HP HP 7936 Installation instructions

HEWLETT-PACKARD
liP 7936 AND HP 7937 DISC DRIVES
HARDWARE SUPPORT MANUAL

CERTIFICATION
Products, materials, parts, and services furnished on this order
have been provided in accordance with all applicable Hewlett-
Packard specifications. Actual inspection and test data per-
taining to this order is on file and available for examination.
Hewlett-Packard's calibration measurements are traceable to
the National Bureau of Standards to the extent allowed by the
Burea u 's calibration facilities.
The Hewlett-Packard Quality Program satisfies the require-
ments of FAR 52.246-15.

HP 7936 and HP 7937 Disc Drives
Hardware Support Manual
Manual part number: 07937-90903
Microfiche part no. 07937-90803
Printed: JANUARY
1987
Printed in U.s.A.
MODELS COVERED
Edition 1
E0187
This manual covers the following models: HP 7936H, 7937H,
7936XP, 7937XP.
OPTIONS COVERED
In addition to the standard model, this manual covers the
following options:
015, 017.
r/;O- HEWLETT
a:~ PACKARD
HEWLETT-PACKARD
P.O. Box 39, Boise, Idaho 83707-0039

Notice
The information contained in this document is subject to change without notice.
HEWLETT-PACKARD MAKES NO WARRANTY
OF ANY KIND WITH REGARD TO THIS
MATERIAL, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. HEWLETT-PACKARD shall
not be liable for errors contained herein or for incidental or consequential damages in connection with the
furnishing, performance or use of this material.
HEWLETT-PACKARD assumes no responsibility
for the use or reliability of its software on equipment
that is not furnished by HEWLETT-PACKARD.
This document contains proprietary information, which
is protected by copyright. All rights are reserved.
No part of this document may be photocopied, reproduced or translated to another language without the
prior written consent
of HEWLETT-PACKARD Company.
2
Copyright @ 1987 by HEWLETT-PACKARD
FOR U.S.A. ONLY
The Federal Communications Commission (in 47 CFR 15.818) has specified that
the following notice be brought to the attention of the users of this product.
FEDERAL COMMUNICATIONS COMMISSION
RADIO FREQUENCY INTERFERENCE
STATEMENT
Warning: This equipment generates,
uses, and can radiate radio frequency energy and if not instal-
led and used in accordance with the instructions manual, may cause interference to radio com-
munications. It has been tested and found to comply with the limits for Class A computing devices
pursuant
to Subpart J of Part 15 of FCC Rules, which are designed to provide reasonable protec-
tion against such interference when operated in a commercial environment. Operation of this
equipment in a residential area
is likely to cause interference in which case the user at his own ex-
pense will be required to take whatever measures may be required to correct the interference.

Printing History
New editions are complete revisions of the manual. Update packages, which are issued between editions,
contain additional and replacement pages
to be merged into the manual by the customer. The dates on the
title page change only when a new edition
or a new update is published. No information is incorporated
into a reprinting unless it appears
as a prior update; the edition does not change when an update is
incorporated.
A software code may be printed before the date; this indicates the version level
of the software product at
the time the manual or update was issued. Many product updates and fixes do not require manual changes
and, conversely, manual corrections may
be done without accompanying product changes. Therefore, do
not expect a one-to-one correspondence between product updates and manual updates.
Edition 1
..................................................... JANUARY 1987
Herstellerbescheinigung
Hiermit wird bescheinigt, daB das Gerat/System HP 7936/7937 in Obereinstimmung mit den Bestimmungen
von Postverfiigung 1046/84 funkentstort
ist.
Der Deutschen Bundespost wurde das Inverkehrbringen dieses Gerates/Systems angezeigt und die
Berechtigung zur Oberpriifung der Serie
auf Einhaltung der Bestimmungen eingeraumt.
Manufacturer's Declaration
This is to certify that the product(s) HP 7936/7937 is in accordance with the Radio Interference
Requirements
of Directive FTZ 1046/1984. The German Bundespost was notified that this equipment was
put into circulation; the right to check the series for compliance with the requirements was granted.
Additional Information for Test and Measurement Equipment
If Test and Measurement Equipment is operated with unscreened cables and/or used for measurements on
open setups, the user has to assure that under operating conditions the Radio Interference Limits are still
met
at the border of his premises.
3

Safety Considerations
GENERAL -This product and related documenta-
tion must be reviewed
for familiarization with
safety markings and instructions before operation.
SAFETY SYMBOLS
...L..
Instruction manual symbol: the product
will be marked with this symbol when it
is necessary for the user to refer to the
instruction manual in order to protect
the product against damage.
Indicates hazardous voltages.
Indicates earth (ground) terminal.
WARNING
The WARNING sign denotes a hazard.
It calls attention to a procedure or prac-
tice that,
if not correctly performed or
adhered to, could result in personal in-
jury. Do not proceed beyond a
WARNING sign until the indicated
conditions are fully understood and met.
ICAUTION I
The CAUTION sign denotes a hazard.
It calls attention
to an operating proce-
dure
or practice that, if not correctly
performed
or adhered to, could result in
damage to or destruction of part or all
of the product. Do not proceed beyond
a CAUTION sign until the indicated
conditions are fully understood and met.
SAFETY EARTH GROUND -This is a safety
class I product and
is provided with a protective
earthing terminal. An uninterruptible safety earth
ground must be provided from the main power
4
source to the product input winng terminals,
power cord,
or supplied power cord set. Whenever
it
is likely that the protection has been impaired,
the product must be made inoperative and be
secured against any unintended operation.
BEFORE APPLYING
POWER -Verify that the
product
is configured to match the available main
power source according
to the input power con-
figuration instructions provided in this manual.
If this product is to be operated with an autotrans-
former make sure
that the common terminal is
connected to the earth terminal of the main power
source.
SERVICING
WARNING
Any servlcmg, adjustment, maintenance, or
repair of this product must
be performed only
by service-trained personnel.
Adjustments described in this manual may
be
performed with power supplied to the product
while protective covers are removed. Energy
available
at many points may, if contacted,
result
in personal injury.
Capacitors inside this product may still
be
charged after the product has been disconnec-
ted from the main power source.
To avoid a fire hazard, fuses with the proper
current rating and of the specified type (nor-
mal blow, time delay, etc.) must be used for
replacement. To install or remove a fuse, first
disconnect the power cord from the device.
Then, using a small flat-bladed screw driver,
turn the fuseholder cap counterclockwise until
the cap releases. Install either end of a prop-
erly rated fuse into the cap. Next, insert the
fuse and fuseholder cap into the fuseholder
by
pressing the cap inward and then turning it
clockwise until it locks in place.

