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Document:	RL01/RL02 Pocket Service Guide
Order Number:	EK-RL012-PG
Revision:	003
Pages:	100
Original Filename:

OCR Text

POCKET SERVICE GUIDE

EK-RLO12-PG-003

RLO1/RLO2

POCKET SERVICE GUIDE

digital equipment corporation
colorado springs, colorado

I1st Edition, September 1979
(Revision) June 1980
(2nd Revision) October 1980

Copyright © 1979, 1980 by Digital Equipment Corporation
The material in this manual is for informational
purposes and is subject to change without notice.
Digital Equipment Corporation assumes no re-

sponsibility for any errors which may appear in

this manual.
Printed in U.S.A.

The following are trademarks of Digital Equipment
Corporation, Maynard, Massachusetts:

DEC

DECUS

DECnet

DECsystem-10
DIBOL
IAS
OMNIBUS

DECSYSTEM-20
Digital Logo
LSI-11
PDP

DECwriter
EduSystem
MASSBUS
PDT

Q-BUS
UNIBUS

RSTS
VAX

RSX
VMS

CONTENTS

INTRODUCTION .................... 1

1.1

Description ...........coiuiiiiin
... 1

1.2

Option Descriptions . ....................... 3

1.3

Sector Format . ................
... ... ...... 4

1.4

Bad Sector File. ............
... ... ... ..... 4

FIELD REPLACEABLE UNITS ....... 7

FRONT PANEL .................... 21

DRIVE CONDITIONS ............... 23

5.1

RL11/RLV11 Register Summary ............ 25

5.2

RLS8-A Register Summary .................. 32

BOOTSTRAPS .........
... ... ..... 41

6.1

RL11/RLV11 Bootstrap . ................... 41

6.2

RL8-A Bootstrap .............c.
... 41

TOGGLE-IN PROGRAMS ........... 43

7.1

Head Selection Program for RL11/RLVI1I ..... 43

7.2

Head Selection Program for RL8-A .......... 44

7.3

Get Status (With or Without Reset)

7.4

Get Status on an RL8-A Subsystem ........... 45

on an RL11/RLV11 Subsystem .............. 44
7.5

7.6

Oscillating Seek for RL11/RLVI1 ........... 46
Oscillating Seek for RL8-A................. 47

CONTENTS

8§

DIAGNOSTICS ..................... 49

8.2

RL11 Diagnostics . ............coovinnnn. 49
RLV11 Diagnostics ....................... 50

8.3

... oot 50
RL8-A Diagnostics. ...........

8.4

Diagnostic SUpervisor . .................... 50

8.1

8.4.2

Hardcore Questions . .................. 50
Console Controls . .................... 53

8.4.3

Hardware Questions . .. ................ 53

8.4.4

Software Question

8.4.1

................... 53

CHECKS, ADJUSTMENTS AND

.. ... .. ... 55
ALIGNMENTS . ........
Introduction
.......... .o
Voltage Checks .............cviiinn
Sector Transducer Output Check
.........
Sector Pulse Timing Check ...............
Positioner Radial Alignment .............
Head Alignment ................
. covoun.
Read Signal Amplitude Check ............
Spindle Runout Check ..................
Position Signal Gain Check ..............
Tachometer AC Noise Pick-Up Check .....
Velocity Profile Check ...................
Servo Drive Motor Current Check ........
... ...,
Access Time Check ............

55
56
57
58
58

63
68
69
71
72
74
75
76

SERVICETIPS ..................... 81

10.2

Loss of +5V Symptom .................... 31
Lossof +5V Causes ...................... 81

10.3

Heads Retract Immediately After Loading . .. .. 81

10.1

10.4

LOAD, READY, and FAULT Indicators

AlLON . ... 81
10.5

RL11T/OCabling .........cccvvuvnnn.. .. 81

10.6

Early RL11/RLV11 Vector Assignment . .. .... 81

10.7

10.8

Role of Checks, Adjustments and

Alignments in Troubleshooting ............

Intermittent Read Check Errors ...........

CONTENTS

FIGURES

1-1

...
....
...
Sector Format .........

1-2

...
Bad Sector File. .........
Interconnection of FRUs . ...................

2-1

2-2
2-3

Signal and Function Diagram of Power
Panel, AC Servo, Brush Drive Assembly . .... 10
Signal and Function Diagram of DC
11
..
...
Servo, Positioner ..........

2-4

Signal and Function Diagram of R/'W

2-5

Module, R/W Heads ...................... 12
Signal and Function Diagram of Front Panel . .. 13
Signal and Function Diagram of Drive

2-6

...,
... ... .....
LogicModule ...........

2-7

Physical Location of FRUs .................

2-8

Rear View........ ...,

2-9

Drive Logic Module Layout ................

2-10

R/W Module Layout — Top View ...........
Power Panel Layout — Front View ..........

2-11
2-12

DC Servo Module Layout — Bottom View .

2-13

AC Servo Module Layout — Front View ...

2-14

Front Panel Layout — Rear View .........

9-1

Sector Transducer Output ..................

9-2

Sector Pulse Timing

9-3

Positioner and Read/ Write Module
Box Assembly

.....................

...........
.. ... ... ...,

9-4

Servo Bursts and Sector Pulse

9-5

Positioner Assembly

............

9-6

Adjusting the Head Cables

9-7

Position Signal

9-8

Position Signal Gain Check Waveform

.....................
...............

.............
...
...

9-9

Summing Amplifier Qutput

9-10

Tachometer Output Velocity Signal

..............

9-11

Positioner Motor Current Check

9-12

Access Time Check (One Track Seek)

9-13

Access Time Check (85 or 170 Track Seek)

9-14

Access Time Check (255 or 511 Track Seek)

.......

..........

.....
.

CONTENTS

TABLES

1-1

Voltage Ranges

2-1

FRU Part Numbers and Interchangeability . . . . .. 7

........................... 2

2-2

Cables ....... .. 8

2-3

Test Points — Drive Logic Module

2-4

Test Points — Drive Logic Module -

54-12175 (Version I) ..........
... ... .... 16

54-13531 (Version 2) .. ..
2-5

oo i ve i

i e

e 16

Test Points — Drive Logic Module

54-14025 (Version 3) .. ..o ov i i ii it 16
4-1

Drive Conditions ............c..ouvninenn.. 23

5-1

Controller Addressable Registers ............ 25

5-2

RL8-A Instruction Set ..................... 32

8-1

RL11/RLO1 DiagnosticS..........couuveun... 49

8-2

RL11/RLO2 DiagnosticsS..............c.c..... 49

8-3

RLS8-A/RLO1 Diagnostics .................. 50

8-4

~RL8-A/RLO2 DiagnosticS .................. 50

9-1

Service Jumpers for Drive Logic Module. ..
.. 55

9-2

Methods for Selecting Heads ............... 56

CHAPTER 1
INTRODUCTION

CHAPTER 2
FIELD REPLACEABLE UNITS

CHAPTER 3
FRONT PANEL

CHAPTER 4
DRIVE CONDITIONS

CHAPTER 5
REGISTER SUMMARY

CHAPTER 6
BOOTSTRAPS

CHAPTER 7
PROGRAMMING EXAMPLES
CHAPTER 8
DIAGNOSTICS

CHAPTER 9
CHECKS, ADJUSTMENTS AND
ALIGNMENTS
CHAPTER 10
SERVICE TIPS
Vil

RLO1/RL0O2 Disk Drive

The following RLO1/RL02 documents are in the microfiche
library.

Name
RLO1/RL0O2 Disk Drive
Technical Manual

Number

EP-RLO12-TM

RL11 Controller

Technical Description Manual

EP-ORL11-TD

RLV11 Controller

Technical Manual

EP-RLV11-TD

RL8A Omnibus Controller

Technical Manual

EP-ORLBA-TM

RLO1 Disk Drive

IMustrated Parts Breakdown

EP-00016-1P

RLO2 Disk Drive

Illustrated Parts Breakdown
RLO1/RLO2
Preventive Maintenance Procedures

EP-00016-IP
EP-00008-PM

CHAPTER 1
INTRODUCTION

1.1

DESCRIPTION

An RLO1/RL02 Disk Subsystem consists of one to four RLO1

or RLO2 Disk Drives, daisy-chained via an I/O drive bus
cable to one of three controllers. The controller may be an

RL11, RLV11 or an RL8-A, depending upon the processor.
The RLO2 (using an RLO2K-DC Cartridge) is the double
density version of the RLO1 (which uses an RLO1K-DC

Cartridge). Below is a list of subsystem characteristics.
® Single platter, top-loading disk cartridge similar to the
5440 type (physically but not functionally)
® The RLOIK-DC and RLO2K-DC cartridges are not func-

tionally interchangeable but are physically interchangeable.

@ RLO1K-DC=5.2 megabytes (formatted), RLO2KDC=10.4 megabytes

® RLOIK-DC=256 cylinders, RLO2K-DC=512 cylinders

® RLO1K-DC=125 tracks/inch, RLO2K-DC=250 tracks/
inch

‘

® Both platter surfaces are used for data (upper=0, lower=1)

® 40 sectors per track — hub notched for sector marks, no
index notch

® 256 eight bit bytes per sector (128 16-bit words or 170
12-bit words)

® Platter rotates at 2400 r/min — 25 ms/rev
® 3725 bits/in — 147 bits/mm max bit density
® 244 ns cell time — 4.1 megabits/sec
® MFM (Miller coding) recording technique

® Peak transfer rate=3.9 ws/16-bit word, 1.9 ws/8-bit byte,
2.9 ws/12-bit word
® Average transfer rate=4.9 ws/16-bit word, 2.4 ws/8-bit
byte, 3.7 ws/12-bit word
® Positioner control=track-following servo information imbedded in data track during sector pulse time (servo infor-

mation is read with data R/W head)
® Positioner type=D.C. servo motor with capstan/cable
drive and tachometer feedback
® Factory-formatted servo and header information cannot be
reformatted in the field

INTRODUCTION

e Seek to next cylinder = 17 ms (max)

e Seek to next surface (switch heads) = 15 ms (max)
® Above two operations combined = 17 ms (max)
® Maximum seek=100 ms
® Average seek=55 ms
® Average rotational latency=12.5 ms

® No hardware (implicit) seek
® No hardware spiral (mid-transfer) seek
® Seeks can be overlapped but subsystem gives no end of

seek interrupt
® Sectors are staggered to optimize software spiral seeks
® Automatic detection of inner, outer guard bands (unique
servo patterns)
® Brush cycle on cartridge spin-up
® Two separate air systems with heat exchanger

1) Open-air cooling system for modules with muffin
fan and coarse filter

2) Closed-loop (recirculated) clean air system for
cartridge using blower on spindle drive motor and
absolute filter

® Spindle is belt driven from spindle drive/blower motor

® Spindle speed feedback/correction loop compensates for
speed variations and allows for ac power frequency range

of 50-60 Hz + 5%
@ Two reversible connectors allow for four ranges of ac

power voltage (see Table 1-1)
Table 1-1

Voltage Ranges

110/220

LOW/NOM

Range

Connector

90-105

110

Connector
LOW

100-128

110

NOM

180-210

220

LOW

200-256

220

NOM

® No change for 50-60 Hz
e RL11 Controller for PDP-11 UNIBUS

M7762 hex-height SPC module

16-bit word format
Normal address=774400
Normal vector=160

Normal interrupt level=BR5

Can handle RLO1s and/or RL02s — can mix
Can handle up to four drives, and a total of 100 feet of
daisy-chain drive bus

INTRODUCTION

® RLVI11 Controller for LSI-11 Q-Bus
M8013 and M8014 quad height modules
16-bit word format
Normal address=174400
Normal vector=160
Interrupt level=standard (there is only one)

Can handle RLO1s and/or RL0O2s — can mix
Can handle up to four drives, and a total of 100 feet of

daisy-chain drive bus
e RL8-A Controller for PDP-8§ OMNIBUS

M8433 hex-height module
8-bit byte or 12-bit word format — program selectable

12-bit word mode=max transfer of one sector/
operation
Normal device code = 60, 61 for first controller, 62, 63
for second (if two controllers, only one can transfer

data at a time)

Normal data break priority 0, can be jumpered for 1
Jumper selection of RLO1 or RLO2. If jumpered for

RLO2, controller can handle either or both —
can mix

Can handle up to four drives, and a total of 100 feet of
daisy-chain drive bus.

