

1.1 INTRODUCfION
This chapter has general information about the RA60 Disk Drive. It also describes the RA60 maintenance
features, philosophy, and lists the RA60 related documentation.
1.2 GENERAL INFORMATION
The RA60 is a random access, imbedded servo, moving head disk drive capable of storing and recovering
information to and from a removable disk pack. The RA60 is static dual ported and is connected to the
host controller via a single standard disk interface (SDI) cable per port. A dual drive configuration attached
to a mid-range system via the UDA50 SDI controller is the primary systems application.
The RA60 drive operates with a RA60-P pack. This pack is a five-platter pack (three gata platters) with
six read/write surfaces for data recording. Track servo information is pre-recorded on each surface. The
servo information is interleaved with the data area at the sector boundaries. The servo information may not
be re-recorded in the field.
The servo information is pre-recorded on the disk at the time of production. It is read with the same head
that reads and writes data.
1.3 RA60 BLOCK DIAGRAM
Figure 1-1 shows a block diagram of the RA60 Disk Drive. The function of each block is described below.
•

Front panel-controls and displays the state of the drive.

•

Port A and Port B connectors-connects the SDI cables to the backplane module.

•

Drive logic module-allows the drive to execute all the drive commands.

•

SDI module-controls communication between the host controller and the drive electronics.

•

Post/amp data separator module-controls the reading and writing of data.

•

Backplane module-provides the cable connections to the other units within the RA60 Disk
Drive. It has no active components.

•

Preamp module-provides the means to receive the read signal from the read/write -heads, amplify the signal, and send it to the post/amp data separator module. It also includes write current
drivers and head select logic.

•

Positioner assembly-loads the heads and moves them to the correct location on the disk pack.

1-1

•

Spindle assembly-spins the disk pack.

•

Capacitor assembly-supplies unregulated power to the heats ink module in conjunction with the
transformer assembly.

•

Transformer assembly-supplies unregulated raw power to the capacitor and regulator modules.

•

Power switch assembly-supplies input ac power to the transformer assembly.

•

Heat sink module-provides the power and control for both the regulator and motor control modules. It also provides power to the backplane module.

•

Regulator module-takes the unregulated power output from the capacitor/rectifier assembly
and regulates it at the heatsink module to the correct voltages required for the RA60 electronics.

•

Motor control module-controls both the spindle and the linear positioner motors.

1-2

CONNECTION FOR HAND HELD TERMINAL

PORT A
DRIVE
LOGIC
MODULE

I/O
MODULE

TO CONTROLLER

PREAMP
MODULE
HAND

~-.L..--<""---HELD

TERMINAL
POWER

HEAT
SINK
MODULE

CAP/RECTIFIER
ASSEMBLY
REGULATOR
MODULE

SWITCH
PLATE
ASSEMBLY

r - -_____----'-------'

MOTOR
CONTROL
MODULE

TRANSFORMER
ASSEMBLY

CZ-0829

Figure 1-1 Simplified RA60 Block Diagram

1-3

1.4 RA60 MAINTENANCE FEATURES
The RA60 Disk Drive has been designed with great emphasis on serviceability. The drive incorporates the
maintenance features listed below.
•

Quick access to all field replaceable parts.

•

Fault reporting by the operator control panel.

•

Hand held terminal capability.

•

Drive-resident diagnostic and utility routines.

•

No head alignment or adjustments.

1.5 RA60 MAINTENANCE PHILOSOPHY
The repair philosophy for the RA60 is "Intelligent Module Replacement". This is accomplished by use of
the drive-resident diagnostics. The field service engineer uses these diagnostics to isolate fault conditions to
the field replacable unit (FRU) level. In addition to the drive-resident diagnostics, host-level diagnostics are
available to support and verify corrective maintenance decisions.
The RA60-trained field service engineers will find the RA60 Maintenance Guide to be a helpful quick
reference tool. The maintenance guide provides an abbreviated form of the troubleshooting information
found in the service manual, though it is not designed to replace the service manual's use as a complete
source of maintenance procedures.
1.6 RA60 RELATED DOCUMENTATION
DIGIT AL customers may order the following list of RA60 related manuals from the Accessories and Supplies Group.

•

RA60 Service Manual (EK-ORA60-SV)

•

RA60 Field Maintenance Print Set (MP-01421)

•

RA60 Illustrated Parts Breakdown (EK-ORA60-IP)

•

RA60 Maintenance Guide (AA-M880A-TC)

•

Maintenance Guide Looseleaf Binder (AV-L980A-TK)

•

UDA50 Maintenance Documentation Kit (QP904-GZ)*

* This kit consists of a small looseleaf binder, the UDA50 Maintenance Guide, and the current maintenance guides for disks that operate on the UDA50 controller.

1-4

Within the United States, DIGITAL customers may order the above manuals from the Accessories and
Supplies Group over a toll free number (800-258-1710). Orders by mail should be addressed to one of the
following primary distribution centers.
Northeast/Mid-Atlantic Region
Accessories & Supplies Group
Cotton Road
Nashua, New Hampshire 03060
Tel: 603-884-5111
Central Region
Accessories & Supplies Group
1050 E. Remington Road
Schaumberg, Illinois 60195
Tel: 312-640-5612

Western Region
Accessories & Supplies Group
Moffett Park Warehouse
32 East Caribbean Drive
Sunnyvale, California 94086
Tel: 408-734-9125

Outside the United States regional areas, consult local DIGITAL offices.
Internal Digital Equipment Corporation customers can order the RA60 User Guide, the RA60 Service
Manual, the RA60 Field Maintenance Print Set, and the RA60 Illustrated Parts Breakdown manuals
directly from Printing and Circulation Services, 444 Whitney Street, Northboro, Massachusetts 01532.
The RA60 Maintenance Guide, the Maintenance Guide Looseleaf Binder, and the UDA50 Maintenance
Documentation Kit can be ordered from the Software Distribution Center, Order Administration/
Processing, 20 Forbes Road, Northboro, Massachusetts 01532.

1-5

CHAPTER 2
REMOVAL AND REPLACEMENT PROCEDURES

2.1 INTRODUCTION
This chapter describes the RA60 part removal and replacement procedures. It includes the power precautions that should be observed before replacing field replaceable units (FRUs) and supplies the RA60 FRU
list, their part numbers, and the detailed procedures that are used for FRU replacement.
2.2 POWER PRECAUTIONS
Because hazardous voltages are present inside this equipment, servicing should be performed only by qualified service personnel. Bodily injury or equipment damage may result from incorrect servicing.
Caution
Always remove power from unit before replacing internal parts or cables.
2.3 POWER SUPPLY LOCATION AND CONTROIS
The power controls for the RA60 Disk Drive and power controller (874) are shown in Figure 2-1.
2.4 REMOVING POWER FROM THE DISK DRIVE
Before replacing assemblies in the RA60 disk drive, the disk should be spun down and the ac line power
removed, using the instructions below.
I.

To remove power to the drive internal assemblies, switch off CBI at the back of the RA60 Disk
Drive.

To remove power to the RA60 power supply, unplug the ac cord from the back of the drive.

2-1

AC OUTLETS
FOR DRIVE
ON FRONT OF
POWER CONTROLLER

POWER CONTROLLER
CIRCUIT BREAKER

CZ-0830

Figure 2-1

RA60 Power Controls

2.5 RA60 FRU LIST AND PART NUMBERS
Table 2-1 is a list of RA60 FRUs. Since these FRU part numbers change occasionally, use the RA60
Illustrated Parts Breakdown as your primary source of information.

2-2

Table 2-1 RA60 FRU List
Part Number

Description

12-17556-01
12-12714-00
12-12714-01
12-12714-02
12-12714-03

Fan DC
RUN/STOP switch cap
WRITE PROT switch cap
FAULT switch cap
A switch cap

12-12714-04
12-12716-00
12-18199-00
17-00083-03
17-00083-06

B switch cap
Lamp, 6.3v, .2a
UNIT READY switch cap
Power cable (125v)
Power cable (250v)

54-15264-00
54-15266-01
54-15268-01
54-15270-01
54-15272-01

Postamp module
Logic/servo module
Preamp module
SDI module
Front panel module

54-15278-01
70-17740-01
70-17742-01
?Q-:18.33.7.-0. 1
70-18452-01

Backplane module
Spindle assembly
Air filter assembly
Home switch a~sembly
Positioner assembly .-,,'

70-18461-01
70-18461-02
70-18461-03
70-18461-04
70-18473-01

R/W head A-up
R/W head A-dn
R/W head B-up
R/W head B-dn
Switch plate assembly

70-18474-01
70-18476-01
70-18477-01
70-19049-01
70-19052-01

Power module assembly
Cap/rectifier assembly
Transformer assembly
Logic cable
Operator control panel cable

70-19053-01
70-19054-01
70-19055-01
70-19056-01
70-19057-01

Pre/postamp/interconnect cable
Positioner power harness
DC spindle motor power harness
OC spindle motor positioner cable
DC power harness

70-19058-01
70-19065-01
70-19066-01
70-19086-01

DC unregulated harness
Spindle ground harness
Positioner ground harness
DC fan harness

2-3

2.6 SPECIAL TOOLS
Table 2-2 lists the special tools required to maintain the RA60 Disk Drive.
Table 2-2 Special Tools
Part Number

Description

29-24192-00
29-24193-00
29-24194-00
29-24195-00
29-24672-00
29-24671-00

Wrench 97, hex adapter, torque
Wrench, cam-over torque
Screwdriver, flat 10 inch blade
Handheld terminal service kit
Head insertion tool
Head separator tool

2.7 RA60 FRU LOCATION
Figures 2-2 and 2-3 show the location of the main FRUs contained within the RA60 Disk Drive.

COVER
RELEASE
BUTTON

CZ-0831

Figure 2-2 RA60 External FRU Location

2-4

HOME SWITCH
ASSEMBLY \

POST AMP/DATA SEPARATOR MODULE

jo/., , ..;-;; '" 'I

\51-15';;"7D ~Ol
RiVE LOGiC MODULE...j-t.f-IS-.,;;,&:-£; -6i

SDI MODULE

POSITIONER ASSEMBLY

DISKWELL
ASSEMBLY

TRANSFORMER
ASSEMBLY

COVER
LATCH

CZ-0832

Figure 2-3 RA60 Internal FRU Location
2.8 REPLACEl\1:ENT SEQUENCE
Figure 2-4 provides a RA60 part removal sequence. To remove a part, find it on the sequential flow diagram and follow the path to the top of the diagram. Start by removing the topmost item on the path that
the flow line passes through. Continue down the flow line until the correct part is reached. Paragraph numbers are provided to assist in locating the removal procedures. Parts that can be removed directly are not
shown on the diagram.
Note
Unless otherwise indicated, reverse the removal procedure to replace each FRU.

2-5

REAR COVER (2.11)

REAR SHIELD( 2.11)
FRONT COVER(2.11)
POST AMP/ DATA SEPARATOR MODULE(2.12)
SDI MODULE(2.13)
DRIVE LOGIC MODULE (2.14)

LBACKPLANE MODULE (2.15)
PREAMP MODULE (2.16)
POWER MODULE ASSEMBLY (2.17)

LTRANSFORMER ASSEMBLY (2.18)
L

cAP/RECTIFIER ASSEMBLY (2.19)

READ/WRITE HEADS (2.20)
BEZEL (2.22)

CRONT PANEL (2.23)
AIR FILTER ASSEMBLY (2.24)

LmsKwELL ASSEMBLY (2.25)
[SPINDLE ASSEMBLY (2.26)
POSITIONER ASSEMBLY (2.27)

DECK ASSEMBLY (2.28)

SWITCH PLA TE ASSEMBLY (2.30)
HOME SWITCH ASSEMBLY (2.32)
REAR FANS (2.29)
CONTROL PANEL SWITCH CAPS (2.10)
LcONTROL PANEL LAMPS (2.10)
CZ-0876

Figure 2-4 Sequential Part Removal and Replacement

2-6

2.9 REMOVING THE REAR CABINET DOOR AND SIDE PANELS
Refer to Figures 2-5 and 2-6 while performing this procedure.
1.

Unlock the rear door with a 5/32 inch hex key.

Disconnect the green/yellow striped ground wire using a Phillips screwdriver.

Unlatch the rear door and lift it off the frame assembly.

Remove the side panels by loosening the screws on the two side panel locks and then lift
the locks off.

Lift the side panels up and away from the cabinet.

Unscrew the green/yellow ground wire from the cabinet and set the side panel aside.

Figure 2-5 Rear Door Removal

2-7

TOP KEY BUTTONS

REMOVE CENTER SCREW

Figure 2-6

CZ-0774

Side Panel Removal

2.10 REMOVING THE SWITCH CAPS AND LIGHTS
Refer to Figure 2-7 while performing this procedure
1.

Turn off power from the drive by turning off CB 1 at the back of the drive.

Remove front panel switch caps by prying the recessed side of the cap with a screwdriver.
Note
A piece of paper or some other material should be
used as a protection to prevent scratching the bezel.

Remove the light by reaching into the switch opening and pull on the metal slide_ The light will
pull forward with the slide.

Insert the new light using the flat portion of the screwdriver. Push the light into the holder as far
as it will go.

Replace the switch cap by pushing it into the switch opening as far as it will go, using only a
small amount of pressure to snap it into place.

2·8

-----

LAMP

PULL OUT METAL SLIDE
TO EJECT THE LAMP
CZ-0636

Figure 2-7 Switch Cap and Light Removal

2.11 ACCESS TO THE INSIDE OF THE DRIVE
Refer to Figure 2-8 while performing this procedure.
1.

Apply power to the drive by turning on CB 1 at the back of the drive. Then release the catch by
pressing the cover release button on the bezel.

Turn off power to the drive by turning off CB 1 at the back of the drive.

Remove the four screws holding the rear cover in place and then lift it off the drive. The front
cover needs to be raised about three inches before the rear cover can be removed.

Remove the four screws holding the rear shield in place.

2-9

REAR SHIELD

Figure 2-8 Access to the Inside of the Drive

Remove the rear shield by lifting the back end of the shield and sliding it toward the rear of the
drive.

Remove the screws located on the back of each side of the front cover.

Raise the front cover completely to the rear and then lift it off the drive.

2-10

2.12 REMOVING THE POST/AMP DATA SEPARATOR MODULE
Refer to Figure 2-9 while performing this procedure.
1

.1.

Turn off power to the drive.

Remove the rear cover and rear shield (Paragraph 2.11).

Disconnect the cable (PI) from the post/amp data separator module.

Lift the module straight up from the logic cage.

Figure 2-9 Removing the Logic Modules

2-11

2.13 REMOVING THE SDI MODULE
Refer to Figure 2-9 while performing this procedure.
1.

Turn off power to the drive.

Remove the rear cover and rear shield (Paragraph 2.11).

Lift the SDI module straight up from the logic cage.

2.14 REMOVING THE DRIVE LOGIC MODULE
Refer to Figure 2-9 while performing this procedure.
1.

Turn off power to the drive.

Remove the rear cover and rear shield (Paragraph 2.11).

Lift the drive logic module straight up from the logic cage.
Caution
Ensure that the above modules are installed in their
proper locations. Failure to do so could damage the
modules.

2.15 REMOVING THE BACKPLANE MODULE
Refer to Figures 2-9 and2-1 owhile performing this procedure.
1.

Turn off power to the drive.

Remove the rear cover and rear shield (Paragraph 2.11)

Remove the post/amp data separator, SDI, and drive logic modules (Paragraphs 2.12,2.13, and
2.14).

Disconnect all cables to the backplane module.

Remove the eight screws holding the backplane module in place.

Remove the backplane module by lifting it so it will clear the card cage and the cap/rectifier
assembly mounting tabs.

2-12

D~I

~OO·
~
•• 0

CZ-0865

Figure 2-10 Removing the Backplane Moduie

2.16 REMOVING THE PREAMP MODULE
Refer to Figure 2-11 while performing this procedure.
1.

Turn off power to the drive.

Remove the rear cover and rear shield (Paragraph 2.11).

Disconnect P201 from the preamp module.

Disconnect the read/write connectors from the preamp module.

Loosen the three captive screws holding the preamp module in place.

Remove the preamp module from the drive.

2-13

Figure 2-11

Removing th e Preampl'f
Iler Module

2-14

2.17 REMOVING THE POWER MODULE ASSEMBLY
Refer to Figure 2-12 while performing this procedure.

Turn off power to the drive.

Remove the rear cover and rear shield (Paragraph 2.11)

Disconnect all connectors from the heat sink module.

Disconnect connector P602 from the regulator module.

Disconnect connector P902 from the motor control module.

Loosen the four captive screws holding the power module assembly in place using a 10 inch flat
bladed screwdriver (29-24193-00).

Lift the power module assembly straight up and remove from the drive.

Figure 2-12 Removing the Power Module Assembly

2-15

2.18 REMOVING THE TRANSFORMER ASSEMBLY
Refer to Figures 2-12 and 2-12 while performing this procedure.
1.

Turn off power to the drive.

Remove the rear cover and rear shield (Paragraph 2.11).

Remove the power module assembly (Paragraph 2.17).

Disconnect the harness connection Jl at the transformer assembly.

Remove the two screws and nylon washers holding the transformer assembly in place.

Disconnect the green/yellow ground wire from the chassis rear panel.

Slide the transformer assembly to the rear of the drive until the assembly is clear of the metal
tabs holding it in place.

Disconnect the harness connector P501 at the cap/rectifier assembly.

Lift the transformer assembly out of the drive.

2-16

Figure 2-13

Removing Transformer Assembly

2-17

2.19 REMOVING THE CAP/RECTIFIER ASSEMBLY
Refer to Figure 2-14 while performing this procedure.

Turn off power to the drive.

Remove the rear cover and rear shield (Paragraph 2.11)

Remove the power module assembly (Paragraph 2.17).

Remove the transformer assembly (Paragraph 2.18).

Unplug P502 from the cap/rectifier assembly.

Loosen the two screws on the cap/rectifier assembly next to the drive logic module. These
screws are accessible through the top of the card cage.
Caution
These are not captive screws. Loosen only enough to
slide the cap/rectifier assembly.

Slide the capacitor assembly from underneath the deck assembly.

Lift and rotate up to remove the cap/rectifier assembly from the drive.

CZ-0864

Figure 2-14

Removing Cap/Rectifier Assembly
2-18

2.20 REMOVING THE READ/WRITE HEADS
Refer to Figures 2-15, 2-16, and 2-17 while performing this procedure.
1.

Stop the drive from spinning by releasing the RUN/STOP switch.

Press the cover release button on the front of the drive and raise the front cover.

Remove the disk pack from the drive.

Turn off CB1 at the back of the drive.

Remove both the rear and front covers and the rear shield (Paragraph 2.11).

Disconnect the head cable of the desired read/write head from the preamp module.
Note
The power module assembly must be removed when
the A side heads are removed (Paragraph 2.16). The
transformer assembly must be moved toward the
rear of the drive. The A side heads are located on the
lower right side of the carriage assembly.

DfSKWELL
ASSEMBLY

Figure 2-15

The Read/Write Heads

2-19

Install the head insertion/removal tool (DIGITAL part #29-24194-00) on the defective head.
Refer to Figures 2-16 and 2-1 7.

Loosen the screw holding the desired read/write head to the positioner using the torque wrench.

Gently slide the desired read/write head forward and remove from the drive.

10.

Remove the head insertion/removal tool.

CAM GUIDE

HEAD INSERTION TOOL
(29-24672-00)
HEAD HOLDING SCREW
(PART OF HEAD)
(TORQUE TO 4.5 INCH LBS)

CZ-0868

Figure 2-16 Position of Insertion Tool for Down Data Head

2-20

DISK HEAD "8"

UP DAr

AM GUIDE

HEAD HOLDING SCREW
(PART OF HEAD)
(TORQUE TO 4.5 INCH L8S)

CZ-0836

Figure 2-17 Position of Insertion Tool for Up Data Head

2.21 REPLACING THE READ/WRITE HEADS
When replacing any read/write head, reverse the removal procedure (Paragraph 2.21).

Caution
Be careful to keep the new head and the already installed heads from connecting.
1.

Make sure that the new read/write head is completely inserted in the carriage and is flush with
the back of the carriage.

Turn the new read/write head to 4.5 inch/pounds using the torque wrench. DIGITAL part
#29-24194-00 .

2-21

2.22 REMOVING THE BEZEL
Refer to Figure 2-18 while performing this procedure.
1.

Press the cover release button on the front of the drive and raise the front cover.

Turn off power to the drive.

Loosen the two captive screws at the back of the drive which hold it in place. Then slide the
drive forward about six inches.

Remove the six screws holding the bezel in place.

Disconnect P401 from the front panel module.

