HP 7957A, 7058A Hardware Manual

HEWLETT -PACKARD

HP

7957 A

AND

HARDWARE

HP

7958A

DISC

SUPPORT

DRIVES

MANUAL

CERTIFICATION

Products,
have
Packard
taining

Hewlett-Packard's
the

National

Bureau's

The

ments

materials,

been

provided

specifications.

to

this

order

Bureau

calibration

Hewlett-Packard

of

FAR 52.246-15.

parts,
in

is

calibration

facilities.

and

accordance

Actual

on

file

of

Standards

Quality

services

inspection

and

available

measurements

Program

with

to

the

furnished

all

extent

satisfies

on

applicable

and

test

for

examination.

are

traceable

allowed

the

this

order

Hewlett-

data

by

require-

per-

to

the

HP 7957 A AND 7958A DISC DRIVES

HARDWARE SUPPORT MANUAL

Manual

Microfiche

Printed: SEPTEMBER 1987
Printed in

This manual covers the following models:
HP

7958A.

In addition
following options: 015, 550.

U.S.A.

to

part

number: 07957-90903

part

no. 07957-90803

MODELS COVERED

OPTIONS COVERED

the standard model, this manual covers

HP

Edition 2

E0987

7957A

and

the

r11;-

a!~

HEWLETT -PACKARD

P.O. Box 39, Boise, Idaho 83707-0039

HEWLETT

PACKARD

Notice

The

information contained in this document

is

subject

to

change without notice.

HEWLETT-PACKARD

MATERIAL, INCLUDING, BUT NOT
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. HEWLETT-PACKARD shall
not

be liable

furnishing, performance

HEWLETT-PACKARD assumes no responsibility
that

is

This document contains proprietary information, which
No

part

prior written consent

for

errors contained herein

not furnished

of

this document may be photocopied, reproduced

The Federal Communications Commission has specified

be brought

MAKES NO WARRANTY

LIMITED

or

for

incidental

or

use

of

this material.

by

HEWLETT-PACKARD.

of

HEWLETT-PACKARD Company.

Copyright © 1986,1987

FOR

U.S.A.

to

the attention

FEDERAL

RADIO

of

the users

COMMUNICATIONS COMMISSION

FREQUENCY INTERFERENCE

STATEMENT

OF

ANY KIND

TO,

THE

or

consequential damages in connection with

for

the use

by

HEWLETT-PACKARD

or

reliability

is

protected by copyright. All rights are reserved.

or

translated

ONLY

that

of

this product.

WITH

IMPLIED

of

to

another language without the

the following notice

REGARD

WARRANTIES

its software

TO

on

equipment

THIS

OF

the

Warning: This equipment generates and

that

is,

properly,

to

radio and television reception.

Class B computing device in accordance with the specifications in

Rules, which are designed
installation. However, there

If

tion.
mined
ference by one
computer with respect
puter into a different branch circuit.
field service representative
prepared by the Federal Communications Commission helpful:
Radio-TV Interference Problems". This booklet
Office, Washington, DC 20402. Stock No. 004-000-00345-4.

2

this equipment does cause interference

by

turning the equipment

in strict accordance with the manufacturer's instructions, may cause interference

to

provide reasonable protection against such interference in a residential

is

no guarantee

or

more

of

the following measures: re-orient the receiving antenna; relocate

to

the receiver; move the computer away

for

uses

radio frequency energy and

It

has been type tested and found

that

interference will

to

radio

or

television reception, which can be deter-

off

and on, the user

If

necessary, the user should consult the dealer

additional suggestions. The user may find the following booklet

is

is

encouraged

available

not

from

"How

from

if

not

installed and used

to

comply with the limits

Subpart J

occur in a particular installa-

to

the receiver; plug

the

U.S.

of

Part

15

of

try

to

correct

to

Identify and Resolve

Government Printing

the inter-

the

or

authorized

for

FCC

the

com-

a

Safety Considerations

GENERAL
tion

must

safety

SAFETY

markings

SYMBOLS

-'-

WARNING

I CAUTION I

- This

be reviewed

Instruction
will be
is
instruction
the

Indicates hazardous voltages.

Indicates

The

It

tice that,
adhered
jury.
WARNING
conditions

product

and

instructions

marked

necessary

product

earth

WARNING

calls

attention

if
to,
Do

and

related

for

familiarization

before

manual symbol:

with this symbol

for

the

user

manual in

against damage.

(ground) terminal.

not

correctly

could

not

sign until

are

fully

order

sign denotes a hazard.

to a procedure

result in personal in-

proceed

understood

to

performed

the

documenta-

with

operation.

the

product

when

refer

to

the

to

protect

or

prac-

beyond

indicated

and

met.

it

or

source
power
it
the
secured against

BEFORE
product
power
figuration

If
former
connected
source.

SERVICING

a

to

the

is

likely

product

this

cord,

or

that

must be

APPLYING

is

configured

source

instructions

product

make

to

the

product

supplied

the

any

unintended

according

is

to

sure

earth

input

power

protection

made

POWER -Verify

to

match
to

provided

be

operated

that

the

terminal

wlnng

cord

has been impaired,

inoperative

operation.

the

the

input

in this manual.

with

common

of

terminals,

set.

Whenever

available

power

an

autotrans-

terminal

the

main

that

WARNING

Any servlcmg, adjustment, maintenance,
repair
by service-trained personnel.

Adjustments described in this manual
performed with power supplied
while protective covers
available
result in personal injury.

Capacitors inside this product
charged
ted from

of

this product must be performed only

may

to

the

product

are

removed. Energy

at

many points may,

after

the

product

the

main power source.

has

if

contacted,

may

still be

been disconnec-

and

main

con-

power

or

be

be

the

is

The

CAUTION

It:

calls

attention

dure

or

practice
performed
damage
of
a
conditions

SAFETY
class I
earthing
ground

EARTH

product

terminal. An

must be

to

the

product.

