IBM System/32 Reference manual

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===~== ~ =Maintenance Library
SYSTEM/3~
Introduction and Maintenance
SY31-0373-4

PREFACE
This manual contains introductory and maintenance
information, and installation instructions for
IBM System/32. The maintenance information
includes checks, adjustments, and removals and
replacements.
Other manuals to be used with this one are:
• IBM System/32 Operator's Guide, GC21-7591
• IBM Diskette For Standard Data Interchange,
GA21-9182
• IBM System/32 Functions Reference Manual,
GA21-9176
• IBM System/32 System ControlProgram
Reference Manual, GC21-7593
For theory of operation and circuit detail, see
IBM Maintenance Library, System/32 Theory
Diagrams,
SY31-0346.
In addition, refer to the System/32 Diagnostic
User's Service Guide for further information on
system diagnostic procedures.
Fifth Edition (May 1977)
This is a major revision of, and obsoletes, SY31-0373-3. Extensive changes have been
made throughout, and this publication should be reviewed in its entirety. Changes are
periodically made to the information herein; any such change will be reported in sub-
sequent revisions or technical newsletters.
A Reader's Comment Form is at the back of this publication. If the form is gone,
address your comments to IBM Corporation, Publications, Department 245, Rochester,
Minnesota 55901.
©Copyright International Business Machines Corporation 1975,1976,1977

CONTENTS
LIST OF ABBREVIATIONS.
xi 2.1.15 Write Safety
2-7
Data Unsafe Conditions
2-7
CE SAFETY PRACTICES. xiii File
Ready.
2-7
Disk Speed.
2-7
1.0.0 INTRODUCTION 1-1
Power Up
2-7
1.1.0 DESCRIPTION
1-1
2.1.16
Seek Operation 2-8
1.2.0 BASIC CONFIGURATION 1-2 2.1.17 Recalibrate Operation 2-8
1.3.0 SYSTEM
DATA FLOW 1-3 2.1.18 Behind Home . 2-8
1.4.0 PROCESSING
UNIT DATA FLOW 1-4 2.1.19
Servo Track Following . 2-9
1.5.0
CHANNEL DATA FLOW.
1-5 2.2.0
MAl NTENANCE . 2-10
1.6.0 SYSTEM MICROPROGRAM. 1-6 2.2.1 Card Sockets 2-10
1.7.0 CONTROL
STORAGE.
1-7 2.2.2 Disk Enclosure (DE) 2-12
1.8.0
FUNCTIONAL UNITS. 1-8 2.2.3 Disk Drive Motor 2-14
1.8.1 Main Storage
(MS) 1-8 2.2.3.1 Old Style Motor 2-14
1.8.2 Control Storage
(CS)
1-8 2.2.3.2 New Style Motor . 2-16
1.'8.3 Storage Address Register (SAR) . 1-8 2.2.3.3 Motor Start Relay 2-16.2
1.8.4 Micro Operation Register
(MaR) 1-8 2.2.4 Brake Assembly
and Brake Coil
1.8.5
Process Condition Register (PCR) 1-8
Assembly.
2-16.4
1.8.6 Storage Data Register
(SD R) . 1-8 2.2.5 Brake Assembly 2-18
1.8.7 X and Y
Registers
1-8 2.2.6 Motor Antistatic Brush . 2-20
1.8.8
Arithmetic Logical Unit (ALU) 1-8 2.2.7 Spindle Antistatic Brush 2-20
1.8.9 Local Storage Registers (LSR) 1-9 2.2.8 Disk
Speed Transducer .
2-21
1.9.0
INITIAL SYSTEM CHECKOUT.
1-10 2.2.9 Motor Tension Spring 2-23
1.10.0 EVENT INDICATOR
SEQUENCE. 1-10 2.2.10 Shock Mount (Top One) 2-24
1.11.0 MICRO
INTERRUPTS.
1-11
2.2.11 Shock Mounts (Bottom Two) 2-24
1.12.0 SYSTEM
PARITY CHECKING AND 2.3.0 CABLE
AND CARD LOCATIONS.
2-26
PARITY GENERATION.
1-12
1.13.0 I/O
PARITY CHECKING AND
3.0.0
33FD DISKETTE DRIVE.
3-1
GENERATION.
1-13 3.1.0 THEORY
3-1
1.14.0 OPERATION RETRY
AND ERROR 3.1.1 33FD Description 3-2
LOGGING 1-14 3.1.2 Diskette Format . 3-4
1.15.0
LOCATIONS.
1-15 3.1.3 Operating
Sequences
3-6
1.16.0 BOARD PIN LOCATIONS 1-16 Initialization 3-6
Seek.
3-6
2.0.0 DISK
DRIVE
2-1
Read or Write . 3-6
2.1.0
THEORY
2-1 3.1.4 Read/Write Circuit Principles. 3-8
2.1.1 Introduction
2-1
3.2.0 MAl NTENANCE . 3-9
2.1.2 Subframe
2-1
3.2.1 Machine Safety 3-9
2.1.3
Grounding.
2-1
3.2.2 Tools 3-9
2.1.4 Disk Enclosure 2-2 3.2.3
Head Cleaning Tools (3.2.10) . 3-9
2.1.5 Disk Spindle
2-2
3.2.3.1
Pressure Pad Replacement Kit
3-9
2.1.6 Transducer. 2-2 3.2.4 Diskette
Care . 3-10
2.1.7 Actuator 2-3 Handling 3-10
2.1.8 Actuator Lock 2-3 Long Term Storage 3-10
2.1.9 Actuator Position Indicator 2-3 Shipping and Receiving. 3-10
2.1.10 Circuitry Location 2-3 Inserting and Removing the
2.1.11 Disk Description .
2-4
Diskette 3-10
Data Tracks 2-4 3.2.5 33FD Diskette Drive
3-11
Servo Tracks 2-4 3.2.6 Latch Assembly 3-12
2.1.12 Landing Zone (LZ) 2-4 3.2.7 Collet 3-12
2.1.13 Guard
Band (GB) . 2-4 3.2.8 Cover Assembly 3-12
2.1.14 Motor and Brake . 2-5 3.2.9
Pressure Pad Actuator 3-13
Sector Format 2-6 3.2.10
Head and Pressure Pad Cleaning 3-13
Contents iii
TNL: SN31-0487 to SY31-0373-4 (25 Nov 77)