Pivot the bezel so that the cover catch retainer will clear the chassis-cross brace.

CZ-0837

Figure 2-18

Removing the Bezel

2-22

2.23 REMOVING THE CONTROL PANEL
Refer to Figure 2-19 while performing this procedure.
1.

Turn off power to the drive.

Remove the bezel (Paragraph 2.22).

Disconnect P401 from the operator panel.

Remove the screws holding the operator panel and the cover catch retainer to the bezel.

Remove the cover catch retainer.

Remove the operator panel from the bezel.

FRONT BEZEL

OPERATOR CONTROL
PANEL

TO J704 ON
BACKPLANE
MODULE
CZ-0838

Figure 2-19 Removing the Control Panel

2-23

2.24 REMOVING THE AIR FILTER ASSEMBLY
Refer to Figure 2-19 while performing this procedure.
I.

Turn off power to the drive.

Remove the bezel (Paragraph 2.22).

Disconnect the cable connector P401 from the operator panel.

Remove the filter clamp from the air filter assembly. This clamp is found at the right side of the
filter.

Remove the air filter assembly by sliding it forward.
Caution
When replacing the air filter, be careful that the
clamp does not get inserted upside down. Closely attend to "up" markings on the clamp. Ensure when
the clamp is installed that the filter sealing gasket is
compressed between the diskwell assembly and
flange on the filter.

2.25 REMOVING THE DISKWELL ASSEMBLY
Refer to Figure 2-21 while performing this procedure.
I.

Turn off power to the drive.

Remove the rear and front covers and rear shield (Paragraph 2.11).

Remove the bezel (Paragraph 2.22).

Disconnect P40I from the operator panel.

Remove the air filter assembly (Paragraph 2.24).

Remove the II screws holding the diskwell assembly in place.

Lift the diskwell assembly from the back. Slide the diskwell toward the back and lift out from
the drive.

2-24

SPINDLE
ASSEMBLY

AIR FILTER ASSEMBLY

FI L TER CLAMP

BEZEL
CZ-0839

Figure 2-20 Removing the Air Filter Assembly

2-25

CZ-OB40

Figure 2-21

Removing the Diskwell Assembly

2-26

2.26 REMOVING THE SPINDLE ASSEMBLY
Refer to Figure 2-22 while performing this procedure.
1.

Turn off power to the drive.

Remove the rear and front covers and rear shield (Paragraph 2.11).

Remove the bezel (Paragraph 2.22).

Disconnect P401 from the operator panel.

Remove the air filter assembly (Paragraph 2.24).

Remove the diskwell assembly (Paragraph 2.25).

Disconnect the three wires from the spindle assembly noting which wire corresponds to each tab.

Disconnect the ribbon cable from the spindle assembly.

Disconnect the ground wire from the right side of the deck mount going to the bottom of the
spindle.

10.

Remove the three screws which hold the spindle assembly in place.

11.

Lift the spindle assembly straight up and out of the drive.

Caution
Be careful of the ground wire routing when replacing

the spindle assembly.

2-27

BROWN-- "'"-

DECK ASSEMBLY

CZ-0841

Figure 2-22 Removing the Spindle Assembly

2-28

2.27 REMOVING THE POSITIONER ASSEMBLY
Refer to Figure 2-23 while performing this procedure.
1.

Turn off power to the driveo

Remove the rear and front covers and rear shield (Paragraph 2.11).

Remove the bezel (Paragraph 2.22).

Disconnect P401 from the operator panel.

Remove the air filter assembly (Paragraph 2.24).

Remove the diskwell assembly (Paragraph 2.25).

Disconnect P706 from the backplane module.

Disconnect P803 from the heat sink module.

Pull the head locking pin from the storage hole on the positioner assembly and put it into the
locking hole.

10.

Remove the screws which hold the positioner assembly in place.

11.

Lift the positioner assembly straight up and out from the drive.
Caution
When replacing the positioner assembly, ensure that
the spindle ground harness is re-connected under the
right rear mounting screw.

2-29

TO J803 ON
HEAT SINK MODULE

TRANSFORMER
ASSEMBLY

CZ-0842

Figure 2-23

Removing the Positioner Assembly

2-30

2.28 REMOVING THE DECK ASSEMBLY
Refer to I:igure 2-24 while performing this procedure.
1.

Turn off power to the drive.

Remove the rear and front covers and rear shield (Paragraph 2.11).

Remove the bezel (Paragraph 2.22).

+
I

CZ-0873

Figure 2-24 Removing the Deck Assembly

2-31

Disconnect P401 from the operator panel.

Remove the air filter assembly (Paragraph 2.24).

Remove the diskwell assembly (Paragraph 2.25).

Remove the positioner assembly (Paragraph 2.27).

Remove the spindle assembly (Paragraph 2.26).

Remove the screws holding the deck assembly in place.

10.

Lift the deck assembly straight up and out of the drive.

2.29 REMOVING THE REAR FANS
Refer to Figure 2-25 while performing this procedure.
1.

Turn off power to the drive.

Loosen the four screws holding the finger guard, fan housing and fan in place.

Disconnect the dc connector to the fans.

Remove the fan from the back of the drive.

~./ , /
tI"'"
fI'"

CZ-0863

Figure 2-25 Removing the Rear Fans

2·32

2.30 REMOVING THE SWITCH PLATE ASSEMBLY
Refer to Figure 2-26 while performing this procedure.
1.

Turn off power to the drive.

Remove the rear cover and rear shield (Paragraph 2.11).

Disconnect the ac power cord from the switch plate assembly.

Remove the four screws holding the power switch assembly in place.

Disconnect the line filter ground.

Remove the switch plate assembly from the back of the drive.

Disconnect the three wires from the back of the power switch assembly. Remember which wire
corresponds to each tab.

AC LINE
CORD CONNECTOR

CZ-Q843

Figure 2-26 Removing the Switch Plate Assembly

2·33

2.31 REMOVING THE HOME SWITCH ASSEMBLY
Refer to Figure 2-27 while performing this procedure.

Turn off power to the drive.

Remove the rear cover and rear shield (Paragraph 2.11).

Locate the home switch assembly on the top right side of the positioner assembly.

Disconnect the two pin connectors.

Remove the two screws holding the home switch assembly in place.

Remove the home switch assembly from the positioner assembly.

Figure 2-27

Removing the Home Switch Assembly
2-34

CHAPTER 3
DRIVE-RESIDENT DIAGNOSTICS

3.1 INTRODUCTION
This chapter describes the RA60 firmware diagnostic capabilities, how to run the drive-resident diagnostics, and explains each test.
3.2 FUNCTIONAL AND DIAGNOSTIC FIRMWARE
Functional and diagnostic firmware are two separate software modules in the RA60 Disk Drive. The functional firmware controls fault monitoring and interface handshaking operations. The drive is operating in
an on-line mode when the functional firmware is controlling the drive operations. The drive is operating in
an off-line mode when it is under control of the diagnostic firmware. This firmware controls all driveresident tests and utility programs.
3.3 THE DIAGNOSTIC TERMINAL
A field service diagnostic terminal used to communicate with the RA60 drive is stocked with every spares
kit. Refer to Figure 3-1. The terminal contains a two-level LED display and a keyboard. The display holds
a maximum of 32 characters at one time while an internal buffer stores 2K characters for the display. The
keyboard contains a standard ASCII set of alphanumeric characters. The larger character on each keybutton is the default character displayed when the button is pushed.
3.4 SHIFT KEYS
The three characters shown on any key button correspond to one of the three shift keys on the right side of
the terminal. When the upper shift key on the terminal is pushed simultaneously with a keyboard button,
the left-most character is displayed.
For example, when the middle shift key and the number five keybutton are pushed simultaneously, the
letter K is displayed. Pushing the lower shift key and the zero keybutton results in the letter Q being displayed.
3.5 CONTROL CHARACTERS
A control character (e.g/'C) is obtained by using the CTRL key, the side shift keys, and the appropriate
letter key. Push the CTRL key and one of the shift keys simultaneously with the appropriate letter key.
Example: A I\C is desired. The following steps should be used:
1.

Push the CTRL key.

Push the upper shift key on the right-hand side of the terminal.

Simultaneously push the number two key with the upper shift key.

3-1

DISPLAY SCROLL
SWITCH

(r:::=======================:::::::~

C
I

~_II

EQUIPMENT

I
I

~ CORPORAnON

CZ-0768

Figure 3-1

Field Service Diagnostic Terminal

3.6 CONTINUE (CONT) AND CLEAR (CLR) KEYS
The X-On, X-Off feature is enabled when power is applied to the terminal. The CONT key disables the
automatic X-On, X-Off feature while the CLR key re-enables it. Keeping this feature in automatic allows
the display buffer to fill and then to automatically transmit a signal (X-Off) to the microprocesser. This
signal stops all transmission of data to the display buffer until the buffer is unloaded. At this time, the
terminal automatically sends an X-Off signal to re-enable transmission.
3.7 X-ON, X-OFF KEYS
These keys manually control the display buffer of the terminal. If the display buffer is full, an automatic
X-Off signal stops all transmission to the buffer. The X-On key is used to reload the buffer with new
information even though the buffer has not been read.
The X-Off key may be used to stop the loading of the buffer even though the buffer is not full. For example, the automatic X-On, X-Off feature is disabled by the CONT key and the diagnostics are inputting test
messages to the terminal. These messages are being sent at a faster rate than can be read by the human eye.
Pushing the X -Off key stops the diagnostic testing and the messages. This enables the user to read the
display and manually scroll through the buffer.

3-2

3.8 DELETE KEY
The delete key is used to correct mistakes in keyboard entries. Once a mistake is discovered, the delete key
may be pushed causing a backslash (\) to be displayed with the last character input. The new character
may now be keyed in. For example, if RUN DIAF was erroneously keyed in, the delete key could be used
as follows.
RUH DIAF\F\G

The command RUN DIAG is now input correctly.
3.9 DISPLAY SCROLL SWITCH
The display scroll switch is located on the left side of the terminal. Its function is to back up or advance the
display within the 2K display buffer. Long messages cannot be read all at once on a 32 character display.
The scroll switch is moved upward for a forward display of the buffer and downward for a backward display of the buffer.
3.10 BREAK KEY
The break key transmits a break character when pushed. Its purpose is the same as a VT100 break key. It
is not used in RA60 diagnostic operation.
3.11 CR KEY (CARRIAGE RETURN)
This key is pushed after typing a command string. It is the same as the carriage return key on a computer
terminal.
3.12 ESCAPE KEY
This key transmits an escape character when pushed. Its purpose is the same as a VT 100 escape key. It is
not used in RA60 diagnostic operation.
3.13 POWERING UP THE DRIVE
Apply power to the drive so that it can run a power-up test sequence. The sequence consists of various
hardcore tests with static master logic. The front panel lights turn on when the hard core tests are being
executed. Successful completion of the power-up sequence is indicated by the front panel lights going off.
The run light will remain on until the drive has verified that the spindle has stopped. The cover will remain
locked until the run light goes off. If the fault light is on, all or part of the power-up sequence has failed.
Chapter 5 of this manual contains the troubleshooting procedures enabling you to repair the RA60 Disk
Drive.
3.14 INSTALLING THE TERMINAL
To use the diagnostic terminal, the diagnostic monitor mode must be entered. The drive does not respond to
the keyboard until both port select switches on the drive are in the out position. If either switch is pushed in,
the drive is in the available state awaiting a command from the controller.
The RS232 interface cable connects to the drive logic module via a connector found at the top of the
module. The +5 voltage cable required to power the hand held terminal is supplied by connector 807 on the
power module assembly. Connect the power cable from the hand held terminal to connector 807. Refer to
Figure 3-2.
Once the cables are connected properly, key in a CTRL C (I\C) on the terminal keyboard. The terminal
responds to the I\C with the following diagnostic prompt.
%RAGO COMPLETED
RAGO TEST )

3-3

~
!

DOOD

0000

0000
0000
RS232
DIAGNOSTIC
TERMINAL
CONNECTOR

))

DIAGNOSTIC
TERMINAL
POWER
CONNECTOR

CZ-0883

Figure 3-2 Diagnostic Terminal Connections

3-4

Upon reception of the diagnostic prompt, testing may now be run by keying in any of the diagnostic commands. These commands are described in the following paragraphs.
3.15 DIAGNOSTIC COMMAND SELECTION
The RA60 Disk Drive has six internal diagnostics that will check out the status, recalibration, and seeking
capability of the drive. Table 3-1 lists the codes and names of the diagnostic tests.

Table 3-1

RA60 Diagnostic Codes

Test
Code

Name

01
02
03
04
05
06

Get Status
Recal
Incremental Seek
Random Seek
Seek
Toggle Seek

3.15.1 Get Status Command
The get status command gives the status of the RA60 Disk Drive. This command will check to see if the
drive is operation or if an error exists. To enter this test, key in the code 01 after you have received the
diagnostic prompt.
%RA60 Completed
RA60 Test) 01<CR)

Upon successful completion, you will receive the following response:
%RA60 Completed
RA60 Test )

If an error occurs, you will recieve the following response:
RA60 Test) 01 ERR XX*

* XX will indicate the hex error code which is listed in Chapter 5, Table 5-2 of this manual.
3.15.2 Recalibrate (Recal) Command
The Recalibrate (Recal) command will return the read/write heads to cylinder 0, head o. This command
allows the drive to perform a seek operation starting from a known cylinder and read/write head. To enter
this test, key in the code 02 after you have received the diagnostic prompt.
%RA60 Completed
RA60 Test ) 02<CR)

Upon successful completion, you will receive the following response:
%RA60 Completed
RA60 Test )

3-5

If an error occurs, you will receive the following response:
RASO Test ) 02 Err XX·

* XX will indicate the hex error code which is listed in Chapter 5, Table 5-2 of this manual.
3.15.3 Incremental Seek Command
The incremental seek command will incrementally seek one cylinder at a time until the maximum cylinder
number is reached. This command allows you to check the drive capability to perform one cylinder seek.
To enter this test, key in the code 03 after you have received the diagnostic prompt. This test will run until
an error is detected. To terminate the test, type in a control C (/\C).
%RASO Completed
RASO Test ) 03<CR)

Upon successful completion, you will receive the following response:
%RASO Completed
RA60 Te!5t )

If an error occurs, you will receive the following response:
RASO Test ) 03 Err XX·

*XX will indicate the hex error code which is listed in Chapter 5, Table 5-2 of this manual.
3.15.4 l{andom Seek Command
The random seek command will randomly seek from the cylinder it is presently at to a random cylinder
specified by the microcode. This command allows you to check the drive capability to randomly seek to
any cylinder. To enter this test, key in the code 04 after you have received ~he diagnostic prompt.
%RASO Completed
RASO Te!5t ) 04<CR)

Upon successful completion, you will receive the following response:
%RASO Completed
RASO Te!5t )

If an error occurs, you will receive the following response:
RASO Te!5t ) 04 Err XX·

*XX will indicate the hex error code which is listed in Chapter 5, Table 5-2 of this manual.
3.15.5 Seek Command (with parameters)
The seek command will seek from the cylinder it is presently at to the cylinder specified. You can also
specify which read/write head to use with this command. This test allows you to check the drive capability
of seeking to a specific cylinder using a specific read/write head. To enter this test, key in the code 05 after
you have received the diagnostic prompt. After you have keyed in the code 05, key in the hex number of
the cylinder desired and the number of the read/write head desired.

%RA60 Completed
RA60 Test > 05 space XXX space X<CR>

XXX is the hex number of the desired cylinder. The valid cylinder address is from 0 to 63F hexadecimal.
X is the number of the desired read/write head to use for the seek test.
Upon successful completion, you will receive the following response:
%RA60 Completed
RAGO Test )

If an error occurs, you will receive the following response:
RAGO Test ) 05 Err XX*

*XX will indicate the hex error code which is listed in Chapter 5, Table 5-2 of this manual.

3.15.6 Toggle Seek (with parameters)
The toggle seek test will seek from the cylinder it is presently at to the cylinder specified. This test allows
you to check the drive capability to seek to a specific cylinder but does not allow you to select a specific
read/write head. To enter this test, key in the code 06 after you have received the diagnostic prompt. After
you have keyed in the code 06, key in the hex number of the desired cylinder. This test will loop until an
error is detected and is terminated by typing in a control C (AC).
%RAGO Completed
RAGO Test ) 06 space XXX<CR)

XXX is the hex number of the desired cylinder. The valid cylinder address is from 0 to 63F hexadecimal.
Upon successful completion, you will receive the following response:
%RAGO Completed
RA60 Test )

If an error occurs, you will receive the following response:
RAGO Test ) OG Err XX*

*XX will indicate the hex error code which is listed in Chapter 5, Table 5-2 of this manual.

3.16 TERMINATING THE TEST
To terminate any of the internal diagnostic tests mentioned above, key in a Control C (AC) on the terminal. The Control C (AC) will return you to the diagnostic prompt.
%RAGO Completed
RAGO Test )

3-7

CHAPTER 4
THEORY OF OPERATION

4.1 INTRODUCTION
This chapter describes the theory of operation of the RA60 Disk Drive. It also includes a general description of the drive, a functional description of the servo system, read/write commands, and the power supply
functions.
4.2 RA60 GENERAL DESCRIPTION
The RA60 is a 205 megabyte removable media disk drive. It is the first removable media drive to become a
part of the new Digital Storage Architecture (DSA) family. DSA defines the hardware interconnects and
software protocols for attaching DSA disks to DIGITAL systems.
The RA60 Disk Drive operates on the intelligent UDA50 Disk Controller, which is the first controller
implementation of the DSA architecture. The UDA50 can control up to four DSA-type disks such as the
RA60, RA80 and RA81. Each drive is radially connected to the disk controller over separate Standard
Disk Interconnect (SDI) cables.
The RA60 Disk Drive may be mounted in a H9642 AP/ AR (120/240 volt) cabinet. This is a new 36 inch
'deep cabinet which can hold up to three disk drives. A power controller is located in the \:lase of the cabinet
which controls the ac power to all three drives.
4.3 RA60 DISK DRIVE FEATURES
The RA60 offers the following features:
•

Advanced read/write system-The read/write system uses a unique 213 rate tree encoding/
decoding scheme which provides 113 more storage capacity on the disk.

•

Embedded servo positioning system-A unique servo code is embedded between sectors that is
used for track following and track seeking. This embedded servo technique eliminates the need
for a dedicated servo surface and head alignments.

•

Dual microprocessor architecture-One microprocessor manages the I/O while the other controls
the major drive functions.

•

Automatic misalignment sensing-The drive automatically senses radial or axial misalignments
in the head-to-disk surface.

•

Optimized cylinder configuration-Disk tracks are organized into groups of four to form logical
cylinders and increase data throughput.

•

DC Spindle motor-A brushless dc spindle motor is used to drive the disk pack. This feature
eliminates a pulley belt and reduces power consumption.

4-1

•

Fault isolating microdiagnostics-ROM-resident diagnostics isolate failures to a field replaceable
assembly. The microdiagnostics can be run locally with the disk off-line or remotely from the
Digital Diagnostic Center through the host system.

•

Automatic self-test-The drive automatically checks out its own functionality during power-up
and initialization.

•

Dual access-Allows the drive to be switched between two controllers on the same or different
computer systems.

4.4 RA60 PERFORMANCE SPECIFICATIONS
The RA60 has the following performance specifications:
•

Storage capacity: 205 MB per drive

•

One cylinder seek latency: 7 ms maximum

•

Maximum seek latency: 70.0 ms maximum

•

Average seek latency: 42 ms maximum

•

Head switch latency: 14 ms maximum

•

Unbuffered transfer rate: 15.84 megabits per second

•

Recoverable seek error rate: 1 misseek in 106 seeks

•

Recoverable data error rate: 1 bit in 10 7 bits read

•

Corrected data error rate: 1 bit in 10 10 bits transferred

•

Unrecoverable data error rate: 1 bit in 10 12 bits transferred

4.5 RA60 POWER SPECIFICATIONS
The power specifications for each RA60 are as follows:
•

Typical input power: 800 watts, 900 watts maximum

•

Maximum VA rating: 1200 volt-amps

•

Power factor: greater than. 75

•

Maximum inrush current for 120 VAC: 190 amps RMS for V2 cycle

4-2

•

Maximum inrush current for 240 VAC: 95 amps for 1/2 cycle

•

Typical 120 volt running current: 7.0 amps

•

Typical 240 volt running current: 3.5 amps

•

120 volt input range: 90-128 VAC at 60 Hz ± 1 Hz

•

240 volt input range: 180-256 VAC at 50 Hz ±1 Hz

•

Heat dissipation: 800 watts or 2728 Btu/hour

4.6 RA60 Options
The following basic RA60 options are available.
•

RA60-AA: 205 MB disk 50/60 Hz, no cabinet

•

RA60-CA: H9642-AP cabinet, 60 Hz

•

RA60-CD: RA60-AA, H9642-AR cabinet, 50 Hz

•

RUA60-AA: RA60-AA, UDA50 controller, no cabinet

•

RUA60-CA: RA60-CA, UDA50 controller, w/cabinet

•

RUA60-CD: RA60-CD, UDA50 controller, w/cabinet

•

RUA60-JA: RA60-CA, (2) UDA50 controllers, w/cabinet

•

RUA60-JD: RA60-CD, (2) UDA50 controllers, w/cabinet

•

RA60-P: RA60 disk pack

•

RA60-PA: lot of 10 RA60-P packs

•

RA60-PB: lot of 5 RA60-P packs

4-3

4.7 RA60 TECHNICAL DESCRIPTION
This section describes the major modules and assemblies within the RA60 Disk Drive. Figure 4-1 shows
how these major modules and assemblies are interconnected.