List of Effective Pages
The List of Effective Pages shows the edition or update number of all pages. Within the manual, any page
changed since the last edition
is indicated by printing the update number on the bottom of the page.
Changes are marked with a vertical bar in the margin.
If an update is incorporated when an edition is
reprinted, these bars are removed. No information is incorporated into a reprinting unless it appears as a
prior update.
To verify that your manual contains the most current information, check that the version
printed
at the bottom of the page matches the version listed below for that page.
Effective Pages Version
all
.................................................................................. Edition 1
5

Chapter 1
Product Information
Contents
Page
1-1
Introduction .' ................................................................................................ 1-1
Product Description ......................................................................................... 1-1
Documentation Supplied .................................................................................... 1-2
Supporting Documentation .................................................................................. 1-2
Product Structure ............................................................................................ 1-2
Specifications ................................................................................................ 1-2
Serial Number ............................................................................................... 1-2
Supported Eq,uipment ....................................................................................... 1-2
Test Equipment Required .................................................................................... 1-2
Warranty ... " ................................................................................................ 1-2
Support Strategy ............................................................................................. 1-2
Chapter 2
Site Planning and Requirements Page
2-1
Introduction ................................................................................................. 2-1
Site Planning ................................................................................................. 2-1
Specifications ................................................................................................ 2-1
Cabling Limitations .......................................................................................... 2-1
Chapter 3
Installation And Configuration Page
3-1
Introduction ................................................................................................. 3-1
Shipping Latch ............................................................................................... 3-1
Drive Installation ............................................................................................ 3-2
Primary Power Requirements ............................................................................... 3-2
Controls, Indicators, and Connectors ........................................................................ 3-2
Line- Switch .............................................................................................. 3-2
Channel Address/Diagnostic Switch ...................................................................... 3-2
Run Time Mode ....................................................................................... 3-3
Diagnostic Mode ...................................................................................... 3-3
LED Display .............................................................................................. 3-4
HP-IB Connector ......................................................................................... 3-4
Power Fuse ............................................................................................... 3-4
Line Connector ........................................................................................... 3-4
CPU Connection -HP-IB Systems ........... " ............................................................... 3-4
7

Contents (continued)
HP-IB Cabling ............................................................................................ 3-4
HP-IB Device Address .................................................................................... 3-5
Chapter 4 Page
4-1
Preventive Maintenance
Introduction ................................................................................................. 4-1
Chapter 5 Page
5-1
Functional Description
Introduction
................................................................................................. 5-1
Block Diagrams .............................................................................................. 5-2
Signal
Notation .............................................................................................. 5-2
List of Mnemonics ........................................................................................... 5-2
Disc
Format ................................................................................................. 5-3
Addressing Structure
......................................................................................... 5-7
Addressing Mode
............................................................................................ 5-7
Disc Sparing
................................................................................................. 5-7
Sector Sparing
............................................................................................ 5-7
Track Sparing ............................................................................................. 5-8
Controller PCA-A6 .......................................................................................... 5-8
Servo System ................................................................................................ 5-11
Head-Disc Assembly A3 ................................................................................. 5-12
Dedicated Servo Code
................................................................................ 5-12
Sampled Servo Code
.................................................................................. 5-13
Servo Head
.......................................................................................... 5-13
Servo Read Preamplifier/Write Driver IC
........................................................... .5-13
Drive ID Circuit
...................................................................................... 5-13
Head Gain Reference PROM and DAC
.............................................................. 5-14
Actuator ..................................................... ~ .. ~ ....................................... 5-14
Speed Sensor .......................................................................................... 5-14
Read/Write PCA-A2 ..................................................................................... 5-14
Dedicated Servo AGC Amplifier.
.................................................................... 5-14
Sampled Servo Switch
................................................................................ 5-15
Sampled Servo AGC Amplifier
....................................................................... 5-15
Servo PCA-Al
........................................................................................... 5-15
Servo Controller
...................................................................................... 5-15
2-Bit ADC
............................................................................................ 5-16
Dedicated Servo AGC Circuit.
....................................................................... 5-17
Sampled Servo AGC Circuit
.......................................................................... 5-17
Sector Mark Decoder
................................................................................. 5-17
Dedicated Servo Circuit
.............................................................................. 5-17
Sampled Servo Circuit
................................................................................ 5-19
8