iv
3.2.10.1 Leadscrew Dust Cover
(if installed) 3-13 4.1.4
Input/Output Lines (continued)
3.2.11 Leadscrew and
Head Carriage Stop Ribbon (A) 4-13
Assembly 3-14 Hammer Check 1-22 (also 23-44
and
3.2.12 Drive Motor 3-15 45-66)
(P)
4-13
3.2.13 Hub Assembly 3-17 Activate
Paper Clamps (A) 4-13
3.2.14 Drive Pulley 3-17 Carriage Advance
(P)
4-13
3.2.15 Belt Tracking 3-17 Home
Pulse (P) 4-13
3.2.16 Idler Assembly 3-17 Throat Closed Switch
(P) 4-13
3.2.17 ReadIWrite
Head
3-18 Cover Closed Switch
(P)
4-13
3.2.18 Leadscrew
Wheel
3-19 Forms
Sensed Switch (P)
4-13
3.2.19 Lower
Limit Stop 3-20 Printer Thermal Switch (P)
4-13
3.2.20 Upper Limit Stop 3-20 4.1.5 Circuit
Cards (50, 100, and 155 Ipm) 4-14
3.2.21 Stepper Motor and Bracket
3-21
Hammer Driver 4-14
3.2.22 Phototransistor 3:22 Motors/Solenoid Driver 4-14
3.2.23 Light Emitting Diode (LED) 3-23 Control Card 4-14
3.2.24 File Control
Card
3-24 4.1.6 Card
Gate Connector Details
Test Points 3-24 (50, 100, 155 Ipm) 4-15
File Card
Pin Assignment 3-24 4.1.7 Printer Power
Plugs (50, 100, and
File Control
Card Socket Pins
3-25 1551pm) 4-15
4.1.8
Pin Reversal In Cables
4-16
4.0.0 BELT PRINTER 4-1
4.2.0 MAINTENANCE-(50, 100, 1551pm) 4-17
4.1.0
THEORY 4-1
4.2.1 Printer Cover and Divider Removal and
4.1.1 Principles
of Printing (50, 100, and Replacement 4-17
1551pm) 4-2 4.2.1.1 Printer Cover Grounding 4-17
4.1.2 Functional Components 4.2.2 Interlock Switch Description 4-18
(50, 100, and 155 Ipm) 4-5 4.2.2.1 Cover Interlock Switch 4-18
Type Belt Transducer 4-5 4.2.2.2 Print
Unit (Throat) Interlock Switch 4-19
Ribbon Drive 4-6 4.2.2.3 End-of-Forms Interlock Switch 4-19
Type Belt Drive 4-6 4.2.3 Thermal Switch 4-20
Carriage 4-7 4.2.4
Fan Assembly 4-21
Throat 4-10 4.2.5
24V Relay (Contactor Kl) 4-21
Paper Clamps 4-10 4.2.6 Diode 01 Service Check 4-22
4.1.3 Checking (50, 100, and 155 Ipm) 4-11 4.2.7 Motor Checkout Procedure (50, 100, and
Forms
Jam Check 4-11 1551pm) 4-23
Belt
Speed Check 4-11 Type Belt
Motor (50, 100, and
Carriage Sync Check 4-11 1551pm) 4-23
Coil Current Check 4-11 Carriage
Motor (50, 100, and
Belt Sync Check 4-11 1551pm) 4-24
Emitter Check 4-11 4.2.8 Motor
Phase Capacitor (50, 100, and
Data Check
4-11
1551pm) 4-25
Hammer Parity Check 4-11 4.2.9 Motor and
Paper Clamp Resistor (50, 100,
End of Forms Check 4-11 and 1551pm) 4-25
Throat
Closed Check 4-11 4.2.10 Print
Unit Assembly (50, 100, and
Cover
Closed Check
4-11
1551pm) 4-26
Unprintable Character Check
4-11
4.2.10.1 Print Units With Pivot
Screws 4-26
4.1.4
Input/Output Lines (50, 100, and 4.2.10.2 Print Units With Pivot
Pins 4-28
1551pm) 4-12 4.2.10.3 Print
Unit Stop Screw
POR/Printer
Reset (A) 4-12
(50,100, and 1551pm) 4-30
Close (+24V) Contactor (A) 4-12 4.2.11 Platen
Gap (50, 100, and 155 Ipm) 4-31
Belt Go (A) 4-12 4.2.12 Platen (50, 100, and 1551pm) 4-33
1
Belt Motion (P) 4-12 4.2.13 Type Belt (50, 100, and 155 Ipm) 4-35
PSS (Subscan) (P)
4-12 Static Test
for Type Belt Binds 4-35
IMPSS (Impression Singleshot) (P) 4-12 Dynamic Test
for Type Belt Binds 4-35
Fire Hammer (A) 4-12 4.2.14 Type Belt Drive Pulley Assembly 4-36
Carriage
Go (A) 4-13 4.2.15 Type Belt Motor
'4-37
4.2.16 Type Belt Positioning Rollers 4-37

