Wang 640 User manual

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-·WANG·
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FLEXIBLE
DISK DRIVE
640
749
2240
Models:
2242
2243
Customer Engineering
Product Maintenance Manual
3102
729-0134-A

PREFACE
This publication is "l combined reprint of 729-0134 and 729-0135 for ease
of handling and stockine.
The purpose of this manual is to provide the Wang-trained Customer
Engineer (CE) with instructions to operate, troubleshoot and repair the Wang
Flexible Disk Drives.
Second Edition (February, 1984)
This edition is a reprint of and obsoletes 729-0134 and 729-0135. The
material in this document may only be used for the purpose stated in the
Preface. Updates and/or changes to this document will be published as
Publication Update Bulletins (PUBs) or subsequent editions.
This document is the property of Wang Laboratories, Inc. All information
contained herein is considered company proprietary, and its use is restricted
solely for the purpose of assisting the Wang-trained CE in servicing this Wang
product. Reproduction of all or any part of this document is prohibited
without the prior consent of Wang Laboratories, Inc.
©Copyright WANG Labs., Inc. 1984
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SERVICE BULLETIN NO. 46
EDITED BY PRODUCT SERVICE DEPT.
MODEL 640/740/2240 DUAL REMOVADLE
~ FLEXIBLE DISK DRIVE
.NOTICE:
This document is the"property of Wang Laboratories, Inc.
Information contained herein is considered company propri·
etary information and its use is restricted solely to the
purpose of assisting you in servicing Wang products. Aepro·
duction of all or any part of this document is prohibited
without the consent of Wang Laboratories.
( G)LABORATORIES, INC.
WAN~ 836 NORTH STREET. TEWKSBURY, MASSACHUSETTS 01876. TEL [phone], TWX 710 343-67119, TELEX 94- 1•21
Printed in U.S.A.
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TABLE OF CONTENTS
DESCRIPTION
1.1 General
1.2 Special Features
1.3 Hardware Nomenclature
INSTALLATION
OPERATION
3.1 Indicator Lights and Switches
3.2 Loading and Handling of Disk Cartridges
3.3 Disk Formatting
3.4 Model 740 Operation
3.5 Model 640 Operation
3.6 Model 2240 Operation
DIAGNOSTICS
4.1 Model 740 Diagnostic
4.2 Model 640 Diagnostics
4.3 Model 2240 Diagnostics
MAINTENANCE
5.1 Head Radial Alignment Check
5.2 Head Radial Alignment Procedure
5.3 Index and Sector Sensing Components
5.4 Carriage Stop Adjustment Procedure
5.5 Track 00 Switch Assembly
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APPENDIX A - 640 Beginning and Ending Track Addresses 48
APPENDIX B - 740 Beginning and Ending Track Addresses 50
APPENDIX C - 2240 Beginning and Enuing Track Addresses 52
APPENDIX D- Conversion from 640/740 to 2240 54
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1. DESCRIPTION
1.1 GENERAL
The Model 40 is a compact, direct access, removable disk unit made
up of two MemorexR 651 Disk Drives and a Wang Controller.
The controller for both drives is located behind the control panel
and consists of the following printed circuit boards:
1)
352 regulator
2) 6296
micro processor
3) *6297
micro processor
4)
6298
ROM
5) 6190
motherboard
6) 6391 power
supply
7)
6392
front panel
8)
6395
interface
9) 6399
disk control
*Per ECN #4074, the 640/2240 use a 6297-1 and the 740 uses a 6297-2.
The 651 drives are placed on either side of the controller and are Leferred
to as Left and Right. The left and right drives utilize FD/IV Flexible
Disk Cartridges each having a capacity of up to 262,144 bytes producing
a unit with a maximum of 524,288 bytes. The disk cartridges are inter-
changeable from one drive to another.
The Model 40 can replace the 710-1 Disk Drive; all adriressing and
read/write commands are identical with a few exceptions.
. R
Registered Trademark, Memorex Corporation
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1.2 SPECIAL FEATURES
Tlw Mo,kl 40 cnntaiils the following design features:
1) Compact: Allows easy exchange of disk drives •
..::) Compatihilitv: Permits the disk cartridges to be swapped between
drives and units.
3) lnt0rlncks: Contains interlocks which prevent damage to a disk
cartridge during loading or unloading.
4) Write Protect: Logic is provided to disable the write circuits
should the user wish to protect data recorded on the disk.
5) Byte addressing and multiple byte transfer to make it com~·:.itible
with 710 DMS's (740 only).
6) Cyclic Redundancy Check: A built-in check to insure tha~ data is
read corrl?ctly.
1. 3
1. 3.1
HARDWARE NOMENCLATURE
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Memorex Portion
The Recd, Write, Safety and Control Logic are the interface electronics
between the Wang controller and the 651 drive (shown in Figure 1).
The electronic circuits are packaged on one PC board and contain:
1) Sector/Index Detector Circuits
2) Track Position Actuator Driver
3) Head Load Actuator Driver
4) Read/Write Amplifier and Transition Detector
5) Data/Clock Separation Circuits
6) Safety Sensing Circuits
RRegiPtered Trademark, Memorex Corporation
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FIGURE 1 INTERFACE ELECTRONICS
ln Figure 2 the track positioning actuator and lead screw positions
the Read/WritL' head to the desired track on the disk. The head load
actuator loads tlw disk against the Re.1d/Write head and data may then
be recorded or read from the disk.
The disk drive motor rotates the spindle at 375 RPM through a belt-
drive system. 50 or 60 Hz power is nccomodated by means of a stepped
pulley. /\ registration huh, centered on the face of the spindle, positions
the disk. A clamp (Lhat moves in conjuncl.i.on with the insertion door)
fixes the disk to Lhe registration hub .
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FIGURE 2
The Read/Write head is mounted on a carriage that is moved by the lead
screw. Ac:: shown in Figure 3, head load is achieved when the disk is
lightly loaded against the rigidly mounted head by energizing a solenoid.
This releases the bail from the spring-loaded carriage load arm and causes
the load arm pad to press against the head. ~eenergizing the solenoid
causes the retracting bail to lift the load pud from the disk thereby
unloading the disk.
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WHEN SOLENOID IS
DEENERGIZED. BAIL
RETRACTS AND PULLS
PAD AWAY FROM DISC
LOAD SPRING
CARRIAGE
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1.3.2 Wang Portion
SOLENOID
(ENERGIZED
FIGURE ~
• BAIL
DISC
Figure 4 is a top view of the Model 40. Facing the unit, the component
side of the PC boards is to the left except for the 352 regulator board
which faces to the right.
Figure 5 shows the PROM layout and part numbers for the various
units and capacities. When changing the storage capacity of a unit,
the only change that has to be made is the change of PROMs.
NOTE:
Figure 5 illustrates PROM loading only and not
conversion procedures from 640, 740, or 2240.
See Appendix Dfor conversion procedures .
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