CAUTION

GROUND

and

is

provided

sign denotes a hazard.

to

or

adhered

or

destruction

Do

sign until

are

fully

provided
uninterruptible

from

an

operating

that,

if

not

to,

could

of

part

not

proceed

the

understood

- This

is a safety

with a protective

safety

the

main

proce-

correctly

result in

or

all

beyond

indicated

and

met.

earth

power

the

type

the

end

Next,

fusehold-

then

proper

(nor-

for

first

device.

of

insert

tUfiting

a

To avoid a fire hazard, fuses with
current
mal blow, time delay, etc.) must be used

replacement.

disconnect
Then, using a small flat-bladed screw driver,
turn
the

properly
the
er by pressing

it

rating

and

To

install

the

power cord from

the

fuseholder

cap

releases. Install

rated

fuse into

fuse and fuseholder

the

cap

clockwise until

it

of

the

specified

or

remove a fuse,

cap

counterclockwise until

either

the

cap.

cap

into

the

inward

locks in place.

and

3

Printing History

New editions are complete revisions
contain additional and replacement pages
title page change only when a new edition
into a reprinting unless it appears

of

the manual. Update packages, which are issued between editions,

to

be merged into the manual by the customer. The dates

or

a new update

as

a prior update; the edition does not change when an update

is

published.

No

information

is

incorporated

on

incorpora ted.

A software code

may be printed before the date; this indicates the version level

the time the manual

or

update was issued. Many product updates and fixes

of

the software

do

not require manual changes

product

and, conversely, manual corrections may be done without accompanying product changes. Therefore,
not

expect a one-to-one correspondence between product updates and manual updates.

Edition 1
Edition 2

Hiermit wird bescheinigt, daB das Gerat/System HP 7957
Obereinstimmung mit den Bestimmungen von
funkentstort

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

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

Herstellerbescheinigung

ist.

DECEMBER

SEPTEMBER

A/HP

1986
1987

7958A in

Postverfligung 1046/84

the

is

at

do

Der Deutschen Bundespost wurde das Inverkehrbringen dieses
Gerates/Systems angezeigt und die Berechtigung zur
auf

Einhaltung der Bestimmungen eingeraumt.

Manufacturer's

This

is

to

certify

that

the product(s) HP 7957

with the Radio Interference Requirements

German

tion; the right

Bundespost

to

check the series

was

notified

for

Declaration

A/HP

of

Directive

that

this

equipment

compliance with the requirements was

Oberpriifung der Serie

7958A

is

in accordance

FTZ

1046/1984. The

was

put

into

circula-

granted.

for

Additional Information

If

Test and Measurement Equipment

and/or

used

for

measurements on open setups, the user has

under operating conditions the Radio Interference Limits are still met

of

his

border

premises.

Test and Measurement Equipment

is

operated with unscreened cables

to

assure

at

that

the

4

Contents

Chapter 1
General Information

Introduction
Scope
Options

Related Manuals
Characteristics

Chapter 2

Interface Information

Introductioll

Supported

Interface Signals

of

Drive Interface Characteristics

Drive Operating Features

Drive/Head Selection Sequence
Media Fc)rmat

Sector
Sector

CS/80 Command Set Implementation

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

Manual.

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

I~SDI

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

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

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

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

Features

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

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

Format

Offset

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

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

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

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

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

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

'

.......... : ...........................................................

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

Page

1-1

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

Page

2-1

2-1
2-1
2-1
2-1
2-8

2-8
2-12
2-12
2-12
2-12

Chapter 3

Of

Theory

Introdllction

CS80/ESDI Controller [CEC] PCA-A2

Transfers
Disc
Sparing

Sequencc;~

Sector SI)aring

Track

Errors

Error
Error
Error

Disc Drive :PCA-Al

Drive

Preamplifier Board

Operation

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

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

Format

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

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

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

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

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

Sparing

Definition
Logs
Detection and Correction

Mechanics

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

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

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

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

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

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

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

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

Page

3-1

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

3-5

3-5
3-6
3-6

3-6
3-6

3-7

3-7

3-9

5

Contents (continued)

Motor Control Board
Device Electronics Board

Read/Write Functional Description

W rite Channel
Read Channel.

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

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

Read/Reference Clock Multiplexer

Read/W rite Head Select

Power Supply Assembly PCA-A3

AC Input Circuits
Switch-Mode Supply
Power-On Reset

Summary

Summary

of

Write Data Operation

Of

Read Data Operation

CEC Functional Theory

Bus Structure

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

Microprocessor Data

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

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

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

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

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

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

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

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

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

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

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

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

Bus

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

Control, Clock Generator And Stretcher Circuit
Disc Data Controller (DDC)
Remote DMA Transfer
ESDI PAL

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

IC

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

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

Write Gate And Address Mark Enable Delay Circuit
Error Correction
Format

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

HP-IB Interface
Buffers

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

DMA Bus Arbiter

Local DMA Transfers
Microprocessor Transfers

Remote DMA Transfers
EEPROM (When Used)
LED Control.

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

IC

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

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

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

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

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

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

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

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

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

3-10
3-10
3-10
3-11
3-11
3-11
3-12

.3-12

3-12

~

..

3-12
3-12
3-13

.3-14

3-14
3-15
3-16
3-16
3-16

3-17
3-17
3-1
3-18
3-18
3-18
3-18
3-18
3-19

3-9
3-9
3-9
3-9

7

Chapter 4 Page
Service Information

Introduction
Service Tools
PCA Locations
Cable Connectors
Signal Distribution
Power Distribution
Signal Notation

Block Diagram

Test Points

CS/80 Implementation Information

Initialize

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

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

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

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

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

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

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

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

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

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

Me~dia

Command

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

6

~

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

4-1

4-1
4-2
4-2
4-2
4-2
4-2
4-8
4-8
4-8
4-8
4-8

Contents (continued)

Initiate Diagnostics Command (DIAG)
CS/80 Describe Command Response

Self-Test Controls

Fault/On Line Indicator
Internal Diagnostics
Self

Test

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

Self-Test

Micro:processor
RAM
ROM 'Checksum Test
HP-IB Interface
Buffer Test

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

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

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

Subtests

Self Test

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

Self Test

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

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

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

IC

Loopback Test

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

Hardware/Software Initialization
Select A Drive
Command Complete
ESDI Status Check
Reset Attention
Check

for

Request Configuration

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

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

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

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

Drive Ready

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

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

Disc Drive Assembly PCA-Al Self Test
Seek

Test Without Position Verify
Read Write ECC Test
Build Spare Tables
Copy

EEPROM Logs

Finish HP-IB Interface

Request

Request

Utilities

Status
Status Example

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

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

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

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

to

Self Test Cylinder (for drives with EEPROM only)