. .
4.2.17 Type Belt Idler ~ulley 4-38 4.2.45.3 Print Units With Pivot
Pins and One Paper
4.2.18 Type Belt Idler Pulley Pivot Assembly 4-38 Clamp Engaging Lever 4-68
4.2.18.1 Without
Clevis (Old Style) 4-38 4.2.46 Forms Jam Detection Device 4-70
4.2.18.2 With Clevis (New Style) 4-38 4.2.47 Examples
of Incorrect Printing (50, 100,
4.2.19 Transducer Assembly (50, 100, and and 1551pm) 4-71
1551pm) 4-39 4.2.48 Lower Forms Guide
To Hammer Bar
4.2.20 Transducer 4-40 Adjustment 4-72
4.2.21 Impression Singleshot Potentiometer 4.2.49 Lower
Paper Guide To Hammer
(50, 100, and 155 Ipm)
4-41
Clearance 4-72
4.2.22 Transducer Position (Character
Cutoff) 4-42 4.3.0 LOCATIONS (50, 100,
and 1551pm) 4-73
4.2.23 Hammer Flight Time (50, 100, and 4.3.1 Back View 4-73
1551pm) 4-42 4.3.2 Front View 4-74
4.2.24 Hammer Coil (50, 100, and 155 Ipm) 4-43 4.3.3 Right
Side
4-75
4.2.25 Hammer (50, 100,
and 155 Ipm) 4-44 4.3.4 Left
Side
4-76
4.2.26 Hammer Block Assembly (50, 100, and 4.3.5
Card Gate (50, 100, and 155 Ipm) 4-77
1551pm) 4-45 4.3.6 Card and I/O Cables (50, 100, and
4.2.27 Ribbon Drive Description 4-46 1551pm) 4-78
4.2.28 Ribbon
Cassette (50, 100, and 155 Ipm) 4-47 4.4.0 OSCILLOSCOPE FIGURES
(50,100, and
4.2.29 Ribbon Drive Assembly 4-47 1551pm) 4-79
4.2.30 Ribbon Drive Clutch 4-48 4.5.1 Principles
of Printing (285 Ipm) 4-82
4.2.31 Ribbon Drive Belt 4-49 4.5.2 Functional Components
(285Ipm) 4-85
4.2.32 Ribbon Solenoid 4-50 Ribbon Drive 4-86
4.2.33 Ribbon Drive Rolls and Idler Rolls Type Belt Drive 4-86
(50, 100, and 1551pm) 4·51 Carriage 4·87
4.2.34 Ribbon Drag (50, 100, and 155 Ipm) 4·51 Throat 4·90
4.2.35 Ribbon Tracking (50, 100, and 1551pm) 4·52
Paper Clamps 4·90
4.2.35.1 For Ribbon Shields Without Guides 4·52 4.5.3 Checking (285 Ipm) 4·91
4.2.35.2 For Ribbon Shields With Guides 4·52 Forms Jam Check 4·91
4.2.36 Ribbon Shield (50, 100, and 155 Ipm) 4·52.1 Belt
Speed Check 4·91
4.2.37 Tractor Drive Shaft 4·53 Carriage Sync Check
4-91
4.2.38 Tractor Cover 4·53 Coil Current Check 4·91
4.2.39 Carriage Tractor/Vernier
!Tractor Drive Belt Sync Check 4·91
Shaft 4·54 Emitter Check 4·91
4.2.40 Carriage Motor 4·55 Data Check 4·91
4.2.41 Carriage Drive Belt 4·55 Hammer Parity Check 4·91
4.2.42 Upper Paper Clamp 4·56 End
of Forms Check 4·91
4.2.43 Upper Paper Clamp Assembly 4·57 Throat
Closed Check 4·91
4.2.44 Lower Paper Clamp (50, 100, and Cover
Closed Check 4·91
1551pm)
4·58
Unprintable Character Check 4·91
4.2.44.1 Two Coil Clamp with Two Engaging 4.5.4
Input/Output Lines (285 Ipm) 4·92
Levers
4·58 POR/Printer
Reset (A) 4·92
4.2.44.2 Single Coil Clamp With One Engaging
Close (+24V) Contactor (A)
Lever 4·60 Belt
Go (A) 4·92
4.2.44.3 Clamp Assembly Removal (Single Coil Belt Motion
(P)
4·92
Clamp With
One Engaging Lever) 4·62
PSS (Subscan) (P)
4·92
4.2.44.4 Clamp Bar Removal (Single Coil Clamp
IMPSS (Impression Singleshot) (P)
4·92
With One Engaging Lever) 4·62 Fire Hammer (A) 4·92
4.2.44.5 Coil Assembly Removal (Single Coil 4.5.5 Circuit
Cards (285 Ipm) 4·94
Clamp With
One Engaging Lever) 4·62 Hammer Driver 4·94
4.2.45 Forms Tension Assembly (50, 100, and Motors/Solenoid Driver 4·94
1551pm) 4·64 Control Card 4·94
4.2.45.1 Print Units
with Pivot Screws and Two
4.5.6 Card Gate Connector Details
Paper Clamp Engaging Levers
4·64
(285Ipm)
4·95
4.2.45.2 Print Units with Pivot Pins and Two Paper
4.5.7 Printer Power
Plugs (285 Ipm) 4·95
Clamp Engaging
Levers
4·66 4.5.8 Pin
Reversal In Cables
4·96
Contents v
TNL: SN31·0487 to SY31-0373-4 (25 Nov 77)