1.2

OPTION DESCRIPTIONS

RLO1A=RLO01 unit, BC20J-10 I/O cable, chassis slide,
mounting hardware

RLO2A=RLO02 unit, BC20J-10 I/O cable, chassis slide,
mounting hardware
RLOIK-DC=RLO01 Data Cartridge

RLO2K-DC=RLO02 Data Cartridge
RLO1-AK=RILO1A, RLO1K-DC
RL02-AK=RL02A, RLO2K-DC

RL11-AK=RLO1-AK, RL11, BCO6R, transition connector,
terminator
RL211-AK=RL02-AK, RL11, BCO6R, transition connector, terminator

RLV11-AK=RLO0O1-AK, RLV11, BCO6R, transition connector, terminator
RLV21-AK=RL02-AK, RLV11, BCO6R, transition connector, terminator
RL8A-AK=RLO0O1-AK, RL8A, BC80J, terminator

RL28A-AK=RL02-AK, RL8A, BC80J, terminator

INTRODUCTION

CABLE DESCRIPTIONS
BCO6R-XX

Flat Berg to Berg. Used on RL11 and

RLV11 subsystems to connect the controller
module to a transition connector which converts Berg to ZIF.

Round ZIF to ZIF I/O drive bus cable. Used

BC20J-XX

to daisy chain one unit to another. Also used
on RL11 and RLV11 subsystems to connect
the transition connector to the first unit. Can
also be ordered as 70-12122-XX.
BC80J-XX

Round Berg to ZIF cable used on RL8-A
subsystems to connect the controller module
to the first unit.

Terminator

1.3

= Required on last unit of a subsystem.

SECTOR FORMAT

See Figure 1-1. Each sector consists of:
® Servo data during the sector pulse time

® Header preamble of 48 bits (47 zeroes followed by one
““1”’ marker bit)
@ First header information of 16 bits (this is the address and
indicates cylinder, surface, and sector)
® Second header word of 16 zero bits
® Third header word of 16 bits of CRC
® Header postamble of 16 zero bits

® Data preamble of 48 bits (47 zeros followed by one ‘1’
marker bit)

@ Data — 2048 bits (can be considered as 256 8-bit bytes or
128 16-bit word or 170 12-bit words with 8 unused bits)

® Data CRC of 16 bits
® Data postamble of 16 zero bits

® Idle time waiting for next sector pulse. Varies but is
approximately 20 microseconds

The user-writable area starts with the data preamble and ends
with the data postamble. The remainder is factory writable
only.

1.4

BAD SECTOR FILE

The Bad Sector File is located on the last track (last cylinder,
last surface) of the cartridge. It occupies all forty sectors. The
layout is illustrated in Figure 1-2.

_ Ve

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INTRODUCTION
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INTRODUCTION

CHAPTER 2

FIELD REPLACEABLE UNITS

Table 2-1 is a list of RLO1/RLO2 Field Replaceable Units
(FRUs). Some of the FRUs contain components that are
easily checked and replaced. In these cases, an FRU may be
repaired instead of replaced. For example, a lamp may be
replaced on the front panel or a pico fuse replaced on the DC

Servo module. The decision to replace or repair an FRU
should be based on such local considerations as part availability, etc.

Some of the FR
Us are interchangeable between the RLO1 and

RLO2 and some are not. The interchangeability is indicated in
Table 2-1.
Table 2-1

FRU Part Numbers and Interchangeability

The following FRUs are downward-compatible only. The RL02
modules can be used on either drive with just a jumper change. The

RLO2 spindle can be used on either drive.
RILL01 Part
FRU

Read/Write Module

RIL02 Part

Number

54-11844

54-13536

DC Servo Module

54-11850

54-13534

Template for DC Servo

74-18588

74-20826

Drive Logic Module (DLM)

54-12175

54-13531 (early)

Spindle

70-12120

70-15116

54-14025 (later)

The following FRUs are the same for both drives.

FRU

RILO1/RL02 Part Number

5 amp fuse (DC Servo)

12-05747-00

AC Servo Module

54-11848

Front Panel

54-11846

Front Panel Lamp (GE 73)

12-12716-01

Sector Transducer

70-12137

Positioner

70-12117

Brush Drive Assembly

70-12112

Brush Assembly

70-16726

Spindle/Blower Motor

70-12114

Spindle Drive Belt

12-13369
74-15294

Spindle Ground Brush

FIELD REPLACEABLE UNITS

RLO1/RL0O2 Part Number

FRU
Head Cable Guide

70-16983

Insulating Sticker

74-22834

Coarse Filter

74-15297

Absolute Filter

12-13097-03

I/O Terminator

70-12293-00

Power Panel

70-12130

@ Terminator Block
(voltage selection)

74-16852-01A

@ Circuit Breaker

12-14360-02

@ Line Filter

12-12877-00

® Rectifier

11-10051-00

@ Transformer

16-13897-00

® Cap, 66,000 uF

for + Vunreg

10-13530-00

® Cap, 20,000 uF
for — Vunreg

10-13531-00

® Cap, for
spindle motor

10-13102-00

e Fan

12-09403-01

The following FRUs are not interchangeable between an RLO1 and
an RLO2.

RL01 Part
FRU

Upper Head
Lower Head

RLO02 Part

Number

74-17178-01
74-17178-00

70-15637-01
70-15637-00

Table 2-2 lists the cables used in the subsystem.
Table 2-2
Cable Description

Cables

Part Number

Comments

Controller (RL11 or
RLV11) to transition
connector

BCO6R-10

Controller (RL8-A) to

first drive

BC80J-20

I/O drive cable

BC20J-XX

Front panel to DLM

70-12107

I/O connector to DLM

70-12123-0H Stocked as part of

AC Servo to DLM

70-12139-O0M Stocked as part of

Also 70-12122-XX

70-14262-00

70-14262-00
Above two cables
assembled together

70-14262-00

Normally stocked

DC Servo to DLM

70-12139-0OF

Signal cable

DC Servo to DLM

70-12140

Power cable

R/W to DLM

70-12139-0F

Brush drive assy harness 70-12126

Part of Brush Drive assy

FIELD REPLACEABLE UNITS

Table 2-2

Cable Description

Cables (Cont)

Part Number

Comments

Power panel harness

70-12108

Part of power panel

Line cord

70-12109

Part of power panel

70-12142

Part of power panel

70-12136-0

Part of positioner

70-12110

Part of power panel

DC Servo to power
panel harness
DC Servo to

positioner harness

Fan cable
NOTE

All cables are the same part for both the RL01 and the RL02.

Figure 2-1 illustrates the interconnection of the FRUs and
shows their approximate physical positions.

BRUSH DRIVE ASSY
HOME

SWITCH

()

RW HEADS
SECTOR
TRANSDUCER

110

CABLE

e o

UNRE

:
23

MOTOR CAP

FOR
SPINDLE

MOTER

SUPPLY XFMR ,‘

S
-

AC POWER$=/
Figure 2-1

crgRaes

RECTIFIER

FILTER CAPS
B

.-i
:

|
e
3
m.;:z*v
TERMINAL BLOCK AND | |

m*-’%.‘4 VOLTAGE SELECTOR |

. (UNEFLTER}

—

NOTE: “R” DENOTES RED STRIPE

—

BIJ1[CE

ERONT
CZ-2039

Interconnection of FRUs on RLO1/RL02

FIELD REPLACEABLE UNITS

Figures 2-2 thru 2-6 illustrate the functional flow and interconnection of the FRUs.
TO
DLM
Js

—_

AC SERVO MODULE

()

CONTROL

REE

SPEED UP L|

SPINDLE

MOTOR

4 | DISK MOTOR OFF L|

BRAKE L

J3
3

BRAKE

CONTROL [+

SPINDLE AND

BLOWER MOTOR

]

(5 é
AC

moTOR
RELAY

O
CART

1MOTOR

T CAP ;151 | BRUSH MOTOR

“

2222

BRUSH HOME

COVER
OPEN l

LOAD

ASSY

\2]

BRUSH

BRUSH CYCLE L|

BRUSH DRIVE

EN H

[soL

SOLENOID

DRIVE

soCLOE\r/\JEng

BRUSH
SH HOME
HON

COVER OPEN SWITCH L

+5V

\_/

TB1-7 | 5

191 _sv
>

)

GND

)

LOGIC

GND

C 2]

)

FRAME
GND

FRAM
77777 FRAME

FAN

]

UNREG POWER
SUPPLY

66—

+VUN

p
T

TRANSFORMER

RECTIFIER

CAME

GND

TERMINAL BLOCK

VOLTAGESELECTOR

~VUN

TO DC SERVO

MODULE
_

GND
FRAME
GND

POWER PANEL
AC POWER

/7‘)77 FRAME GND
CZ-2040

Figure 2-2

Signal and Function Diagram of Power

Panel, AC Servo, Brush Drive Assembly

FIELD REPLACEABLE UNITS

POSITIONER

Home switcH| |

TACH

MOTOR

[

MAINT A
CONN
.

TO DLM

DC SERVO MODULE
9

HOME SWITCH

VEL SIG

A 6 TACH

VEL MODE
VEL COMMAND

bOSITIONER

POS MODE

CONTROL

POS SIG

DC MOTOR DRIVE

_‘>

1
7

6 2])

s3(3)1]5]a

94
B

DC MOTOR RETURN

DIRECTION

POWER ON

RESET

r—
A

14,16

SIG GND

| PR |

L
15|

INTEGRATOR GND

EMERGENCY

RETRACT

UNDERVOLTAGE

DAL

BETECT

HOME SWITCH

-V

-8

“] +5v|

DC LO
+5

PICO FUSE

DISABLE

+8V

+av]2 |

REG

-8v] 3

-8V

REG

V.. 9

+V[

INTEGRATOR

UN| UN

a(z|

GND

pu
T

SIG

GND

+vun]s ]

-vUN]s |

LOGIC

GND

L
FROM POWER

N—
TO DLM J2

PANEL UN REG PS
CZ-2041

Figure 2-3 Signal and Function Diagram of DC
Servo, Positioner

FIELD REPLACEABLE UNITS

Zp0Z-20

aH3vI3MOH1
A
A

)

V1VA/OAH3S Ll

V1VQ/OAE3sSZ

3dLNIHVM

|
ar

FIELD REPLACEABLE UNITS

FRONT PANEL
J1

(4)

LOAD IND

LOAD LPH

IAa

s1
-

RUN

RUN SW

READY IND

READY LPH Al

()

_O-sy

)

TO DLM
J11

SELECTBITOL

SELECTBIT1L

ASSERTED 3 /}_——:L
UNIT
# SW

FAULT IND

FAULTLPH

(@)

WR PROT IND

-8vQ

WRPROTL

(@)
S2

18
B3]

AA—O--gy
A

WR PROT SW

100 65 -sv
]

()

1.0GICGND

CZ-2043

Figure 2-5
Panel

Signal and Function Diagram of Front

FIELD REPLACEABLE UNITS

10 BUS CONNECTORS ON POWER PANEL

DRIVE LOGIC MODULE

J12
3

4
5

16
19

: .

POSITIONER CONTROL

‘

SERVO/DATA HANDLING

: H <]

]

|
|

l
I

GUARD BAND DETECTION
SECTOR HANDLING

:
>|—+—

DR cmD

AND RECEIVERS

L
H |

|
>—

DATA

GATE

P
I

——r—-1

SEL

H >

5V REG FOR /O CABLE DRIVERS

TO FRONT PANEL

ENABLE

orive

DR | SELECT

D SEL|

LOGIC

)

TO DC SERVO
FROM DC SERVO

TO R'W MODULE
TO AC SERVO

OUT J11, J4, J6, J5

DC POWER DISTRIBUTION:
IN J2 FROM DC SERVO

T
S

STATUS GATHERING

]

L (l}——u—— RD DATA

> ERROR DETECTION

COMMAND RESPONSE

p—t—— STATUS

25
26

SPINDLE SPEED CONTROL

STATUS CLK

SPIN UPIDOWN CONTROL

ROY

:
TM
t

L gfif——r—— SEC PLS

21
22

—1
L

o5 -

BRUSH CONTROL

- i}_‘—“. DR ERR

; (1 [vm

]

MAJOR STATE LOGIC

————— 1

H |>— SYS CLOCK

”

WV, |UU, LL, KK, FF, EE,

J14

POWER

FAIL L

hee SECTOR PULSE _——aW Q
—-————<[

RET

BB, AA. U,V <y.ocslc GND
P,R,K, LA

LOGIC GND

SECTOR
TRANSDUCER
L/

/7777
FRAME GND
CZ-2044

Figure 2-6

Signal and Function Diagram of Drive

Logic Module
Figures 2-7 and 2-8 illustrate the physical location of the
FRUs.
Figures 2-9 through 2-14 illustrate the essential component

layout of the major FRUs and identify the different versions
when appropriate.