IC

Initialization

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

Run Time and Fault Logs (Media Based)

Run Time and Fault Logs (EEPROM Based)
EEPROl\l[
Fault
Physical

Run Time

Error Rate Test

Error Byte Description

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

Status Bytes

Jt\ddress Reporting

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

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

Sectors Read Count (Media and EEPROM Based)

(.ERT)

Log

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

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

CS/80 No Execution Message Utilities

Clear

:Logs

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

Preset

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

Faults/Errors During Error Rate Testing

CS/80 Send

Read Fault Log

Message Utilities

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

Read Run Time Error Log

Read Error (ERT) Log
Measure
Read

Locatc~

Servo Test

Seek Time

Spare Table

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

And Read Full Sector

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

4-9

4-9
4-10
4-10
4-10
4-12
4-14
4-14
4-14

4-15

.4-15

4-16

.4-16

4-16
4-17
4-18
4-19
4-19

4-20
.4-20
.4-21

4-21

4-22

.4-2

.4-22

4-22

4-23

4-23
.4-24
.4-24

4-25

4-26

4-27

4-27

4-28

4-29
.4-30

4-30

4-30
.4-30
.4-31

4-31

4-31

4-32

4-33
4-33
4-34
4-34

7

Contents (continued)

Pattern
Random
Read
Random
Read Revision Numbers

Troubleshooting

Chapter

Only

5

Error

Rate

Test (ERT) (Log Option)

Pattern

Read Only

Error

Error

Rate

Rate

Test (Log Option)

Error

Rate

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

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

Remo,'al and Replacement

Introduction
Preparation
Removal and Replacement

Top
Front
LED
ROM

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

For

Service

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

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

Shroud

Cable Removal.

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

Panel

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

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

RemovaL

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

CS80/ESDI Controller (CEC) PCA-A2
Fan

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

Power
Disc Drive Assembly (HDA)
Tray

Supply Assembly PCA-A3

Removal

and

Replacement

PCA-A I

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

Test (Log Option)

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

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

Test (Log Option)

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

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

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

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

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

.4-35
.4-36
.4-37
.4-38

4-38
4-39

Page

5-1

5-1
5-3
5-3
5-3
5-3
5-4
5-4
5-4
5-5
5-5
5-6
5-6

Chapter

6

Replaceable

Introduction
Ordering

Information

Parts

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

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

Page

6-1

6-1
6-1

8

Figures and Tables

Figure or Table

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure
Figure
Figure
Figure
Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

2-1.

Drive Selection/Deselection Timing

2-2.

Write

2-3.

Write

2-4.

Read

2-5.

TRANSFER REQ/TRANSFER ACK Handshake Timing

2-6.

Index/Sector Timing

2-7.

Track-To-Track Sector Offset

2-8.

Recommended Drive/Head Selection Sequence

2-9.

Sector Offset

3-1.

Disc Recording Format

3-2.

Sector Format

3-3.

Disc Drive Assembly PCA-Al Block Diagram

3-4.

Disc Drive Assembly PCA-Al Functional Elements

3-5.

Disc Drive Functional Block Diagram

3-6.

CS80/ESDI Controller (CEC) PCA-A2 Functional Block Diagram

4-1.

Field Replaceable Assembly (FRA) Location

4-2.

CS80/ESDI Controller (CEC) PCA-A2 Layout and Cable Connections

4-3.

Disc Drive Assembly PCA-Al, Layout and Cable Connections

4-4.

Power Supply (PCA-A3) Test Points and Voltages

4-5.

Cabling Diagram

4-6.

Self-Test Displa y

4-7.

Signal Distribution

5-1.

Order

6-1.

Disc Drive, Exploded View

Gate

Timing During Format

Gate

Timing During Normal Write

Gate

Timing

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

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

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

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

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

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

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

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

of

Disassembly

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Page

2-6
2-7
2-7

2-8
2-10
2-11
2-11
2-12
2-13

3-3

3-4

3-7

3-8
3-25
3-27

4-3

.4-4
.4-5

4-6

.4-7
.4-11
.4-47

5-2

6-3

Table
Table

2-1.

Table

2-2.
2-3.

Table

Table

2-4.

Table

2-5.

2-6.

Table

Table

Table

2-7.
3-1.
3-2.
3-3.
3-4.

Table
Table

Table

Table 4-l.

4-2.

Table

Disc Drive Characteristics
General Configuration Response Bits

Specific Configuration Response Bits

Standard Status Response Bits

~(alid

I-lead

Select

Values

CS/80 Command Implementation
Request Status Summary
Utility Command Summary
I)isc Drive Capacity
llead

Selection
Mnemonic Table
I:<'lag

Status Values
Supported ·Utilities
Error Codes

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

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

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

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

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

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

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

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

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

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

1-1.

Table 6-l. Disc Drive Replaceable Parts

6-2.

Table
Table

j:\bbreviations

6-3.

Code List

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

of

Manufacturers

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

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

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

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

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

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

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

2-6

2-9

2-14
2-15

3-3

3-10
3-20
3-23
4-13
4-40

6-2
6-4
6-5

9

General Information

1

1-1. INTRODUCTION

The Hewlett-Packard 7957A and HP 7958A Disc
Drives are random access, data

for

designed
computer systems. The formatted storage
capacities

megabytes and
manual, unless otherwise specified,

to

refers

The

disc drive employs three (HP
(HP 7958A) nonremovable 130-millimetre
(5.12-inch) discs
face employs one movable head
tracks. The bottom surface
the stack contains continuous prerecorded servo
data which
of

the read/write heads.

Head positioning

and a closed-loop servo positioning system.

Mechanical and contamination protection
discs, heads, and the rotary actuator
a sealed head-disc module. The head-disc module
includes a self-contained air filtration system
which supplies clean air and temperature equaliza­tion throughout the module.

Also included in the disc drive are a
Hewlett-Packard Interface
and

a power supply.