vi
4.6.0
MAINTENANCE
4-97 4.6.41 Carriage Drive Belt 4-136
4.6.1 Printer Cover and Divider Removal and 4.6.42 Upper
Paper Clamp 4-137
Replacement 4-97 4.6.43 Upper
Paper Clamp Assembly 4-138
4.6.1.1 Printer Cover Grounding 4-97 4.6.44 Lower
Paper Clamp (285 Ipm) 4-139
4.6.2 Interlock Switch Description 4-98 4.6.44.1 Two Coil Clamp with
Two Engaging
4.6.2.1 Cover Interlock Switch 4-98
Levers 4-139
4.6.2.2 Print
Unit (Throat) Interlock Switch 4-99 4.6.44.2 Single Coil Clamp With
One Engaging
4.6.2.3 End-of-Forms Interlock Switch 4-99 Lever 4-142
4.6.3 Thermal Switch 4-100 4.6.44.3 Clamp Assembly Removal (Single Coil
4.6.4 Fan Assembly 4-101 Clamp
with One Engaging Lever 4-144
4.6.5 24V Relay (Contactor K1) 4-101 4.6.44.4 Clamp
Bar Removal (Single Coil Clamp
4.6.6 Diode D1 Service Check 4-102 with One Engaging Lever) 4-144
4.6.7 Motor Checkout Procedure
(285Ipm)
4-103 4.6.44.5 Coil Assembly Removal (Single Coil
Type Belt Motor (285Ipm)
4-103 Clamp with One Engaging Lever) 4-144
Carriage Motor (285 Ipm) 4-104 4.6.45 Forms Tension Assembly
(285Ipm) 4-146
4.6.8 Motor
Phase Capacitor (285Ipm)
4-105 4.6.45.1 Print Units
with Two Paper Clamp
4.6.9 Motor and
Paper Clamp Resistor
Engaging Levers 4-146
(285Ipm)
4-105 4.6.45.2 Print Units
with One Paper Clamp
4.6.10 Print
Unit Assembly (285 Ipm) 4-106
Engaging Lever 4-148
4.6.10.1 Print
Unit Stop Screw (285 Ipm) 4-108 4.6.46 Forms
Jam Detection Device 4-150
4.6.11 Platen Gap (285 Ipm) 4-109 4.6.47 Examples
of Incorrect Printing
4.6.12 Platen (285 Ipm) 4-112
(285Ipm)
4-151
4.6.13 Type Belt (285 Ipm) 4-113 4.6.48 Lower Forms Guide
To Hammer Bar
Static Test for Type Belt Binds 4-113 Adjustment 4-152
Dynamic Test
for Type Belt Binds 4-113 4.6.49 Lower
Paper Guide To Hammer
4.6.14 Type Belt Drive Pulley Assembly 4-114 Clearance 4-152
4.6.15 Type Belt
Motor
4-115 4.7.0 LOCATIONS (285Ipm)
4-153
4.6.16 Type Belt Positioning Rollers 4-115 4.7.1 Back View 4-153
4.6.17 Type Belt Idler Pulley (285 Ipm) 4-116 4.7.2
Front View 4-154
4.6.18 Type Belt Idler Pulley Pivot Assembly 4-116 4.7.3 Right
Side
4-155
4.6.19 Transducer Assembly (285 Ipm) 4-117 4.7.4 Left
Side
4-156
4.6.20 Transducer 4-118 4.7.5
Card Gate (285 Ipm) 4-157
4.6.21 Impression Singleshot Potentiometer 4.7.6 Card and I/O
Cables (285 Ipm) 4-158
(285Ipm)
4-119 4.8.0 OSCILLOSCOPE FIGURES
(285Ipm)
4-159
4.6.22 Transducer Position (Character
Cutoff)
4-120
4.6.23 Hammer Flight Time (285 Ipm) 4-120 5.0.0 DISPLAY
UNIT
5-'
4.6.24 Hammer Coil (285Ipm)
4-121 5.1.0 THEORY
5-1
4.6.25 Hammer
(285Ipm)
4-123
5.1.1
Formation of Characters
5-1
4.6.26 Hammer Block Assembly (285 Ipm) 4-124 5.2.0
FUNCTIONAL CIRCUITS 5-2
4.6.27 Ribbon Drive Description 4-125
5.2.1
High Voltage Oscillator
5-2
4.6.28 Ribbon Cassette (285Ipm)
4-126 5.2.2 Brightness Control 5-2
4.6.29 Ribbon Drive Assembly 4-126 5.2.3 Video Dot
Amplifier
5-3
4.6.30 Ribbon Drive Clutch 4-127 5.2.4 Wiggle
Sweep Circuit
5-3
4.6.31 Ribbon Drive Belt 4-128 5.2.5 Horizontal Deflection Control
5-3
4.6.32 Ribbon Solenoid 4-129 5.2.6 Vertical Line Control 5-3
4.6.33 Ribbon Drive Rolls and Idler Rolls 5.3.0 OPERATION
5-4
(285Ipm)
4-130 5.4.0
MAINTENANCE 5-5
4.6.34 Ribbon Drag (285 Ipm) 4-130
5.4.1
CRT Safety 5-5
4.6.35 Ribbon Tracking (285 Ipm) 4-131 Protective Equipment 5-5
4.6.36 Ribbon Shields (285 Ipm) 4-132 Cathode
Ray Tubes-Safe Handling 5-5
4.6.37 Tractor Drive Shaft 4-134 Transportation Handling 5-5
4.6.38 Tractor Cover 4-134 Storage 5-5
4.6.39 Carriage Tractor/Vernier/Tractor Drive Testing 5-5
Shaft 4-135 Defective CRT Disposition 5-5
4.6.40 Carriage Motor 4-136 5.4.2 Display Assembly
5-7