FIELD REPLACEABLE UNITS

DRIVE LOGIC MODULE

AC SERVO MODULE
SPINDLE/BLOWER

MOTOR

SPINDLE

SECTOR TRANSDUCER—

COARSE FILTER

ABSOLUTE
FILTER

POWER PANEL
(REAR PANEL
OF UNIT)

R/W MODULE

(INSIDE RIW BOX)
DC SERVO MODULE

I.(

§‘)

..I‘

FRONT PANEL

N -

COVER LOCKING SOLENOID

ACCESS COVER

BRUSH DRIVE ASSY

RIW HEADS

POSITIONER

WR PROT IND-SW
FAULT

IND

READY IND- UNIT #PLUG
LOAD

IND-RUN SW

CZ-2045

Figure 2-7

Physical Location of FRUs

/0 CABLE

(“CABLEIN")

TERMINATOR

NORMALLOW
LINE VOLTAGE

TERMINAL BLOCK —oo
COVER

CABLE "OUT”

110/220 VOLTS

TERMINAL

BLOCK COVER

AC LINECORD

CIRCUIT BREAKER
C2Z-1056

Figure 2-8

Rear View

FIELD REPLACEABLE UNITS

Table 2-3

Test Points — Drive Logic Module 54-12175
(Version 1)

SIGNAL

1
2
3
4
5
6
7
8

Logic Ground
Logic Ground
Logic Ground
Logic Ground
Logic Ground
Logic Ground
Integrator Ground
Filtered POS SIG

9
10
11
12
13
T1
T2
T3

Sector Time
+8V
-8V
VEL SIG
Signal Ground
Input to POS SIG
El
E2

Table 2-4

Test Points — Drive Logic Module 54-13531
(Version 2)

SIGNAL

1
2
3

Logic Ground
Logic Ground
Logic Ground

12
13
14

Logic Ground
Borrow
Raw Sector Pulse

Logic Ground

Signal Ground

Integrator Ground
Filtered POS SIG

5
6

VEL SIG
+8V
—8V

8
-9
10
11

POS SIG

16
17

Ready To R/W
Clock Error} j

T1
T2
T3

Input to POS SIG
El
E2

Clock Error

pet

Sector Time

Table 2-5

Test Points — Drive Logic Module 54-14025
(Version 3)

SIGNAL

1
2

Logic Ground
Logic Ground

16
17

Ready to R'W
Clock Error} Jumber

Logic Ground

Cover Open

Jumper

Filtered POS SIG

+5V

} Jumper

VEL SIG

11
12
13
14
15

Sector Time
Logic Ground
Borrow
Raw Sector Pulse
POS SIG

Logic Ground

Integrator Ground
Signal Ground

+8V

—8V

Clock Error
GND

Select Head 1

GND

25
26
T1
T2
T3

Seek Error

Timer } Jumoer
pe

GND
POS SIG
Input to POS SIG

El
E2

NOTE

T1, T2 and T3 are pads for the formatter

TP 17 and 18 are normally jumpered (except for mfg. checkout)

FIELD REPLACEABLE UNITS

1273
VERSION 1

TP1e

TP6
TP2

TP5
.

TP12

TP7

TP8

« TP11

TPy

o0
!
< TP10G +7pg @ LS
R
J1
° TP3
DO

J11R

J14

54-12175

RLO1 ONLY

NOTE:
J11 AND J4
POINT DOWN

TP4

P12

TP13

TP2°

TP16

TP11

P3|

712

TP14

[52]

R) [J11 R|®o

TP1'5-7'- 8-10-9 TP1° —

54-13531

NOTE:

RLOZ OR RLOT

J4 AND J11 POINT UP

W1 OUT FOR RL02
;A
TP4

NO TP19 THRU 26
e TP21®@ TP22
TP12

e TP13

TP25 ®

©TP2

TP14

TP®23

T.3

H
'TP6

J12

TP2

TP16
o

® TP19

TP3

— TP17

VERSION 2

?zj rfi

* TP5

TP15-7- 8-10-9

TP24 ~
=

T
a

TP1 =

NOTE: R DENOTES RED STRIPE
54-14025

JUMPER

RLO2 OR RLO1
W1 IN FOR RLO1

TEST LUGS
EFFECT
19-20
DEFEAT COVER CLOSED

W1 OUT FOR RLO2

21-22

SELECT HEAD 1

NOTE:

23-24

DISABLE SKTO

J& AND J11

HAS TP19

POINT UP

THRU

(THESE TEST LUGS ARE CIRCLED)
CZ-2046

Figure 2-9

Drive Logic Module Layout

FIELD REPLACEABLE UNITS

Jz
4

J2
4

TP2

TP1

TP3

54-11844

RL0O1 ONLY
R41

4 4

R40

*—°

Q_C.) w2
w1

TP1

NOTE: ONE JUMPER IN AT A TIME

W1 IN FOR RLO1
W2 IN FOR RL02

TP3

54-13536 RLO1 OR RLO2

o~
w0

wN
=

R/W Module Layout — Top View

(o200
I =

Figure 2-10

CzZ-2047

]

[ Jwour

J15
MUFFIN FAN

C1+V

c2 -V

MOTOR CAP

cB1

[

FL1

TB1

CZ-2050

Figure 2-11

Power Panel Layout — Front View

FIELD REPLACEABLE UNITS

54-11850

RLO1T ONLY

TE
W

-5

[

fl
—-—

[

—-—

)

54-13534
RLO1 OR RLO2

F1]

l
HEAT SINK

w2 wi

/ 14

[
W1 IN FOR RLO1
OUT FOR RLO2

W2 ALWAYS IN

J:z J3
321

CZ-2048

Figure2-12

DC Servo Module Layout — Bottom

View

NOTE

Later versions of the DC Servo Module have the jumpers
(W1 and W2) on top of the module. Thus, they are
accessible through the plastic template.

FIELD REPLACEABLE UNITS

=
J3

4 2

J2
CZ-2049

Figure 2-13 AC Servo Module Layout—FrontView

== 5 Eiutuiateits atuiitenls S

i 1
|

;

2aB]

()

SIS N

411

Bl12aB52a
, 3

613

S R T——|

_J:-L\

(10 8 6 4 2‘\

1 9 753 11J1
e e

e eJ

CZ-2051

Figure 2-14

Front Panel Layout — Rear View

CHAPTER 3
FRONT PANEL

FRONT PANEL SWITCHES AND INDICATORS
@ LOAD indicator is on when the spindle is stopped and the
cover is unlocked. This indicates that the operator can
open the cover to load or unload the cartridge.
® LOAD switch is an alternate action switch that is used to
start or stop the spindle. The IN position corresponds to

RUN and the OUT position to STOP.
® UUNIT NUMBER plug has cams on the back to encode the

unit number into electrical signals. The corresponding
number is stamped on the front for the operator to read.
The number can be 0 through 3. The plug also serves as a
READY indicator.
® READY indicator is on when the cartridge is up to speed,
brush cycle finished, heads loaded, and the heads are ‘‘on

track’’. The unit is ready to perform a Read, Write, or Seek
operation.
® FAULT indicator is on when certain drive conditions

exist. These conditions are shown in Table 4-1 — Drive
Conditions.
® WRITE PROT indicator is on when the Write Protect

condition is true. It is the result of the state of the WRITE
PROT switch.
® WRITE PROT switch is an alternate action switch that

establishes the Write Protect condition. The IN position
corresponds to the Write Protect state.

CHAPTER 4

DRIVE CONDITIONS

Table 4-1

Condition
Device

Bit*
8

FAULT

Light
Yes

Drive Conditions
Drive

Error
Yes

Heads

Unld. Comment
No Setby Drive Select
and SEC PLS from
unit.
another

Select
Error

Cleared by Reset

(DSE)

or Power On Reset
(POR).

Volume
Check

Yes

Write
Gate
Error

Yes

Setby Load Heads
cycle. Cleared by
Reset or POR.

(VO)

(WGE)

Set during Write
Gate if one or more
of the following
occur:
® Drive

1is

not

‘“‘Ready
to
Read/Write”’
® Drive is Write
Protected

® Sector pulse is
occurring
® Drive

has

another error
Cleared by Reset

or POR.

Spin
Error
(SPE)

Yes

Spin-up Timeout
prevents loading of
heads. Set by
Spin-up Timeout
(40 sec) or Overspeed. Cleared by
Reset or POR.

Seek
Timeout
(SKTO)

Yes

Set by timeout of
approximately 1.5
sec. Cleared by
Reset or POR.

*Bit in Multipurpose Register after a Get Status command

DRIVE CONDITIONS

Table 4-1

Drive Conditions (Cont)

Condition

Bit*

FAULT
Light

Drive
Error

Write

Heads
Unld. Comment
No

Not an error con-

Lock

dition.

Status

cleared by WRITE

and

PROT switch.

(WLS)

Current
In Heads

Set

Error

(CHE)

Yes

Set by Current in
Heads AND NOT
'
Write Gate.
Cleared by Reset
or POR.

Data

Set by Write Gate
AND No Write

Error

‘Data Transitions.

(WDE)

Cleared by Reset

Write

or POR.

Clock
Error

(=)

Does not latch. No
status bit. Set by
loss of SYS CLK
from controller.
Clears itself if
condition corrects
itself.

*Bit in Multipurpose Register after a Get Status command

CHAPTER 5
REGISTER SUMMARY

5.1

RL11/RLV11 Register Summary
Table 5-1

Controller Addressable Registers

Type

Address (read/
write)
(octal)

Name/
Mnemonic Basic Function

774400

Control

Indicates drive ready condition; de-

Status

codes drive commands and provides

(CS)

overall control functions and error

Bus

Indicates memory location involved

Address
(BA)

or write operation

Disk
Address

(1) Holds disk address during a data
transfer such as Read or Write; or

R/W

indications

774402

R/W

774404

R/W

in data transfer during a normal read

(DA)

(2) holds the drive command word
for a Seek command; or (3) holds
the drive command word for a Get

Status command
774406

R/W

Multi-

purpose

(1) Functions as word counter

when transferring read/write

(MP)

data between UNIBUS and

drives; or (2) holds results of a Get
Status command; or (3) holds
results of a Read Header gommand.
CONTROL STATUS REGISTER (CSR)

{14

12 .11

ERR DE | NXM ]| E2

DS1 | DSO |CRDY| I[E |BA17[BA16] F2

06§

~—
READ/WRITE

READ ONLY

0302

FO DRDYI
N
8%"/}_(3
CZ-2009

Bit(s)

Name

Function

Drive Ready
(DRDY)

When set, this bit indicates that the
selected drive is ready to receive a
command. The bit is cleared when a
seek operation is initiated and set
when the seek operation is com-

pleted.

Bit(s)

Name

Function

1-3

Function Code

These bits are set by software to
indicate the command to be executed.

Command execution requires that
Bit 7 (Controller Ready) be cleared
by software. A zero bit being trans-

ferred into bit 7 of the CSR can be
considered as a Go bit.
Octal

Command

NoOp

Code
0

(RL11) or
Maint.

Write Data

=
O

O
=

Seek
Read

st
OO

O
=
O

—_

O
O

Get Status

(RLV11)

Write Check

Read Data

~J
O\ L

O
e
—

e
Pt

Header

Without
Header

Check
4-5

Extension Bits

The two most significant bus address bits. Read and written as data

(BA16, BA17)

bits 4 and 5 of the CS register but

Bus Address

considered as address bits 16 and 17
of the bus address register.

Ifit’errupt
Enable (IE)

When this bit is set by software, the
controller is allowed to interrupt the
processor at the normal command or
error termination.

Controller Ready

(CRDY)

8-9

Drive Select
(DSO, DS1)

When cleared by software, this bit
indicates that the command in bits
1-3 is to be executed. When set, this
bit indicates the controller is ready
to accept another command.
These bits determine which drive
will communicate with the controller via the drive bus.

Operation

When set, this bit indicates that the

Incomplete (OPI)

current command was not completed within 200 ms.

Bit(s)

Name

Function

Data CRC (DCRC)

If OPI (bit 10) is cleared and this bit

or Header CRC

i1s set,

(HCRC) or Write

when reading the data (DCRC).

Check (WCE)

a CRC error has occurred

IfOPI (bit 10) is set and bit 11 is also
set, the CRC error has occurred on

the header (HCRC).
If OPI (bit 10) is cleared and bit 11 is
set and the function command was a

write check, a write check error

(WCE) has occurred.
12

Data Late (DLT)

This bit is set during a write when

or Header Not

the silo is empty but the word count

Found (HNF)

has not yet reached zero (meaning
that the bus request was ignored for
too long). The OPI bit will not be
set.

This bit will be set during a read
when the silo is full (meaning that
the word being read could not enter
the silo and the bus request has been
ignored for too long). The OPI bit

will not be set.
When this bit and OPI are both set, a

200 ms timeout occurred while the
controller was searching for the
correct sector to read or write (no

header compare — HNF).
Error Summary
Bits

Error

OPI

Read Data

CRC

Write Check

Header CRC

Data Late

Header Not
Found

Non-Existent

This bit is set when the addressed

Memory

memory does not respond within the

(NXM)

proper time frame during a direct
memory access (DMA) data trans-

fer.