POST AMP/
DATA SEPARATOR
MODULE

B
A
C
K
P
L
A
N

SDI
INTERFACE
MODULE

DRIVE
LOGIC
MODULE

CZ-0844

Figure 4-1

Simplified RA60 Block Diagram

4.7.1 SOl Interface Module
The SDI interface module converts the serial SDI messages sent by the disk controller into a parallel command format recognizable by the drive master microprocessor. In the process, it strips away the sync byte
and frame bytes, leaving only the actual command bytes that are stored in RAM memory on the drive
logic module.
The SDI interface module also encodes the parallel drive response messages into serial SDI format and
transmits them to the controller. In the process, it adds the sync byte and frame bytes. This module also
contains all the SDI cable receivers and drivers.
During write data transmission, the SDI interface module converts the SDI bipolar data into the NRZ data
stored on the disks. When reading data from the disks, this module converts the NRZ data back into the
SDI bipolar data required for transmission. Refer to Figure 4-2 for a block diagram of the SDI module.

4-4

RTDS

RD/RES DATA

WRT /CMD DATA

.-CABLE
DRIVERS
AND
RCVRS

.....

ENCODERS
AND
DECODERS

-..

RTCS

-..

.......- PARALLEL

.......-

TO SERIAL
CONVERTERS

' ; { DRIVE STATE

I' MASTER).IP BUS

XLATORS
RD DATA
WRT DATA

...........

---

r-----

SERIAL TO
PARALLEL
CONVERTERS

A
K-MASTER).IP BUS

....
CNTLR STATE
V

POST AMP
ERROR
DETECTION

... ,...------

MODULE

CZ-0845

Figure 4-2 SDI Module Block Diagram

4.7.2 Drive Logic Module
The drive logic module contains a master microprocessor, a slave microprocessor, some RAMs and ROMs,
and some other servo associated logic. Refer to Figure 4-3 for a block diagram of the drive logic module .

./'

POST AMP

~r------I/O SAMPLE
MASTER

SLAVE

}JP

J.JP

ROM
RAM
UART

ROM
RAM

CONTROL
LOGIC

CZ-0846

Figure 4-3

Drive Logic Module Block Diagram

4-5

The master microprocessor controls the SDI interface handshaking logic, the slave microprocessor, and the
operator control panel. \Vhen command bytes are received from the SDI interface module and stored in
RAM, the master microprocessor interprets them to determine how many more bytes are needed to complete that command sequence. When the full command sequence is received, the slave microprocessor executes them.
The slave microprocessor operates under the control of the master microprocessor. It controls the spindle
motor, positioner motor, and the other real-time drive operations. An analog to digital converter changes
the serial tachometer and disk track information into the parallel format needed by the slave microprocessor. Similarly, a digital to analog converter reformats the microprocessor parallel information back into the
serial signals required by the seek mode circuits. More is explained about how the linear and seek mode
operation works in the RA60 servo system section.

4.7.3 Post Amp/Data Separator Module
The post amp/data separator module performs both data read/write functions and some servo positioning
functions. This module is included in the servo positioning loop because the read heads are used to detect
the embedded servo bursts. Refer to Figure 4-4 for a block diagram of the post amp/data separator module.
2/3 WRT DATA

NRZ READ DATA

READ CLOCK
ENCODER/
DECODER
READ GATE
READ/AMP
EQUALIZER

NRZ WRT DATA

15 MHZ ClK

WRITE CLOCK

:------

1
Pll

DATA
DIGITIZER

2/3 READ DAT A

AGC

RD DATA
~

FAST AGC

CZ 0847

Figure 4-4 Post Amp/Data Separator Module Block Diagram
During the write operation, the 213 encoder circuit transforms the incoming NRZ write data into the 2/3
format to be written on the disk. When the data is read back, it is passed through an amplifier and equalizer circuit to slim the pulses and equalize their rise times. These equalized pulses are then converted into
digital information in the data digitizer circuit. The read data out of the data digitizer is then passed
through the 213 decoder for conversion back to NRZ read data.
The Phase Lock Loop (PLL) oscillator may lock onto one of three different frequencies. It is normally
locked onto the 15 MHz oscillator signal when the drive is neither reading or writing. During a write operation, the PLL oscillator locks onto the WRITE CLOCK signal. During a read operation, it locks onto the
READ DATA signal.

4-6

4.7.4 Preamp Module
The preamp module contains the head select logic, the write drivers, and low noise read preamplifiers.
Refer to Figure 4-5 for a block diagram of the preamp module.

PREAMPLIFIER

WRT DATA

WRITE
DRIVER

R/W
HEADS
READ DATA

HEAD
SELECT

PREAMP

HEAD SELECT

2::J

DISK

CZ-0869

Figure 4-5

Preamplifier Module Block Diagram

4.7.5 Front Panel Module
The RA60 front panel consists of five switches and one switch cap (UNIT/READY). Under each indicator
cap is a light that can be on or off regardless of the switch position. The state of each switch and light is
periodically sampled and controlled by the master microprocessor.
The front cover interlock switch is mounted on the cover latch assembly. This switch prevents the drive
from spinning up whenever the front cover is open. The state of this switch is sampled periodically by the
master microprocessor.

4.7.6 Motor Control Module
The motor control module contains a portion of the power amplifier circuits needed to drive the positioner
motor voice coil. The power transistors for this function are located on the heat sink module.
The motor control module also contains the circuitry to control the spindle motor. Refer to Figure 4-6 for
an overview block diagram

4.7.7 Positioner Motor
The positioner motor is a linear dc motor actuated by a voice coil. Its function is to move the read/write
heads in and out across the disk tracks. On the rear of the positioner motor is a tachometer that converts
the carriage velocity into an analog signal.
Also located on the positioner motor assembly is the home switch that informs the microprocessor and the
power-down logic when the read/write heads are home (off the disk pack).

4-7

MOlOR C,Oi\lTROi...

DRIVE
LOGIC
MODULE

SPINDLE
MOTOR
CONTROL
CIRCUIT

SPINDLE
MOTOR
HEAT
SINK
MODULE

POSITIONER
MOTOR
CONTROL
CIRCUIT

POSITIONER
MOTOR

CZ-0848

Figure 4-6

Motor Control Module Block Diagram

4.7.8 Spindle Motor
The spindle motor is the de motor that rotates the disk spindle. In the RA60 Disk Drive, the spindle motor
drives the disk spindle directly without any belt or pulley. The spindle motor also has a built-in encoder that
converts the motor rotational speed into digital pulses. The output signals from this encoder are monitored
by the slave microprocessor to determine disk speed.

4.8 POWER SUPPLY ASSEMBLIES
The RA60 power supply includes five assemblies. These are the switchplate assembly, transformer assembly, cap/rectifier assembly, regulator module, and heat sink module. Figure 4-7 shows a block diagram of
the power supply.

CAP/
RECTI FIER
ASSEMBLY

+5V
-5.2V
+15V

BACKPLANE
ASSEMBLY

-15V
SWITCHPLATE
ASSEMBLY

HEAT
SINK
MODULE

XFMR

REGULATOR
MODULE

+27.5V] POSITIONER
-27.5V
MOTOR

+27.5V] SPINDLE
-27.5V
MOTOR

CZ-0849

Figure 4-7

Power Supply Block Diagram

4·8

4.8.1 Switch plate Assembly
The switchplate assembly contains the main drive circuit breaker and an ac line filter. The circuit breaker
has three poles rated at 12 amps, 6 amps and 6 amps respectively_ Switch capacity is 12 amps at the 120
volt setting and 6 amps at the 240 volt setting.
4.8.2 Transformer Assembly
A ferro-resonant transformer is used in the RA60 to obtain good line voltage regulation. The raw output
voltages from the transformer are fed to the cap/rectifier assembly for rectification. The transformer puts
out raw ac voltages of 11 volts, 27.5 volts, and 20 volts.
The ac voltage range switch and frequency range plugs mounted on top of the transformer permit easy
voltage and frequency range selections. The location of the ac voltage range switch and the frequency range
plugs is shown in Figure 4-8.

FREQUENCY
PLUG

CZ-0872

Figure 4-8

Voltage Range Switch and Frequency Plugs

Also located on the transformer assembly are six thermal circuit breakers that protect the output of the
transformer from short circuits and overheating. The location of these circuit breakers for both the old and
new style transformers are shown in Figures 4-9 and 4-10.
In addition to the six thermal circuit breakers located on the transformer, two 5 amp fuses are located on
the regulator module to fuse the on-board raw ac 20 volt lines.

4·9

FREQUENCY
PLUGS

~1I--~-+----.:::::::...:t11 V

15 AMP

±20V
6 AMP

TRANSFORMER
ASSEMBLY

CZ-0850

Figure 4-9

Location of Circuit Breakers (Old Style Transformer)

4-10

! 20V

! 11V

6 AMP

15 AMP

THERMAL
4-CIRCUIT
BREAKERS

FREQUENCY
PLUG

CZ-0871

Figure 4-10 Location of Circuit Breakers (New Style Transformer)

4.8.3 Cap/rectifier Assembly
The cap/rectifier assembly rectifies the raw ac received from the transformer assembly. It puts out the
following dc voltages: ±11 volts, ±20 volts, and ±27.5 volts.

4.8.4 Regulator Module
The regulator module contains the low level circuitry to regulate the rectified dc voltages on the heat sink
module. The regulator module also senses the dc voltage levels and controls the series regulating transistors
located on the heat sink module.
The regulator module also contains all the ac and dc shutdown logic and the power resumption logic. See
paragraph 4.13 for a description of the causes of power shutdown and the sequence of events that occur
prior to shutdown.
Figure 4-11 shows a block diagram of the functions provided by the regulator module. It has an on-board
power supply to provide dc voltages for its own logic circuits and reference voltages. Also located here is
the fault circuitry to detect ac failures, dc overvoltage, and dc undervoltage conditions. There are also some
timers to control power shutdown and resumption. Monitoring all these failure conditions is the fault controllogic circuit. The regulator module also provides accurate voltage references for the regulator control
circuits.

4-11

20V
AC
XFMR

REGULATOR MODULE

If
lJ~

ON BOARD
POWER
SUPPLY

r--VOLTAGE
REFERENCE

----AC
FAIL
DETECT

!
DC VOLTAGE
OVER/UNDER
DETECT

---

!
POWER ON
AND RESET
TIMERS

I PREAMP I

WRITE INHIBIT

FAULT
CONTROL
LOGIC

+5.2V
-15V
+15V
+5V
REGULATOR
CONTROL
CKTS

<=r>

HEAT
SINK
MODULE

f---+
RETRACT HEADS
~

DC SENSE AND OVER VOLTAGE SCRS

~
CZ-0851

Figure 4-11

Regulator Module Block Diagram

The heat sink module also supplies the motor control module with ±15 volts and ±27.5 volts. Power to the
dc fans is also supplied from the heat sink module. Refer to Figure 4-12 for a block diagram of the heat
sink module.

4·12

HEAT SINK MODULE

MOTOR
CONTROL
MODULE

-I

SPINDLE
MOTOR
DRiVE

SPINDLE
MOTOR

POSITIONER
MOTOR
DRIVE

PASS
TRANSISTORS

POSITIONER
MOTOR

DC
VOLTAGES

REGULATOR
MODULE

BACKPLANE
OVER VOLTAGE
SCR'S

CZ-0852

Figure 4-12 Heat Sink Module Block Diagram

4.9 RA60 FUNCTIONAL DESCRIPTION
This section describes the physical disk layout, physical sector format, logical disk format, and the operation of the RA60 servo system, read/write commands, and the power supply functions.
4.9.1 RA60 Physical Disk Layout
The RA60 operates with an RA60-P removable disk pack. This pack contains five disk platters. The three
middle ones are used for data storage, while the two outer ones are for protection. The three data storage
platters provide a total of six read/write surfaces. Each disk data surface has 1600 physical tracks. Each
track contains 39 sectors with 18 bit data packs or 43 sectors with 16 bit data packs. The data field within
each sector contains 256 data words regardless of whether it is written in 16 bit or 18 bit mode.
Note
The RA60 disk pack formatting information is protected under the copyright laws.
© Digital Equipment Corporation 1983

4.9.2 RA60 Physical Sector Format
Each RA60 sector begins with a servo data interval followed by the sector header, data field, their supporting preambles, postamble, and error correcting codes. These are described in greater detail in the following
paragraphs.

4-13

4.9.3 Servo Data Interval
Since the RA60 Disk Drive uses an embedded servo system, each sector begins with a servo data interval.
Pre-recorded in this servo data interval is the following information. Refer to Figure 4-13 for an illustration
of the servo data interval.
•

Servo sync pulse-to synchronize servo timing circuits

•

Sector index next code-to mark sector zero on each track

•

Module 16 gray code-to indicate track crossings

•

Two guard band codes-to distinguish guard hands from the data area

•

Two offset servo bursts-to indicate an offset from track centerline
SERVO DATA INTERVAL

SERVOSYNC'NDr~ ~ F:;
\

IDX GC3 GC2 GC1 GCO GB1 GBO

_L_A_ST_D_A_TA---J1&....1_ _ _
GA_P_2_ _~III~S_YN_C---JIUUUUUUU4

BIT
TIMES

II GAPO

l~nnnnnnnlGAP1

r
R

LB1

LBO

11 - - - 1

'1'

.....

HEADER

DIRECTION OF ROTATION
CZ-0853

Disk format protected by © DIGITAL EQUIPMENT CORPORATION 1983

Figure 4-13 Servo Data Interval Format

4.9.4 Head/Disk/Preamp Configuration
The RA60 read/write head to disk layout is straight forward. The layout of the head connectors on the
preamp module is unusual. Refer to Figure 4-14 for the head/disk/preamp configuration.

4-14

J8 ~r

CARRIAGE ASSEMBLY

"ide...", , .

,------l

ri'i}

v-HDO

HD1

TOP PLATTER

o c::::::J

B UP

I
3 r=l
4 t::::J

5 r=J
BOTTOM PLATTER

I
I
I
I

HD2t""cREADIWRITE
HEAD
CONNECTORS

HD3

B DWN

r---HD4
~#-HD5

B UP

'--------~

PREAMP MODULE

CZ-0854

Figure 4-14 Head/Disk/Preamp Configuration

4.9.5 Sector Header and Data Field
After the servo data interval, the remainder of the sector contains the header preamble, header sync,
header, data preamble, data sync, data field, error detection code (EDC), error correction code (ECC), and
the data postamble. The sector byte format is shown in Table 4-1.
Table 4-1 Sector Byte Format
Description

Bytes

Servo data interval

Equivalent to 37 byte times

Header preamble

18 bytes maximum

Header sync

2 bytes

Header (repeated 4 times)

16 bytes

Data preamble

34 bytes maximum

Data sync

2 bytes

Data 16/18 bit words

512/576 bytes

Error detection code (EDC)

2 bytes

Error correction code (ECC)

22 bytes

Data postamble

2 bytes

4-15

4.9.6 Logical Disk Format
The RA60 disk pack logical format meets the criteria set forth in the Digital Standard Disk Format
(OSDF) specification, which is DEC Standard 166. This standard describes how a physical disk is constructed into the logical format for SOl devices. It also describes the host view of mass storage device
formats.
This specification redefines many of the old disk terms, such as track and cylinder, as a function of their
access characteristics. The following terms will help you to understand the OSOF.
1.

Sector-A sector is the smallest unit in which data is physically addressed. Sectors are available
for reading or writing once per disk revolution.

Track-A track is a logical entity that represents sets of sectors occupying contiguous physical
disk locations. This is a strictly logical entity that relates sectors to each other as a function of
their access characteristics.

Group-A group is a logical entity that contains a set of tracks. Groups with the same physical
sector address on each of the tracks are simultaneously available for reading or writing. Groups
also have the property that any track within the group can be selected within the inter-sector
rotation time. This definition of groups is independent of the physical construction of the device
and relates tracks to each other as a function of their access characteristics.

Cylinder-A cylinder is a logical entity that represents a collection of groups. Individual groups
on the same cylinder can be accessed in less than the minimum seek time. The selection of a new
cylinder has the longest average positioning time.

Physical Block Number (PBN)-A PBN is a 28 bit number which identifies a physical sector's
lV\4il.ltll\n
4il.pt I\f 4il.Pl'tArc An 0:1 cllhllntt
r"'
.......... "' ...... ullthln
" ....................... ~ .....
...., ... '-' .................... V.l.U V.I..1.
t.,Juvu..II. .. ".
~

&,..&.

Logical Block Number (LBN)-An LBN is a 28 bit number which identifies a physical sector's
position within a set of sectors directly accessible to the host. These are used for host data storage and revector control information.

Replacement Block Number (RBN)-An RBN is a 28 bit number which identifies a physical
sector's replacement position.

Bad Block-A bad block is a sector that contains a defect which exceeds the error correction
capability of the subsystem.

Bad Block Replacement-The substitution of a spare sector (replacement block) for a bad sector.

10.

Bad Block Revectoring-Locating the replacement block as a result of attempting to access a bad
sector.

11.

Primary Replacement Block-A replacement block with the lowest track RBN which has been
allocated to replace a logical block on the same track.

12.

Secondary Replacement Block-A replacement block which is allocated to replace a logical
block on another track.

13.

External Block Number (XBN)-A 28 bit number which identifies a physical sector's position
within a set of sectors in the external format area of the subunit.

4-16

14.

Diagnostic Block Number (DBN)-A 28 bit number which identifies a physical sector's posItIon
within the set of sectors in the diagnostic area of the subunit.

Using the above definitions, Figure 4-15 shows how the RA60 disk physical cylinders and sectors are organized into LBNs, XBNs, DBNs and RBNs.
- - - - - - - - PHYSICAL C Y L I N D E R - - - - - - - - - - -.....~.

1588

1592

1596

1599

HOST
APPLICATION
AREA
(LBN'S)

PHYSICAL
SECTOR

REVECTOR
CONTROL
TABLES
(LBN'S)

FORMAT
AREA

DIAGNOSTIC
AREA

(XBN'S)

(DBN'S)

_----------L-----~

REVECTOR AREA (RBN'S)

I
CZ-0855

Disk format protected by © DIGITAL EQUIPMENT CORPORATION 1983

Figure 4-15

RA60 Overview of the 16 Bit Logical Disk Format

Note that in the RA60, four physical cylinders make up one logical cylinder. Also in the RA60, one physical cylinder is equivalent to a group so there are four groups in one logical cylinder. Figure 4-16 shows how
the physical cylinders translate into logical cylinders.
_ _ _ _ _ _ _ _ _ PHYSICAL _ _ _ _ _ _ _ _ _--I.~
.
CYLINDER
1588

PHYSICA L
SURFAC E

396

2382

2388

2390

793

397

2383

2389

2395

794

1190

2384

2390

2396

1587

1191

2385

2391

2397

1588

1984

2386

2392

2398

2381

1985

2387

2393

2399

RCT---. !+FORMAT-. ~DIAG---,

HOST AREA

Disk format protected by © DIGITAL EQUIPMENT CORPORATION 1983

Figure 4-16

1599

1596

1592

RA60 Physical to Logical Cylinder Translation
4-17

CZ-0856

In the RA60. one LBN is equivalent to one physical sector. Thus there are forty-two logical blocks and one
replacement block per physical cylinder. Figure 4-16 shows the physical location of block numbers for a 16
bit formatted disk. The logical block numbers are shown inside the squares of Figure 4-17.
_ _ _ _ _ _ _ _ PHYSICAL:,...-_ _ _ _ _ _ _--II~~
CYLINDER
0

1588

1596

1592

1599

66695

400176-400303

0-171

133391

66696

400344-400511

172-343

133392

200088

400512-400679

344-515

266783

200088

400680-400847

516-687

266784

333479

400848-401015

688-859

608-859

400175

333480

401016-401183

860-1031

PHYSICA L
SURFAC E

XBN'S ..... ~DBN'S ____

LBN'S

CZ-0857
Disk format protected by © DIGITAL EQUIPMENT CORPORATION 1983

4.10 RA60 SERVO SYSTEM
The RA60 Disk Drive does not have a dedicated servo module. Instead, the servo circuits are distributed
over most of the electronic modules. The servo system has two modes of operation. These are the linear (or
track centering) mode and the seek (or track crossing) mode. The major functional blocks in the servo
control system are shown in Figure 4-18.