5.4.3
5.4.4
6.0.0
6.1.0
6.1.1
6.1.2
6.1.3
6.1.4
6.2.0
6.3.0
6.3.1
6.3.2
6.3.3
6.3.4
6.3.5
7.0.0
7.1.0
7.1.1
7.1.2
7.1.3
7.1.4
7.1.5
7.1.6
7.1.7
7.1.8
7.2.0
7.2.1
(
Yoke Adjustment
MAP/Diagnostic Test Display Patterns
KEYBOARD
THEORY
Introduction
Key Modules
Key Detection
Clicker
Shift.
Character Repeat.
Character Storage
Control.
Input Lines
Basic Oscillator
Repeat Oscillator.
Error.
Busy Tone
Output Lines
Kbd Go .
Input Lines
Bit Lines
Key B
it Codes.
FUNCTION KEYS
MAINTENANCE.
Keyboard Assembly.
Key Module
Space Bar
Flyplate Replacement
CODE Key.
CONSOLES
OPERATOR
CONTROL PANEL
CONTROLS.
LOAD Key/Light
START Key/Light
POWER ON/OFF Switch
STOP Key/Light .
KEYBD RDY (Keyboard Ready) Light
PROC CH K (Processor Check) Light
PWR CH K (Power Check) Light.
TH CH K (Thermal Check) Light.
CE CONTROL PANEL .
MODE SELECTOR Switch
PROC RUN
INSN STEP/DPLY LSR
I
I
\
LSR Subdivision and Micro Interrupt
Levels
AL TERMAR IRPT
ALTER STOR
DPLY STOR
INSN STEP/DPLY
CH KS
Processing Unit Error Byte
(High-Order) .
Port Error Byte (Low-Order Byte)
INSN STEP/DPLY PCR
SYS INSN STEP.
(
5-7
5-8
6-1
6-1
6-1
6-1
6-1
6-1
6-1
6-1
6-1
6-2
6-2
6-2
6-2
6-2
6-2
6-2
6-2
6-2
6-3
6-4
6-7
6-7
6-7
6-7
6-8
6-8
7-1
7-2
7-2
7-2
7-2
7-2
7-2
7-2
7-2
7-2
7-3
7-3
7-3
7-3
7-3
7-4
7-4
7-4
7-5
7-5
7-5
7-5
7-5
"
7.2.2 IMPL-IPL Switches
7-6
IMPL Switch
7-6
IPL Switch.
7-6
7.2.3 PROC
INTERRUPT Lights
7-6
7.2.4 RESET Key
7-6
7.2.5
ADDRESS/DATA DISPLAY/DATA
Switches
7-7
7.2.6 CLOCK Light.
7-7
7.2.7 FORCE CLOCK Switch
7-7
7.2.8 CHECK Switch
7-7
7.2.9 CE START Key
7-7
7.2.10 LAMP TEST Switch.
7-7
7.2.11 DISPLAY INTENSITY Control
7-7
7.2.12 STOR SE L Switch
7-7
7.2.13 PWR FAULT DPLY Switch and DPLY
PWR CHK Key
7-8
7.2.14
ADD COMP Switch
7-8
RUN Position. 7-8
STOP Position
7-8
7.2.15 Feature Switches
7-9
COMM DPL Switch
7-9
8.0.0 POWER SUPPLIES
8-1
8.1.0 HIGH FREQUENCY
AND TRILEVEL
POWER SUPPLIES
8-1
8.1.1
Introduction
8-1
8.1.2 Power Sequence and
Distribution
8-2
8.1.3 Power On Sequence .
8-3
8.1.4 Power
Off Sequence.
8-4
8.1.5 Voltage
Sense and Power Fault Display
8-6
8.1.6 Power Faults
8-7
8.1.6.1 Thermal Switches
and Faults.
8-7
8.1.6.2 Overvoltage Fault
8-7
8.1.6.3 Undervoltage Fault
8-7
8.1.6.4 Overcurrent Fault
8-7
8.1.7 Control Voltage
Checkout.
8-7
8.1.8 Manual Bring-Up
Of The Multilevel,
Dual Level,
And Trilevel Supplies .
8-8
8.1.9 Power Supply Voltages.
8-9
8.1.10 Power Sequence Card
Pins And Test
Points
8-10
8.1.11 Power Supply Plug And Pin
Locations.
8-11
8.1.12 Terminal Board Locations
And Pins
8-12
8.2.0 FERRO RESONANT POWER
SUPPLIES 8-13
8.2.1 Introduction
8-13
8.2.2 Power Sequence
And Distribution
8-14
8.2.3 Power On Sequence .
8-15
8.2.4 Power Off Sequence.
8-16
8.2.5 Voltage
Sense And Power Fault
Display 8-18
8.2.6 Power Faults 8-19
8.2.6.1 Thermal Switches and Faults .
8-19
8.2.6.2 Overvoltage Fault 8-19
Contents
vii

viii
8.2.6.3 Undervoltage Fault 8-19 9.2.35 Print
Head Forms Guide 9-40
8.2.6.4 Overcurrent Fault 8-19 9.2.35.1 Print
Head Retract Ramp 9-40
8.2.7 Control Voltage
Checkout.
8-19 9.2.36 Print
Head Cable . 9-42
8.2.8 Manual Bring-Up
Of The DC Power 9.2.37 Felt and Wick Service 9-44
Supply.
8-20 9.2.38 Print
Head Ribbon Shield 9-44
8.2.9 Power Supply Voltages. 8-20 9.2.39 Print
Head Ribbon Lifter
9-44
8.2.10 Power Sequence Card
Pins And Test 9.2.40 Ribbon Drive 9-45
Points .
8-21
9.2.42 Ribbon Drive Clutches 9-45
8.2.11 Power Supply Plug And
Pin
9.2.43 Ribbon Drive Shaft 9-46
Locations.
8-22 9.2.44 Ribbon Drive Lines 9-46
8.2.12 Terminal Board Locations And
Pins
8-23 9.2.45 Ribbon
Feed Rolls 9-47
9.2.46 Ribbon Box and Cover . 9-48
9.0.0
SERIAL PRINTER
9-1
9.2.47 Ribbon Changing. 9-48
9.1.0
THEORY
9-1
9.3.0 LOCATIONS.
9-49
9.1.1 Introduction
9-1 9.3.1
Front and Right Side Locations 9-49
9.1.2 Functional Components 9-2 9.3.2 Front
and Left Side Locations 9-50
9.1.2.1 Stepper Motors 9-2 9.3.3
Bottom Locations
9-51
9.1.2.2 Print
Head Carrier 9-3 9.3.4
Base Locations 9-52
9.1.2.3 Forms
Feed
9-9 9.3.5 Power Supply Board Locations 9-53
9.1.2.4 Circuit
and Power 9-12 9.4.0 PRINT
QUALITY PROBLEMS 9-54
9.2.0
MAINTENANCE.
9-13 9.5.0
PR EVENTIVE MAl NTENANCE 9-55
9.2.1 Printer Cover 9-13
9.2.2 Separating The Printer From The 10.0.0
DATA COMMUNICATIONS.
10-1
Power Supply 9-14 10.1.0
INTRODUCTION
10-1
9.2.3 Platen
and Paper Deflector 9-16 10.1.1 Data Communications Abbreviations
10-1
9.2.4 Platen
Release Eccentrics 9-17 10.1.2 BSCA/SDLC Locations. 10-2
9.2.5 Platen
Gears
9-17 10.2.0 BSCA/SDLC CARD STRAPPING 10-3
9.2.6 Platen
Pressure Rolls 9-18 10.3.0 1200
BPS INTEGRATED MODEM.
10-4
9.2.7 Forms Tractor Unit . 9-19 10.3.1 Transmit Level Adjustment 10-4
9.2.8 Forms Tractor
Unit Chain Cover 9-19 10.3.1.1 WT
PSN Line Plate and Cable
9.2.9 Forms Tractor
Unit Chain.
9-20 Connections . 10-6
9.2.10 Platen Gear Backlash 9-20 10.3.2 Board Strapping 10-7
9.2.11 Forms Feed Motor Gear Backlash
9-21
Leased Line Board 10-7
9.2.12 Forms Feed Motor/Emitter
9-21
Switched Network Board 10-7
9.2.13 Forms Feed Motor/Emitter
9-22 10.3.3
Card Strapping 10-8
9.2.14 Forms
Feed Emitter Disk 9-23 Auto-Answer Basic
Card (A 1) 10-8
9.2.15 Forms
Feed Motor/Emitter
9-24 Equalizer Card
(A 1) . 10-8
9.2.16 A-Frame 9-25 Auto-Answer Interface Card (B2) 10-9
9.2.17.1 End-of-Forms Switch (Old Style) 9-26 Ring Integrity Card (E2) 10-9
9.2.17.2 End-of-Forms Switch (New Style) 9-27 10.4.0 2400
BPS INTEGRATED MODEM.
10-10
9.2.18 Print Emitter Pickup 9-29 10.4.1 Controls
and Indicators 10-10
9.2.19 Print Emitter 9-30 Test/Operate Diagnostic 10-12
9.2.20 Print
Emitter Hold Down Bracket 9-30
OPE RATE Switch 10-18
9.2.21 Left Margin 9-31
CADUCEE Feature . 10-18
9.2.24 Power Supply Board 9-32 Transmit Level
Limiting and Signal
9.2.25 Capacitor C3 9-33 Meter Adjustment 10-18
9.2.26 Power Transformer 9-34 10.4.2 Dial Tone
Detect.
10-19
9.2.27 Fan 9-34 10.4.3 Interface Signal Timings 10-20
9.2.28 Carrier Main
and Support Shafts. 9-36 10.4.4 Card Population Check and Card Strapping
9.2.29 Carrier and Main Shaft 9-36 Procedure. 10-21
9.2.30 Carrier Support Shaft 9-37 10.4.5 Preamplifier Strapping . 10-23
9.2.31 Carrier Drive Belt 9-38 10.4.6 Transmitter Interface Strapping . 10-24
9.2.32 Print Stepper
Motor.
9-39 10.4.7 Test/Operate, Timing Options Strapping 10-26
9.2.33 Carrier Leaf Spring and Bearing 9-39 10.4.8 SNBU Strapping . 10-29
9.2.34 Print Head . 9-40 10.4.9 Auto-Answer Interface
and Strapping . 10-30