The disc drive contains internal self-test diagnostics
and a fault-finding system which exercise key
functions

automatically
itiated by the host. Go/no-go test results are indi­cated by a green/red indicator
If

a failure occurs, information
failure
the green/red indicators.

can

use with small and medium sized

of

the HP

the

HP

is

used

of

the disc drive. Self test

at

be determined

7957

A and HP 7958A are

130

megabytes, respectively. In this

7957A and HP 7958A.

for

storage media. Each disc sur-

to

ensure the precise positioning

is

performed by a rotary actuator

Bus

power

on

by

storase devices

"disc drive"

7957

A)

or

five

to

service its data

of

the lowest disc in

for

is

provided by

(HP-IB) controller

is

performed

and can also be in-

on

the

front

panel.

on

the cause

viewing the status

of

81

the

the

of

mounting the disc drive in a standard EIA

is

equipment rack

This manual provides all the service information
needed
control functions provided by the host
are described in the installation documentation
provided with the computer.

to

maintain the disc drive. Details

1-2. SCOPE

The manual

a.

Chapter 1 contains a general description

disc drive.

b.

Chapter 2 provides information

Interface between the controller

head disc assembly (HDA).
formation
tion, Request
Command summary.

c.

Chapter 3 describes the operating principles

the disc drive.

d.

Chapter 4 contains servicing information

disc drive, including instructions

the diagnostics tools.

e.

Chapter 5 supplies step-by-step removal

replacement procedures

assemblies and parts in

f.

Chapter 6 lists and illustrates all

replaceable assemblies and parts in

drive.

Appendix A provides a listing and copy
service notes applicable
7958A Disc Drives.

also available.

OF

MANUAL

is

divided into

on

CS/80 Command Set implementa-

Status Summary

six

chapters as follows:

about

It

also contains in-

on

for

all field-replaceable

the

disc drive.

to

the

HP

7957 A and

PCA and

and

how

of

of

the

computer

of

the

the

ESDI

the

Utility

of

for

the

to

use

and

the field-

the

disc

of

all

the

HP

The

disc drive
cabinet.
stand-alone cabinet designed

other

and

is

packaged in a stand-alone desktop

AClcessories

desktop stack modules. A kit

available include a desk-height

to

hold the disc drive

for

rack

1-1

General
7957

A/7958A

Inf

orma

tion

1-3. OPTIONS

Option
requirement
to
the
from

015

is

is

be placed in

deletion

the

of

order.

for

the

the

power

the

switch

proper

the

Model 10833B HP-IB Cable

option.

in

the

position.

The

power

Option

1-4. RELATED MANUALS

For

operating

the

H P 7957 A and H P 7958A Disc Drive Owners
Manual,
Environmental Requirements
Manual,

formation.

and

part

no. 07957-90901.

part

no. 5955-3456.

refer

installation instructions.

and

lor

Disc/Tape

For

instruction set in-

to

the

CS/80

Instruction Set

only

module

550

refer

the

Drives

is

to

Site

Programming Manual,

additional service

part

no. 5955-3442.

information,

refer

to

External Exerciser Reference Manual,

5955-3462.
and

HP

The

CE

7958A Disc

Handbook

Drive

is

for

the

part

no. 07957-90905.

1-5. CHARACTERISTICS

Characteristics
dimensions
Table
specifications

vironmental requirements.

1-1,

Environmental Requirements for
Manual,

supplied

of

the

disc drive. including physical

and

power

Disc

Drive

for

the

part

no. 5955-3456. This

with

the

disc drive.

requirements,

Characteristics.

disc drive, including en-

are

are

listed in

Disc/Tape

publication

the

CS/80

part

HP

listed in
Detailed

the

For

no.

7957A

Site

Drives

is

1-2

SAFETY

Table

1-1.

Disc Drive Characteristics

General Information

7957

A/7958A

Meets
UL
CSA

POWER

all

Listed

certified

REQUIREMENTS

Specified

Voltage

(true

F reqw3ncy:

Typical

Typical

Current

Power:

applicable
UL

114 and

to

CSA

Source

RMS):

(true

safety
UL

478.

C22.2

(selected

switch)

115V

230V

RMS):

standards

No.

by

range;

range;

47.5
115V

230V

115V

230V

of

IEC

380 and

143 and

rear

No.

panel

154.

VOLTAGE

100V, 115V, 120V,

(inclusive

220V, 240V,
tolerance

to

66

range;
range;

range;
range;

tolerance

single

range

Hz

0.87A

0.48A
65W

65W

IEC

SELECTOR

single

range

phase,

is

180V

435.

phase,

is

(inclusive

to

264V)

90V

to

132V)

SIZE/\~EIGHT

Height:
Width:

Depth:
Net

W~:dght:

Shipping

Weight:

132

325
285

9.9

14.0

mm

(5.2

mm

(12.8

mm

(11. 2 in.

kg

(21.8

kg

(31.0

in.

in.

lb)
lb)

)

)
)

1-3

Interface Information

2

2-1.

This chapter describes the implementation
Enhanced
disc drive mechanisms. Also included at the end
of
Command Set implementation, request status sum-

mary and utility command summary. Included
the ESDI information specific to these products,
well as a discussion
to
in this chapter
sight into how the product operates within the
ESDI environment.

The disc drives conform fully to the specifications
defined in the following industry-standard docu­ment:

Specification

reader
operation

When used in conjunction with the
specification,
information necessary

with the drive

INTRODUCTION

of

the

Small Device Interface (ESDI) on the

this section

improve system performance. The information

Enhanced

is

thoroughly familiar with the general

of

is

information

of

operating features designed

is

intended to give the user an in-

Small

(REV

ESDI as defined in the specification.

this chapter provides the additional

'Over

F). It

to

successfully communicate

ESDI.

on

the CS/80

Device Interface

is

assumed that the

ESDI

is

as

NOTE

• Daisy Chain Configuration (up

• Power-On Sequencing

• Track Offsets

•

Internal Self-Test Diagnostics

• Media Defect List

to

7 drives)

2-3. DRIVE INTERFACE

CHARACTERISTICS

The drive complies with the physical interface
characteristics defined in the
Refer

to

the specification
and connector pin assignments. The physicalloca­tion

of

the

two

interface, one power and
ground connectors are shown in figure
clarity, the power connector pin assignments
also shown.)

