MAI Basic Four 4399 User manual

Basic Four®
System S/10 (Machine Type 4399)
Office Display Terminal (Machine Type 4398)
Service Manual ·
April 1983
BFISD 8072PA

SECTION I
1.1
1. 2
1.3
1. 4
1.5
1.5 .1
1. 5. 2
1. 5.3
1. 5.4
1.6
1. 7
SECTION
II
2 .1
2. 2
2.3
2.3.1
2.3.2
2. 4
2.5
2 .5.1
2.5. 2
2.6
2. 6. 1
2.6. 2
2.6 .3
2.6 . 4
2.6. 5
2.6. 6
2.6 .7
2.7
2. 7.1
2 .7. 2
2.8
SECT I ON
III
3. 1
3.2
3.2 . l
3.2 . 2
3.2 . 3
3. 2. 4
3.2 .5
3.2.6
3. 2 .7
3.2. 8
BFISD 8072
TABLE OF CONTENTS
Pa ge
INTRODUCTION
. . . . • • • 1-1
. .. • • • 1-1
Purpose • • • • • • •
Related Documents • •
Safety Precautions.
S/ 10 Overview •••
Physical Desc ripti on •. •
. • • • . • • • • . 1-1
Office Display Te rminal •
System S/ 10 •••
Ma in Console •••••
Keyboard Assembly • •
O perati onal Description •
Spec if ica t ions •••••
INS TA LLAT ION
1- 2
• • • • • . 1- 3
• • 1- 3
•• 1-4
• • • • • 1- 4
• 1-5
• • 1-5
• • 1-8
Intr o duction •• ••• •••• • ••• • • 2 -1
Unpacking And Inspecting The S/10 - 0DT
Preinstal l a ti on Ch ecks .
AC Power Requirements •
Ground Checks • • • •
Power Requirements ••••
Instal lin g The S/10-0DT ••
••• 2- 1
• 2 -1
• • • • • • • • 2 -1
• • • • • 2- 2
• 2- 2
• 2- 3
Attaching And Detaching The Keyboa rd •••• •
Serial Po rt Interface • • • • • • • • 2- 5
• 2- 6
2- 9
Operationa l Funct i ons ••
St anda rd Keyboard L ayo ut •••••
Key Combinat ion • • ••
The Main Key Gr oup . • •
The Auxiliary Pad G rou p • • • • •
The Motor Bar Gr oup • • •
The Function Key Gr oup .
Inte rn atio n al Keyboard.
Use A nd Ca r e Of Disk And Drive .
Disk Insertion ••
Wr i te Protection . . . .
. . .. .
• 2- 9
• • • 2- 9
. . .
. . .. .
• 2 -1 0
• 2 -11
• 2 -1 2
• 2-13
2- 14
• 2-20
• • 2- 21
• 2- 23
Resetting The S/ 10 . . . . . . . . .. •
2-23
FUNCT I ONA L DESCRIPTION
Introduction •••• • •
Ope r atio n Of The Office
• • • • • • • • . 3-1
Display Terminal •••••• • 3 -1
• • • • • • • • • 3- 2
Display Characte rs ••••
Video Di splay Data. • •• • • • • • • • • • • • 3- 5
• • • • • • 3- 6
. . . . . . .
Line Buff er W it h The DMA. • • 3-6
Status Line • • • • •
Loadin g Da t a Into The
Assembling a Ch arac t er Line • • • • • • • • • • • • 3- 7
• • • • • 3- 7
• 3 -7
• • 3- 7
Refres h ••• • • • • • • • • • • • • • •
The Do ubl e -Hi gh Cha r acte r L in e . • • • • • •
The Non - Volatile RAM . • · • • • • • • • •
ii i