10.4.10 Leased Line, Multipoint or Point-to-Point
Strapping. . . . . . . .. 10-31
10.4.11 CADUCEE Feature Card
Strapping. 10-32
10.4.12
Wave Forms . . . . . . . 10-33
10.5.0 MODEM
CABLING TO COMMON
CARRIER
10.6.0 MODEM CONTROL LINES . . 10-39 10-41
APPENDIX A. NUMBERING SYSTEMS. . A-1
BINARY AND HEXADECIMAL
CONVERSION. . . . . . A-l
Binary Number Notation . . . A-l
Hexadecimal Numbering System A-l
Hexadecimal and Decimal Conversion A-2
APPENDIX B. STEPPER MOTORS B-1
PRINTER STEPPER MOTORS B-1
Stepper Motor Characteristics B-1
Stepper Motor Operation . . B-1
Home Position A B (Reset) B-2
First Advance
Pulse A B (Generated by
Adapter) . . . . . .
B-2
Second Advance Pulse AB . B-3
Third Advance Pulse A B B-3
33FD STEPPER MOTOR . B-4
APPENDIX C. INSTALLATION
INSTRUCTIONS . . . . . C-1
SYSTEM/32 INSTALLATION AND
CONFIGURATION C-l
Disk Drive . . . . C-2
33FD Diskette Drive C-3
Belt Printer C-3
Serial Printer C-3
Forms Stand C-4
Display Unit C-4
Keyboard . C-4
Power Sequence C-4
BSCA/SDLC . C-5
Integrated Modem Installation Data Table. C-7
Power On Checks and Testing C-8
I/O Features . . . . . . . . C-9
To Complete the Installation. . . C-9
SCP SYSTEM CONFIGURATION AND
INSTALLATION . . . . C-l0
Diskettes Required . . . C-l0
System Configuration Steps C-l0
IN IT Procedure . . C-ll
BACKUP Procedure. C-12
APPLYPTF Procedure C-13
CNFIGSCP Procedure C-13
INDEX. . . • . . X-1
Contents ix

x

List Of Abbreviations
J1S
Microsecond FRU Field replaceable unit
OC
Overcurrent
FSL Field service logics
OP
Operating point
ac Alternating current func Function/functional
OV
Overvoltage
adr Address
adv Advance
GB Guard band
PIN
Part number
AGC Automatic gain control gnd Ground
PC
Parity check/printed circuit
ALD Automated logic diagram
PCR
Process condition register
ALU Arithmetic and logic unit hex Hexadecimal
PG
Parity generation
AM Address marker
Hz Hertz
PID
Programming information
distribution
bfr Buffer I/O
Input/output
PM
Preventive maintenance
BH
Behind home
ID Identification
POR Power on reset
bksp Backspace
IDB Identification buffer
PP Parity predict/program product
BPC
Block processor check IMPL Initial microprogram load pres Present
BSCA Binary synchronous communications
IMPSS
Impression singleshot prev Previous
adapter
ind Indicator proc. Process
inh Inhibit
PSR
Program support representative
C Celcius init Initialization
PSS Print subscan
CE
Customer engineer insn Instruction PTF Program temporary fix
CEM
Customer engineering 10CL
Input/output control load pwr Power
memorandum IOCS I
nput/output control sense
chk Check IOL
Input/output load
R/W
Read/write
ckt
Circuit lOS I
nput/output sense rdy Ready
COMM
Communications
IPL
Initial program load
reg
Register
comp compare
IR Incident report rep Repeat
cps Characters per second irpt Interrupt
RPG
Report program generator
CPU
Central processing unit/processing rpm Revolutions per minute
unit kbd Keyboard
CRC Cyclic redundancy check Kg
Kilogram S Second
CRT Cathode ray
tube
SAR Storage address register
CS Control storage
Ib Pound
SBI System bus in
LED Light emitting diode
SBO System bus out
db Decibel Ipm Lines per minute SCP System control program
DBI
Data bus in
LSR Local storage register SDR Storage data register
DBO
Data bus out
Ivl Level
SDLC Synchronous data link control
dc Direct current
LZ
Landing zone SEL Select/selector
DCP
Diagnostic control program SS Singleshot
DE
Disk enclosure
MAB
Microprogram address backup stor Storage
dec Decimal (register) sw Switch
displ Display
MAR Microprogram address register/
SWG
Start wri te gap
DPLY Display memory address register sys System
dsply Display max Maximum
dup
Duplicate
MCU Magnetic card unit
TB
Terminal board
MLM
Maintenance library manual
TH
Thermal
EBCDIC Extended binary coded decimal mm Millimeter TP Test point
interchange code
MOR
Micro operation register
tr Trigger
EOF End of forms/End
of file
MS
Main storage/millisecond
ERAP Error recording and analysis
MST
Monolithic system technology
procedure
EWG End write gap N/A Nonapplicable
F Fahrenheit N/C Normally closed
FC
File control N/O Normally open
FET Field effect transistor nom Nominal
xi