4-18

DRIVE LOGIC MODULE

POST AMP/DATA
SEPARATOR

J DEMODULATOR

i'r
SLAVE

4
I SAMPLE &
o SAMPLE

A/D
CONVERTER

LINEAR
MODE

- FLT POS

..A

FET
SWITCH

I
I
I

-.1

1-1-----'

I
I
I

D/A
CONV

I
I
I
I
I

II'"

"4-I

CONTROL
LOGIC

_...1

Figure 4-18 Servo Control System Block Diagram

HEAT
SINK

MOTOR
CONTROL

POWER
AMP

SEEK
MODE

L-

AMP

HEAD
SELECT

I
_ _ _ _ _ _ .JI

"""-

K;=

I
I

~ §-1 + 4

MASTER
J,lp

PREAMP

TACH I
POSITIONER
MOTOR

..L
....
,...

L __ ~ EMERGEN(;Y
UNLOAD

SPINDLE
MOTOR

CONTROL
SERVO
ERROR

REGULATOR
MODULE

EMERGENCY
UNLOAD
RESERVOIR

CAPACITOR
ASSEMBLY

:>
----- -

ANALOG
DIGITAL BUS
CONTROL
CZ-085 8

4.10.1 Servo T,inear Mode
In the linear mode, the servo circuits use the embedded servo information on the disk to detect the head
position relative to track centerline. This servo information consists of two bursts of high frequency signals
that are offset in opposite directions from track centerline. As the read/write head passes over the servo
bursts, amplitude of one burst will be greater than the other if the head is slightly off track centerline.
The servo burst information is detected by the read/write heads and is amplified on the preamp module.
This servo information is then demodulated on the post amp/data separator module. Here these servo
bursts go through a band pass filter to separate the servo burst signals from the rest of the data coming off
the disk. Once separated, these servo bursts are rectified, integrated, and passed through sample and hold
circuits. The two dc signals produced by this process are I SAMPLE (for the inner servo burst) and 0
SAMPLE (for the outer servo burst), which are sent to the drive logic module.
On the drive logic module, the I SAMPLE and 0 SAMPLE signals enter a differential amplifier in the
linear mode circuits and produce an error signal called FLT POS. FLT POS is passed through a FET
switch to produce two servo error signals, SVO ERR 1 and SVO ERR2, which are sent to the motor control
module.
The servo control signals are amplified by the motor control module and heat sink modules and drive the
positioner motor through a relay contact on the heat sink module.
A difference signal is derived from the I SAMPLE and 0 SAMPLE signals entering the drive logic module. This difference signal is converted to a digital format by the A/D converter and is monitored by the
slave microprocessor.

4.10.2 Servo Seek Mode
The servo system normally ooerates in linear mode to keen the read/write heads above track centerline,
However, ~hen the drive ~ec~ives a seek command, the se~vo system' is placed into seek mode. The slave
microprocessor is given the number of tracks that the heads must cross, and it fetches a value from a
velocity table to send to the seek mode circuits. This velocity value is converted into an analog voltage in
the D/ A converter and then applied to the velocity error circuits. The control logic on the drive logic
module places the FET switch in the correct state to allow the seek mode signals to pass to the motor
control module. The motor control module and heat sink module amplify the seek mode signal and start the
positioner motor moving.
As the read/write heads cross tracks, the servo system detects the track crossings by monitoring a 4 bit
gray code at the beginning of each sector. This gray code is demodulated and passed on to the slave microprocessor, where the number of track crossings is used to decrement a track counter.
The slave microprocessor is also monitoring the velocity of the positioner motor by reading the output
voltage from the tachometer. An A/D converter changes the tachometer voltage to a digital format that
can be read by the slave microprocessor.
As the heads get closer to the destination track, the slave microprocessor issues smaller velocity values to
the D/ A converter. When the destination track is reached, the servo system switches back to linear mode
and centers the heads over the track.

4.11

RA60 READ/WRITE OPERATION

The following paragraphs describe the rate 213 code, the write command and the read command.

4-20

4.11.1 The Rate 2/3 Modulation Code
The RA60 uses a new rate 2/3 modulation code for encoding the write data on the disk. This coding technique allows one-third more data to be stored on the disk than is possible with the former Modified Frequency Modulation (MFM) code. For a given data stream, the rate 213 code spreads out the magnetic
transitions on the disk, reducing the need for peak shift compensation. Since the data transitions are further
apart due to the 2/3 code, they can be electrically squeezed back together to obtain one-third more data than
MFM would allow. The data transitions are not squeezed to the point where peak shift problems become
significan t.
4.11.2 RA60 Write Commands
Figure 4-19 shows a simplified flow diagram for the RA60 write command. Use this diagram as a reference when reading the following description.

Prior to issuing the write command to the drive, the controller issues a seek command (if necessary) to
position the heads onto the desired cylinder.
When a write command is issued by the disk controller, the drive sends the next encountered sector header
to the controller. The disk controller reads the header and does a compare with the desired header. If they
don't match, the write command is terminated. Otherwise, the controller asserts the WRITE GATE signal
and sends the data.
The controller asserts WRITE GATE on the SDI cable Real Time Controller State (RTCS) line. The
RA60 SDI interface module decodes the WRITE GATE signal and enables the Phase Locked Loop (PLL)
oscillator on the post amp/data separator module. The PLL oscillator locks onto a multiple of the WRITE
CLOCK frequency and begins clocking NRZ write data into the 213 encoder. The 213 encoded write data is
then sent on to the preamp and write heads to be recorded on the disk. Because of the high data speeds, the
microprocessors on the drive logic module do not get involved in the writing process.
SDI CABLE

RTCS

SDI
INTERFACE
MODULE

WRT/CMD DATA ---.

WRITE CLOCK

NRZ WRT DATA

PLL
PREAMP &
HEADS

2/3 WRITE DATA

ENCODER
DECODER
WRT GATE

POST AMP/
DATA SEP
MODULE

CZ-0859

Figure 4-19

RA60 Simplified Write Command Diagram

4-21

4.12 RA60 READ COMMANDS
Figure 4-20 shows a simplified flow diagram of the RA60 read command. Use this diagram as a reference
when reading the following description.
When a read command is issued by the disk controller, the drive sends the next encountered sector header
to the controller. The disk controller reads the header and does a compare with the desired header. If they
don't match, the read command is terminated. Otherwise, the controller asserts READ GATE and receives
the data. READ GATE enables the 2/3 decoder circuits on the post amp/data separator module. The 2/3
READ DATA comes off the disk through the read heads and preamp module. This 2/3 READ DATA is an
analog waveform that is amplified and shaped in an equalizer circuit. The output of the read/amp equalizer circuit is then digitized in the data digitizer circuit. Once digitized, the read data is then decoded from
its 213 format back into the NRZ READ DATA which is sent to the SDI interface module for transmission
to the disk controller.
4.13 Power Supply Functions
The RA60 power supply consists of the following five assemblies: switchplate assembly, transformer assembly, cap/rectifier assembly, regulator module, and the heat sink module. The power supply converts ac
power into the regulated dc voltages needed by the RA60 circuits and motors. A power distribution diagram showing these voltages is illustrated in Figure 4-21.
The dc current ratings for the unregulated cap/rectifier assembly output voltages are:
•

+11 volts at 8 amps

•

-11 volts at 6 amps

•

+20 voits at 2 amps

•

- 20 volts at 2 amps

•

+27.5 volts at 8 amps average

•

-27.5 volts at 8 amps average

All the regulated voltages have a tolerance of ±5 per cent. The current ratings for the regulated voltages on
the heat sink module are:
•

+5 volts (4.75 volts to 5.25 volts) at 8 amps

•

-5.2 volts (4.94 volts to 5.45 volts) at 6 amps

•

-15 volts (14.25 volts to 15.75 volts) at 2 amps

•

+15 volts (14.25 volts to 15.75 volts) at 2 amps

4-22

SDI CABLE

~
NRZ READ DATA

READ/RESP DATA
...-

RTDS

SDI
INTERFACE
MODULE

READ CLOCK

ENCODER
DECODER

READ GATE

DRIVE
LOGIC
MODULE

PLL

READ/AMP
EQUALIZER

[

AGC

2/3 READ DATA

...-

DATA
DIGITIZER

PREAMP &
HEADS

FAST AGC
POST AMP/DATA SEPARATOR MODULE

CZ-0860

Figure 4-20 RA60 Simplified Read Command Diagram

NOTE : 6 CIRCUIT BREAKERS
ARE MOUNTED ON
POWER TRANSFORMER

REAR L
DC
[...
FAN

REAR
J DC
FAN

R/W
PREAMP

:306

CAP/RECT
ASSY

[ lr
.c

VOLTAGE
SWITCH AND
FREQUENCY
RANGE
PLUGS

=~
:r-"-'
-l

:r~

L ...:t ~

11V RAW
11V CT
11V RAW
27.5V RAW

,22l

3
4

27.5V CT

27.5V RAW

20V RAW
20V CT
20V RAW

'---

I--

.§.QL

804

-502
+llV
11V CT
-llV
+20V
20V CT
-20V
+27.5V
27.5V CT
-27.5V
V-UNREG
V+UNREG

1
2
3

3
2
4

POSITIONER
MOTOR
LM+

COIL~ ~

LMHMSWC

20V CT
20V RAW

REGULATOR

33,34
29,30
27,28
25,26
23,24

1
2
3

21,22

XFMR

---

19,20

-5.2V
-15V
+15V

I----

MOTOR
CONTROL

902

25,26

23
21
19,20
17,18
I----

i-J

802

5
6
7

1
2
3

PHA
PHB
PHC

ORN
RED
BRN

GND
+15V
-15V
-27.5V
+27.5V

JO-A
_B
=C

805
-59,60

2,3
4

55,56
53,54
51,52
49,50

5,6
7

47,48
45,46

SPINDLE
MOTOR

8,9

2.Q2..
-5.2V

2,3

-15V

GND

5,6

+15V

BACKPLANE

+5V

703 CONNECTOR
A30,A31 ,C30,C31 (-5.2V)
A29,C29(-15V)
A 1,C1,A5,C5,A28,C28,A32,C32(GND)
A4,C4(+15V)
A2,A3,C2,C3(+5V)

L!)

(!J

((J
C'J

POST AMP /
DATA
SEPARATOR
MODULE

INTF
SDI
MODULI:

DRIVE]
LOGIC
MODULE

704

> > 0 0 >
+ z z

701 CONNECTOR
B2,C2,B3,C3(+5V)
B4,C4(+15V)
B29,C29(-15V)
B30(-5.2V)
A 1,B1 ,C1 ,A5,B5,C5,A32,B32,C32(GND)

r--

807

(1)'"

,..-

702 CONNECTOR

GND

l..C')~

C"\i

CD
N
___

3
4 1,2
5 7,8
9 6 26

HANDHELD
TERMINAL
POWER

_ ..

",,'" ~ _ ... Lrl m'"
J 1 ___ N t ' J -

A2,B2,C2,A3,B3,C3(+5V)
A4,B4,C4(+15V)
A21,B21 (-15V)
A22,B22,A23,B23(-5.2V)
A 1,B1 ,C1,A5,B5,C5,A20,B20(GND)

8,9

r-;o-r

5
.I

,........ _ ..

-. -

SDI~

ill=!

. r==l

SDI~

25,26
23
21
19,20

CD N N
cr' 0
201 -~-N('.JN

SPEED
XDCR

J.;~

HEAT
SINK

HOME
SWITCH

~
20V RAW

m= r--x-

HMSWNC

'---

GND
-27.5V
+27.5V
+5V

XDCR

....

+5V
+15V
GND

401
1,2,3,4
3,4,5,6
9

FRONT
PANEL

CZ-0877

Figure 4-21

Detailed Power Distribution Diagram

4.14 POWER SHUTDOWN
In addition to supplying all the RA60 dc power, the shut-down and power-up logic that protects the storage
data from ac or dc failures is on the regulator module.

In the RA60 Disk Drive, an ac failure occurs whenever power is lost for more than 20 milliseconds. This
will cause the shut-down logic to implement the following ac shut-down activities.
•

Wait for 20 milliseconds outage.

•

Assert CMDINH signal to finish sector write command and ignore any pending write commands.

•

Assert PSFLT signal to prevent writing on the disk.

•

Assert NOT RETRACT signal to unload heads.

•

Turn off regulated power.

When the ac power resumes, the logic will implement the following power resumption sequence.
•

Assert the PSFLT signal to prevent writing on the disk.

•

Assert NOT RETRACT signal to unload heads for 200 milliseconds.

•

Turn on regulated power supplies.

In addition to ac shut-downs, the regulator board controls dc shut-downs. This is necessary to protect the
power supply from momentary or permanent short circuits. There are three conditions that can cause a dc
shut-down. These are a dc over-voltage condition, a dc under-voltage condition, and an over-current condition. A dc shut-down follows the same sequence as the ac shut-down, except there is no 20 millisecond
delay. After a a dc shut-down, the power supply will remain off until the fault is removed and the main
circuit breaker is reset.

4-25

CHAPTER 5
FAULT ISOLATION

5.1

INTRODUCTION

This chapter discusses the RA60 fault isolation procedures. It also describes the troubleshooting aids used by
the RA60 Disk Drive which include the front panel fault codes, error code tables, the power supply tables,
and a fault isolation flowchart.

5.2 RA60 TROUBLESHOOTING AIDS
The RA60 has several troubleshooting aids. Two of them are as follows:
• Front panel fault codes
• Hand held terminal error messages/host diagnostic error messages

5.2.1

Front Panel Codes

Figure 5-1 describes the fault codes, shows the front panel light configuration and the hex code of the lights.
Table 5-1 lists the fault codes, gives a description of the fault, and calls out the most likely failing FRUs.

5-1

DESCRIPTION
OF ERROR

MICROCODE
ERROR (NOT
SENT TO
FRONT PANEL)
HEADS HOME
SWITCH FAULT
FRONT PANEL
FAULT
LONG SPIN-UP
TIME FAULT
BAD SERVO
SAMPLES FAULT
BAD VELOCITY
FAULT
LINEAR MODE
FAULT
RETRY ON SEEK
FAULT
LOST SERVO
SAMPLES FAULT
HEADS HOME
SWITCH WOULD
NOT OPEN
MASTER
PROCESSOR
FAULT
SOl FAULT
INVALID SOl
LEVEL 1
COMMAND
MASTER
PROCESSOR
FAULT

~
~

HEX
CODE

OFF

" THE RUN/STOP SWITCH MAY BE ON OR OFF DEPENDING ON THE STATE OF
THE DRIVE.

CZ-0888

Figure 5-1 Front Panel Fault Codes

5·2

Table 5-1

RA60 Front Panel Fault Codes

FRONT PANEL
CODE

DESCRIPTION

MOST LIKELY
FRUFAILURE

Microcode error (not sent
front panel)

1. None

Heads home switch fault

1. Push heads home
2. Check P803
3. Heads home switch
assembly

Front Panel Fault

1. Front panel module
2. Drive logic module
3. Front panel ribbon
cable

Long spin-up time fault

1. Check Spindle motor
connections
2. Heat sink module l ~ ~~)
3. Spindle Motor
4. Drive logic module

Bad servo samples fault

1. Pack
2. Post amp/data
separator module
3. RlW preamplifier module
4. Heads

Bad velocity fault

1. Pack
2. Post amp/data
separator module
3. RlW preamplifier module
4. Drive logic module
5. Positioner assembly

Linear mode fault

1. Pack
2. Post amp/data
separator module
3. Drive logic module

Retry on seek fault

1. Pack
2. Post amp/data
separator module
3. RlW preamplifier module
4. Drive logic module

Lost servo samples fault

1. Pack
2. Heads
3. Post amp/data
separator module

5-3

TableS-l

RA60 Front Fault Codes (Cont)

FRONT PANEL
CODE

DESCRIPfION

MOST LIKELY
FRUFAILURE

Heads home switch will
not open

1. Shipping pin not
removed
2. Check P803
3. Heads home switch
assembly
4. Heatsink module

Master processor fault

1. Drive logic module
2. SDI module
3. Post amp/data
separator module
4. Backplane module

SDI faults

1. SDI module
2. Drive logic module
3. SDI cable
4. Backplane module

Invalid SDI level one
command

1. SDI module
2. Post amp/data
separator module
3. RlW preamplifier module
4. Backplane module

Master processor fault

1. Drive logic module
2. SDI module
3. Post amp/data
separator module
4. Backplane module

S.2.2 RA60 Error Messages
Refer to Table 5-2 for the RA60 error messages. They are displayed on the hand held terminal when internal
diagnostics are run or are printed out on the system console when running host diagnostics. Table 5-2 shows
the error code, description of the error, and the most likely failing FRU.

5-4

Table 5-2 RA60 Error Messages
ERROR
CODE

DESCRIPTION

MOST LIKELY
FRU FAILURE

Command cannot be executed with the drive in
its current state
Nonexistent head or cylinder requested with
seek
Opcode is not one of six valid opcodes
Cover open when run command is issued
Program error during head load

1. Drive logic module

Heads not home when run command is issued
Heads home switch open during spin-up
Heads home switch will not close during
unload
Cover or lid lock open during head load

1. Push heads home
2. Check P803
3. Heads home switch assembly

Spin-up L high during spin-up
Lid lock open during spin-up
Cover open during spin-up
Cover or lid lock open during head load
Lid unlocked when run command is issued

1. Front panel module
.' .' j~:- -:c::' .~)
2. Drive logic module~'t"'I.s
~_;::)'
3. Front panel ribbon cable ;0 -i<) ./.5'',.;.{).