The drive electrical interface circuits
the specified electrical requirements. The drive uses

220/330-ohm termination option

the
all control signals originating

ESDI specification.

for

cabling requirements

6-1.

conform

to

terminate

at

the controller.

one

(For

are

to

To

maintain consistency with standard
ESDI terminology, the term "drive"
used

to

refer

to

the disc mechanism in

this chapter.

is

2-2. SUPPORTED ESDI FEATURES

The

disc drives support the following standard

ESDI features:

• Serial Mode Operation
10

Megabit Per Second Transfer Rate

•

• Configuration Reporting

• Drive Hard Sectoring

2-4. INTERFACE SIGNALS

The serial-mode use
lines

is

defined in the ESDI specification. The fol­lowing paragraphs include additional product­specific considerations regarding the use
signal line. Tables
bit information.

• DRIVE SELECT LINES.

to

selection by asserting its DRIVE SELECTED
line within
When selecting a drive, the controller must en-

sure that all drive select lines change within less

100

than
desired drive selection during transition
drive select lines.

nanoseconds. This precludes any un-

of

all data and control signal

of

2-1,

2-2

and

2-3

provide response

The

drive responds

250 nanoseconds (see figure

of

each

2-1).

the

2-1

Interface Information

7957

A/7958A

Table

2-1.

General Configuration Response Bits

BIT

POSITION

15

14

13

12

11

10

9
8

7

6
5

4

3

2

1

o

Tape

Drive
Format Speed
Track
Data

Rotational
Transfer
Transfer
Transfer

Removable
Fixed
Spindle
Head

RLL
Controller

Drive

Offset

Strobe

Speed
Rate>
Rate>
Rate

Cartridge

Media

Motor

Switch

Encoded

Soft

Hard

Controller

DRIVE

Tolerance
Option

Offset

Tolerance>
10
5

<=

5

Drive

Control

Time>

(not

Sectored
Sectored
Hard

Sectored

FEATURE

Gap

Implemented

Option

MHz

MHz

<=

MHz

Drive

Option

15

usec

MFM)

(Sector

Required

Implemented

0.5%

10

MHz

Implemented

(Address

Mark)

Pulses)

(Byte

Clock)

BIT

VALUE*

o
o

1

1

o
o

1

o
o

1
1

o

1

o

1

o

* 1

indicates

If

the controller attempts a write with an in-

valid head selected, the drive responds by set-

ting A

Unimplemented Command status bit.

controller attempts

head, the read will be executed with the last
valid head selected.

•

HEAD

head, the controller must ensure that all head

select lines change within

nanoseconds. This avoids an inadvertent head

selection during transition

lines. Valid head select values
are shown in table

TTENTION and Invalid Or

to

read with an invalid

SELECT

LINES.

2-4.

that

When

of

selecting

less

than

the head select

for

each drive

drive

If

implements

the

a

100

specified

• WRITE GATE. The WRITE GATE timing
used during formatting and normal writing
shown in figures

The following timing restrictions apply
WRITE GATE signal:

- When the drive performs a head switch opera-

tion,

the

controller

GATE until COMMAND COMPLETE
tivated, indicating completion
switch.

- When performing a write following a read,
WRITE GATE must
imum
is

of

500 nanoseconds

deactivated.

feature.

2-2

and

must

not

2-3,

respectively.

not

activate

be

activated

after

of

the head

for

READ

to

the

WRITE

is

ac-

a min-

GATE

is

2-2

Table

2-2.

Specific Configuration Response Bits

Interface

Information

7957 A/7958A

CMD

MODIFIER

11

10

0 0 0
0 0 1
0 0 1

0 1 0

0 1 0
0 1
0 1 1

BITS

9

1

8

1

Number
Number

0

Number

1

Bits

Bits

Minimum

0

track

Unformatted

1

Sectors

0

Minimum

1

including
tolerance)

CONFIGURATION

REQUESTED

cy 1

of
of
of

15-8:

2-0:

inders,

cy 1

inders,

heads

Removable
Fixed

unformatted

bytes

per

track

bytes

in

ISG
intersector
:

DATA

fixed
removable

drive

heads

bytes

per

sector

field

per

speed

heads

(not

DRIVE

RESPONSE

HEX

05DD

DEC

1501

0000 0

00 0
* *

5780

22400

015E 350

0040

64

Bits

15-8:

Bits

2-0:

1

0 0

1 0 0

0

1

Minimum
Number

of

status

*HP

7957A -

(includes

- When formatting the disc media, the controll­er

must activate WRITE GATE a minimum

2.5

microseconds before the beginning

Address

activated, WRITE

the entire track.
must remain inactive
nanoseconds.

- After writing the address field

PLO Sync field (see figure

GATE

If

06/6;

servo

may remain active

deactivated. WRITE GATE

for

HP

7958A -09/9

head)

2-2).

at

least 200

or

data field,

ISG

Bytes

bytes

words

available

of

of

the

Once

for

bytes

per

per

PLO

of

vendor-unique

two
written. This

cause an 8-bit delay between the time the data

is
ly written
written in the Address Pad
appropriate.

- The drive must not be deselected while
WRITE GATE

after

INDEX

ISG
Sync

field

additional bytes

is

transmitted

to

on

OC
2E

OOOE

12
46

13

0001 1

of

dummy data must be

due

to

encoding delays, which

the drive and when it

the media. This dummy data

or

Data Pad field as

is

activated.

is

actual-

is

2-3

Interface

Information

7957A/7958A

Table

2-3.

Standard

Status Response Bits

(l

of

2)

BIT

POSITION

15
14

13

12

11

10

9

8

DESCRIPTION

Reserved. This bit

Removable Media
therefore

Write

therefore

Write

ture,

this bit

Protected, Removable Media.

this bit

Protected, Fixed Media.

therefore

Reserved. This bit

Reserved. This bit

Spindle

If

Start

Motor

this bit

Spindle

is

cessful execution

does

not

cause

is

always zero.

Not

Present.

is

always zero.

The

The

is

always zero.

The

drive does

this bit

is

always zero.

is

always zero.

is

always zero.