Bit(s)

Name

Function

Drive Error (DE)

This bit is tied directly to the DE
interface line. When set, it indicates
that the selected drive has flagged an
error. (The source of the error can be
determined by executing a Get
Status command.)

DE can be cleared by executing a
Get Status command with bit 3 of
the DA register set.

Composite Error
(ERR)

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

BUS ADDRESS REGISTER (BAR)

BA15|BA14| BA13|BA12| BA11}|BA10| BA9 | BAB | BA7 | BA6 | BAS5 | BA4 | BA3 | BAZ | BA1

o] J

J
READ/WRITE

C2-2035

Bit(s)

Name

Function

0-15

BAO thru BA15

These bits point to the Unibus address
that data is to be transferred to/from.
Normally a memory address. BA16

and BA17 are inthe CSR bits 4 and 5.
DAR DURING SEEK COMMAND
07

LDFB DF7 | DF6 | DF5 | DF4 | DF3 | DF2 | DF1 DFO

DIR

0 ] 1‘l

Bit(s)

Name

Function

Must be a 1.

Must be a O.

Direction (DIR)

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

" REGISTER SUMMARY

Bit(s)

Name

Function

Must be a 0.

Head Select (HS)

Indicates which head (disk surface)

is selected. A one indicates the
lower head; a zero, the upper head.
Reserved.

5-6

7-15

Cylinder Address

Indicates the number of cylinders

Difference

the heads are to move on a seek.

DF 08:00

DAR DURING READING OR WRITING DATA COMMANDS
15

[CAB lCA7 CAB ICAS CA4 | CA3 | cA2 ] CAT1 | CAO

HS | SA5 | SA4 | SA3 | SA2 | SAt1 | SAOQ

Bit(s)

Name

0-5

Sector Address

Address of one of the 40 sectors on a

SA 05:00

track.

Function

Head Select (HS)

Indicates which head (disk surface)

is to be selected. A one indicates the

lower head; a zero, the upper head.
The correct track (head and cylinder) must be previously selected by
a Seek.
Cylinder Address

Address of the cylinder being ac-

CA 08:00

cessed.

‘

DAR DURING GET STATUS COMMAND
15

X l X l X<, X l X

Bit(s)

Name

Function

Must be a 1.

Get Status (GS)

RST’ 0

l v]

Must be a 1, indicating to the drive
that the status word is being requested. At the completion of the

Get Status command, the drive
status word 1is read into the controller Multipurpose (MP) register.

Must ber ao.

Bit(s)

Name

Reset (RST)

Function

When this bit is set, the drive clears
its error register before sending a
status word to the controller.

4-7

Must be a O.

8-15

Not used during a Get Status.

MPR AFTER GET STATUS COMMAND

154 14

121 11

CHE|

|SKTO|

WDE|

o9 i

SPE | WGE | VC

, 05

DSE | DT

BH | STC | STB | STA

CZ-2012

Bit(s)

Name

Function

0-2

State C:A

These bits define the state of the

ST C:A

drive.

State Bit Definitions
Bit
Bit
A Definition
B
0 Load Cartridge
0

1
1
0
0

1
0
1
0
1

Spin Up
Brush Cycle
Load Heads
Seek (Track Counting)
Lock On (Keeping

1
1

0
1

Unload Heads
Spin Down

Bit

0
1
1

on track)
1
1

Brush Home (BH)

Heads Out (HO)

Set when the brushes are home.

Set when the heads are over the
disk.

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

Cover Open (CO)

Head Select (HS)

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

Drive Type (DT)

A zero indicates an RLO1; a one, an

Drive Select Error

Set when a multiple drive selection

(DSE)

is detected.

Volume Check

Set when a cartridge is spun up.
Cleared by execution of a Get Status
command with Bit 3 asserted.

place.

RLO2.

(VO

Bit(s)

Name

Write Gate Error

Function

Set during Write Gate if one or more

(WGE)

of the following conditions occur.
* Drive is not ‘‘Ready to Read/

Write”’
* Drive is Write Protected
* Sector pulse is occurring

* Drive has another error

Spin Error (SPE)

Set when spindle has not reached
speed in the required time during
spin-up or when spindle speed is too

high.

Seek Time Out

Set when the heads do not come on

Error (SKTO)

track in the required time during a

Seek command or when ‘‘Ready to

Read/Write”’ is lost while the drive
is in position (lock-on) mode.

Write Lock (WL)

Set when the drive is Write Protected.

Current Head Error

Set if Write Current is detected in

(CHE)

the heads when Write Gate is not

‘

asserted.

Write Data Error
(WDE)

Set if Write Gate is asserted but no
transitions are being detected on the
Write Data line.

MPR AFTER READ HEADER COMMAND
15

l CAS8 J CA7 l CA6 | CAB | CA4 | CA3 | CA2 | CA1 | CADO | HS | SAS l SA4 | SA3 | SA2 | sA1 , SAO ,
15

L
156

ZEROES
14

l
07

CZ-2013

Bit(s)

Name

Function

0-5

SAOQ:SAS

Sector Address

Head Select — Upper head=0,
lower head=1

7-15

CAO:CAS8

Cylinder Address

MPR DURING READ/WRITE COMMANDS FOR WORD COUNT

[ 1 l 1 ] 1 wc12lwceitwcei1o} weca | wes | WC7 | WC6 WC5 | WC4| WC3| WC2 | WC1 WCi]
Bit(s)

Name

0-12

Word Count

WC 12:00

Function

Contains the two’s complement of

total number of words to be
transferred.

Must be ones.

13-15

MP Register Programming Note — The RL01/
RLO2 Disk Drive will not do spiral read/writes. If
data is to be transferred past the end of the last
sector of a track, it is necessary to break up the
operation into the following steps.

1. Program the data transfer to terminate at the
end of the last sector of the track.
2. Program a seek to the next track. This can be
either a head switch to the other surface but same
cylinder or a head switch and move to the next
cylinder.

3. Program the data transfer to continue at the
start of the first sector at the next track.

5.2

RLS-A Instruction Set and Register Summary
Table 5-2

Octal

RIL8-A Instruction Set

Code

Mnemonic

Function

6600
,

RLDC

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

6601

RLSD

Skip on function done. Then clear if

6602

RLMA

Load break MA register from AC0:11

6603

RLCA

6604

RLCB

6605

RLSA

function.)

set to a one.

Load command register A from AC
0:11

Load command register B from AC

0:11, execute command

Load sector address register from AC
0:5

Table 5-2

RL8-A Instruction Set (Cont)

Octal

Code

Mnemonic

6607

RLWC

Function
Load word count register from AC

0:11

6610

RRER

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

6611

RRWC

Read word count register into AC 0:11

6612

RRCA

Read command register A into AC

6613

RRCB

Read command register B into AC
0:11

6614 -

RRSA

0:11

Read sector address register into AC

6615

RRSI

Read silo word into AC 0:11

6617

RLSE

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

COMMAND REGISTER A DURING A SEEK COMMAND

CYLINDER DIFFERENCE
CZ-2016

Bit(s)

Name

ACO

Direction (DIR)

’

Function

(to a lower cylinder address). The
actual distance moved depends on

the cylinder address difference (bits
3-11).

ACl1

Head Select (HS)

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

AC2

Spare

AC3:11

Cylinder Address

Indicates the number of cylinders

Difference

the heads are to move on a seek.

COMMAND REGISTER A DURING A READ/WRITE DATA COMMAND
00

04
LSB

CYLINDER ADDRESS
€2Z-2017

Bit(s)

Function

Name

Must be zero

ACO

Head Select (HS)

AC1

Indicates which head (disk surface)
is to be selected. A one indicates the
lower head; a zero, the upper head.
The correct track (head and sector)
must be previously selected by a
Seek.

AC2

Must be zero

AC3:11 Cylinder Address

Cylinder address.

COMMAND REGISTER B
00

RES

MAIN |MODE|

| MSB

LSB

|EMAO | EMA1|

EMA2;

FA]

DRIVE SELECT
CZ-2018

Bit(s)

Name

AC1

Function
Reserved

ACO

Maintenance

The contents of the Disk Address
(DA) register are looped back to the
silo for maintenance purposes. Bit 2

of Command Register B must also

be set for this function to work correctly.

AC2

Mode

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

AC3

Interrupt Enable

(IE)

When this bit is set, the controller is

allowed to interrupt the processor at
the conclusion of a normal command or error termination.

Bit(s)

Name

Function

AC4:5

Drive Select
(DSO0, DS1)

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

AC6:8

Extended Memory

These three bits define the memory

Addressed (EMA)

field location. This allows up to 32K
memory locations to be addressed
on processors having more than 4K
of memory.

AC9:11

Function Code

These bits indicate the command to

(FC, FB, FA)

be executed by the controller/disk
subsystem.

Bit

Command

Maintenance

Reset

Get Status

Seek

Read Header
Write Data

Read Data

Read Data Without
Header Check

BREAK MEMORY ADDRESS REGISTER

Bit(s)

Name

Function

ACO0:11 BMO:11

Memory Address
WORD COUNT REGISTER

wc oo wc o1|wc o2{wc 03] wc o4|wc 05| WC 06| WC 07| wc o8|wC og|wc
10w 11
CZ-2020

Bit(s)

Name

ACO:11 WCO:11

Function

Word Count

SILO BUFFER - HEADER WORDS

NOT DEFINED

I LSB | HS | MSB

WORD 1

LSBJ
_J

CYLINDER

SECTOR ADDRESS

ADDRESS

NOT DEFINED

MSB

WORD 2

NOT DEFINED
WORD 3

r NOT DEFINED
WORD 4

NOT DEFINED
WORD 5

HEADER CRC

: r NOT DEFINED
WORD 6

MSB
-

‘

HEADER CRC
CZ-2025

WORD 1 — HEADER
ACO:3

Name

Function

Undefined

Cyl Add

LSB of Cylinder Address

AC6:11 Sec Add

Head Select — lower head = 1,

upper head = 0
Sector Address

WORD 2 — HEADER
ACO:3

Name

Function

Undefined

AC4:11 Cyl Add

Cylinder Address — eight high
order bits

WORD 3 — HEADER
Bit(s)

Name

ACO:3

Undefined

AC4:11

Zer10s

Bit(s)

Name

ACO:3

Undefined

AC4:11

Zeros

Bit(s)

Name

ACO:3

Undefined

AC4:11

CRC

Eight LSB of CRC word

Function

WORD 4 — HEADER
Function

WORD 5 — HEADER

Function

WORD 6 — HEADER
Bit(s)

Name

ACO:3

Function
Undefined

AC4:11

CRC

Eight MSB of CRC word

SILO BUFFER — STATUS WORD 1

NOT DEFINED

coO

BH | STC| STB STA]

WORD
1

Bit(s)

Name

Function

ACO:3

Undefined

AC4

Drive Type

A zero indicates an RLO1; a one, an
RLO2.

ACS

Head Select (HS)

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

the lower head.

AC6

Cover Open (CO)

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

place.
AC7

Heads Out (HO)

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

the heads are home.

Bit(s)

Name

Function

ACS8

Brush Home (BH)

AC9:11

State Bits

Set when the brushes are home.
These bits define the state of the disk
drive.

Bit
C

State Bit Definitions
Bit Bit
Definition
A
B

0
0O
0
0
1

O
O
1
1
0

O
1
0
1
0

Load Cartridge
Spin-up
Brush Cycle
Load Heads
Seek (Track

Lock-on (keeping

1
1

Unload Heads
Spin-down

Counting)
on track)

SILO BUFFER — STATUS WORD 2

[

NOT DEFINED

WDE‘ CHE | WL | STO | SPE |WGE| VC DiE—l
WORD 2

Bit(s)

Name

Function

ACO:3

Undefined

AC4

Write Data Error
(WDE)

This bit is set when the Write Gate is
on but no transitions were detected

ACS

Current Head Error
(CHE)

This bit is set when Write Current is
detected in the heads but the Write

AC6

Write Lock (WL)

AC7

Seek Time Out
Error (SKTO)

ACS

on the Write Data line.

Gate was not asserted.

Set when the drive is Write Protected.

Spin Error (SPE)

Set when the heads do not come on
track in the required time during a
Seek command or when ‘‘Ready to
Read/Write’’ is lost while the drive
is in position (lock-on) mode.

Set when the spindle does not come

up to speed within 40 seconds or
when the spindle speed is too high.

AC9

Write Gate

Set if Write Gate is asserted and one

Error

or more of the following conditions

(WGE)

is true.

1. Drive is not ‘‘Ready to Read/
Write’’
2. Drive is Write Protected
3. Drive is in the midst of sector

time
4. Drive has another error asserted

AC10

Volume Check

Set when a cartridge has been spun

(VC)

up. This bit is reset by a Reset command.

AC11

Drive Select Error

Set when one or more drives have

(DSE)

the same number (unit select plug)
or have responded to the same

number.