18
19
20
24

Spin-up too lengthy
Motor sample will not change during spin-up
Spin-up too brief
Too long to acquire spindle speed control on
head load

1. Check spindle motor connections
2. Heat sink module
3. Spindle motor
4. Drive logic module

26
27

More than 32 sectors to settle on track

1. Pack
2. Post amp/data separator module
3. R!W preamplifier
4. Heads

02
03
04
06
08
09

OA
OB
,r--OC
10
11
12

13 &
14

28
29

2A
2B
2C
2D
2E

More than 32 sectors to settle on track retry
failure
Too many bad servo samples during RTZ
Too long to acquire good samples on head load
Head load seek does not return to track 0
Bad servo samples when bumping guard band
on head load
Bad servo samples during RTZ on head load
B ad samples during linear mode
Off speed when in linear mode

5·5

Table 5-2 RA60 Error Messages (Cont.)
ERROR
CODE

DESCRIPTION

MOST LIKELY
FRU FAILURE

Off track in linear state

1. Pack
2. Post amp/data separator module
3. R!W preamplifier module
4. Drive logic module
5. Positioner assembly

40
41
42
43

Retry on seek due to bad servo samples
Retry on seek due to bad servo samples failing
Retry on seek due to bad guard band flags
Retry on seek due to bad guard band flags, retry
failed
Retry on seek due to wrong polarity entering
linear mode
Retry on seek due to wrong polarity entering
linear mode, retry failed

1. Pack
2. Post amp/data separator module
3. R!W preamplifier module
4. Drive logic module

46
47
48

Retry on seek due to wrong grey code
Retry on seek failing due to wrong grey code
Lost servo samples

1. Pack
2. Heads
3. Post amp/data separator module

Too long for heads home switch to open on
head load

1. Shipping pin not removed
2. Check P803
3. Heads home switch assembly
4. Heatsink module

81
82
83
84
85
86
87
88

Initializes and test control panel module
Checks processor registers
Test RAM #0
Test ROM #0
Tests ROM # 1
Tests ROM #2
Verify ROM version numbers
Tests the SOl clear interface bit

1. Drive logic module
2. SOl module
3. Post amp/data separator module
4. Backplane module

89
8A
8B
8C
80
8E
8F
90

Tests the SOl control/status register
Test front panel and serial number ROM
Initializes the U ART
Tests the error registers
Tests the 8155 timer
Tests the slave control port
Slave diagnostics
Command available or slave done already set
when issuing a new slave command
Slave command receiver timeout on opcode

1. Drive logic module
2. SOl module
3. Post amp/data separator module
4. Backplane module

44
45

5-6

Table 5-2 RA60 Error Messages (Cont.)
ERROR
CODE

DESCRIPTION

MOST LIKELY
FRU FAILURE

92
93
94
95
96

Slave attention timeout
Slave done timeout to slave stop (TOSTP)
Slave done timeout to status (1 ms)
Slave done timeout
Slave attention timeout

1. Drive logic module
2. SDI module
3. Post amp/ data separator module
4. Backplane module

97
98
99
9A
9B

Solenoid release timeout
Watchdog timer detects master insane
Watchdog timer detects slave insane
Run switch or cover invalid at spin-up
Spindle not ready during recalibrate command

1. Drive logic module
2. Post amp/data separator module
3. SDI module
4. Backplane module

9C
9D
9E
9F
AO
Al

SDI transfer error from DC703
Write or format when write-protected
Format when format-disabled
Transfer command during drive error
Sector read/write overrun error
Transfer command during read/write error

1. SDI module
2. Post amp/data separator module
3. R!W preamplifier module
4. Backplane module

A2
A3
A4
A5
A6
A7

SDI command checksum error
SDI frame error
SDI command parity error
SDI command out of range
SDI command length error
SDI error status byte in non-zero

1. SDI module
2. Drive logic module
3. Post amp/data separator module
4. Backplane module

AS
A9
AA
AB
AC

Slave done timeout to seek command
Slave done timeout to RTZ command
Slave response error to RTZ command
Slave done timeout during first pass
Command receiver timeout during diagnostic
stop or ASCII port command time = todgn 2
Slave done timeout during diagnostic stop or
ASCII port time = 1MS

1. Drive logic module
2. SDI module
3. Post amp/ data separator module
4. Backplane module

Drive off-line
Command bytes 4 & 5 are not zero
Invalid group number
Invalid head-select number
Invalid cylinder range
Spindle not ready

1. Drive logic module
2. Post amp/data separator module
3. SDI module
4. Backplane module

AE
AF
BO
Bl
B2
B3

5-7

Table 5-2 RA60 Error Messages (Cont.)
ERROR
CODE

DESCRIPTION

MOST LIKELY
FRU FAILURE

B4
B5
B6
B7
B8
B9

Controller timeout = 0
Spindle not ready
Illegal memory region
DD bit set
Tried to clear hard fault
Slave done timeout (1 MS) to get status

1. Drive logic module
2. Post amp/data separator module
3. SDI module
4. Backplane module

Non-zero level
Wrong subunit error
Diagnostic command, memory region high,
not zero
Diagnostic command, invalid parameters
Write enable a write-protect drive
Setting S7 = 7

1. Drive logic module
2. Post amp/data separator module
3. SDI module
4. Backplane module

BB
BC

BD
BE
BF

5.3 POWER REGULATOR MODULE LEDS
The regulator module has seven LEDs on the top to help in fault isolation. Five of the LEDs are green and the
remaining two LEDs are red. The green LEDs indicate normal operation and the red LEDs indicate an abnormal condition. The location of these LEDs is shown in Figure 5-2. Use the chart in Table 5-3 to help isolate
power supply problems.

5·8

RED

GREEN

D19
REF

D18

GREEN

THERMAL
FAULT

D15
-5.2

D13
+15

RED

D17
+27.5
-27.5

~L..... :~?~ ........
++ • • • • +++ • • • • • ++.

REGULATOR MODULE

CZ-0889

Figure 5-2 Regulator Module LEDs

5·9

Table 5-3 Regulator LED Fault Codes
REGULATOR LEDS

POSSIBLE CAUSES

Green

Red

Green

D19

D18
Thermal
Fault

D16
+5

D15
-5.2

D14
-15

D13
+ 15

Listed in order of most likely

REF

D17
+27.5
-27.5

a
a

Normal state

a
a

Suspect voltage reference on regulator
1. Check AC cabling and switch plate assembly
2. Transformer
3. Regulator
4. Cap/rec assembly

a
a

+-27.5 volt failure
1. Heat sink module
2. Cap/rec assembly
3. Transformer
4. Regulator
I-----at least one off-----I

Suspect a short circuit
1. Logic module shorts
2. Heat sink module

Suspect short or overvoltage to + 5 and -5.2
1. Logic module shorts
2. Check circuit breaker
3. Heat sink module
4. Capacitor assembly
5. Regulator module

Suspect shorts to + -15 v
1. Logic module shorts
2. Check circuit breaker
3. Heat sink module
4. Capacitor module
5. Regulator module
Thermal shutdown
1. Check fans
2. Regulator module

I-----at least one off-----I

Thermal shutdown with faulted supply
1. Check fans
2. Heat sink module
3. Regulator module

5·10

5.4 RA60 FAULT ISOLATION FLOWCHART
Use the RA60 fault isolation flowchart in Figure 5-3 as a guide to isolating disk subsystem problems. The
description of each block is keyed by numbers.

TYPE PROBLEM

INTERMITTENT FAULTS

SOLID

19.

EXAMINE
ERROR LOGGER

21.

?_YES-,

RUN HHT
DRIVE DIAG.

10.

DIAG. FAIL

REPLACE FRU

? -YES ---"l

RUN SUBSYSTEM
DIAGNOSTICS

11.

LOOK UP ERROR
CODE, TABLE 5-2

DID TEST
1 FAIL ?

r
13. DID TESTS

25. CHECK WITH SYSTEM
MGR. TO SEE IF SYSTEM
CAN BE TAKEN DOWN FOR
DIAGNOSTIC RUN
(FROM BLOCK 22)

LOOK UP FAULT
CODE, TABLE 5-1

NO -

I
4.

24. REPLACE FRU
SUGGESTED BY SPEAR

16.

PUSH FAULT
BUTTON, DECODE
LIGHTS

8. DID HHT

r NO -

23. DID SPEAR
?_

CHECK POWER
SUPPLY LEDS

DECODE STATUS
TABLES

22. RUN SPEAR IF
AVAI LABLE, OTHERWISE
GO TO BLOCK 25
PICK AN FRU
YES

IS FAULT LIGHT ON ?

I NO.1 \.YES-,

I
20. ARE STATUS
WORDS AVAILABLE

FAULTS

_YES--,
I
12. LOOK UP ERROR
CODE, TABLE 5-2

2,3,4, & 5 FAIL?

I
14.
NO -

IS FAULT
LIGHT ON ? - - - Y E S _ _---,

IS STATUS BYTE 15
AVAILABLE?

YES

18.

LOOK UP SUBSYSTEM ERROR
NUMBER AND DETERMINE
FAI LING FRU

17.

15.

PUSH FAULT BUTTON,
LOOK UP ERROR CODE,
REPLACE FRU, TABLE 5-2

DECODE STATUS BYTE 15

CZ-0891

Figure 5-3 RA60 Fault Isolation Flowchart

5.4.1

Block 1- Type Problem

Block I is a decision block asking whether the fault is an intermittent or a solid one. Intermittent faults are
difficult to solve because they do not occur consistently and do not always show up in fault codes or fault
lights. They take the form of random software correctable errors or the slow degeneration of error rates or
seek rates.
Solid faults, on the other hand, are consistent enough to be pinned down to a physical or software cause. Usually, solid faults will either light the fault lamp or be caught by the drive internal diagnostics or the subsystem
diagnostics and result in an error code.
Determine whether the fault is solid or intermittent and then follow that leg of the fault isolation chart shown
in Figure 5-3.

5.4.2 Block 2 - Is The Fault Light On?
When the FAULT light is on, it indicates that there is an error condition within the RA60 Disk Drive. If the
FAULT light is on, go to block 3. Otherwise, go to block 6 to check the power supply.

5·11

5.4.3 Block 3 - Push The Fault Button
Assuming that the FA ULT light is on in block 3, push the FA ULT button to obtain the blinking fault identification code in the front panel lights. This blinking light pattern will give you a hexadecimal fault code.
Figure 5-1 assists in interpreting the front panel lights.

5.4.4 Block 4 - Look Up The Fault Code
The fault code can be found in Table 5-1. This table also gives the most likely failing FRUs for that fault
code.
~.4.5

Block 5 - Replace The Failing FRU

Replace the most likely failing FRU indicated in Table 5-1. Since more than one FRU can be the cause of a
fault code, the most likely is listed first. Always replace that FRU first.

5.4.6 Block 6 - Check Power Supply LEDs
If you have a solid fault and the front panel FAULT light does not come on, two possible causes are a bad
light bulb or a power supply problem. Perform a front panel lamp test by pushing in the FAULT button. All
the front panel lights should stay on as long as the FAULT button is held in.
If no lights work, open the rear of the drive and check the power supply LEOs on the regulator module.
Figure 5-2 shows the location of these LEOs. Look up the light pattern of these LEOs in Table 5-3 to determine if the power supply is at fault. If Table 5-3 does indicate a bad voltage supply, check to see if the thermal circuit breaker for that supply voltage has tripped.

There are six circuit breakers located on top of the transformer assembly. Figures 5-4 and 5-5 show the location of these circuit breakers for both the old style and the new style transformer assemblies.
If the fault light is not on during the lamp test, go to block 7 to run the drive-resident diagnostics.

5-12

FREQUENCY
PLUGS

~---~-+---""::::::::::::-±11 V

15 AMP

±20V
6 AMP

TRANSFORMER
ASSEMBLY

CZ-0850

Figure 5-4 Location of Circuit Breakers
(Old StyIe Transformer)

5-13

~. 27.5\'

:: 20V

:: 11V

6 AMP

15 AMP

THERMAL
4-CIRCUIT
BREAKERS

FREQUENCY
PLUG

Figure 5-5 Location of Circuit Breakers
(New Style Transformer)

5.4.7 Block 7 - Run The Drive-Resident Diagnostics
There are six drive-resident diagnostic tests that can be run with the field service hand held terminal (HHT).
Refer to Chapter 3 of this manual to run these tests. These tests can only be run if the drive is placed off-line
(both Port A and B buttons out).
Normally, consult with the system manager before placing a drive off-line to ensure that the disk information
is not required by the operating system software. However, since this block is entered through a solid fault, it
is assumed that RA60 disk information is unavailable to the operating system.

5.4.8 Block 8 - Did The HHT Invoked Diagnostic Tests Fail?
A test completes its sequence successfully when it returns to the %RA60 - COMPLETED prompt. If an error
is detected, the HHT display will show an ERR:XX prompt with the error code in the XX spot. If an error
code display is obtained, go to block 9 for decoding.
If all the HHT diagnostic tests are completed successfully, go to block 10 to run the subsystem diagnostics.

5.4.9 Block 9 - Look Up HHT Error Code
Block 9 assumes that you obtained an error code during one of the HHT drive-resident diagnostic tests. Look
up this error code in Table 5-2 and replace the most likely failing FRU first.

5-14

5.4.10

Block 10 - Run The Subsystem Diagnostic Tests

The following description assumes that the RA60 is running on a UDA50 disk controller. The subsystem
diagnostics on an RA60 disk pack are run under the control of the diagnostic supervisor program. The VAX
EVRLA and the PDP-II CZUDC are the two subsystem diagnostics described here. They consist of the following five tests.
• Test 1: The UNIBUS interrupt/address test checks out UDA50 functionality.
• Test 2: The disk-resident diagnostic test runs the drive-resident diagnostics.
• Test 3: The disk function test performs drive seek tests.
• Test 4: The disk exerciser test performs a limited read and write test only in the diagnostic cylinder area.
• Test 5: The manual intervention test allows Test 4 to be run with new input parameters that include the
customer data area if desired.

5.4.11

Block 11 - Did Test 1 Fail?

Since test 1 is a UDA50 diskless test, any failure indicates a UDA50 problem or possibly a host CPU problem. If test 1 prints out an error message, go to block 12 to see how to interpret it. If test 1 does not fail, then
go to block 13.

5.4.12

Block 12 - Look Up UDA50 Error Code

A failure during test 1 is indicated by the CZUDC printout shown below.
CZUDC DVC FTL ERR 00005 ON UNIT 00 TST 001 SUB 002 pc: 023710
UDA INITIALIZE ERROR
UDA RESIDENT DIAGNOSTICS DETECTED FAILURE
UDASA REGISTER = 108040

The last line of the error printout shows the contents of the UDA50 UDASA register as 106040. The UDASA
error code 106040 indicates that either the UDA50 module M7161 or M7485 is at fault.
The UDA50 Disk Controller has two versions. The first version, the UDA50, consists of two hex height
modules, M7161 and M7162. The second version, the UDA50A, increases the memory buffer size of the
controller from 4K to 16K, adds more PROM space, and introduces selectable jumpers for varying UNIBUS
delays. The module numbers of the UDA50A have been changed to M7485 and M7486 respectively.

Note
Never intennix the old UDASO and the new UDASOA
modules due to incompatibility.
5.4.13

Block 13 - Run Subsystem Tests 2,3,4,5

Subsystem diagnostic tests 1 through 4 will run in sequence automatically without manual intervention. If
test 1 passes successfully without detecting any failures, chances are likely that there is a drive related problem rather than a UDA50 related problem.
If an RA60 drive problem has not been detected previously with the drive-resident diagnostics, chances are
likely that subsystem diagnostic tests 2 through 5 will detect the failure. Test 5 is to be initiated manually
because it involves a deliberate attempt to read and write in the customer data area of the disk pack.

5.4.14 Block 14 - Is The Fault Light On?
Block 14 asks if the front panel FA ULT light comes on as a result of running diagnostic tests 2 through 5. If
yes, proceed to block 15. If not, go to block 16.

5-15

5.4.15

Block 15 - Push The Fault Button

Block 15 assumes that the front panei FAULT light cume~ un when subsystem diagnostic tests 2 through 5
are run. If so, push the FAULT button to display the front panel hexadecimal error code. Use Figure 5-1 to
convert the front panel light into an error code. Then look up this error code in Table 5-1 and replace the suggested FRU.

5.4.16 Block 16 - Is Status Byte 15 Available?
Status byte 15 is important because it will give you the drive error codes. If you find that status
byte 15 is available, go to block 17.

If the status message is not printed out, you will most likely obtain a subsystem error message from the
EVRLA or CZUDC diagnostics. If so, proceed to block 18 to see what to do with the subsystem error message.

5.4.17

Block 17 - Decode Status Byte 15

When present, byte 15 will contain a two hexadecimal digit error code. This is the same drive error code that
the drive-resident diagnostics report through the hand held terminal. For example, byte 15 of the status message contains a drive error code of 9C. The error can be decoded by referring to Table 5-2.
The error code 9C in Table 5-2 is described as an SDI transfer error from the DC703 chip. Table 5-2 also
indicates which FRU is the most likely failing module. In this case, it lists the SDI module as the first most
likely failure and the post amp/data separator module as the second most likely failure.
After finding the error code in Table 5-2, replace the most likely FRU first. Go to the second FRU only if the
first does not correct the problem.

If status byte 15 is unavailable, rely on help from the subsystem diagnostic error messages described in block
18 or in the ERROR LOG or SPEAR (Standard Package for Error Analysis and Reporting) information
described in blocks 19 and 22, respectively.

5.4.18 Block 18 - Look Up Subsystem Error Messages
This block assumes that when you run the EVRLA or CZUDC diagnostics, one of the five diagnostic tests
prints out a subsystem error message.

5.4.19 Block 19 - Examine Error Log
No attempt is made here to teach the field engineer how to run the error log program. It is assumed this information is available or can be accessed through an operator who runs error log reports. Training courses are
available for that purpose.

5.4.20 Block 20 - Are Status Words Available?
The status words contain important disk controller and drive status and error information. These status
words, however, are only available when the error log is reporting an SDI error format message. (Format
code equals 03.) Therefore, you must determine if the status words are available by checking which error format applies.
In the VMS error log report, this is easily determined by reading the MLSG$B line that gives the format code
directly. In a RSTS/E error log report, first decode word 4 of the MSCP packet. If the status words are available, go to block 21 of the flowchart to see how to decode this information.

5-16

5.4.21

Block 21 • Decode Status Words

Block 21 of the flowchart assumes that the error log report is decoded as an SDI error format type. (Format
code equals 03.) SDr error format reports contain useful information on the UDA and disk drive in the SDI
status message.
For VMS error log reports, the SDI status word information is found on the MSLG$ZSDI line. It is reported
as three lines of hexadecimal data.
For RSTS/E error log reports, the SDI status word information is given in words 22 through 27 of the MSCP
packet. This information is given in an octal word format.

5.4.22 Block 22 • Run SPEAR, If Available
Run the SPEAR (Standard Package for Error Analysis and Reporting) program if it is available on your operating system. SPEAR goes beyond the typical error log capabilties. It not only accumulates data, but has the
capability of analyzing and predicting which FRU is at fault. SPEAR is a library of functions that sorts, evaluates, and reports on events recorded in the local system event file.
SPEAR is currently used on TOPS-IO, TOPS-20, and VMS operating systems. Plans are underway to incorporate the RA60 and other RA drives under its diagnostic analysis though it is uncertain when this added tool
will become available.
A SPEAR Reference Card can be ordered from Printing and Circulation Services under part number EKSPEAR-RC-002. This reference card summarizes the SPEAR function codes, system event codes, and provides other useful information.

If SPEAR is unavailable, consult the operating system manager for permission to run the subsystem diagnostics. This will involve a temporary timeout in customer system use.

5.4.23 Block 23 . Did SPEAR Pick Out A Bad FRU?
If the SPEAR program did not pick out a failing FRU, consult with the operating system manager to see if the
suspect disk drive can be taken off-line to run the drive-resident diagnostics with the hand held terminal. It is
important to consult with the system manager before taking the drive off-line since the operating system may
depend on the disk pack for a system image or back-up file.
After approval is received, place the suspect disk off-line by releasing the two port switches on the front of
the drive. Then run the drive-resident diagnostics described in block 7.

If the SPEAR program suggests a faulty FRU, go to block 24.

5.4.24 Block 24 • Replace The FRU Suggested By SPEAR
Again, consult the system manager before placing the disk drive off-line. If the drive is already off-line, then
there is no danger of bringing down the customer's operating system. The disk drive is placed off-line by
releasing the two front panel port switches. Use the RA60 Service Manual to see how to replace the FRU.

5.4.25

Block 25 • Obtain System Manager Approval

It is strongly recommended to consult the system manager before you remove the disk drive off-line in case
the operating system depends on the disk drive in question for a system image or back-up file.
The customer must relinquish the system before you can run the host-resident subsystem diagnostics. Go to
block 10 to see how to run the subsystem level diagnostics.

5-17

5.5

THE STATUS MESSAGE

The last line of the sample error message printout shown below gives the status message. The status message is a
result of the controller issuing a get status command to the drive.

CZUDC SFT ERR 00008 ON UNIT 00 TST ooa UB 000 pc: 0210aa
DISK EXERCISER DM PC:532a UDA AT 172150 DRIVE 032 RUNTIME 0:00:37
TIMEOUT OF DRIVE DURING WRITE ATTEMPT
WRITE ATTEMPT RETRIES: 0
L/DBN NUMBER 5252
ACTUAL L/R/DBN )
TRK 1 GRP 0 CYL 8
ORIGIN OF LAST SEEK WAS CYL 5 GROUP 1
REAL TIME DRIVE STATE 8001
STATUS: SCOl 1100 0000 OAOO 0000 0813 1020

5.5.1

LAYOUT OF THE STATUS MESSAGE

The status message consists of 28 numbers arranged into seven groups of four hexadecimal digits. Each group of
four hexadecimal digits can be decoded into two status bytes as shown in Figure 5-6. Only bytes 2 through 15 are
printed in the status message error printout. Status bytes 2 through 8 give some general status information about
the drive and the controller. Status bytes 9 through 15 give drive specific information about the RA60 drive under
test.

STATUS:

9Clo1 111°0

BYTE:

15 1a 13 12 11 10

°°1°0 0:r: °T:

13 20
1°1
51a 3 2

CZ-0937

Figure 5-6 Separating the Status Message into Bytes
After separating the two hexadecimal digits in each status byte, use the bit map chart in Figure 5-7 to decode the
bit mnemonics (letter abbreviations). Since each hexadecimal digit is represented by four binary bits, you will
find a total of eight binary bits in each status byte of Figure 5-6.
Decode the bit mnemonics present in the drive status message and use Table 5-4 to look up the meaning of the
mnemonics.