Stopped. This bit indicates

set,

the

controller

Motor

operation. A

of a Start

ATTENTION

should send a

change

Spindle

to

go active.

drive

drive

the

Motor

does

of

or

not

does

not

include a

spindle

Control

state

on

Stop

Power-On Reset Conditions Exist. This bit notifies
drive

operating
following a
curs

that

tary

loss

of

ing conditions.

status bit (bit 9)

parameters have been set

power-on

causes

dc

power).

sequence

an

internal power-on reset

The

The

controller

and

perform a motor-on

or

when

controller

should also

to

their

an

internal

operation

may

have

check

sequence

default

to

the

if

use

removable

not

use

removable

write

motor

is

not

command

this bit

Spindle

the

Motor

controller

values. This bit

drive

fault

to

occur

reconfigure

Spindle

necessary.

media,

media,

protect

up

to

fea-

speed.

specifying a

due

to

the

suc-

operation

that

the

is

condition

oc-

(e.g., a momen-

drive

operat-

Motor

Stopped

set

2-4

7

Command

parity
drive

6

Interface

protocol

respond
protocol

5

Invalid
received an invalid
parameter.
mand
the

spindle

4

Seek Fault. This bit indicates
bit will be set
complete
however

Data

Parity

error

on

the

will

not

attempt

Fault. This bit indicates

timeout.

to

an

edge

within

Or

that

13

Unimplemented Command. This bit indicates

The

drive will also set this bit

the

drive

motor

Fault. This bit indicates

serial

execution

An

Interface

of

command

the

TRANSFER

of

Fault

data

the

command

that

the

occurs

REQ/TRANSFER

milliseconds (see figure 2-5).

or

reserved

command,

if

is

currently

is

stopped).

unable

to

execute

received

command

that a catastrophic

only

after

the

drive

has

made

the

seek.

The

controller

may

elect

such retries will most likely be unsuccessful.

that

if a parity

drive has

when

the

controller

(e.g.,

seek

every

to

the

from

detected

the

modifier,

a Seek

failure

attempt

retry

drive

detected

the

controller.

error

is

detected.

an

controller

ACK

handshake

that

the

drive

or

command

sends a valid

command

occurred.

to

successfully

the

seek

operation,

The

interface

fails

to

has

com-

while

This

a

Interface Information

7957A/7958A

Table

2-3.

Standard Status Response Bits

Write

Gate

3

With Track Offset. This bit indicates
WRITE GATE while the drive was configured
controller should restore the track offset

(2

of

2)

that

the controller activated

for

a nonzero track offset.

to

zero, and then retry the write

The

operation.

2

Vendor-Unique

valid and available
service-trained personnel. The controller should
on

the content

Write Fault. This bit indicates
be caused
troller should retry the write operation a minimum
simplification, the controller may elect
recommended

A Write Fault can be caused by one

• The controller activated WRITE
off

track center.

• The controller activated WRITE GATE while the spindle

by

a variety

for

Status

of

Available. This bit indicates

to

the controller. This information

the vendor-unique status.

that

of

conditions; however, regardless

the preceding Write

that

vendor-unique status

is

intended

not

initiate any action based

for

use by

a write fault has occurred. This fault can

of

the cause, the con-

of

five times.

to

use the same recovery routine

Gate

With Track Offset fault.

of

the following conditions:

GATE

while the head was physically

motor

was

speed.

• The controller activated WRITE GATE while COMMAND COMPLETE
was inactive. The controller must wait

for

the drive

to

activate

COMMAND COMPLETE before retrying the write operation.

• The controller attempted a write with an illegal head selected.

is

For

off

• The controller attempted a write while the spindle was

out

of

tolerance.

• The controller attempted a write while the spindle was

not

spinning.

• The controller attempted a write while ATTENTION was set.

• The drive's

R/W

preamp chip indicated a Write Unsafe condition.

write speed

2-5

Interface Information
7957 A/7958A

DRIVE

DRIVE

I£SDIAI5

SELECT

~~~~~~~~

SELECTED

_______

~I:=-

Tl ~ 2Sca

...

__

T

______

t

NSEC

Figure

3

2

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

1 0 0

1
1 0 1
1
1 1 X

2-1.

Table

HEAD

22

0

1 0
1 1

0 0

0

Drive Selection/Deselect ion Timing

2-4.

SELECT

~

__

ID

____

Valid Head Select Values

~)

)~

...

''''""J

_______

IJ

LINES

21

1
1

1

2°

0

1

0

1

0

1

0

1

0

1

0

1

X

HP

__________

HEAD

SELECTED

7957A

0 0

1 1

2

3 3

4 4

HP

5
Inv
Inv 7
Inv
Inv
Inv
Inv
Inv Inv

J

___

7958A

2

5

6

Inv
Inv
Inv
Inv

~~~~~~~~~~~

Tl

F

• READ GATE. The READ GATE timing
shown in figure

The following timing restrictions apply to the

READ GATE signal:

- When the drive performs a head switch opera-

tion, the controller should not activate READ
GATE until
tivated, indicating completion
switch.

- When performing a read following a write,

READ GATE should not be activated

least

500 nanoseconds

deactivated.

2-6

2-4.

COMMAND COMPLETE

after

WRITE GATE

of

is

is

ac-

the head

for

at

is

- READ GATE must be deactivated when
passing over a Write
be deactivated a minimum
(one bit time) before the Write
remain deactivated
nanoseconds following the Write Splice (see
figure

2-2).

- READ GATE must be activated
bytes before the Sync Pattern byte.

• DRIVE SELECTED. The drive activates this
signal within
selection address
signal

is

deactivated within 250 nanoseconds

being deselected by the controller.

Splice. READ GATE must

of

100
Splice, and must

for

a minimum

250 nanoseconds

is

valid (see figure

after

nanoseconds

of

100

at

least

14

its drive

2-1).

This

of

INDEX

or

SECTOR

WRI

TE

GATE

FORMAT

------:

12

BYTES

I

--,

ISG

Interface Information

7957

A/7958A

U...j

: I

..........

:

j...-

o. 8 USEe

(WRITE

II

I N

SPLICE) I I

-+l

I--

J\

200

NSEC

MIN.

1 : n &

~.~,---------------------------~

~

ADR

PLO

SYNC

ADR

SYNC

PATTERN

ADDRESS

FIELD

ADR
CHECK
BYTES

ADR
PAD

..

WRITE

SPLICE

IESOIA10

INDEX

~fCTOR

FORMAT

READ
GATE

WRITE

GATE

LJ

------------~I~--------------------------

IESOIA12

&

ISG

WRITE

Figure

ADDRESS

FIELD

Figure

GATE

MAY

REMAIN

2-2.

Write

WRITE

SPLICE

DATA
SYNC

Jl=100

2-3.