SECTOR ADDRESS REGISTER
00

BOO SA01|SA02[SA03{SA04 SAOS]

Bit(s)

Name

Function

ACO0:5

SAO:5

Sector Address

ERROR REGISTER
00

DCRC| OPI

DLT

HCRC

HNF

NOT DEFINED

DRDY]

Bit(s)

Name

Function

ACO

Data CRC (DRCR)

If OPI is cleared and this bit is set,

or Header CRC

the CRC error occurred in the data

(HCRC)

(DCRC). If OPl is set and this bit is
also set, the CRC error occurred on

the header (HCRC).

ACl1

Operation

When set, this bit indicates that the

Incomplete (OPI)

current command was not com-

pleted within 200 ms. It is also used
in conjunction with bits O and 2 of
this register.

Bit(s)

Name

Function

Data Late (DLT) or
Header Not Found

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

AC2

(HNF)

not be set.

This bit is set during a Read if the
silo is full and the word count is not
yet zero (meaning that the word
being read could not enter the silo).
OPI will not be set.

When this bit and OPI are both set,
then a 200 ms timeout occurred
while the controller was searching
for the correct sector to read or write
(no header compare — HNF).

ACO0:2

Error Code

Summary

Error
DLT

OPI
HNF
DCRC
HCRC
AC10

Drive Error (DE)

Bits
01

0
0
1
1

1
1
0
1

02
1

0
1
0
0

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

The DE bit is cleared with a Reset
command to the drive.
AC11

Drive Ready

(DRDY)

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

CHAPTER 6
BOOTSTRAPS

6.1

RL11/RLV11 BOOTSTRAP

Ensure that the heads are over cylinder O and head O is

selected by releasing the LOAD switch, waiting for the
LOAD indicator to light, then depressing the LOAD switch.
After the drive is READY, initialize the controller with a
system INITIALIZE. Perform a bit status clear. Load the

following program into memory.
LOC

Contents

Comments

10000

012737

Load CSR

10002

000014

10004

174400

10006

000001

Wait

Start the program at 10000 and allow it to run for a few

seconds. Halt the program and restart at 00000.

6.2

RIL8-A BOOTSTRAP

Ensure that the heads are over cylinder O and head O is
selected by releasing the LOAD switch, waiting for the
LOAD indicator to light, then depressing the LOAD switch.

Load the following program into memory.

LOC

Contents

Comments

7600

Clear AC and constant

6600

Clear RL8-A

7332

Generate constant

6605

Load SAR with 20

1021

Load constant into AC

6607

7327

Load WC
Generate constant

6604

Load CMD B

6601

Skip on done

5031

Loop

Start program at 21. The OS*8 monitor will overlay this

bootstrap.

CHAPTER 7
TOGGLE-IN PROGRAMS

7.1

HEAD SELECTION PROGRAM FOR

RL11/RLV11
The following program causes Head 1 (lower head) to be
selected (on unit 0) if the WRITE PROTect switch is in and
Head O (upper head) to be selected if the switch is out.

1000

012700

1002

174400

1004

012701

1006

174404

1010

105710

1012

100376

1014

012711

1016

000013

1020

012710

1022

000004

1024

105710

1026

100376

1030

013702

1032

174406

1034

006302

1036

010203

1040

006303

1042

105702

1044

100405

Housekeeping

Wait
Get Status Command

Wait
Status Word

Check HS Bit

1046

005703

Check WL Bit

1050

100357

Equal, Loop

1052

012711

Set HS Bit

1054

000021

1056

000404

Go to Seek Command

1060

005703

Check WL Bit

1062

100752

Equal, Loop

1064

012711

Reset HS Bit

1066

000001

1070

012710

1072

000006

1074

000745

|
Seek Command
Loop

TOGGLE-IN PROGRAMS

7.2 HEAD SELECTION PROGRAM FOR RLS8-A
The following program causes Head 1 (lower head) to be
selected (on unit 0) if the WRITE PROTect switch is in and
Head O (upper head) to be selected if the switch is out.
200

6600

201

1234

202

6604

203

6601

204

5203

205

6615

206

0232

207
210
211

7640
5217
6615

212

0233

213
214

7650
5201

215

7332

216

5224

217

6615

220

0233

221
222

7640
5201

223

7300

224

6603

225

7325

Clear Controller

Get Status Command
Wait

First Word of Status
Check HS Bit
HS=1, Go to 217
Second Word of Status
Check WL Bit
HS=WL, Go to 201

Second Word of Status
Check WL
HS=WL, Go to 201

HS to Command REG A

Seek Command to Command REG B

226

6604

227

6601

230

5227

231
232

5201
0100

Loop to 201
Constant

233
234

0040
1002

Constant

7.3

Wait

GET STATUS (WITH OR WITHOUT RESET)

ON AN RL11/RLV11 SUBSYSTEM
To accomplish this it is necessary to:

1) Deposit a 3 into DAR at 774404 (or 13 to Reset)
2) Deposit a 4 into CSR at 774400 (or 404, 1004, 1404 for
units 1, 2, 3)

3) Wait for operation to be complete
4) Examine contents of MPR at 774406.

TOGGLE-IN PROGRAMS

On some PDP-11 systems this can be accomplished manually
using the console. On other PDP-11 systems it is necessary to
run a program such as given below. Start at 1000 and when it

halts, examine memory location 1032.
To get status on unit 1, 2, or 3 modify location 1010 to 404,

1004, or 1404.
To reset drive modify location 1002 to 13.

1000

012737

Get Status Command

1002

000003

Use 13 to Reset

1004

174404

1006

012737

1010

000004

1012

174400

1014

105737

1016

174400

1020

100375

1022

013737

1024

174406

Use 404, 1004, 1404 for Units 1,2, 3
Wait

Move Result to Memory

1026

001032

1030

000000

Halt

1032

000000

Result

7.4

GET STATUS ON AN RLS8-A SUBSYSTEM

The following program will GET STATUS from unit 0. To
access unit 1, 2, 3 change location 212 to 1102, 1202, 1302.
Start the program at 200 — at the first halt, the first byte of the
status word 1s displayed in the accumulator — at the second

halt, the second byte is displayed.
200

7300

201

1212

202

6604

203

6601

204

5203

Get Status
Wait

205

6615

Get First Byte

206

7402

Halt and Display First Byte

207

6615

Get Second Byte

210

7402

Halt and Display Second Byte

211

5200

Jump to Start

212

1002

Constant

TOGGLE-IN PROGRAMS

OSCILLATING SEEK FOR RL11/RLV11
The following program will cause unit zero to perform an
oscillating seek. To drive units other than unit 0, swap the
unit number plugs or modify locations 1044 and 1054 to
7.5

reflect the unit number in bits 8 and 9.

The number of cylinders involved is inserted into bits 15
through 7 and bit 0 is set in the switch register before starting
the programs at 1000. If no switch register is available,
modify location 1012 from 177570 to 001060 and put the
number of cylinders in bits 15 through 7 and set bit O in
location 1060.

The common values for the switch register are:
Number of cylinders

Value of Switch Register

(in decimal)

(in octal)
000205

025205

170

052405

255

077605
177605

511

Set Stack Pointer

1000

012706

1002

001000

1004

012700

1006

174400

1010

013701

1012

177570

1014

004537

1016

001032

1020

042701

1022

000004

1024

004537

1026

001032

1030

000767

Loop back

1032

105710

Wait

1034

100376

1036

010137

1040

174404

Set Device Address into RO
Set Difference into R1
Go Seek

Change direction bit in R1
Go Seek

Seek

TOGGLE-IN PROGRAMS

1042

012710

1044

000006

1046

105710

1050

100376

1052

012710

1054

000010

1056

000205

7.6

Wait
Read Header to kill time for SKTO.

Return

OSCILLATING SEEK FOR RLS-A

The following program will cause unit 0 to perform an
oscillating seek. To drive units other than 0, swap unit
number plugs. Insert the number of cylinders into the

switches before starting at location 200. The usual values for
the switch register are: 1 cylinder=1, 85 cyl=125, 170

cyl=252, 255 cyl=377 and 511 cyl=777.
200

7201

201

6604

Reset

202

7604

Get number

203

4221

Go Wait for Ready

204

3225

Store number

205

1225

206

6603

207

7325

Seek

210

6604

211

4221

Go Wait for Ready

212

7307

213

Read Header to Delay for SKTO

6604

214

1225

215

1226

Change Direction Bit

216

7500

Check for Time to Restore

217

5202

Loop to Start

220

5203

Loop

221

0000

Wait for Ready

222

6601

223

5222

224

5621

225

0000

Temp

226

4000

Constant

CHAPTER 8
DIAGNOSTICS

8.1

RIL11 DIAGNOSTICS

The original set of six diagnostics (Table 8-1) drove an RLO1
only. They were replaced by a new set of seven diagnostics
(Table 8-2) that can handle RLLO1s and RLO02s. The kit
number for the new set is ZB283. One of the programs

(CZRLMADO) in the new set is a utility rather than a test. It is
used to examine the Bad Sector File and to write entries into

e m%@, g

the field-written portion of that file. The original DECX11
module (RLAA) can handle RLO1 only while revision B

(RLAB) can handle both RLO1 and RLO2. This module is
part of Option Library #5 (DXQLQ). There is an RL driver
available for M.P.G.

Table 8-1
Name

‘

RL11/RL01 Diagnostics
Description

CZRLABO

Controller Test #1

CZRLBBO
CZRLCBO
CZRLDBO
CZRLEBO
CZRLFBO

Controller Test #2
Drive Test #1
Drive Test #2
Performance Exerciser
Compatibility Test

Table 8-2

RL11/RL02 Diagnostics

Name

Description

CZRLGAO

Controller Test #1

CZRLHAO
CZRLIAO
CZRLJAO
CZRLKAO

Controller Test #2
Drive Test #1
Drive Test #2
Performance Exerciser

CZRLLAO

Compatibility Test

CZRLMAO

Bad Sector File Utility

8.2

DIAGNOSTICS

RLV11 DIAGNOSTICS

The RLV11 subsystem is tested with the same set of diagnostics as the RL11 except that the RLV11 required an additional
test (CVRLAAO) for the MAINT command. Kit number
73285 includes kit ZJ283 plus CVRLAAO. Since CVRLAAQ
is a diskless controller test it can handle either an RLO1 or an
RLO2.

8.3

RLS-A DIAGNOSTICS

The original set of diagnostics (Table 8-3) could handle only
the RLO1 drives. The new set of diagnostics (Table 8-4) can
handle RLO2 only (except AIRLACO which can handle either
an RLO1 or an RLO2). Kit number ZF241 includes the six
diagnostics plus the DECX8 module.

Table 8-3

Name

AJRLAAO
AJRLBAO
AJRLCAO

RLS8-A/RL01 Diagnostics

Description
Diskless Control Test
Drive Test #1
Drive Test #2

Compatibility Verification
Performance Exerciser

AJRLDAO
AJRLEAO
AXRLAAO
AJRLGAO
Table 8-4

DECX8 Module
Pack Verification

RL8-A/RL02 Diagnostics
Description

Name

AJRLACO
AJRLHAO
AJRLIAO
AJRLJAO
AJRLKAO
AJRLLAO
AXRLBAO
8.4
8.4.1

Diskless Control Test
Seek/Function
Read/Write
Drive Compatibility
Performance Exerciser
Pack Verify
DECXS8 Module

DIAGNOSTIC SUPERVISOR
Hardcore Questions

The statement ‘“‘“TYPE TWO CHARACTERS FOUR
SECONDS APART”’ will be asked when no clock is
on the system. The system will then subdivide the
spacing for use as a clock.

DIAGNOSTICS

The prompt “‘DS-C>’" is requesting one of eleven

superior ‘‘commands ,’ which are:
STA — STArt diagnostic and then produce questions for generation of the diagnostic parameter
(‘“‘P’’) tables.

RES — REStart diagnostic at the point following
the hardware questions. The ‘‘P’’ tables set up by
the STA command will be used.

CON — CONtinue the diagnostic at the beginning
of the subroutine that was being executed when
the diagnostic was halted by an error or a control

“C.
PRO — PROceed testing with the diagnostic at
the starting address of the subroutine following
the one that caused the error report.
DIS— DISplay the hardware ‘‘P’’ tables for all
the drives being tested.

DRO

DROp the desired units from being

tested. ‘‘UNITS, *’in this case refers to the ‘P’
table unit numbers, not necessarily the device unit
numbers.

The DIS command will give the

operator the device unit number.
ADD — ADD units back into the testing sequence
after they had been dropped by the DRO com-

mand.

’

PRI — PRInt any performance or statistical tables
accumulated by the diagnostic.

FLA — FLAgs command — The current setting
of all the flags set up under the STA command are
printed out for inspection.
ZFL — Zero FLags command — All current flags
set up by the STA command are cleared by this

command.