5-18

MSB
BYTE

LSB

RESPONSE CODE

BYTE 2

UNIT

BYTE 3

SUBUNIT MASK

HI UNIT

BYTE 4

BYTE 5

BYTE 6

BYTE 7

BYTE

RETRY COUNT/FAILURE CODE

BYTE

PREVIOUS LOW PHYSICAL CYLINDER ADDRESS

BYTE 10

PREVIOUS HIGH PHYSICAL CYLINDER ADDRESS

BYTE 11

PREVIOUS HEAD ADDRESS

BYTE 12

CURRENT LOW PHYSICAL CYLINDER ADDRESS

BYTE 13

CURRENT HIGH PHYSICAL CYLINDER ADDRESS

BYTE 14

CURRENT HEAD ADDRESS

BYTE 15

DRIVE ERROR CODE
CZ-0938

Figure 5-7 Bit Map of the Drive Status Message Bytes

5-19

Table 5-4 Bit Description of Status Message Bytes
STATUS
BYTE

DESCRIPTION

Byte 1

Response Code Field - Byte 1 is the response code to a controller command. Byte 1 is not printed
out in the status message.

Byte 2

Unit Number - The unit number consists of two hexadecimal digits representing the unit number
of the selected disk drive returning the status (0-254). On RA drives, the unit address is set by the
front panel READY plug.

Byte 3

Subunit Mask - The subunit mask is a four-bit representation of the subunit that is returning the
status message. The right-most bit position represents subunit o. The left-most bit position
represents subunit 3. Only one bit can be set at a time. UDA50 subsystems can handle only drives
with up to two subunits (mutiple packs or software groups). Therefore, the valid numbers in this
status byte can only be a hexadecimal 1 or 2. For drives that contain no subunits (e.g. the RA80,
RA81, and RA60), the right-most bit position is always set indicating subunit o.

Byte 3

High Unit Number - Byte 3 contains the upper four bits to a 12-bit (three hexadecimal digits) unit
number. For example, if the drive unit number were 136, the hexadecimal 1 would be present in
byte 3.

Byte 4

OA - A logical 1 in this position indicates the drive is unavailable to the UDA50. A logical 0
indicates the drive is available to the UDA50.

Byte 4

RR - A logical 1 in this position indicates that the drive requires an internal readjustment. Some
drives do not use this bit.

Byte 4

DR - A logical 1 in this position indicates that there is a request for a diagnostic to be loaded in
the drive microprocessor memory. A logical 0 indicates that no diagnostic is being requested of the
host system.

Byte 4

SR - A logical 1 in this position indicates that the drive spindle is up to speed. A logical 0
indicates the drive spindle is not up to speed.

Byte 4

EL - A logical 1 in this bit position indicates that there is drive specific information available in
the extended status area of drive memory. This extended status area information is found in bytes 9
through 15 in the VAX/VMS error report SDI message. In the RSTS/E error report, the extended
status area information is found in words 24 through 27 of the MSCP packet message field. A
logical 0 indicates that no information is available in the extended status area.

Byte 4

PS - A logical 1 in this bit position indicates that the drive port select switch for this controller is
pushed in (selected). A logical 0 indicates that the port switch is out.

Byte 4

RU - A logical 1 in this position indicates that the RUN/STOP switch is pushed in (RUN). A
logical 0 indicates the switch is out (STOP).

Byte 5

W4-Wl - Logical Is in any of these four bit positions represent the write-protect status for the
sub-unit represented. (e.g., a 000 1 indicates that sub-unit 0 within the selected drive is
write-protected.) RSTS/E does not support sub-units.

Byte 5

DD - A logical 1 in this bit position indicates that the drive has been disabled by a controller error
routine or diagnostic. The FA ULT light is on when this bit is set. A logical 0 indicates that the drive
was enabled by a controller error routine or diagnostic .

Byte 5

FO -

A logical 1 in this position indicates that the drive can be formatted.

5-20

Table 5-4 Bit Description of Status Message Bytes (Cont.)
STATUS
BYTE

BIT DESCRIPTION

Byte 5

DB - A logical 1 in this position indicates that the diagnostic cylinders on the drive can be
accessed.

Byte 5

S7 - A logical 1 in this bit position indicates that the 576 byte sector format (18 bit words) is
selected. A logical zero indicates that the 512 byte sector format (16 bit words) is selected. RSTS/E
and VMS have 512 bytes per sector.

Byte 6

DE - A logical 1 in this position indicates that a drive error has occurred and the drive FAULT
light may be on.

Byte 6

RE - A logical 1 in this position indicates that an error occurred in the transmission of a command
between the drive and the UDA50. The error could be a checksum error or an incorrectly formatted
command string.

Byte 6

PE - A logical 1 in this position indicates that improper command codes or parameters were
issued to the drive.

Byte 6

DF -

A logical 1 in this postion indicates a failure in the initialization routine of the drive.

Byte 6

WE -

A logical 1 in this position indicates a write lock error has occurred.

Byte 7

S4-S1 - This is a four:-bit representation of the subunits have their attention-available messages
suppressed in the UDA50. The right-most bit position represents subunit o. The left-most bit
position represents subunit 3. RSTS/E does not support subunits.

If one of the (S4-S 1) bits is set, it indicates that the controller is not to interrupt the host CPU with
an attention available message when the specified subunit raises its available real-time drive status
line to the UDA50. The S4-S 1 bits reflect the results of a change controller flags command in
which attention-available messages are not desired for certain subunits.
Byte 7

CI-C4 - This is a four-bit drive status code indicating various states of drive operation. At the
present time, only three codes are valid. A code of 0000 = drive normal operation. A code of 1000
= the drive is off-line due to being under control of a diagnostic. A code of 1001 = the drive is
off-line due to another drive having the same unit identifier (e.g. serial number, drive type, ciass
etc.).

Byte 8

RETRY COUNT/FAILURE CODE - This 8-bit byte contains one of two types of information
depending upon the status of the DF bit (byte 6). The DF bit monitors the drive initialization
process. The DF bit remains a 0 if initialization is successful. Byte 8 contains the retry count from
the previous operation. For example, if a seek operation required fourteen retries to be successful,
byte 8 would contain the number 14.
When the DF bit is set, it indicates that the drive initialization failed and therefore byte 8 now
contains a specific drive error code. This error code can be looked up in the appropriate drive
service manual.

Byte 9
to Byte 15

Byte 9 through Byte 15 are self-explanatory, and are related to drive specific information about the
RA60 under test.

5-21

CHAPTER 6
INSTALLATION

6.1 INTRODUCfION
This chapter describes the procedures necessary for RA60 installations. It includes safety precautions, site
preparation and planning, joining disk cabinets, cabling, and checkout.
Warning
Hazardous voltages are present inside this equipment. Installation and servicing should be performed
by a qualified and trained service person. Bodily injury or equipment damage may result from incorrect
servicing.
6.2 SITE PREPARATION AND PLANNING
Some site preparation and planning is necessary before installing an RA60 disk subsystem. The paragraphs
that follow discuss some of the things to consider.
6.2.1 Cleanliness
Cleanliness is always an important consideration when working with disk drives. The close tolerances between the read/write heads and the media make disk drives very sensitive to dust and other particulates.
The RA60 is designed to operate in an office or light industrial environment. The air particulates should .
not exceed five million particles of 0.05 micron per cubic foot of air.
6.2.2 Floor Loading
The weight of one RA60 in a cabinet is 159.64 kg (352 lbs). The weight of each additional disk drive is
approximately 68.95 kg (152 lbs). This should not place any abnormal stress on a raised computer room
floor. However, the weight of existing equipment should be considered before installing additional drives.
6.2.3 Heat Dissipation
The heat dissipation of each RA60 is approximately 2730 Btu/hour. To calculate the total heat dissipation
of each drive cabinet, multiply the above Btu/hour by the number of drives it contains.
6.2.4 Temperature and Humidity
The operating temperature range for the RA60 is between 100 C (50 0 F) and 40 0 C (104 0 F). The relative
humidity range is between 10% and 90% with a wet bulb temperature of 28 0 C (82 0 F).
6.3 EQUIPMENT UNPACKING AND EXTERNAL INSPECTION
Before unpacking a carton, inspect it for external damage. Report any damage to the DIGITAL field service or sales office and the local carrier. If no external damage exists, the disk drive may be unpacked using
the following procedure.
1.

Remove the external packing material shown in Figure 6-1.

6-1

LAG SCREW AND NAILS
STAPLED TO RAMP

RAMP SUPPORT
BLOCK

SHIPPING
STRAPS

CZ-0564

Figure 6-1

Unpacking the Disk Subsystem

6·2

Remove the four shipping bolts that fasten the drive cabinet to the pallet. See insert in Figure
6-1.

Build the ramp to roll the disk cabinet off the pallet. Use the lag screw and nails in the plastic
bag stapled to the ramp. Figure 6-2 shows how the ramp is assembled.
Warning
At least two persons will be needed to perform the
next step of this procedure.

Remove the four wooden blocks from under the disk cabinet.

Carefully roll the drive cabinet down the ramp.

PALLET

NAILS

LAG SCREW

Figure 6-2 Ramp Construction
6.4 RA60 INSTALLATION CHECKLIST
The installation procedure for the RA60 requires the placement of leveler feet and SDI cables. The head
locking pin must be removed and the drive must be set up for the right voltage and frequency ranges. The
drive unit address plug must also be programmed and a shipping retainer bracket must be released. If
cabinets are to be joined, this should be done first. If only one cabinet is being installed, go to Paragraph
6.6.
Use the following installation checklist to perform the RA60 installation. The list indicates the Paragraph
number where each procedure is described.

6-3

•
•

Joining cabinets (6.5)

•
•

Installing the SDI cable (6.7)

Installing the leveler feet (6.6)

Setting the voltage and frequency (6.9)

•
•

Removing the locking pin (6.10)

•
•

Removing the retaining bracket screw (6.12)

•
•

Installing add-on drives (6.14)

Programming the unit address plug (6.11)

Plugging in the power cable (6.13)

Performing drive checkout procedures (6.15)

6.5 JOINING CABINETS
The H9642 AP/AR (l20/240 volt) cabinet will hold up to three disk drives. It comes equipped with two
side panels for standalone use. If more than three drives are required, a second drive cabinet may be joined
to the first. The H9642 BP/BR (l20/240 volt) expansion cabinet comes with a joiner panel and no side
panels. This expansion cabinet may be joined to the first cabinet by removing one of the side panels on the
first cabinet and placing it on the outer side of the expansion cabinet. Figure 6-3 shows the side panel and
joiner panel locations.
JOINER PANEL

CZ-0763

SIDE PANELS

Figure 6-3 Side Panels and Joiner Panels

6-4

Use the following procedure to join disk cabinets.
1.

Open the rear door on the cabinet by turning the hex lock counterclockwise. Refer to Figure 6-4.

Figure 6-4 Opening the Rear Door
2.

Remove the rear door by unscrewing the ground wire from the door and then pulling down on
the top door latch. The door should now be free to lift off of the bottom end panel lock. Refer to
Figure 6-5.

6-5

PULL DOWN ON DOOR LATCH

CZ-0761

Figure 6-5 Rear Door and Side Panel Lock Removal

Loosen the two hex screws that secure the end panel lock to the base of the disk cabinet. Then
lift the end panel lock off. Refer to Figure 6-5.

Remove the side panel by lifting it vertically to disengage it from the four key buttons on the
side of the cabinet frame. Unscrew the ground wire attached to the side panel. Refer to Figure
6-6.

6·6

TOP KEY BUnONS

REMOVE CENTER SCREW

CZ-0774

Figure 6-6 Side Panel and Bottom Key Button Removal
5.

Install the side panel just removed from the first cabinet on the open side of the expansion cabinet. Begin by removing the back end panel lock from the expansion cabinet. Next, attach the
ground wire just removed from the first cabinet to the exposed side frame of the expansion
cabinet. Attach the other end of the ground wire to the side panel being installed. Then lower the
side panel over the keyhole buttons on the cabinet. Secure the side panel by replacing the end
panel lock. Refer to Figure 6-6.

Disconnect the two lower key buttons from the open side of the first drive cabinet by removing
the screws in the center of the key buttons. Refer to Figure 6-6.

6·7

Join the two cabinets together as shown in Figure 6-7. Engage the top two key buttons on the
first drive cabinet into the keyhole slots on the expansion cabinet joiner panel. Adjust the cabinets until their fronts are flush.
TOP VIEWS:
JOINER PANEL

DRIVE
CABINET

EXPANSION
CABINET

KEY BUnONS

DRIVE
CABINET

EXPANSION
CABINET

DRIVE
CABINET

EXPANSION
CABINET

CZ-0744

Figure 6-7 Joining the Cabinets

6·8

Disconnect the bottom trim panels from the front of the cabinets by removing the two screws at
the base of each. Refer to Figure 6-8.

BOTTOM
TRIM PANEL

./"

!jf?/
CZ-0745

Figure 6-8 Bottom Trim Panel Removal

6-9

Remove the screws that hold the two retainer trim brackets at the point where the two cabinets
are joined. Refer to Figure 6-9.

RETAINER TRIM BRACKET

FRONT LEFT
END-PANEL LOCK

FRONT LOCKING BRACKET
CZ-0760

Figure 6-9 Installing the Front Locking Bracket
10.

Place the front locking bracket over the retainer trim brackets and bolt the two cabinets together with the existing hardware.

11.

Replace the two bottom trim panels previously removed from the front of the cabinets.

6·10

12.

Open the back doors of the cabinets and loosen the screws that hold the two back end panel locks
at the point where the two cabinets are joined. Slide the locking bracket over the end panel locks
and tighten the four screws. Refer to Figure 6-10.
=---

'"1" III/II 1111'1.
111111 111111 11111
111111 111111 11111

"11/ 1/111 11111
111,1/11/ 111111
1111' 'III'

1/1 'Ii

111111

111111,
111111

111111

/1/1'

111111
111111
11111

'11111

'1111 1

,1111 11111
::::::; 111111

1111111

11111 "III .",1
lilli'
IIIf

11111

BACK LOCKING BRACKET

CZ-0746

Figure 6-10 Installing the Back Locking Brackets
13.

Replace the back door and any end panel locks removed in this procedure.

6.6 INSTALLING LEVELER FEET
Use the following procedure to install the leveler feet.
1.

Remove the four red shipping brackets and leveler nuts shown in Figure 6-11.

6-11

.......
.AIlI~--

LEVELER NUT

CZ-0566

Figure 6-11
2.

Shipping Bracket Removal

Assemble the four leveler feet as shown in Figure 6-12. Screw the leveler foot into the leveler nut
far enough that the nut may be slid into place without raising the drive cabinet.

~LEVELER

NUT

FLAT WASHER

LOCK WASHER

HEX NUT

Figure 6-12 Leveler Feet Installation
6·12

Slide the leveler nut into the slots in the cabinet as shown in Figure 6-13. Wheel the disk cabinet
to its final location before making the final leveler feet adjustments.

Screw the leveler feet down until they make firm contact with the floor. Adjust the four leveler
feet until the drive cabinet is level.

---~

LEVELER
FOOT

CZ-0607

Figure 6-13 Leveler Feet Adjustments

6.7 INSTALLING SDI CABLES
Both the internal and external SDI cables are mounted in the I/O bulkhead. Internal SDI cables connect to
the top of the bulkhead and external SDI cables connect to the bottom.
6.7.1 Installing the External SDI Cables
The external SDI cables coming from the central processing unit (CPU) are connected to the bottom of the
I/O bulkhead. Refer to Figure 6-14. Use the following procedure to install the external SDI cables:
1.

Loosen the two screws holding the I/O bulkhead connector to the bracket.

Plug the external SDI cable from the disk controller into the Port A connector on the bottom of
the I/O bulkhead. Note the orientation key on the SDI cable.

Install the two screws that hold the SDI cable shield terminator in place. Refer to Figure 6-14.

Clamp the external SDI cable to the cable entry retainers below the I/O bulkhead with either a
hose clamp or tie wrap.

6·13

EXTERNAL
SDI CABLES

CZ·081S

Figure 6-14 External SDI Cable Installation
5.

If a second disk controller is used, mount its SDI cable into the Port B connector on the bottom
of the I/O bulkhead. Note the orientation key.

Repeat Steps 2, 3, and 4 for the Port B SDI cable.

Reconnect the I/O bulkhead connector to the bracket.

6·14

6.7.2 Internal SDI Cable Installation
The two internal SOl cables that exit from the back of the drive connect to the top of the I/O bulkhead.
Refer to Figure 6-15. Use the following procedure to install the internal SOl cables:
1.

Locate the Port A SOl cable where it exits the back of the disk drive. Plug the end of the Port A
connector on the top of the I/O bulkhead. Note the orientation key on the SOl cable.

Install the two screws that hold the SOl cable shield terminator in place. Refer to Figure 6-15.

Repeat Steps 1 and 2 for the Port B SOl cable.

INTERNAL
SOl CABLES

I/O BULKHEAD
ASSEMBLY BRACKET

CZ-0816

Figure 6-15 Internal SOl Cable Installation

6-15

6.8 RA60 SAFETY LABELS
There are three safety labels on the back of the RA60. Be sure to read these safety labels before installing
an RA60. Refer to Figure 6-16 for their location.

r-------- ---------.
CAUTION: EXTEND STABILIZER FOOT ..

FAN HOUSING

(l)qoop
(0)

• ••
CZ-0812

Figure 6-16 RA60 Safety Labels
6.8.1 Safety Label Information
Each of the safety labels located on the back of the RA60 is printed in four languages.
1.

Label # 1 gives voltage and frequency settings for the drive.

Label #2 is a CAUTION reminder to extend the stablizer foot before pulling the drive out to the
full service position.

Label #3 is a CAUTION reminder to use the correct voltage and frequency settings. Refer to
Paragraph 6.9.

6.9 SETTING THE VOLTAGE AND FREQUENCY
The RA60 contains a universal power supply that may be used for 120/240 volt ac and 50/60 Hz operations. Use the following procedure to set the voltage and frequency to the desired range.
1.

Remove the rear cover and shield from the disk drive. Refer to Figure 6-17.

6-16

Figure 6-17 Removing the Rear Covers

6-17

Locate the vo1tage switch and frequency p1ugs located on top of the transformer assembly. See
Figures 6-18A and 6-18B.

RED
FREQUENCY
PLUG

WHITE

FREQUENCY
PLUG

CZ-0814

Figure 6-18A 120V/60Hz Voltage/Frequency Configuration

6-18

WHITE

FREQUENCY
PLUG

RED
FREQUENCY
PLUG

CZ-0814

Figure 6-1SB 240V/ 50Hz Voltage/Frequency Configuration
3.

Place the voltage switch into the needed 120- or 240-volt position. The 120-volt position will
handle an ac voltage range of 90 to 12S volts. The 240-volt position will handle an ac voltage
range of ISO to 254 volts.

Select either 50- or 60-cyc1e drive operation by installing the red and white frequency plugs in
one of the configurations shown in Figure 6-1SA or Figure 6-1SB.

Leave the back cover and shield off the drive to remove the head locking pin described in the
next paragragh.

6-19

6.10 REMOVING THE HEAD LOCKING PIN
The head locking pin is used to lock the head assembly in place during shipment. It must be removed
before the read/write heads can move. Assuming that the back cover and shield have been removed to
perform the voltage settings above, pull the head locking pin out of its locking hole on the positioner assembly and store it in the storage hole. Refer to Figure 6-19. Replace the back cover and shield when this
operation is completed.
HEAD LOCK PIN SHOWN
IN SHIPPING AND LOCKING
HOLE

PIN STORAGE
HOLE

ENGINEERING TEST
PIN LOCKS HEADS
HALFWAY OUT

CZ-0821

Figure 6-19 Head Locking Pin Removal

6-20

6.11 PROGRAMMING THE UNIT ADDRESS PLUG
The READY switch cap on the operator control panel is also the drive unit address plug. A drive unit
number from 0 to 654 can be programmed into this plug. To set the drive unit number, remove the
READY switch cap from the control panel and cut off the tabs that add up to the required number. Figure
6-20 shows the binary value represented by each tab.

----B

READY INDICATOR LAMP
AND MICROSWITCH CONTACTS

--------

16
REAR PIN CONFIGURATION

CZ-0576

Figure 6-20 Drive Ready Switch and Unit Address Plug
If you wish to set a specific drive to a unit number of 7, for example, cut tabs 1, 2, and 4 off of the switch
cap.

After the drive unit number has been selected, place the gummed label with the corresponding number
onto the recessed area of the READY switch cap and replace the cap on the drive.

6-21

6.12 REMOVING THE RETAINING BRACKET SCREW
A retaining bracket will be found on the back of all disk drives shipped in a cabinet. This retaining bracket
serves to keep the drives from sliding out of the cabinets during shipment. Once at the customer site, the
screws securing the drive to this retaining bracket must be removed as follows.
1.

Open the back door of the disk cabinet by turning the hex lock clockwise.