xii
UV Undervoltage
V
Volt
VFC Vertical forms control
VFO Variable frequency oscillator
vol Volume
VOL-ID Volume identification
VOM Volt-ohm meter
VTL Vendor technology logic
VTOC Volume table of contents
WR Work register
WTC World Trade Corporation (IBM)

CE SAFETY PRACTICES
All customer engineers are expected to take
every precaution possible and observe the fol-
lowing safety practices while maintaining IBM
equipment:
1. Do not work alone under hazardous con-
ditions or around equipment with dan-
gerous voltage.
Note: Always advise your manager if you
MUST work alone.
2. Remove all
power, ac and dc, when you
are removing or assembling major compo-
nents, working in the immediate area of
power supplies, performing mechanical
inspection
of power supplies, and installing
changes in machine circuitry.
3.
4.
5.
Lock or tag the wall box power switch after
you turn it off. Attach "DO NOT OPER-
ATE" tags, form 229-1266, when applicable.
Pull
the power supply cord whenever
possible.
When it
is absolutely necessary to work on
equipment having exposed operating mech-
anical
parts or exposed live electrical cir-
cuitry anywhere in the machine, take the
following precautions:
a. Ensure that another person, familiar
with the power off controls, is present.
b. Do
not wear rings, wristwatches, chains,
bracelets, metal
cuff links, or any
other metal personal jewelry.
c. Use
only insulated pliers, screwdrivers,
and
probes.
d. Keep one hand in your pocket.
e. Be certain that the controls are set
correctly and that you have the
proper capacity probes when using
test instruments.
f. Avoid contacting a ground potential
(metal floor strips, machine frame,
metal lamps, etc); use rubber mats pur-
chased locally,
if necessary.
6. Wear
safety glasses when you are:
a. Using a hammer to drive pins, rivets,
stakes,
etc.
b. Using power tools for drilling, reaming,
grinding,
and other metal work.
c. Attaching springs with a spring hook.
d. Soldering, cutting wire, or removing
steel bands.
e. Cleaning
parts or using solvents, sprays,
cleaners,
or any other chemicals.
f. Working under any other condition
that might be hazardous to your eyes:
SAFEGUARD YOUR EYES.
7. Follow the special safety instructions out-
lined in the CEMs and in the safety sec-
tion of the maintenance manuals when
handling cathode ray tubes and high
voltage.
8. Do not use solvents, chemicals, grease, or
oil that are not approved by IBM.
9. Do not use tools or test equipment that is
not approved by IBM.
10. Replace worn or broken tools and test
equipment.
11. Do not lift a load that you and your man-
ager feel
would jeopardize your health
12.
13.
14.
15.
16.
17.
and well-being or that of other employees.
Restore all guards, shields, signs, ground
wires, and other safety devices after
mai ntenance.
Avoid touching moving mechanical parts
when lubricating, checking for gap, etc.
Do not touch ANYTHING while using
the stroboscope; parts could be moving
even
though the strobe light makes them
appear to be stopped.
Do not wear loose clothing that might
catch in the machinery.
Keep your shirt sleeves buttoned or roll
them above the elbow.
Tuck your tie in your shirt or wear a non-
conductive tie clasp attached approxi-
mately 3 inches from the end of your tie.
Do NOT use a
tie chain.
KNOWING SAFETY IS NOT ENOUGH. AN
UNSAFE ACT INEVITABLY LEADS TO AN
ACCIDENT. USE GOOD JUDGEMENT-
ELIMINATE UNSAFE ACTS.
Be sure that your actions do not render the
product unsafe or expose customer personnel to
unsafe conditions. Practice the following pre-
cautions to protect customer personnel:
1. Maintain good housekeeping in the ma-
chine area during and after maintenance.
2.
3.
a. Place removed machine covers in an
out-of-the-way place where no one can
trip over them.
b. Place the CE tool kit away from walk
areas
(under a desk or table) so no one
can trip over it.
Make
sure that fellow CEs and customer
personnel are not in a hazardous position
before starting the equipment.
Replace all machine covers before returning
the machine to the customer.
DANGERS
Resistors and solenoids become extremely hot
after prolonged use. Be sure the components
have cooled before performing maintenance
in these areas:
2.2.2
2.2.4
3.2.12
4.2.3
4.2.9
4.2.10
4.2.30
4.2.32
5.2.2
5.2.3
8.0.0
Disk Enclosure Removal
Disk Brake Assembly
Adjustment
33FD Drive Motor Removal and
Replacement
Printer Thermal Switch Removal and
Replacement
Motor and Paper Clamp Resistor
Removal
and Replacement
Print Unit Removal and Replace-
ment
Ribbon Drive Clutch Removal and
Replacement
Ribbon Solenoid Adjustment,
Removal and Replacement
Display Assembly Removal and
Replacement
Display Assembly Yoke Adjustment
Power Supplies
xiii