CCI — Create Core Image command — This
command enables a BIC file to be created on these

diagnostics to be run under the XXDP media. (See

listing for directions.)

DIAGNOSTICS

Program Parameter Changes — Type in any combination of the following parameters to affect the indicated
commands.

With the STA command:

DS-C>STA/TESTS: Insert test numbers shown
in the appropriate diagnostic listing; e.g., 1:2
means tests 1 and 2, or 1-5:8-10 means tests 1

through 5 and 8 through 10.

DS-C>STA/TESTS:6/PASS: Insert the-number
of passes the diagnostic should take before halting.

DS-C>STA/TESTS:6/PASS:2/FLAGS: Insert
any of these mnemonic(s) representing a program
flag(s):

® HOE — Halt On Error
® LOE — Loop On Error
® JER — Inhibit Error Report

@ IBE — Inhibit Basic Error reporting
@ [XE — Inhibit eXtended Error reporting
© PRI — PRInt messages on line printer
®PNT — PriNT test numbers as they are being
executed

® BOE — Bell On Error

® UAM — Bypass manual intervention tests

@ISR — Inhibit Statistical Reports

e DR — Inhibit DRopping of units

DS-C>STA/TESTS:BOE:IDR/EOP: Insert a
number equalling the pass intervals at which the
end of pass message will be printed; e.g., every
other pass, every third pass, etc.

EXAMPLE:

Using all the possible parameter changes, the STA
command would look like this:

DS-C>STA/TESTS:6/PASS :Z/FLAGS JER:PNT:

BOE:IDR/EOP:3

DIAGNOSTICS

With the RES command: Use TESTS, PASS,

FLAGS and/or UNITS to be tested; e.g., DSC>RES/TESTS:6/UNITS:1 (this will run only
test 6 on the device specified in ‘P’ table 1).
With the other commands:

8.4.2
1.

CON command:

Use PASS or FLAGS only

PRO command:

use FLAGS only

DRO command:

use UNITS only

DIS command:

use UNITS only

ADD command:

use UNITS only

PRI command:

no variations

FLLA command:

no variations

ZFL command:

no variations

CCI command:

use TESTS, PASS or FLAGS

Console Controls

Control “‘C’’ causes testing to cease and a return to the
start (DS-C>).

Control *‘Z’’ causes default values to be taken in any of
the three operator dialogues.

Control “‘O’” causes a supression of typeouts for the
remainder of the diagnostic or until another control ‘O’
1s typed.
8.4.3
1.

Hardware Questions

Supervisor ‘‘P”’ (Parameter) tables are built here, one
for every unit to be tested.
““UNITS’’ pertains to the ‘‘P’’ table number, not the
device unit number. If there is doubt as to which unit
number has been assigned to which drive, the DIS command (see above) will supply the necessary information.

8.4.4

Software Question

““CHANGE SW(L)?”’ asks if any of the software parameters
are to be changed. A *‘Y’’ will cause various questions to be

asked. For details, refer to the individual program document.

CHAPTER 9
CHECKS, ADJUSTMENTS AND ALIGNMENTS

9.1

INTRODUCTION

Many of the checks, adjustments and alignments described in

this chapter deal with the Drive Logic Module (DLM). Because there are three different versions of the DLM, it is

necessary to first identify the particular type of module on the

drive being serviced. The three versions are shown in Figure
2-9.

® Version 1 (Part No. 54-12175) can be identified by the

fact that the two Berg connectors in the lower right hand

of the module point down, while the other two along the
bottom row point up. This board will only operate in an

RLOL1.

® Version 2 (Part No. 54-13531), has all four connectors

in the bottom row pointing up, as in Figure 2-9. This
module will function in an RLO1 or an RLO2.

® Version 3 (Part No. 54-14025) has the same arrangement of Berg connectors as Version 2,.but it also has test
lugs (shown in Figure 2-9) that are not on either of the

other two modules.

The service jumpers used in these checks and adjustments are

listed in Table 9-1.

Table 9-1 Service Jumpers for Drive Logic Module

Defeat

Version
1

2
3

Cover

Defeat

Switch

POS SIG SK TO

Head1

E33-3to

TP8to

El7-6to

—

E33-7

ground

E17-7

Defeat

E54-12to TP6to

E10-8 to

E54-7

E10-7

ground

Select

—

TPI9 to

TP6to

TP23to

TP20

TP2I to

ground

TP24

TP22

Tables 2-3, 2-4 and 2-5 list ground points.
In the course of performing some of the alignments, it is
necessary to select Head 1 and then later reselect Head 0. The

methods for accomplishing this are shown in Table 9-2.

CHECKS, ADJUSTMENTS AND ALIGNMENTS

Table 9-2

Methods for Selecting Heads

For a PDP-11-based subsystem:

DLM Version 1 or 2

DLM Version 3

Load DZRLCXX or
CZRLIXX and run
head alignment routine.

Jumper TP21 to TP22
to select Head 1.
Removing the jumper

Having the WRIT

selects Head O.

PROT switch in selects
Head 1: having it out
selects Head 0.
For a PDP-8-based subsystem:

Load AJRLBXX or

Same as above

AJRLHXX and run

head alignment routine.
Having the WRIT PROT
switch in selects Head 1;
having it out selects
Head 0.

NOTE

If diagnostics are not available, toggle in the appropriate

program shown in Chapter 7.

9.2

VOLTAGE CHECKS

The DC Servo module template indicates voltage test points.
Check the following voltages.

Voltage

Limits

+Vin
un
+5V
+8V

+14V to +18V
—14V to —18V
+4.85V to +5.35V
+7.7V to +8.3V
—7.7V to —8.3V

—8V

The regulators on the DC Servo module are not adjustable. If
a voltage is out of tolerance, the faulty FRU should be
replaced.

The +5V can be killed by a blown pico fuse, a thermal switch

on the DC Servo heat sink, an overvoltage crowbar, or a
home switch on the positioner not closed during power up.

CHECKS, ADJUSTMENTS AND ALIGNMENTS

9.3

SECTOR TRANSDUCER OUTPUT CHECK

This check verifies a correct output of the sector transducer.

Required Tools:

Oscilloscope with probe

DIP clip

Check:
1.

Remove both top cover assemblies.

Install cartridge.

Defeat the cover interlock (Table 9-1).

Depress LOAD switch.

While waiting for the heads to load onto the
pack, set up the oscilloscope (sync internal

negative-going). Set vertical coupling to AC.
6a.

Version 1 of DLM: Place oscilloscope probe on
E8 pin 8.

6b.

Version 2 of DLM: Place oscilloscope probe on
TP14.

6¢c.

Version 3 of DLM: Place oscilloscope probe on
TP14.

The signal displayed on the oscilloscope should
be similar to that shown in Figure 9-1. The peak
output of the negative portion of the waveform

should be between 0.35Vp and 1.5Vp.
+V.

N
1

35V.

1.5V. \

v [V

TIME = 100 uSEC/DIV.

VOLTS = 200 MV/DIV.

Figure 9-1

Sector Transducer Output

-V.

MA-1602

CHECKS, ADJ USTMENTS AND ALIGNMENTS

NOTE

The waveform must be negative-going first.
8.

If the specification cannot be'met, the sector
transducer must be replaced.

SECTOR PULSE TIMING CHECK
This is a check of the sector pulse width and repetition rate.
The repetition rate is a function of spindle speed.
9.4

Required Tools:

Oscilloscope with probe.
B.

Check:

1.
2.

Remove both top cover assemblies.
Defeat cover interlock (Table 9-1).

3.
4.

Install cartridge.
Depress LOAD switch.

5a.
5b.
5c.
6.

9.5

Version 1 of DLM: Place the probe on TP9.
Version 2 of DLM: Place the probe on TP11.
Version 3 of DLM: Place the probe on TP11.
Set the oscilloscope to sync internal, negativegoing. The signal displayed on the oscilloscope
should be the same as in Figure 9-2. Sector
pulse width should be 62.5 microseconds.
Correct disk speed ranges from 594 microseconds to 639 microseconds, with 624 being
the desired norm. The sector pulses should be
stable at some time period within that range.

POSITIONER RADIAL ALIGNMENT

The positioner radial alignment checks assure that the
conditions listed below are true.

The servo bursts (as read by the read/ write heads)
must occur during the correct time relative to the
sector pulse (as detected by the sector transducer at
the hub). Because the sector transducer is fixed,
changing the head postioner location will affect
this timing relationship.

The servo burst/sector timing relationship must be
the same at track O as it is at the innermost track
because the head carriage moves straight toward
the center of the disk.

a1y

TV Vv

g 8

L e aun amm 4

—

ailag
A g

A a8

CHECKS, ADJUSTMENTS AND ALIGNMENTS

vy Vv

]62.5 1S

625 us

TIME = 100 us/DIV.
VOLTS = 2V/DIV.

Figure 9-2
A.

CZ-1078

Sector Pulse Timing

Tools Required:
l.

Oscilloscope with two probes

Two flat-blade screwdrivers

One Phillips head screwdriver

4a.

One DIP clip, one pin-to-pin jumper and one

4b.

Two pin-to-pin jumpers and two DIP clips

Diagnostic listed in Table 9-2.

test lead, or

Positioner Alignment Check:
1.

Remove both top cover assemblies.

Defeat POS SIG, SKTO and cover interlock
(Table 9-1).

Place the Read/Write module box assembly up
Now
e

and out of the way of the carriage assembly.

Install cartridge.
Depress LOAD switch.

Wait for heads to load onto the pack.
Disable servo drive to the carriage by disconnecting the in-line connector (Figure 9-3).

Select Head 1 (Table 9-2).

CHECKS, ADJUSTMENTS AND ALIGNMENTS

9. Place the Channel B oscilloscope probe on
TP2 of the Read/ Write module (data) and
Channel B ground on any signal ground
(TP1 - TP4).

10a. Version 1 of DLM: Place Channel A probe
on TP9 (SEC TIME) and Channel A ground
on any signal ground (TP1-TP4).

10b. Version 2 of DLM: Place Channel A probe
on TPI1 (SEC TIME) and Channel A
ground on any signal ground (TP1-TP4).
10c. Version 3 of DLM: Place Channel A probe
on TPI1 (SEC TIME) and Channel A
11.

ground on any signal ground (TP1-TP4).
Set the oscilloscope to sync internal,
negative-going on Channel A and observe
the waveform shown in Figure 9-4.
PLUG FOR
LOWER HEAD?

PLUG FOR

S
UPPER HEAD

HOLDING
FLANGES

““ml

SR
S
& &

g
N

IN-LINE

SERVO

CONNECTOR

POSITIONER

ASSEMBLY

/
CZ-2054

Figure 9-3

Positioner and Read/Write Module Box

Assembly
NOTE

S1 and S2 servo bursts may not appear in the positive/

negative proportions shown in Figure 9-4, depending
upon which track the head is centered on.

man
o o

Lisdlbiaeta

CHECKS, ADJUSTMENTS AND ALIGNMENTS

HEADER

i il

| SRR
AR S

CHAN. B

Ll
¥y -t

111

GND. REF.

TNk

15 + 3 4S

'M“l“’"ISR
uc"nuwuwflw\"\m.w w

CHAN. A
SECTOR PULSE

GND. REF.

I
TIME: 10 MICROSEC/DIV.

Figure 9-4
12.

CHAN: "A”

2 VOLTS/DIV.

CHAN:

500 MILLI VOLTS/DIV.

“B”

CZ-1077

Servo Bursts and Sector Pulse
Measure the time between the negative-going

edge of the sector pulse and the beginning of
the S1 servo burst when the positioner is at

Cylinder 0. Record this value.
13.

Select Head O (Table 9-2).

14.

Repeat Step 12 for Head 0. Record this value.

15.

If the difference between these two values is
greater than six microseconds, replace Head
0 (see the RLOI/RLO2 Disk Drive Technical
Manual) and go back to Step 14. If either of
these two values falls outside of the 15 & 3
microsecond specification, perform the

alignment procedure (Part C) below. Other-

wise, continue.

Manually move the carriage to the last data
track (track 255 on an RLO] ortrack 511 on an
RLO2). As Head O enters the inner guard band,

S1 disappears. Move the positioner back until

S1 appears.
Measure the time between the negative-going
edge of the sector pulse and the beginning of

the S1 servo burst when the positioner is at the
last cylinder.
roseconds.

It should be

If so,

3 mic-

the check is complete.

Otherwise perform the adjustment (Part C)

below.

CHECKS, ADJUSTMENTS AND ALIGNMENTS

Positioner Alignment

. Using Figure 9-5 as a guide, locate the six
largest Phillips screws on the positioner baseplate.