Loosen the retaining bracket captive screws shown in Figure 6-21.
REAR VIEW OF DRIVE
o
o

o
o

o
LOOSEN CAPTIVE
SCREWS FROM
RETAINING
BRACKET

o
o
:>

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

o
o

o
o
o

o
o

o
.0

o
o
o

':)

o
o

o
")

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

CZ-0824

Figure 6-21

Removing the Retaining Bracket Screws

6-22

6.13 PLUGGING IN THE POWER CABLE
The power cables from each disk drive are already plugged into the power controller at the base of the drive
cabinet. Only the ac power cord from the power controller needs to be plugged into an external power
source. Figure 6-22 shows the power plugs and receptacle types that are used in this power controller.
Access to the power cord is gained through the back door of the disk cabinet. Do not switch on the circuit
breaker on the power controller until you reach the drive checkout procedure.

POWER CONTROLLER
AT BASE OF CABINET

\...

POWER CONTROLLER

~PLUG

RECEPTACLE

PLUG

SOURCE

HUBBEl@

120V
30A
1-PHASE

2611

2610
L5-30R
12-11194

G
NEMA L5-30P
DEC 12-11193

I
240V
20A
1-PHASE

HUBBEL
2321

~~,
y

G(gX/

I
2320
L6-20R
12-11191

NEMA L6-20P
DEC 12-11192

@}
e~

CZ-0823

Figure 6-22 Power Controller Plugs and Receptacles

6-23

6.14 INSTALLING ADD-ON DRIVES
In its basic configuration, the RA60 subsystem comes with only one disk drive in a cabinet. Use the following procedure to install a second or third drive in a cabinet.
Caution
Because of the weight of the disk drives, do not try
to complete the add-on installation without the help
of a lifting device.
6.14.1 Removing the Front FiDer Panel
The first add-on drive should be placed in the center bay of the cabinet and the second in the bottom bay.
Remove the filler panel at the proper location by unscrewing the four 10-32 hex nuts that hold it to the
cabinet frame. These nuts can be reached through the back of the cabinet. Refer to Figure 6-23.

HEX NUT
10-32

(4 PL)
FILLER
PANEL

/if
1\
1\
1\
\\

•

•
•

•

CZ-0577

Figure 6-23 Removing Cabinet Filler Panels

6-24

6.14.2 Installing the Slide Assembly
Each RA60 add-on must be mounted in the drive cabinet on a slide assembly. Use the following procedure
to install the slides on the drive cabinet.
1.

Find the left and right chassis slides. Slide brackets are already attached.

Set aside the following hardware:

•

Eight Phillips head sems screws-l0-32 x 1f2 inch

•

Four nut bars

Mount the chassis slides to the front vertical upright as shown in Figure 6-24. If this is a first
add-on drive (middle drive), use mounting holes 26 and 29, counting from the bottom. If this is a
second add-on drive (bottom drive), use mounting holes 8 and 11, counting from the bottom.
VIEWED FROM FRONT OF CABINET
SLIDE MOUNT
SPACER

NUT
BAR

CABINET FRONT
LEFT UPRIGHT

CHASSIS SLIDE
BRACKET
LOCK

w~~/

PHILUPS HEAD SCREWS

10-32 X 5/8"

NOTE
1. REPEAT FOR FRONT RIGHT UPRIGHT.

Figure 6-24 Mounting Chassis Slide to Front Upright

6-25

CZ-0822

Mount the chassis slides to the back vertical uprights as shown in Figure 6-25. Use the same
mounting holes as specified in step 3 above.
VIEWED FROM FRONT OF CABINET

PHILLIPS HEAD
SEM SCREWS
10-32 X 112"

CHASSIS
SLIDE

NOTE
1. REPEAT FOR RIGHT BACK VERTICAL UPRIGHT.

CZ-0749

Figure 6-25 Mounting Chassis Slide to Back Upright

6.14.3 Mounting the RA60 Drive on the Slides
Use the following procedure to mount the drive on its slides.
1.

Extend the stabilizer foot as shown in Figure 6-26.
Caution
Failure to pull out the stabilizer foot can cause the
drive cabinet to tip over when the disk drive is fully
extended to its service position.

Extend each chassis slide all the way forward until it locks (Figure 6-27.)
Warning
Because of the weight of the disk drive, a lifting device will be needed to place the drive on the chassis
slides.

With the help of a lifting device, place the drive on top of the chassis slides as shown in Figure
6-27. Push the drive toward the back of the slides until the mounting rails touch the stop.

Fasten the drive to the chassis slides using five 8-32 x 1/4 inch Phillips pan head screws as shown
in Figure 6-27.

6-26

CZ-0608

Figure 6-26 Extending Cabinet Stabilizer Foot

Figure 6-27 Mounting the Chassis Slides
6-27

6.14.4 Extending the Drive on the Slide
The slides on the RA60 have a restraint mechanism which prevents the drive from being fully extended
inadvertently. To slide the drive all the way forward use the following procedure.

Extend the stabilizer foot as show in Figure 6-26.

Extend the drive until the restraint mechanism engages. Refer to Figure 6-28.

DRIVE IN
OPERATOR
POSTION

•
-_.....

PUSH LOCK

STABILIZER FOOT

CZ-0813

Figure 6-28

Extending the Drive
6-28

Insert a flat-bladed screwdriver under the restraint lever lock and push the lock toward the back
of the slide. Refer to Figure 6-28.

Push down on the restraint lever and extend the drive to the service position. Refer to Figure
6-28.

After completing service on the drive, be sure to re-engage (lock) the slide restraint mechanism.
Caution
Make certain that the restraint locks are fully engaged so the drive cannot be pulled to the full service
position inadvertently.

6.14.5 Set Drive AC Voltage and Frequency
The RA60 Disk Drive contains a universal power supply that may be used for 120/240 volt ac and 50/60
Hz operations. The only requirement is that you preset the voltage and frequency to the desired range.
Refer to Paragraph 6.9 and to Figures 6-17, 6-18A and 6-18B to perform this procedure.
6.14.6 Remove the Head Locking Pin
The head locking pin is used to lock the head assembly in place during shipment. Refer to Paragraph 6.10
and Figure 6-19 to perform this procedure.
6.14.7 Program the Drive Unit Address Plug
The READY switch cap on the operator control panel is also the drive unit address plug. A drive unit
number from 0 to 254 can be programmed into this plug. To properly program the drive unit address plug,
refer to Paragraph 6.11 and to Figure 6-21.
6.15 RA60 CHECKOUT PROCEDURE
Use the following checkout procedure after installing each RA60.
6.15.1
1.

Applying Power
Verify that the ac circuit breaker on the power control unit is off. Also verify that the circuit
breaker on each disk drive is off.

If this is an add-on drive, plug the RA60 power cord into the ac power outlet on the power
control unit at the bottom of the cabinet.

Plug the ac power cord from the power control unit into an external ac receptacle.

Switch on the ac circuit breaker on the power control unit.

6.15.2 Drive Checkout Procedure
The following procedure is used to check out each RA60.
Caution
This checkout procedure should be used only by
trained maintenance personnel.
1.

Verify that the head locking pin has been removed (Paragraph 6.10).

Verify that the voltage and frequency has been properly set (Paragraph 6.9).

Switch on the ac circuit breaker on the RA60.

6-29

Open the front cover on the RA60 by pushing in the latch release on the front of the drive.

Load the disk pack on the RA60. Refer to Paragraph 3.4.1.

Press the RUN/STOP switch on the front of the RA60.

6.15.3 Internal Diagnostics
Run the six internal diagnostics to check-out the status, recalibrate, and seek capability of the RA60. Refer
to Chapter 3 of the RA60 Service Manual or the RA60 Maintenance Guide for instructions on running
these diagnostics.
6.15.4 Subsystem Diagnostics
Run the following diagnostics when the RA60 is connected to a PDP-II system.
CZUDCCO (UDA and disk drive diagnostic)
Run the following diagnostics when the RA60 is connected to a VAX system.
ZZ-EVLRA (UDA50 disk subsystem diagnostic)

6-30

EK-ORA60-SV-CNI

--------------------------------------------------------------TECHNICAL DOCUMENTATION
CHANGE NOTICE

RA60 Disk Drive Service Manual
Addendum
This information is a supplement to the RA60 Disk
Drive Service Manual. This addendum notifies the
DIGITAL Field Engineers of the changes to the RA60
Disk topology and RA60 Error Codes.

CHAPTER 4

Replace pages 4-16, 4-17, 4-18 and Figures 4-15, 4-16 and 4-17 in
the existing RA60 Disk Drive Service Manual ( EK-ORA60-SV-001,)
with the following paragraphs and figures.
4.9.6 RA60 Physical Disk Layout
The RA60 disk pack (RA60-P) contains five disk platters.
The
three middle platters are used for data storage, while the two
outer ones are used for protection.
The three data storage
platters provide a total of six read/write data surfaces, each
containing 1600 physical data tracks.
Each track contains 39
sectors on 18-bit data packs or 43 sectors on 16-bit data packs.
The last sector on each track in the host operating systems area
is always reserved for revector control information. The data
field within each sector contains 256 data words regardless of
whether the information is written in l6-bit or l8-bit words.
4.9.7 DIGITAL Standard Disk Format
The RA60 disk pack logical format meets the criteria set forth in
the DIGITAL Standard Disk Format (DSDF) specification, which is
DEC Standard 166.
This standard describes how a physical disk is
constructed
into
the
logical
format
for Standard Disk
Interconnect (SOl) devices.
It also describes the host view of
mass storage device formats. This specification redefines many
of the classical disk terms, such as sector, track, and cylinder,
as
a
function of their access characteristics.
It also
introduces the concept of groups as a fixed number of tracks.
The following terms will help you to understand the Digital
Standard Disk Format.
1.

Sector - A sector is the smallest unit by which data is
physically addressed.
It
is available for reading or
writing once per disk revolution.

Track - A track is a logical entity that represents sets
of sectors occupying contiguous physical disk locations
and relates sectors to each other as a function of their
access characteristics.

4-16

Group - The DSDF Specification defines a group as a
logical entity that contains a set of tracks. The
sectors
with
the
same
physical
address
are
simultaneously
available
for
reading and writing.
Groups also have the property to select any track within
the group during the inter-sector rotation time. This
definition of groups
is independent of the physical
construction of the device and relates tracks to each
other as a function of their access characteristics.
In
the case of the RA60, there is only one track per group.

Cylinder
A cylinder
is a logical
entity
that
represents a collection of groups. Cylinders have the
property of allowing access to individual groups on the
same cylinder
in less than the minimum seek time. The
selection of a new cylinder has the longest average
positioning time.
In the RA60, one logical cylinder
equals four groups.

Physical Block Number (PBN) - A PBN is a 28-bit number
identifying a physical sector's position within a set of
sectors on a subunit.

Logical Block Number (LBN) - An LBN is a
28-bit number
identifying a physical sector's position within a set of
sectors directly accessible to the host.
LBN's are used
for host data storage and revector control information.

An RBN is a 28-bit
Replacement Block Number (RBN) number
identifying a physical sector's replacement
position.

Bad Block - A bad block is a sector that contains a
defect which exceeds the error correction capability of
the subsystem.

Bad Block Replacement - Bad block replacement is the
substitution of a spare sector (replacement block) for a
bad sector.

10.

Bad Block Revectoring - The replacement block is located
as a result of attempting to access a bad sector.

11.

Primary Replacement Block - A primary replacement block
with the lowest track RBN is used to replace a bad block
on the same track.

4-17

12.

Secondary Replacement Block - A secondary replacement
block replaces a bad block when the primary replacement
block is in use. The secondary replacement block may be
located on another track as defined by the bad block
revectoring table.

13.

External Block Number (XBN) - An external block number
is a 28-bit number identifying a physical sector's
position within a set of sectors in the external format
area of the subunit.

14.

Diagnostic Block Number (DBN) - Diagnostic block number
is a 28-bit number identifying a physical sector's
position within the set of sectors in the diagnostic
area of the subunit.

4.9.8 RA60 Logical Disk Format
This section describes how the RA60 disks are organized into the
new Digital Standard Disk Format. This disk organization is at
times referred to as the RA60 disk topology.
Figure 4-15
provides an overview of the RA6~logical disk format. Note that
the X axis shows the physical sectors for both the 16 and 18-bit
data formats. Note, also, the last sector is always reserved for
replacement information. This is similar to the skip sector
concept used in the RM80 Disk Drive to replace bad blocks. The Y
axis gives the physical cylinder numbers defining the boundaries
of the maj or log ica.l areas on the disk. These physical cyl inders
are defined as six vertical tracks, one on each of the six disk
data sur faces.
Note that the 1600 physical cylinders on an RA60 disk surface are
divided into the following four logical areas.
a

Host applications area (cylinder 0 - 1587)

Replacement/caching tables (cylinder 1588 - 1591)

Format area (cylinder 1592 - 1595)

Diagnostic area (cylinder 1596 - 1599)

4-18

1<---18 16
BIT BIT
1
1

V 38

1591 1592

1595 1596

1599

-------------1-----------1---------1
1
DIAGNOSTIC
HOST
1REPLACEMENT 1 FORMAT

1
1

I 37

1587 1588

APPLICATION 1
AREA
1
(LBNs)
1
1

PHYSICAL
SECTORS

---------------------->1

PHYSICAL CYLINDERS

AND
CACHING
TABLES
(LBNs)

1 AREA
1
1 (XBNs)
1

AREA

(DBNs)

-------------1-----------1
REPLACEMENT AREA (RBNs) 1
-------------1-----------1---------1 VISIBLE

1<-- TO ----->1
1
1 HOST

1
1

I
1

IAPPLICATIONS

1<--- VISIBLE TO HOST --->1

I
I
I

OPERATING SYSTEM

1
1

1<----- VISIBLE TO THE CONTROLLER --------------->1

Disk format protected by (c) Digital Equipment Corporation 1983
Figure 4-15 RA60 Overview of the Logical Disk Format

4-18A

4.9.9 Host Applications Area
The host applications area is the space available to normal
customer host activities. Each sector in this area is assigned a
logical block number (LBN).
The only exception is the last
sector on each track, which is assigned a replacement block
number (RBN). If the controller encounters a bad block, (a block
header that cannot be read), it skips that block and stores the
information in the last sector on the track, the RBN.
Bad blocks are detected when a disk pack is manufactured.
These
blocks are always replaced when the disk packs are formatted.
Other blocks become bad during normal use and must be replaced
dynamically.
During dynamic bad block replacement, the host
accesses and updates the replacement and caching tables and
informs the disk controller.
This allows the controller to
reformat the disk to reflect the bad block replacement.
4.9.19 Replacement/Caching Tables
The replacement and caching area of the disk also contains LBNs
and RBNs. This area is used to store the revector addresses for
the RBNs in the host applications area. It contains a reference
table for the controller to locate revectored information.
The revectored information may be stored in the RBN at the end of
the track if it has not been used to replace a bad block. If it
has been used, then the bad blocks may be stored in RBNs on
adjacent tracks.
4.9.11 Format Area
The format area is only visible to the controller and has
addresses known as external block numbers (XBNs). The format
tables store manufacturing format control information and media
error lists.
This area is inaccessible to the host. It is
always written in 512 byte format and is used when formatting the
disk in either 512 or 576 bytes.

4-l8B

4.9.12 Diagnostic Area
The diagnostic area contains blocks used for controller-resident
diagnostics.
These blocks have addresses known as diagnostic
block numbers (DBNs). The DBNs are visible only to the disk
controller.
The diagnostic area occupies the last four cylinders in the pack.
They are used by the drive-resident diagnostic tests to verify
the drive's ability to read and write data. They are also used
in test four of the UDA50 subsystem diagnostics to exercise the
disk without endangering customer data.
4.9.13 RA60 Disk Topology
The RA60 disk topology defines how the physical cylinders,
tracks, and sectors of the disk pack are organized into logical
addressable units to be accessed in the most efficient manner.
These logical units are:
o

Groups

Logical cylinders

Logical block numbers

Replacement block numbers

4.9.14 RA60 Groups
In the RA60 Disk Drive, a group is defined as one
drives may have more tracks per group.

4-l8C

track.

Other

4.9.15 Logical Cylinders
In the RA60 Disk Drive, a logical cylinder
is defined as four
groups. The number four is chosen on the basis of most efficient
access times for the RA60 drive characteristics.
Several other
logical cylinder sizes were tested.
The final choice was
affected by the fact that it takes longer to do a head switch
than a one-track seek in the RA60.
A head switch requires a
level one SOl command from the disk controller.
The way that the logical cylinders are organized in the RA60 disk
pack is somewhat determined by how the RA60 disk drives will be
used. When first developed, it was thought the drives would be
used mostly as a backup disk for the RA80 and RA81.
For this
reason, the old topology used in the pre-production RA60 disk
drives aligned the logical cylinders sequentially along one disk
surface (from 0 to 396), and then dropped vertically to 397 on
the next disk surface and so on. The entire disk was arranged as
one long sequential file.
However, this disk topology prevented
the use of seek optimization by the SOl disk controllers, which
operates most efficiently with randomized data. When it became
obvious that the RA60 would also be used in system operations as
well as for data backup, a new RA60 disk topology became
imperative for greater data access speeds.
The new RA60 disk topology is shown in Figures 4-16
(16-bit
format), and 4-17 (18-bit format). Notice the logical cylinders,
shown inside parentheses, are arranged in vertical order from top
to bottom disk.
After the bottom disk is reached, the next
sequential logical cylinder starts at the top again.
This
arrangement allows for seek optimization by the disk controller
and can increase system throughput by 10 to 20% depending on the
systems application.

4-180

PHYSICAL CYLINDERS

o ---------------------11588 ---------11592 --11596-1599

--------------------------------------1--------------(0)
(2376)
(2382)
1 (2388)
(2394)
0-167
[0-3]

399168-399335
[9504-9507]

400176-400343 1 0-171
[9528-9531]
1

0-171

168-335
[4-7]

399336-399503
[9508-9511]

400344-400511
[9532-9535]

172-343

--------------------------------------1--------------(1)
(2377)
(2383)
(2389)
(2395)

H 1
Y

-------- --------

S--I

(2 )

C 2

336-503
[8-11]

(2378 )
399504-399671
[9512-9515]

(2384 )
400512-400679
[9536-9539]

(2379)
399672-399839
[9516-9519]

(2385 )
400680-400847
[9540-9543]

L--(3 )

S 3
U

504-671
[12-15]

(4 )

A 4

672-839
[16-19]

(2390 )
344-515

(2396 )
344-515

-------- -------(2391)
516-687

(2397 )
516-687

-------- --------

R---

E--S

172-343

(2380)
399840-400007
[9520-9523 ]

(5)
(2381)
840-1007 400008-400175
[20-23]
[9524-9527]

(2386)
400848-401015
[9544-9547]

(2392)
688-859

(2387)
1 (2393)
401016-401183 1860-1031
[9548-9551]
1

--------------------------------------1-------(LOG. CYL.)
1
(LOG
------------- LBN'S --------------------1 XBN'S
[RBN'S]
1
NOTE:

(X-XXXX)
X-XXXXXX
[X-XXXX]

(2398 )
688-859

CYL. )
DBN'S

= LOGICAL CYLINDER NUMBERS
= LOGICAL BLOCK NUMBERS (LBN'S)
= REPLACEMENT BLOCK NUMBERS (RBN'S)

LOGICAL CYLINDERS SEQUENCE VERTICALLY DOWNWARD
THROUGH THE DISK SURFACES. AFTER THE BOTTOM
SURFACE HAS BEEN REACHED, THE NEXT LOGICAL
CYLINDER STARTS ON THE TOP SURFACE.
FOR
EXAMPLE: LOGICAL CYLINDER (6) IS ON SURFACE ZERO.
Disk format protected by (c) Digital Equipment Corporation 1983
Figure 4-16 RA60 Disk Topology for 16-Bit Format

4-18E

PHYSICAL CYLINDERS

o ---------------------11588 ---------11592 --11596-1599

----- ------------------------ --------------- -------- -------0

(0 )
0-151
[0-3 ]

(2376)
361152-361303
[9504-9507]

(2382)
362064-362215
[9528-9531]

(2388)
0-155

(2 394)
0-155

------------------------ --------------- -------- -------P
H 1
Y

(1 )
152-303
[4-7 ]

(2377)
361304-361455
[9508-9511]

(2383)
362216-362367
[9532-9535]

(2389)
156-311

(2 395)
156-311

S--- ------------------------ --------------- -------- -------I
(2 )
(2 3 84 )
(2 390)
(2 3 96)
(2378)
C 2
362368-362519
312-467 312-467
304-455 361456-361607
A
[9536-9539]
[8-11]
[9512-9515]
L--- ------------------------ --------------- -------- -------(3)
(2379)
(2385)
(2391) 1 (2397) I
S 3
456-607 361608-361759
362672-362823 468-623 1468-623 1
U
[12-15]
[9516-9519]
[9540-9543]
1
1
R--- ------------------------ --------------- --------1--------1
F
(4)
(2380)
(2386)
(2392) 1 (2398) 1
A 4
608-759 361760-361911
362672-362823 624-779 1624-779 1
C
[16-19]
[9520-9523]
I [9544-9547]
I
t
E--- ------------------------1--------------- --------1--------1
S
(5)
(2381)
1 (2387)
(2393) 1 (2399) 1
5
760-911 361912-362063 1 362824-362975 780-935 1780-935 1
[20-23]
[9524-9527]
1 [9548-9551]
I
I
--------1--------1
(LOG. CYL.)
(LOG. CYL.)
I
------------- LBN'S -------------------- XBN'S
1 DBN'S
1
[RBN'S]
1
1

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

NOTE:

(X-XXXX)
X-XXXXXX
[X-XXXX]

= LOGICAL CYLINDER NUMBERS

= LOGICAL BLOCK NUMBERS (LBN'S)
= REPLACEMENT BLOCK NUMBERS (RBN'S)

LOGICAL CYLINDERS SEQUENCE VERTICALLY DOWNWARD
THROUGH THE DISK SURFACES. AFTER THE BOTTOM
SURFACE HAS BEEN REACHED, THE NEXT LOGICAL
FOR
CYLINDER STARTS ON THE TOP SURFACE.
EXAMPLE: LOGICAL CYLINDER (6) IS ON SURFACE
ZERO.
Disk format protected by (c) Digital Equipment Corporation 1983
Figure 4-17 RA60 Disk Topology for 18-Bit Format

4-18F

4.9.16 Logical Block Numbers
Logical block numbers (LBNs) are the smallest addressable units.
Each physical sector in the host applications and replacement
area of the disk is assigned an LBN.
These LBNs are arranged
sequentially over the four groups (tracks)
in each logical
cylinder. After the last LBN in logical cylinder zero is
reached, the next LBN begins in logical cylinder one. In Figures
4-16 and 4-17, the LBNs are given in the middle positions with no
parentheses or brackets. In 16-bit formatted packs, the LBNs run
from 0 to 401183. In 18- bit formatted packs, the LBNs runs from
o to 362975.
In 16-bit formatted packs, there are 168 LBNs per logical
cylinder.
This is the product or four tracks times 42 sectors
per track. In 18-bit formatted packs, there are only 152 LBNs
per logical cylinder. This is the product of four tracks times
38 sectors.
4.9.17 Replacement Block Numbers
The replacement block occupies the last sector on each track.
This replacement block is assigned a replacement block number
(RBN). Since there are four tracks in each logical cylinder,
there are also four RBNs per logical cylinder. Figures 4-16 and
4-17 show these RBN numbers in square brackets.
There are a
total of 9551 RBNs in an RA60 disk pack.