Write

Gate

ACTIVE

Gate

Timing During

DATA

PLO

SYNC

PATTERN

NSEC

MIN

Timing During Normal Write

DURING

Format

DATA

FIELD

THIS

DATA
CHECK
BYTES

TIME.

DATA

PAD

u

ISG

L

• READY. This signal
ESDI specification.

• COMMAND DATA. The following commands
are supported by the drive (refer

Seek
Recalibrate
Request
Request Configuration
Select Head
Control (Reset Interface, Stop Spindle

Track
Initiate Diagnostics

Status

Motor, Start Spindle Motor)

Offset

Group

is

used

as

defined in the

to

table

2-5):

All other commands and reserved
codes are treated

• TRANSFER REQUEST. The TRANSFER
REQUEST
2-5.

• ADDRESS MARK ENABLE. This signal
used. The drive will ignore any activity
line.

• TRANSFER
TRANSFER

is

timing

shown in figure

as

illegal commands.

handshake timing

ACKNOWLEDGE.

ACKNOWLEDGE handshake

is

2-5.

command

shown in figure

is

not

on

this

The

2-7

Interface Information

7957

A/7958A

INDEX

or

SECTOR

Lr

FORMAT

READ

GATE

ISG

*1.

IE50IA11

• ATTENTION. There are no product-specific
for

details

• INDEX. The INDEX timing (relative

SECTOR)

• SECTOR. The SECTOR timing (relative

INDEX)

• COMMAND COMPLETE.

product-specific details

• OAT A TRANSFER SIGNALS. All

transfer signals (NRZ WRITE DATA, WRITE
CLOCK,
conform

the specification. There are no product-specific

timing requirements associated with any

these signals.

this signal.

is

shown in figure

is

shown in figure

NRZ

READ DATA, READ CLOCK)

to

the timing requirements defined in

ADR
PLO

SYNC

_1*_1

READ

SYNC

for

ADR

SYNC

PATTERN

AP?~[~S

100

NSEC

_______________

GATE

SHOULD

PATTERN.

Figure

2-6.

2-6.

There are no

this signal.

four

BE

2-4.