2. Loosen (but do not remove) the six screws
holding down the positioner.
THESE 2 SCREWS ARE
NEAREST THE MOTOR

SHAFT AND ARE THE LONGEST
OF THE SIX MOUNTING

(6
(i

HEADS HOME SWITCH

& 2

(]

{

N &

ADJUSTING SCREW

POSITIONER

ADJUSTING
|

SLOT

POSITIONER

ADJUSTING SLOT

CZ-1079

Figure 9-56

Positioner Assembly

CHECKS, ADJUSTMENTS AND ALIGNMENTS

Take the two flat-blade screwdrivers and insert
them into the adjusting slots on the positioner.

Move the positioner assembly against the right
hand side of the drive (toward the Read/Write
module).

Manually move the carriage to its approximate

Using the two flat-blade screwdrivers in the
adjusting slots, slide the positioner baseplate

center of travel.

until the 15 £ 3 microsecond specification between the fall of the sector pulse and the rise of

the S1 servo burst can be met. (See Figure 9-4.)

NOTE

|
Equal pressure must be exerted on the screwdrivers when

sliding the positioner to ensure that the baseplate is kept

straight.

Tighten the six retaining screws in small increments.

Check the 15 = 3 microseconds specification
for Head O at track O and the last track. If the

head 1s within the specification, the check is
complete. Otherwise, repeat the adjustment
(Part C) above.

HEAD ALIGNMENT
This procedure will ensure that the two heads are in line

with each other to cut down on the servo tracking time
when switching heads.
NOTE
The Positioner Radial Alignment (Paragraph 9.5) should
be done before attempting the head alignment, so that any

head skew that may be present will be detected BEFORE
the head alignment.

A. Required Tools:
1.
2.

Oscilloscope with one probe
3/32” Allen wrench

3. Flat-blade screwdriver
4a. One DIP clip, one pin-to-pin jumper and one

~ test lead (alligator clip), or
4b. Two pin-to-pin jumpers and two DIP clips

Diagnostic listed in Table 9-2

CHECKS, ADJUSTMENTS AND ALIGNMENTS

NOTE

No alignment cartridge is required.
B. Alignment Check:

1.
2.

Remove both top cover assemblies.
Defeat SKTO, POS SIG and cover interlock
(Table 9-1).

NOTE

These jumpers enable the diagnostic routine to work by

disabling the Seek Timeout Error.

3. Place the Read/ Write module box assembly
Nownk

up and out of the way of the carriage assembly.
Install cartridge.

Depress the LOAD switch.

Wait for the heads to load onto the pack.
Disable servo drive to the carriage by
disconnecting the servo in-line connector

(Figure 9-3).

Select Head 1 (Table 9-2).

9. Place oscilloscope probe A on POS SIG and
connect probe A ground lead to ground. Set
the vertical gain for 1 volt per division. Set

oscilloscope horizontal circuit to free run
(unsynced). The horizontal sweep rate is not
important.

10. Manually move the positioner back to the
head loading ramp and then forward toward
the center of the disk while watching the

READY indicator and the oscilloscope pres-

entation of POS SIG. These two will indicate
the position of the head relative to the tracks
written on the disk surface.

When the head is over the head loading zone
(outside the outer guard band), POS SIG
floats slowly toward +8 V and the READY
indicator is on. When the head is over the
outer guard band, POS SIG is at maximum
negative (about —1.5 V) and the READY indicator is off. Asthe head approaches cylinder 0,
POS SIG starts to move up toward 0 V and the
READY indicator turns on.

CHECKS, ADJUSTMENTS AND ALIGNMENTS

As the positioner continues to move forward,
the READY indicator remains on and POS

SIG is 0 V when the head is directly over the
center of cylinder 0. POS SIG continues to

move in the positive direction as the head
passes cylinder 0 and reaches its maximum
normal value of about +1.5 V as the head is
halfway between cylinder 0 and cylinder 1.
POS SIG then starts down as cylinder 1 is

approached and is at 0 V when the head is over

cylinder 1. If cylinder 1 is overshot, POS SIG
goes negative, then back to 0 V over cylinder 2,

and so on.
By observing the oscilloscope and READY
indicator, it is possible to locate cylinder 0 by

moving the positioner into the outer guard
band (POS SIG is negative and the READY
indicator is off), and then moving the positioner forward to cylinder 0 (POS SIG rises to
0 V and the READY indicator turns on). The

verification process is to move the positioner
in reverse and observe the POS SIG go negative as the reverse and observe the POS SIG go
negative as the READY indicator goes off and
see the POS SIG stay negative as the head
moves over the outer guard band.

11.

Position Head 1 directly over cylinder 0.

13.

Hold the positioner still and select Head 0.
If POS SIG is within 0.5 V of 0 V, then verify

that Head 0 is over cylinder 0. If both of these

criteria are met, the head alignment is satisfactory. Be sure to reconnect the in-line servo
connector before unloading the heads. The

head alignment check is complete. Go on to

the next check.

If either of these criteria is met, go to Step 14.
14.

If POS SIG was not within 0.5 V of ground or
Head 0 was over a cylinder other than 0, per-

form the head alignment procedure (below).

CHECKS, ADJUSTMENTS AND ALIGNMENTS

Head Alignment Procedure
1.

Move the positioner all the way back to the
home position so that the heads are up on the

ramp. Loosen the mounting screw for Head 0
and move Head 0 all the way back to its
extreme position against the stop.
W

Select Head 1.

Move the positioner so that Head 1 is directly

over cylinder 0.

= o

Select Head 0.
Hold the positioner still while sliding Head 0
forward by twisting a screwdriver between the
end of the head assembly and the stop.

Observe the READY indicator and POS SIG
and move Head 0 until it is over cylinder 0.
Select Head 1.
Verify that Head 1 is within 0.5 V of 0 V and
that Head 1 is still over cylinder 0. If these two
criteria are not met, repeat the procedure.
Snug the mounting screw for Head 0 while the
heads are over the surface. Move the posi- tioner to its home position before tightening
the mounting screw. Do not overtighten the
SCrew.

Verify that tightening the mounting screw did
not change the alignment enough to make it

10.

unsatisfactory. To do this, select Head 1, move
it over cylinder 0, select head 0, and verify that
it, too, is over cylinder 0 and within 0.5 V. If
these specifications cannot be met, repeat the
procedure. Otherwise, continue with Step 10.
If the head cable clips are on the Read/ Write
module box, replace the head cables in the
clips, and go to Step 14.

If the head cable clips are on the positioner,
proceed with Step 11.
11.

Manually move the heads toward the spindle,
as far as they will go.

12.

Mount the head cables into the clips on the
cable guide. The cable for the lower head
should go into the lower clip.

CHECKS, ADJUSTMENTS AND ALIGNMENTS

13.

Ensure that the cables do not touch the corner
of the cable guide bracket (as shown in Figure

9-6). If they do, readjust the cables in the clips
so that they do not touch the corner of the
bracket.

<
q

READ/WRITE
|~ MoouLE

h’to

ASSEMBLY

PLUG FOR

FLANGES,

LOWER HEAD

PLUG FOR

UPPER HEAD

IN-LINE

PLASTIC INSULATING

NEWER HEAD

SERVO

CABLE GUIDE

CONNECTOR

ASSEMBLY

STICKER

POSITIONER
ASSEMBLY

CABLES MUST NOT

TOUCH THIS BRACKET
WHEN HEADS ARE
FULLY EXTENDED

NEWER RLO1 AND ANY RLO2
CZ-0136

Figure 9-6

Adjusting the Head Cables

NOTE
The positioner MUST be fully extended when performing

this check.
-

NOTE

The Read/Write module box assembly will have to be

removed from the baseplate holding flanges and held in

one hand to readjust the cables, as the cables are not long

enough to reach.

14.

Replace the servo in-line connector to unload
the heads. At this point, the procedure is
finished.

CHECKS, ADJUSTMENTS AND ALIGNMENTS

9.7

READ SIGNAL AMPLITUDE CHECK

This procedure checks the amplitude of the read signal in

the read amplifier.
A. Required Tools:

Oscilloscope with two probes

2a. One DIP clip, one pin-to-pin jumper and one
test lead (alligator clip), or

2b. Two pin-to-pin jumpers and two DIP chips
3.

Diagnostic listed in Table 9-2

B. Check:

1.
.

Remove both top cover assemblies.
Defeat SKTO, POS SIG and the cover interlock (Table 9-1).

Place the Read/ Write module box assembly
up and out of the way on the carriage

assembly.

Install cartridge.
Depress the LOAD switch.
Wait for the heads to load.

Disable the servo drive to the carriage by dis-

connecting the servo in-line connector.

8a. Version 1 of DLM:

Place Channel A

8b. Version 2 of DLM:

Place Channel A

8c. Version 3 of DLM:

Place Channel A

probe on TP9 (Sector Time).

probe on TP11 (Sector Time)..
probe on TP11 (Sector Time).

Place the Channel B oscilloscope probe on
TP2 of the Read/ Write module (Servo Data).

10. Set the oscilloscope to sync internal on Chan-

nel A, negative-going, and observe the waveform shown in Figure 9-4.

11.

Move the positioner forward until the S1
servo burst loses amplitude and finally disappears. This will be the inner guard band area of
the disk.

12.

Pull the positioner back slowly until the Sl
servo burst returns. This will be the last data
track on the disk (track 255 on an RLOI, track
511 on an RL02).

CHECKS, ADJUSTMENT AND ALIGNMENTS

13.

Measure and record the peak-to-peak amplitude of the S1 burst for both heads (see Table
9-2 to select heads). The minimum allowable

amplitude at the innermost track is 500 mv.

14.

Reposition the carriage to track 0 by moving

the positioner back until S2 disappears (outer
guard band) and then forward until S2
reappears.

15.

Measure and record the peak-to-peak amplitude of S1 for both heads. The maximum
allowable amplitude of the S1 burst on track 0

is 2.25 V.
16.

Replace either or both heads that do not meet
the specification.

NOTE
‘
If both heads fail to meet the specification, it is possible

that the Read/Write module is bad. Replace the module

(see the RLOI/RLO2 Technical Manual) and repeat the
procedure. If a head is replaced, it must be aligned (see

Paragraph 9.6). The radial alignment must also be
checked (Paragraph 9.5).

9.8

SPINDLE RUNOUT CHECK

Excessive runout in the spindle assembly or cartridge can
cause severe tracking problems for the positioning system.

This check will determine whether:
1. Runout exists or does not exist
2. Runout is in the cartridge

3. Runout is in the spindle
A.

Required Tools:
1.

Oscilloscope with probe and ground leads

DIP clip

Jumper

Several test cartridges

Runout Check:
1.

Remove both top cover assemblies.

Place the Read/Write module box assembly up

Defeat cover interlock (Table 9-1).

and out of the way of the carriage assembly.

4.
5.

Install cartridge.

Depress LOAD switch.

CHECKS, ADJUSTMENTS AND ALIGNMENTS

Wait for heads to load onto the pack.

Disable servo drive to the carriage by discon-

necting the in-line connector (Figure 9-3).

8a. Version 1 of DLM: Place Channel A oscilloscope probe on E11 pin 7 (Position Signal) and
place Channel A ground on TP7 (Integrator
Ground).
8b. Version 2 of DLM: Place Channel A oscillo-

scope probe on TP15 (Position Signal) and
place Channel A ground on TPS (Integrator
Ground).

8c. Version 3 of DLM: Place Channel A oscilloscope probe on TP15 (Position Signal) and
place Channel A ground on TP5 (Integrator
Ground).

9. Set the oscilloscope to sync internal, negativegoing, and observe the waveform in Figure 9-7.

’

NOTE

Ideally, the oscilloscope will display a nearly straight line

of dots.

PCl)SITI(I)N SIG NA!I_

<350 ;\2“_/ NI
-

' |

i‘%“‘
b ['YRY)

TIME = 5MS/CM
VOLTS = 200MV/DIV.

Figure 9-7

.
CZ-1068

Position Signal

10.

The amplitude of the runout should be no

11.

If the specification cannot be met, runout exists
and another cartridge is needed to determine if
the runout exists in the cartridge or the spindle.

greater than 350 mv.

CHECKS, ADJUSTMENTS AND ALIGNMENTS

To confirm a seating problem, re-seat the car-

12.

tridge and repeat the runout check. If the runout
is within specification, the problem has been
solved. If the runout is still out of spemficatlon
continue with Step 13.

13.

Spindle and cartridge are still suspect, so 1nstall
a second cartridge and repeat check. If runout is
now within the specification, the first cartridge

is bad. If the runout check fails once more,
assume that the spindle bearings are bad and
replace the spindle assembly.

9.9

POSITION SIGNAL GAIN CHECK

Insufficient amplitude of the Position Signal could result in
the carriage not being able to hold itself on track, resulting in
read errors and possible seek errors. Too high an amplitude

could result in a jitter which, in turn, emits a vibrating-type
noise from the carriage that may generate seek timeout
CITOIS.