4-18G

4.9.18 Converting RA6~ LBNs To Head Numbers
It may be necessary sometimes to correlate an LBN number with a
read/write head number
to determine which head is bad.
This
conversion is done by a
two step process.
First, find
the
logical cylinder number where the LBN is located. Divide the LBN
number by the number of LBNs in a logical cylinder.
For l6-bit
formatted
packs, divide the LBN by 168.
For 18-bit formatted
packs, divide the LBN by 152.
EXAMPLE:

FIND LOGICAL CYLINDER FOR l6-BIT FORMATTED RA6~ PACKS:

LBN NO.

361470 / 168 = LOGICAL CYLINDER 2151.6071

EXAMPLE:

FIND LOGICAL CYLINDER FOR l8-BIT FORMATTED RA6~ PACKS:

LBN NO.

361470 / 152 = LOGICAL CYLINDER

2378.~92l

In the above divisions, only the whole number part of the answer
is important.
The whole number gives you the logical cylinder
address in which the LBN is located. The results show that in
l6-bit formatted packs, an LBN of 361470 is located in logical
cylinder 2151.
For l8-bit formatted
packs, it is located
in
logical cylinder 2378.
The second step of the process involves converting the logical
cylinder address to a disk surface. Divide the logical cylinder
adress by the number of read/write heads. Since the RA6~ has six
read/write heads, you divide by six.
In this division, the
decimal part of the answer is more important.
EXAMPLE:

FIND HEAD SURFACE FOR l6-BIT FORMATTED RA60 PACKS:

LOGICAL CYLINDER 2151 / 6 = 358.5
EXAMPLE:

FIND HEAD SURFACE FOR l8-BIT FORMATTED RA6~ PACKS:

LOGICAL CYLINDER 2378 / 6 = 396.3333

4-l8H

In the above divisions, the decimal part of the answer is the
disk surface (or head) the logical cylinder is on. Ignore the
whole number and convert the decimal part of the answer to a
fractional part of a sixth and obtain the disk surface number.
For example, .5 = 1/2 = 3/6, or head surface 3. For example the
decimal .3333 yields 1/3 = 2/6 or a head surface of 2.
4.19 RA60 SERVO SYSTEM
The RA60 Disk Drive does not have a dedicated servo module.
Instead, the servo circuits are distributed over most of the
electronic modules. The servo system has two modes of operation.
These are the linear (or track centering) mode and the seek (or
track crossing) mode. The major functional blocks in the control
system are shown in Figure 4-18.

4-181

CHAPTER 5

Replace Tables 5-1 and 5-2 in the existing RA60 Disk Drive
Service Manual (EK-ORA60-SV-00l), with the following tables.
Table 5-1
Front
Panel
Codes

RA60 Front Panel Fault Codes

Desc r ipt ion

Most Li kely
FRU Failure

Microcode error (not
sent to front panel)

No ne

Heads home switch
faul t

Push heads home
Check P803
Heads home
swi tch
assembly

2.
3.

Front panel fault

1.
2.

3.
03

Long spin-up time
faul t

1.
2.
3.
4•

Bad servo samples fault

1.
2.
3.
4.

5-3

Front panel
modul e
Dr ive log ic
module
Front panel
ribbon cable
Check spindle
motor
connections
Heat sink
module
Spindle motor
Dr i vel og i c
modul e
Pack
Post amp/
data separ ato r
module
R/W preamplifier
module
Heads

TABLE 5-1

RA6~

Front panel Fault Codes (cont)

Front
Panel
Codes

Desc r ipt ion

Most Li kely
FRU Failure

Bad velocity fault

1.
2.

3.
4•

5.
07

Linear mode fault

1.
2.

3•

Retry on seek fault

1.
2.

3.
4•

Lost servo samples fault

Heads home switch
wo uld no t open

Pack
Po st amp
/data separator
modul e
Dr i vel og i c
module
Pack
Po st amp/
data separ ato r
modul e
R/W preamplifier
module
Dr i vel og i c
module

1.
2.
3.

Pack
Heads
Po st amp/
data separ ato r
module

Shipping pin
not removed
Check P8~3
Heads home
switch assembly
He at sin k mod ul e

2.
3.
4.

5-4

Pack
Post amp/
data separato r
module
R/W preamplifier
module
Dr i vel og i c
module
Positioner
assembly

TABLE 5-1

RA6~

Front panel Faul t Codes ( cont)

Front
Panel
Codes

Oesc r ipt ion

Most Likely
FRU Failure

Ma ster processor faul t

1.
2.
3.

4.
11

sor Faul ts

3.
4.

sor Modul e
Dr ive logic
module
sor cable
Backplane module

sor module

Post amp/
data separ ato r
modul e
R/W preamplifier
module
Backplane module

1.
2.

rnvalid sor level 1
command

3.
4.
3F

Master processor
faul t

1.
2.
"\

5-5

Orive logic
modul e
sor module
post amp/
data separato r
module
Backplane module

Drive logic
module
sor module
Post amp/
data separato r
module
Backplane module

5.2.2 RA60 Error Messages
Refer to Table 5-2 for the RA60 error messages.
They are
displayed on the hand held terminal when internal diagnostics are
run or are printed out on the system console when running host
diagnostics.
Table 5-2 shows the error code, description of the
error, and the most likely failing FRU.

5-6

Table 5-2 RA69 Error Messages
ERROR
CODE

DISCRIPTION

MOST LIKELY
FRU FAILURE

Heads not home when
run command is issued
Heads no t home
during spin-up
Heads home switch will
not open during unload

1.
2.
3.

Push heads home
Check P8~3
Heads home switch
assembly

Spin-up L high
dur ing spin-up
Lid lock open during
spin-up
Cover open during
spin-up
Cover or lid lock
open dur ing head
load
Lid unlocked when
run command is
issued

1.
2.
3.

Front panel module
Drive logic module
Front panel ribbon
cable

Spin-up too lengthy
Motor sample will not change
during spin-up
Too long to acquire spindle
speed control on head load

1.
2.
3.
4.

Check spindle motor
Heat sink module
Spindle motor
Drive logic module

18
19
24

5-7

Table 5-2 RA60 Error Messages(cont.)
ERROR
CODE

DISCRIPTION

MOST LIKELY
FRU FAILURE

1.
2.

More than 32 sectors to
settle on track
More than 32 sectors to
settle on track retry
fa il ure
Too many bad servo samples
dur ing RTZ
Too long to aquire good
samples on head load
Bad servo samples during RTZ
on head load
Bad samples during linear
mode
Off speed when in linear mode

Off track in linear state

1.
2.

27
28
29

2C
2D

3.
4.

4.
5.

Pack
Post amp/data
separator module
R/W preamplifier
module
Drive logic module
Positioner assembly

No pac k install ed

Spin-up too brief

5-8

Pack
Post amp/data
separator module
R/W preamplifier
Heads

Table 5-2 RA6~ Error Messages (cont.)
ERROR
CODE

DISCRIPTION

MOST LIKELY
FRU FAILURE

Retry on seek due to bad
servo samples
Retry on seek due to bad
servo sampl es failed
Retry on see k due to bad
guard band flags
Retry on seek due to bad
guard band fl ag s, retry
failed
Retry on seek due to wrong
polarity entering linear mode
Re tr yon see k due to wrong
polarity entering seek mode,
retry failed

1.
2.

Retry on seek due to wrong
grey code
Retry on seek failing due
to wrong grey code
Lost servo samples

Too long for heads home
switch to open on head load

41
42
43
44
45

46
47

48
50

3.
4.

5-8A

Pack
Post amp/data
separato r modul e
R/W preamplifier
module
Drive logic module

Pack
Heads
Post amp/data
separato r modul e

Shipping pin not
removed
Check P803

Heads home switch

assembly
Heatsink module

Table 5-2 RA60 Error Messages (cant.)
ERROR
CODE

DISCRIPTION

MOST LIKELY
FRU FAILURE

Command cannot be executed
with the drive in its current
state
Nonexistent head or cylinder
requested with seek
Opcode is not one of six
val id opcodes
Cover open when run command
is issued
Program error during
head load

1.
2.

Drive logic module
Cover open

Initializes and tests control
panel
Checks processor register
Tests RAM 40
Tests ROM 40
Tests ROM 11
Tests ROM 42
Verify ROM version numbers
Tests the SOl clear interface
bit

1.
2.
3.

Drive logic module
SOl modul e
Post amp/data
separator module
Backplane module

Tests the SOl control/status
register
Tests front panel and serial
number ROM
Initializes the UART
Tests the error registers
Tests the 8155 timer
Tests the slave control port
Slave Diagnostics
Command available or slave
done already set when issuing
a new slave command
Slave command receiver
timeout on opcode

1.
2.
3.

62
63
64

81
82
83
84

85
86

89
8A
8B
8C
80
8E

8F
90

5-8B

Drive logic module
SOl modul e
Post amp/data
separator module
Backplane module

Table 5-2 RA6~ Error Messages (cont.)
ERROR
COOE

OISCRIPTION

MOST LIKELY
FRU FAILURE

92
93

Slave attention timeout
Slave done timeout to slave
stop
Slave done timeout to status
(1 ms)
Slave done timeout
Slave attention timeout

94
95

97
98
99
9A
9B

9C
90
9E

9F
A~

A3
A4

AS
A6
A7

3.
4.

Solenoid release timeout
Watchdog timer detects
master insane
Watchdog timer detects
sl ave insane
Run switch or cover
invalid at spin-up
Spindle not ready during
recalibrate command

1.
2.

SDr transfer error from OC7~3
Write or format when write
protected
Format when format disabled

Transfer command during drive
error
Sector read/write overrun
error
Transfer command when
read/write error

SDr command checksum error
sor frame error
SDr command parity error
sor command out of range
SDr command length error
SDr error status byte is
non-zero

3.
4.

5-8C

2.
3.

Drive logic module
sor module
Post amp/data
separator module
Backplane module

Drive logic module
Post amp/data
separator module
SDr module
Backplane module

sor modul e
Post amp/data
separator module
R/W preamplifier
module
Backplane module

SDr module
Drive logic module
Post amp/data
separator module
Backplane module

Table 5-2 RA6~ Error Messages (cant.)
ERROR
CODE

DISCRIPTION

MOST LIKELY
FRU FAILURE

Slave done timeout to seek
command
Slave done timeout to RTZ
command
Slave respone error to RTZ
command
Slave done timeout during
fi r st pass
Command receiver timeout
during diagnostic stop or
ASCII port command time =
TODGN 2
Slave done timeout during
diagnostic stop or ASCII port
time = IMS

1.
2.

Orive off-line
Command byte 4 & 5 are
no t zero
Invalid group number
Invalid head select number
Invalid cylinder range
Spindle not ready

1.
2.

AA
AB
AC

AE
AF
BQJ

Bl
B2

B3
B4

B5
B6
B7

BS
CQJ

Cl
C2
C3
C4
C5
C6
C7

3.
4.

Controller timeout = QJ
1.
Spindle not ready
2.
Illegal memory region
3.
DO bit set
Tried to clear a hard fault
4.
Slave done timeout (1 MS) to
get status
Error response to GET STATUS
Invalid group number
Microcode fault errors
No watchdog interrupt
Slaved 0 net i meo u t ( ASC I I Po r t)
Slave command received error
(ASCII port)
Invalid 'TT' bit

5-SD

Dr ive log ic modul e
SOl modul e
Post amp/data
separator module
Backplane module

Drive logic module
Post amp/data
separato r modul e
SOl modul e
Backplane module

Drive logic module
SOl module
Po st amp/data
separator module
Backplane module

Table 5-2 RA6~ Error Messages (cont.)
ERROR
CODE

DISCRIPTION

MOST LIKELY
FRU FAILURE

Read/Write error - multi-head
selec t

2.
3.

BA
BB
BC
BD
BE
BF

Non-zero level
Wrong subunit error
Diagnostic command, memory
region high not zero
Diagnostic command, invalid
parameters
Write enable a write
protect drive
Setting S7 = 1

1.
2.

3.
4.

R/W preamplier
module
Post amp/data
separator module
SDr module
Drive logic module
SDr module
Post amp/data
separator module
Backplane module

5.3 POWER REGULATOR MODULE LEDS
The regulator module has seven LEDs on the top to help in fault
isolation. Five of the LEDs are green and the remaining two LEDs
are red. The green LEDs indicate normal operation and the red
LEDs indicate an abnormal condition. The location of these LEDs
is shown in Figure 5-2. Use the chart in Table 5-3 to help
isolate power supply problems.

5-8E

•

'A'f"-~-+-----':::::::"'±11 V

15 AMP

t20V
6 AMP

TRANSFORMER
ASSEMBLY

CZ-0850

Figure 4-9

Location of Circuit Breakers (Old Style Transformer)

4·10

REGULATOR MODULE

rh/

ON BOARD
POWER
SUPPLY

20V
AC

XFMRlJ

VOLTAGE
REFERENCE

----+

AC
FAIL

r---

n~TI=(~T

!
DC VOLTAGE
OVER/UNDER
DETECT

+5.2V
-15V
+15V
+5V
~r

I\1.-U"-

l
POWER ON
AND RESET
TIMERS

J PREAMP I

WRITE INHIBIT

LATOR
CONTROL
CKTS

FAULT
CONTROL
LOGIC

....

...

HEAT
SINK
MODULE

f---+
RETRACT HEADS
~

DC SENSE AND OVER VOLTAGE SCRS

~
CZ-0851

Figure 4-11

Regulator Module Block Diagram

4.8.5 Heat Sink Module
The heat sink module contains all the series pass transistors used for voltage regulation and the power
transistors used for the motor control logic. All these power transistors share a common heat sink. The heat
sink module supplies the backplane with the following dc regulated voltages: +5 volts, -5.2 volts and ±15
volts.
The heat sink module also supplies the motor control module with ±15 volts and ±27.5 volts. Power to the
dc fans is also supplied from the heat sink module. Refer to Figure 4-12 for a block diagram of the heat
sink module.

4-12

MOTOR COf\lTROL

DRIVE
LOGIC
MODULE

SPINDLE
MOTOR
CONTROL
CIRCUIT

SPINDLE
MOTOR

HEAT
SINK
MODULE
POSITIONER
MOTOR
CONTROL
CIRCUIT

POSITIONER
MOTOR

CZ-0848

Figure 4-6 Motor Control Module Block Diagram

4.8

POWER SUPPLY ASSEMBLIES

The RA60 PQwer supply includes five assemblies. These are the switchplate assembly, transformer assembly, cap/rectifier assembly, regulator module, and heat sink module. Figure 4-7 shows a block diagram of
the power supply.

CAP/
RECTIFIER
ASSEMBLY

+5V
-5.2V
+15V

BACKPLANE
ASSEMBLY

-15V
SWITCHPLATE
ASSEMBLY

HEAT
SINK
MODULE

XFMR

REGULATOR
MODULE

+27.5V] POSITIONER
-27.5V
MOTOR

+27.5V] SPINDLE
-27.5V
MOTOR

CZ-0849

Figure 4-7

Power Supply Block Diagram

4-8

4.7.4 Preamp Module
The preamp module contains the head select logic, the write drivers, and low noise read preamplifiers.
Refer to Figure 4-5 for a block diagram of the preamp module.

PREAMPLIFIER

WRT DATA

WRITE
DRIVER

,
READ DATA

HEAD
SELECT

PREAMP

HEAD SELECT

R!W
HEADS

2::r

DISK

CZ-0869

Figure 4-5 Preamplifier Module Block Diagram

4-7

4.8.1 Switchplate Assembly
The switchplate assembly contains the main drive circuit breaker and an ac line filter. The circuit breaker
has three poles rated at 12 amps, 6 amps and 6 amps respectively. Switch capacity is 12 amps at the 120
volt setting and 6 amps at the 240 volt setting.
4.8.2 Transformer Assembly
A ferro-resonant transformer is used in the RA60 to obtain good line voltage regulation. The raw output
voltages from the transformer are fed to the cap/rectifier assembly for rectification. The transformer puts
out raw ac voltages of 11 volts, 27.5 volts, and 20 volts.

The ac voltage range switch and frequency range plugs mounted on top of the transformer permit easy
voltage and frequency range selections. The location of the ac voltage range switch and the frequency range
plugs is shown in Figure 4-8.

FREQUENCY
PLUG

CZ-0872

Figure 4-8

Voltage Range Switch and Frequency Plugs

In addition to the six thermal circuit breakers located on the transformer, two 5 amp fuses are located on
the regulator module to fuse the on-board raw ac 20 volt lines.

4·9

:: 20V
6 AMP

:: 11V
15 AMP

THERMAL
4-CIRCUIT
BREAKERS

FREQUENCY
PLUG

Figure 4-10 Location of Circuit Breakers (New Style Transformer)

4.8.3 Cap/rectifier Assembly
The cap/rectifier assembly rectifies the raw ac received from the transformer assembly. It puts out the
following dc voltages: ±11 volts, ±20 volts, and ±27.5 volts.
4.8.4 Regulator Module
The regulator module contains the low level circuitry to regulate the rectified dc voltages on the heat sink
module. The regulator module also senses the dc voltage levels and controls the series regulating transistors
located on the heat sink module.
The regulator module also contains all the ac and dc shutdown logic and the power resumption logic. See
paragraph 4.13 for a description of the causes of power shutdown and the sequence of events that occur
prior to shutdown.
Figure 4-11 shows a block diagram of the functions provided by the regulator module. It has an on-board
power supply to provide dc voltages for its own logic circuits and reference voltages. Also located here is
the fault circuitry to detect ac failures, dc overvoltage, and dc under voltage conditions. There are also some
timers to control power shutdown and resumption. Monitoring all these failure conditions is the fault controllogic circuit. The regulator module also provides accurate voltage references for the regulator control
circuits.

4-11

RA60 SERVICE MANUAL
EK-ORA60-SV-001

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