to

to

data

of

ADR

ADR

WRITE

SPLICE

MINj

PAD

L 1

~~~f~

1

ACTIVATED

Read

Gate

2-6.

Before performing a data transfer with a drive,
controller may have
operations: drive selection, a seek

track, and head selection.
formance, these operations should be performed in

the following order:

AT

Timing

DATA DATA

PLO

SYNC

~

~I

LEAST

DRIVE/HEAD

SEQUENCE

SYNC

PATTERN

100

__________

13

BYTES

to

fteI't

NSEC

MIN

PRIOR

SELECTION

initiate up

To

optimize drive per-

DATA

PAD

TO

to

three separate

to

NOTE

Figure
quence. The timing references
in the discussion refer
The drives used in the example have ar­bitrarily been assigned addresses
and

2.

2-8

illustrates the following se-

to

this figure.

(TO)

ISG

~r_

the desired

used

of

1

the

• TRACK OFFSET. This command causes the
to

disc drive

as

inches)
bits. See figure

specified by the command modifier

perform

2-7

a track

for

track offset definition.

offset

2-5. DRIVE OPERATING FEATURES

The

following paragraphs explain specific operat-

of

ing features

ploit the full performance
these features.

2-8

the drive. The controller can ex-

of

the drive by utilizing

(±80 micro-

1)

Deselect drive 1

selected head value in
tion occurs. This step
multi-drive environments.

2)

Set the head select lines

head currently selected
regards
Drive 1 selected all the time because there
Drive 2 option.

3)

Initiate a seek

drive will deactivate COMMAND COMPLETE
and begin the seek operation.

to

1,

2,

(TO).

or

to

The drive retains

effect

3.

the desired track (T3).

when

is

necessary only in

to

the value

on

drive 2 (T

The disc drive leaves

the

the

deselec-

of

the

1)

with

is

no

The

Table

2-5.

CS/80 Command Implementation

Interface Information

7957

A/7958A

COMMAND

Transparent

Universal Device Clear
Amigo Clear
Channel Independent Clear
Selected Device Clear
Cancel
Loopback
HP-IB Parity Checking
Identify

Real

Time

Loca te and Read
Cold Load Read
Locate and Write
Write File Mark (tapes only)

Complementary

Set Unit (unit 0 and
Set Volume (volume zero only)
Set Address
Set Block Displacement
Set Length
Set Burst
Set RPS (Rotational Position Sensing)
Set Retry Time
Set Status Mask
NoOp
Set Release
Set Options

Return Addressing Mode

Set

(l

and 3 vector)

General Purpose

Spare Block
Describe
Locate and Verify
Release
Release Denied
Copy Data
Initialize Media

Diagnostic

Request Status
(refer

to

Table

2-7.

Request Status Summary)
Initiate Utility (refer
No execution message
Device
Device will send execution message

will receive execution message

Commands

15)

to

table

Commands

Commands

Commands

Commands

2-7)

IMPLEMENTED

yes
yes
yes
yes
yes
yes
yes
yes

yes
yes
yes

no

yes
yes
yes

no
yes
yes

no

op

no

op
yes
yes

no

op

no

yes

yes
yes
yes

no

op

no

op

no

yes

yes

yes

no

yes

yes

no =

no op =

= Implemented

Will
Command
are

return

ignored

incorrect,

as

illegal

defined

opcode

but

parameters

then

illegal

by

CS/80

if

received

are

checked.

parameter/bounds

If

is

the

parameters

returned.

2-9

Interface
7957A/7958A

Information

TRANSFER

COMMAND

TRANSFER

Fol

lowing

imposed on

REO. 0 ----..,

1

50

NS

MIN

I:

ACK. 0 --------

transfer

the

next

of

last

transition

ONE

l.---

145

NS

MIN

245

NS

MAX

bit,

BIT

VALID

50

NS

MIN

10

MS

MAX

....

no

maximum

of

TRANSFER

TRANSFER

J

:

I
I I

1145

I

MIN

245

MAX

time I imit

REO.

TO

DRIVE

0

r·

NSt

NS

is

NS

I

150

10

1

I

MIN

NS

MS

MIN
MAX

&

TRANSFER

TRANSFER

CONFIG/STATUS

Following

IESDIAOt

REO.

ACK.

DATA

imposed on

0

1

ld

250

NS

MAX

0

1

100

NS

MIN

:d?d

transfer

the

of

next

ONE

L

-I

last

bit,

transition

BIT

50

10

VALID

no maximum

of

TRANSFER

TRANSFER

NS

MIN

MS

MAX

time

REO.

FROM

150

MS

250

MS

limit

DRIVE

is

2-10

Interface

Information

7957 A/7958A

INDEX

SECTOR

IESOIA06

---------------------------------.

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

LAST LAST

SECTOR-1

-I·

SECTOR

Figure

H

~

I

.I-

2-6.

Index/Sector Timing

INDEX

~

I I
I I

~TX~

1.6

us

..f

0.1

us

H1.6

US

..f

0.1

US

~

SECTOR

0

I

-I·

LAST

DATA

(TRACK

SECTOR

SURFACE

N)

T x -

1-TRACK

IESOIA16

4)

Before the seek completes (COMMAND

COMPLETE

By

(T4).
seek, the head switch operation

part

of

the seek.
before the controller changes the head select
lines, the head select will be performed
separate operation, resulting in an additional

as

delay

5)

When the newly selected head has arrived

target track, the drive asserts
COMPLETE

activated), select the new head

changing the head select lines during the

If

the seek operation completes

the new head seeks

(T5). This sequence assumes

SEEK

DELAY

Figure

to

2-7.

is

performed

the target track.

COMMAND

~

SECTOR

Track-To-Track Sector Offset

as

at

that

as

a

the

0

all three operations are necessary; however, it
also applies
the controller wants
and data surface on the currently selected drive,
only steps 3 and 4 would be required.

important element

is

that

required, the controller should always initiate

the seek and then follow it immediately with

head switch. This avoids the additional delay in­curred
after

the seek.

to

when both a head switch and seek

if

the head switch

DATA

SURFACE

(TRACK

simpler situations.

to

N+1)

to

access a

recognize in this sequence

is

performed before

0

For

example,

different

if

track

The

are

the

or

2-11

Interface Information
7957A/7958A

COMPLETE

IESOIA'.

DRIVE

SELECT

HEAD

SELECT

COMMAND

DATA

o

COMMAND

DRIVE 1 I

DRIVE

HEAD

Figure

1

VALUE

2-8.

Recommended Drive/Head Selection Sequence

o (DESELECT) I

I
I

> 1

uSEC

~

CURRENT

FOR

DR I VE

HEAD

DRIVE

2

VALUE

2

SEEK

CMD

--..J

T4

I

I

.

I

I

I

L.-

I

NEW

FOR

< 100

HEAD

DRIVE

uSEC

VALUE

2

2-7. MEDIA

The following paragraphs address the physical
format

of

the disc media.

FORMAT

2-8. SECTOR FORMAT. The drive employs

"hard

sectoring"

defined by the occurrence
The

beginning

by the INDEX pulse. Each sector
315 bytes long.
bytes are used
ing 299 bytes
the controller. Although sector format
dependent, it

conform

tained

to

in

the ESDI specification.

with

the

beginning

of

of

each track (sector

Of

315 bytes, a minimum

for

the intersector gap. The remain-

of

the sector are available

is

recommended that the format used

the fixed-sector format example con-

of

each

sector

the SECTOR signal.

0)

is

defined

is

a minimum

for

is

of

use

of

16

by

user-

SECTOR OFFSET. The sector

2-9.

of

improves the performance
include successive cylinders. When the end
cylinder

I-track seek to the next cylinder to continue the
transfer
last
the next cylinder, the track-to-track sector

provides the delay necessary

latency

2-10.

head

is

reached, the drive must perform a

(see

of

(see

CS/80

figure

figure

2-9).

When switching

one cylinder

2-7).

COMMAND SET

data transfers

to

the first head

to

avoid a rotational

offset

from

also

that

of

the

(0)

of

offset

IMPLEMENTATION

Table

mands and their implementation on these disc

drives. Table

REQUEST STATUS Command and table

provides a summary

2-5

provides a listing

2-6

of

the CS/80 com-

provides a summary

of

the Utility Commands.

of

the

2-7

a

2-12

INDEX

Interface Information

7957

A/7958A

, ,

SECTOR

0

104

OFFSE T (T

I I

1 )

------U

SECTOR

T 1 -

HEAD

SWITCH

10

~

I

0

i.-OFFSET

I

DELAY

INDEX

(T

SECTOR

).1

1

20

10

I
I

u

0

INDEX

DATA

DATA

DATA

SURFACE

SURFACE

SURFACE

0

1

2

IESOIA04

Figure

2-9.

Sector Offset

2-13

Interface

7957

A/7958A

Information

Table

2-6.

Request Status Summary

COMMAND

Reject

Channel Parity
Illegal Opcode
Module addressing

(only volume

or

15

are supported)
Address Bounds
Parameter Bounds
Illegal
Message Sequence
Message Length

Parameter

Error

0 and unit 1

Fault

Cross-Unit (copy data
Controller Fault
Unit

Fault

(set whenever a problem

disc mechanism)

Diagnostic Result

(set when a failure occurs during a disc

diagnostic)
Operator Request (release never required)
Diagnostic Request (release never required)
Internal Maintenance (release never required)
Power Fail
Retransmit

Access

Illegal Parallel Operation (only support 1 unit)
Uninitialized Media (formatted
No

Spares Available

Not

Ready

Protect

Write
No

Data

Found
Unrecoverable Data Overflow
Unrecoverable Data

of

End
End

File (only

of

Volume

for

Information

Operator Request (release never requested)
Diagnostic Request (release never requested)
Internal Maintenance (release never requested)
Media Wear
La tency Ind uced
Auto

Sparing Invoked

Recoverable Data

Marginal

Recovera ble
Maintenance

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

yes

no

=

Data

bit

under

Overflow

Track

will

error

no

Errors

Errors

not

supported)

is

Errors

tapes)

Overflow

be

set

as

described

condition

detected in

at

factory)

Errors

by

the

by

will

controller

the

eS80 manual

this

bit

in

be

response

set

IMPLEMENTED

yes
yes
yes

yes
yes
yes
yes
yes

no
yes
yes

yes

no

no

no
yes

no

no

no

yes

no

no

no
yes
yes

no

yes

no

no

no
yes
yes
yes

no

yes

no

no

to

an

~---

2-14