Oscilloscope with probe and ground leads

One DIP clip, one pin-to-pin jumper

Gain Check:
1.

Remove both top cover assemblies.

Place the Read/Write module box assembly up
and out of the way of the carriage assembly.

Required Tools:

Defeat SKTO and cover interlock (Table

9-1).

Nowva

Install cartridge.
Depress LOAD switch.
Wait for heads to load onto the pack.

Disable servo drive to the carriage by disconnecting the in-line connector (Figure 9-3).
. Version 1 of DLM: Place Channel A oscilloscope probe on E11 pin 7 (Position Signal) and
place Channel A ground on TP7 (Integrator

Ground).

8b. Version 2 of DLM: Place Channel A oscilloscope probe on TP15 (Position Signal) and
place Channel A ground on TP5 (Integrator

Ground).
8c. Version 3 of DLM: Place Channel A oscilloscope probe on TP15 (Position Signal) and
place Channel A ground on TP5 (Integrator

Ground).

CHECKS, ADJUSTMENTS AND ALIGNMENTS

Observe the waveform in Figure 9-8 while
manually moving the carriage back and forth.

10. Measure the peak-to-peak deviation of the
Position Signal amplitude about the ground
reference. It should be 3.7 = 0.7 volts.

POSITION SIGNAL
®

L XY

[]

®
[]

[

':.

YHHHHHSHHHHH-HHHHH
¢
]

GND. REF.

[

éle

pe-)

(]

ryx. 2

)

".
-

[}

TR
® 1)

.' @

o |®

e | e

“@

T @ @

e ®

e
®
®

[

o
@

®
[}

TIME = 5 MS/DIV.
VOLTS = 1 VOLHDIV.

Figure 9-8

9.10

Position Signal Gain Check Waveform

TACHOMETER AC NOISE PICK-UP CHECK

This procedure checks the amount of noise being picked up
by the tachometer. If the noise is excessive, the positioner
will have a hard time holding on to a track signal. In this case,

the READY light may flicker.
A.

Required Tools:

1. Oscilloscope with probe and ground leads

DIP clip

Jumper

Check:

1. Remove both top cover assemblies.
2. Place the Read/Write module.up and out of the
way of the carriage assembly.
3. Defeat cover interlock (Table 9-1).

Install cartridge.

5. Depress LOAD switch.

6. Wait for heads to load onto the pack.

CHECKS, ADJUSTMENTS AND ALIGNMENTS

Disable servo drive to the carriage by disconnecting the in-line connector (Figure 9-3).

Set the oscilloscope (sync 1nternally) as follows:
a. Channel A probe should be on TP1 of the
DC Servo module (Summing Amp).

b. Channel A ground should be on TP11

of the

DC Servo module (Signal Ground).
9.

Each drive’s summing amplifier output at this

point will look slightly different, but it should
be similar to the waveform shown in Figure
9-9.

SUMMING AMELIFIER OUTPUT
—

A
<600 MV

TIME = 10MS/DIV.
VOLTS = 50MV/DIV.
CZ-1070

Figure 9-9

Summing Amplifier Output

10.

The signal seen should-have-a_peak-to-peak

11.

If the signalis out of tolerance the DC Servo

value of no more than. 600 mv. ~

module could be bad or the drive motor may

be too noisy. Replace the module, and if that
does not solve the problem, replace the drive
motor (see the RLOI/RL0O2 Disk Drive

Technical Manual).

CHECKS, ADJUSTMENTS AND ALIGNMENTS

9.11

VELOCITY PROFILE CHECK

By causing the positioner to perform an oscillating seek, the
velocity profile can be checked for duration, amplitude, and
waveshape.

Required Tools:

1. Oscilloscope with probe and ground leads
2. Toggle-in oscillating seek program shown in
Chapter 7

DIP clip

Jumper

Check:
U
W —

Remove both top cover assemblies.
Install cartridge.

Defeat top cover interlock (Table 9-1).
Depress LOAD switch.

Wait for heads to load onto the pack.
Using the oscillating program shown in Chapter
7, cause an oscillating seek from track O to track
255 (RLO1) or track 511 (RLO2).

7a. Version 1 of DLM: Place the Channel A oscilloscope probe on TP12, place the Channel A
ground on any of the DLM ground points (TP1
through TP6 are ground) and place the external
trigger on E38 pin 12 (SIGN FWD).

7b. Version 2 of DLM: Place the Channel A oscilloscope probe on TP8, place the Channel A
ground on any of the DLM ground test points
(TP1 through TP4 are ground) and place the

external trigger on E25 pin 12 (SIGN FWD).
7c. Version 3 of DLM: Place the Channel A oscilloscope probe on TP8, place the Channel A
|
ground on any of the DLM ground points (TP1
through TP4 are ground) and place the external
trigger on E25 pin 12 (SIGN FWD).

8. Set the oscilloscope to sync internal, positivegoing, and observe the waveform shown in
Figure 9-10.

9. The peak amplitude of the waveform should be’
between 4.6 and 5.0 volts.

10. The maximum seek time should be between 80
and 86 milliseconds.

CHECKS, ADJUSTMENTS AND ALIGNMENTS

| |

TACHOMETER OUTPU1 VELOCITY SIGNAL
_

‘f
4.6 TO

—

Al i

5.0 V

4.6 TO
50V

LI BRI

N %

I
T

[ le\l :: t ] s i 4t i i) t b ard e
¥

I'VI::

pe— 80 TO 86 MS —b

]

BRI

]

B |

| IR LI

TIME = 20 MS/DIV.
VOLTS = 2V/DIV.,

Figure 9-10
11.

rromm

Tachometer Output Velocity Signal

Observe the trailing edge of the waveform (as

indicated’ by an asteriskin Flgure 9-10). There

should be a slight ‘‘stepping’’ slope. If the
observed slope has spikes in it, the positioner
needs replacing as it is not rolling smoothly.

12.

If the other specifications (in Steps 9 and 10)
cannot be met, the DC Servo module is probably at fault.

9.12

SERVO DRIVE MOTOR CURRENT CHECK

One possible cause of seek errors is excessive drive motor
current. This check will determine if there is too much
current.

Required Tools:
1.

Oscilloscope with probes and ground leads
Toggle-in oscillating seek program shown in
Chapter 7

DIP clip

Jumper

Check:
Remove both top cover assemblies.

Defeat top cover interlock (Table 9-1).
Install cartridge.
Depress LOAD switch.

Wait for heads to load onto the pack.

CHECKS, ADJUSTMENTS AND ALIGNMENTS

6. Using the oscillating seek program listed in
Chapter 7, cause an oscillating seek from track
0 to track 255 (RLO1) or track 511 (RLO2).
7. Place Channel A oscilloscope probe on TP3 of
the DC Servo module.

8a. Version 1 of DLM: Place the external trigger on
E38 pin 12 (SIGN FWD).

8b. Version 2 of DLM: Place the external trigger on
E25 pin 12 (SIGN FWD).

8c. Version 3 of DLM: Place the external trigger on
E25 pin 12 (SIGN FWD).

9. Observe the waveform shown in Figure 9-11.
C
o

POSlTlONIIER MOTOR CURRENT

GND. REF. HH+ ::3;. H
\e

--7 1

Tty
-

TIME = 20MS/DIV.

VOLTS = 500MVIDIV.

Figure 9-11

Cz-1072

Positioner Motor Current Check

10. Measure the points called out in the figure and
compare them to the following:

# 1 should be between 750 and 780 mv.

# 2 and # 3 are the midpoints of the waveform
and should be less than or equal to 500 mv.

11.

Failure to meet specifications requires
replacement of the positioner/drive motor
assembly or DC Servo module (see the

RL01/RLO2 Disk Drive Technical Manual).
9.13

ACCESS TIME CHECK

The access time is checked by performing oscillating seeks
and observing the “ready to read/write” signal.

CHECKS, ADJUSTMENTS AND ALIGNMENTS

A. Required Tools:

1.
2.
3.

DIP clip

Jumper

Check:

SR
-

Oscilloscope with probes and ground leads
Toggle-in oscillating seek program shown in
Chapter 7.

Remove both top cover assemblies.

Defeat the top cover interlock (Table 9-1).
Install cartridge.
Depress LOAD switch.

Wait for heads to load onto the pack.
Using the oscillating seek program shown in
Chapter 7, issue a one track seek.

7a. Version | of DLM: Place Channel A oscilloscope prove on E25 pin 12 (Ready to Read/

Write).
7b. Version 2 of DLM: Place Channel A oscilloscope probe on TP 16 (Ready to Read/Write).
7c. Version 3 of DLM: Place Channel A oscilloscope probe on TP 16 (Ready to Read/Write).

—p—

—pn

——

TTrrrrriyrr

T T

(17 MS

Lip bt gl
Pripvarrrr

b
v

aliriqg
Ty

Observe the waveform depicted in Figure 9- 12.

TIME=2 MS/DIV

VOLTS=2 V/DIV

Figure 9-12

CZ-2063

Access Time Check (One Track Seek)

CHECKS, ADJUSTMENTS AND ALIGNMENTS

Measure the time the “Ready to Read/ Write”
signal is low. It should be less than or equalto

17 milliseconds.

10. Issue a seek from track O to track 85 (RLO1) or
track 170 (RLO2) and check to see that ‘‘Ready
to Read/Write’’ is low for slightly less than 55

NN IR

milliseconds. See Figure 9-13.

W
P

—f

-l

LA
L
=

cera b rev

e bl

-t

[

-t

——

—p—

—~f

(55 MS

TIME=10MS/DIV

CZ-2064

VOLTS=2V/DIV

Figure 9-13

Access Time Check (85 or 170 Track
Seek)

11. Issue aseek from track O to track 255 (RLO1) or
track 511 (RL02) and check to see that ‘‘Ready
to Read/Write’’ is low for slightly less than 100
milliseconds. See Figure 9-14.

12. If the specifications are not met, the DLM,
DC Servo module or the positioner itself
could be at fault. (See Paragraph 9.11.)

CHECKS, ADJUSTMENTS AND ALIGNMENTS

—y—

[

——

—rp—

—

| IR L]

bEs

ity

rtryrtTryrvyverad

——

—

—p—

“4

i1
LR
LR

TIME=20 MS/DIV

CZ-2065

VOLTS=2 V/DIV

Figure 9-14

Access Time Check (255 or 511 Track

Seek)

CHAPTER 10
SERVICE TIPS

10.1

LOSS OF +5V SYMPTOM

If the unit does not function and the WRITE PROTect lamp is
dim, check the +5V.

10.2

LOSS OF +5V CAUSES

If the +5V is missing but the +8YV is present the following
causes should be checked (in addition to a defective reg-

W
-

ulator).
. Pico fuse on DC Servo Module.

. Thermal switch on DC Servo Module heat sink.

+5V overvoltage crowbar.

. Home switch on positioner not closed.

10.3

HEADS RETRACT IMMEDIATELY AFTER

LOADING
If the heads retract immediately after loading, the head cables
may be reversed. Also, the positioner radial alignment may
be off. (Positioner radial alignment is described in Paragraph

9.5.)
10.4

LOAD, READY, AND FAULT INDICATORS

ALL ON
If those three indicators are all on, check the cabling from the
controller. See Paragraph 10.5.

10.5

RL11 /O CABLING

On RL11 systems it is fairly easy to have the I/O cabling
reversed because of early documentation errors. The correct
method is to have the BCO6R red stripe toward the top of the

M7762, the BCO6R red stripe up at the transition connector,
and the BC20J cable pointing down at the transition connector.

10.6

EARLY RL11/RLV11 VECTOR ASSIGNMENT

Early RL11/RLV11 Controllers were shipped with a vector
address of 330 instead of 160.

SERVICE TIPS

10.7 ROLE OF CHECKS, ADJUSTMENTS AND
ALIGNMENTS IN TROUBLESHOOTING
A prerequisite to module swapping as a troubleshooting
procedure is to perform one or more of the checks, adjustments and alignments described in Chapter 9.

Example 1:

Header Not Found and Seek Timeout errors

Typical action taken: All modules replaced; head alignment checked—problem not solved.

Solution: Radial alignment is off due to excessive head
skew. This can be determined and corrected by the
Positioner Radial Alignment procedure (Paragraph 9.5).
Example 2:

Write Gate errors

Typical action taken: All modules replaced; head alignment checked; radial alignment checked—problem not
solved.

Solution: Excessive spindle runout requires replacement of
spindle. This can be determined by the Spindle Runout
Check (Paragraph 9.8).

Many other problems can be solved by the checks and adjustments described in Chapter 9.

10.8 INTERMITTENT READ CHECK ERRORS

There is a new head cable guide designed to reduce the
number of intermittent read check errors. See Paragraph
I1/2.7.1 of the RLOI/RLO2 Technical Manual.

NOTES