xiv

1.0.0 Introduction
1.1.0 DESCRIPTION
This system is a desk-size business system with
the following features:
• Programs are written in system instructions
and converted to machine language by a
microprogram.
• Large storage capacity is provided by an
integrated disk storage faciIity.
• Operating instructions and prompting
messages are displayed on a display screen.
• Input/output and processing unit errors are
recorded and can be retrieved.
• Diagnostic programs are automatically run
after the initial microprogram load.
• Whenever possible, instructions are automat-
ically retried after an error.
The disk drive provides 3.2, 5.0,9.1, or 13.7
million bytes of accessible storage depending on
the system model number. In addition, various
diagnostic programs reside on the 62GV.
The processing unit contains 16K, 24K, or 32K
. (K = 1024 bytes) addressable positions of main
storage and 4K or 8K addressable positions of
control storage. FET (field effect transistor) tech-
nology is used for both main and control storage.
The processing unit also contains registers,
gates,
and ALUs that are controlled by the
microprogram.
The CE control panel contains lights and
switches used
for maintenance of the system.
See Section 7 for detail.
The 33FD diskette drive provides input/output
capabilities by IBM diskettes. For example,
data can olso be entered on the diskettes by
key entry devices such as the IBM 3740 Data
Entry System.
Various diagnostic programs reside on the
diskettes.
The IBM System/32 can be ordered with either
the serial printer or the belt printer.
The serial printer has 132 print positions and uses
a
64-character set. It is a 7 x 7 wire matrix printer.
The serial printer is available in four models:
120 CPS (characters per second) bidirectional
80 CPS bidirectional
40 CPS bidirectional
40 CPS unidirectional
The two models of the 40 CPS printer are identical.
The attachment circuitry controls whether they
print only left-to-right or in both directions.
The belt printer has 132 print positions and a 48-
character set, a 64-character set, or a 96-character
set. The printing speed is 50,100,155, or 285 lines
per minute with a 48-character set.
The display unit is used for prompting, job
output, and error messages. Up to six lines of
40 characters per line can be displayed at one
time.
The keyboard controls system functions.
It is the key entry device for diagnostic pro-
grams
and is also used as a data input device.
The communications adapter (BSCA/SDLC) is an
optional feature that allows the System/32 to
function as a point-to-point or a multipoint terminal
Data is transmitted or received serially-by-bit and
serially-by-character over voice grade communica-
tion networks (switched or nonswitched network).
The system can be connected to a half-duplex or a
full-duplex facility; however,
the communications
adapter operates in half duplex only. That is,
transmission
of data is only in one direction at a
time.
The operator control panel is used to turn the
power OFF and ON, load the diagnostic pro-
grams
and control programs, and start and stop
the processing. The keyboard ready, processor
check, thermal check, and power check indi-
cator lights are also on the operator console.
Introduction 1-1

1.2.0 BASIC CONFIGURATION
Disk Drive
33FD Diskette Drive
Display Unit
r- -------.,
I I
I I
L _______ ....J
Processing Unit, Channel,
Attachments, Control
Storage, and Main
Storage
Keyboard
Top View
Printer
ffa:OtlDCCDc=J~ DC
'I DDOCOOOCC \
I
tlDOOooaS]otJ DO
Doccn DO CU
I
DC 0' DCC --
I
Operator Control
Panel
1-2
l~
~~WER81
OFF ~
000 0
KEYBO PROC TH PWR
ROY CHK CHK CHK

1.3.0 SYSTEM DATA FLOW
Processing
Unit
ALU Clocks,
Controls and
Registers
Channell
Port
Attachments
I Channel, as used in this system, refers to the internal
interface
between the processor and logic for control
of I/O function. The channel contains a port through
which part of this control passes.
Display Key-
board
Printer
33FD BSCA
or
SDLC
Modem
or
Data
Set
Other
Attach
ments
Other
liD
Devices
Introduction 1-3

1.4.0 PROCESSING UNIT DATA FLOW
15 r-----t---~-
8
Control
Main
Storage
~ )
(1 byte)
Storage r--
~ , 12bY',,1
I I SAR I
Processing Unit
I ~r--15
~~ Stg Sys Bus Out Low
_ ..,........, Gate
~~B
r===={>~ 7
-== = ===C> Stg Sys Bus Out
~ Gate r--
I~ High
f>~o
High
.---
I
I
Display Low Byte J'-,. I
~ I ... Sys Bus Out Low I :f>
~~~========~====~~==========~ ... ~
1-4
T 1f
~====~~====~~~===========================I- = ~I========II======~ ---- i~
0 5}7 o
'\/
7
8V
15
8\
7\
715
I
X-High
V-High I
~ X-Low II V-Low 1
r--
JI
~ ~ r
t>
Adr
I
AdrSw
Comp ....
\l
[>
Adr
\ / \ / I
Comp
V
:f>
ALU
ALU
I
High
Low
I
'----
7 I
0 8
15
I
--
--I
,7 \7 ~
VV~
I
pB=
r--
I
Event Ind
:{>
Display
ALU Gate I I ALU Gate I I
High
Byte
High
Low
I
OR
:f>
0 7 8
15
~
t::=::::f>
Sys Bus Out High
.....
Status
'----
~
$
CK 1
.....
~
1 Gate
r----
Adr Sw 1 & 2 r 0 7 8
15
....
....
1/ ~
r--
Adr Sw 3 & 4
-">
F===f>
OR
=-
Select
-..
32 LSRs
Status
...
Status
r=t>
I/O Clocks
r 2 Gate
....
V
'----
'-----
0
JI
7 8
15
Channel SBI <
:J:====
- --

1.5.0 CHANNEL DATA FLOW
Channel
Sys Bus Out Low
Command Bus Out
Port Data Bus Out
Att
Device
Gate
Port Data Bus in
Control Lines
Processing Unit
Channel SBI
~====~======~==============~
Introduction 1-5

1.6.0 SYSTEM MICROPROGRAM
All the functions performed by the system are
controlled by the microprogram.
The system microprogram
is composed of micro-
routines of varying sizes, each having a specific
task
to perform. Each microroutine is composed
of bit-significant micro instructions that are
machine language instructions.
The microprogram handles:
• System instructions
• Data in main storage
• Channel operations
The microprogram must
be loaded into control
storage (initial microprogram load) before any
processing
can begin. The microprogram can be
loaded from either the disk or the 33FD (CE
only) depending on the setting of the IMPL switch
on the CE
control panel.
To begin the initial microprogram load operation,
press the LOAD key on the operator control
panel.
Press
LOAD
Key
IMPL
Switch
Activate Disk -
Disk
[Skette (33FD)
Activate 33FD
,-
Disk
33FD
~
IMPL
Control Storage
Main Storage \ \ ,\
Microroutines
~--------------~
1-6
Micro
Instructions
2 E A 3
E D 0 6
580
2 6 A 3