BFISD 8072
SECTION III
3.2.9
3.2.10
3.3
3.3.1
3.3.2
3.4
3. 4 .1
3.4.2
3.4.3
3.4.4
3.4.5
3.5
3.5.1
3.5.2
3.6
3.6.1
3.6.2
3.6.3
3.6.4
3.6.5
3.6.6
3.6.7
3.6.8
3.6.9
3.6.10
3.6.11
3.6.12
3.6.13
3.6.14
3.6.15
3.7
3.7.1
3.7.2
3.7.3
3.7.4
3.7.5
3.7.6
3.7.7
3.8
3.9
3.9.1
3.9.2
3.9.3
3.9.4
3.9.5
3.9.6
3.9.7
3 .10
3.10.1
3.10.2
iv
TABLE OF CONTENTS (continued)
Page
FUNCTIONAL DESCRIPTION (cont'd)
Interrupt System. • • • • • • • •••••• 3-8
System Clocks • • • • • • • • • ••••• • 3-8
Opera ti on Of The Systern SI IO. • • • • • • • • 3-9
The Disk Controller System. • • • • • • •••• 3-9
Vectored Interrupt System • • •••••• 3-11
System Description For The Office Display Terminal •• 3-11
Serial Input and Output Ports • • • 3-11
Z80-l, The DMA And The DMA Controller ••••••• 3-12
Line Buffer And Attribute Generator • • • ••• 3-12
Video Generator And Attribute Control • • • • • • • 3-12
RAM-1, EPROM-1, And The Non-Volatile RAM •••••• 3-12
System Description For System S/10. • • • ••• 3-13
Z80-2 And The Floppy Disk Controller •••••••• 3-13
AFC Timing. • • • • • • • • • • • • • • • •
Advanced Video Processor Circuit Description ••
The Z80-l CPU ••••••••••••••
•• 3-13
• 3-13
• • 3-14
3-15 The Interrupt System And Timer.
The I/O Ports •••••••••
Device Enable Signals • • • • •
.. • • • • • 3-15
3-16
• • • 3-17
Master Clock And Divider Chain. • ••••••
Line Buffer Control • • • • • • • • • •
3-17
•• 3-18
•• 3-19
• • • • 3-19
Line Buffer • • • • • • • • • •
Attribute Generator And Cursor Address.
Character Genera tion ••
... . •
3-19
• • .• 3-20
• • • • • • 3-20
Video Out • • • • • • •
Direct Memory Access (DMA).
The DMA Controller. • • •
Initializing With EPROM-1 •
Non-Volatile RAM (NVR) ••
• • • 3-21
• • 3-21
RAM-1 • • • • • • • • • • •
3-22
• 3-22
• 3-22
Advanced Floppy Controller Circuit Description •••
AFC Timing. • • • • • • • • ••
The Microprocessor 280-2. • •••
• 3-22
EPROM-2 • • • • • • • • • • 3-23
Z80-2 Vectored Interrupts • • • • • 3-23
32-Bit Port • • • • • • • • • • • • • • • 3-23
Floppy Disk Controller. • • • • • • • • • • 3-23
Disk Controller Clocks. • • • • • ••• 3-23
The Motherboard • • • • • • • • • • • • • • • 3-24
Disk Drive Circuit Description. • • • • 3-25
Head Positioning Control. • • • • •••• 3-25
Track 00 Sensor • • • • • • • 3
• • -26
Spindle Drive Control • • • • • • • • • • • 3-27
Index Sensor. • • • • • • ••••••••• 3-27
Head Load Mechanism • • • • • • • • • • • • • • 3-27
Side Selection. • • • • • • • 3
• • • • • • -27
Data Recording and Retrieving • • • 3-28
Video Monitor Circuit Description • • • • • 3
V • •
-30
ideo Arnplif ier • • • • • • . • • . . . • • . • • •
3-32
Horizontal Driver • • • • • • • • • • • • • • • 3-32

SECTION III
3.10.3
3.10.4
3.11
SEC TI ON IV
4 .1
4.2
4.3
4.3.1
4.3.2
4.4
4.5
4.5.1
4.5.1.1
4.5.1.2
4.5.1.3
4.5.1.4
4.5.1.5
4.5.1.6
4.5.1.7
4 .5.1. 8
4.5.1.9
4. 5. 1.1 0
4.5.2
4.6
4.6.1
4 .6.2
4.6.3
4. 6.4
4.6.4.1
4 .6. 4.2
4 .6. 4 .3
4.6.4.4
4 .6. 4.5
4.6.4.6
4.6.4.7
4. 6.4 . 8
4.6 .5
4.6.6
4. 6. 7
4. 6.8
4. 6. 8 .1
4. 6.8.2
4.6. 8. 3
4. 6.8.4
4. 6. 8.5
4.6 . 8. 6
T AB LE OF CONTENTS (continued)
FUNCTIONAL DESCRIPTION (cont'd)
Horizontal Ou tput Transformer • • • • • •
Ve rti ca l Deflection • • ••••
Page
• 3-33
•• 3-33
BFISD 8072
The Power Supplies ••••••••
• • • • • 3-34
MAINTENANCE
Introduction. • • • • • • • • • • • • 4-1
Tools And Test Equipment. • • • • • • • • 4-1
Periodic And Preventive Mainte n ance • • • 4 -2
C le aning . • • • • • • • ••••••• 4-2
Visual Check. • • • • • • • • • • • • • • • 4-2
Voltage Checks . • • • • • • • • • •••• 4 -5
Adjustment Procedures • • • • 4-5
Disk Drive Adjustments . • • ••••••• 4 -7
Radial-Track Alignment. • • • • • • 4-7
Ind ex - To -Data Alignme nt • • •• • ••••• 4-9
Track 00 Sensor Alignment • 4 -1 0
Speed Control Adjustment. , • • • • • • • 4 -10
Track 00 En d Stop Adjus tment. • • • • • 4- 10
Drive Belt Adjustment • • • • • • • • • 4-11
Azimuth Alignment • • • • • • • • • • • • • 4 -11
Disk Drive Compliance Meas ur eme nt •••••• 4 -1 2
Disk Drive Er ase Meas urement. • • • • • 4-13
Disk Drive High Frequency Playback Measurement •• 4 -1 3
Video Display Adjustment •••••••••••••• 4 -1 4
Symptom A nd Fault Analys is. • • • • • • • • • • • • • 4 -1 6
S/ 10 And Office Display Trouble Analysis •••••• 4 -1 6
Advanced Video Processor (AVP) T rou bleshooting Aid. 4-17
Advanced Video Processor Test Procedure ••• . ••• 4- 21
Test 24 Diagnostic. • • • • • • ••••••• 4- 22
Setup • • • • • • • • • • • 4- 23
Key Functions •••••••••••••••••• 4- 23
Test 24 Output. • • • • 4- 23
Keyboard Test • • • • • • • 4 -2 4
T est 24 Detail. • • • • • • • • • • • • • 4-24
Initialization. • • • • • 4- 24
Normal Execution. • • • • • • •••• 4- 25
Line 25 Interrupt Servicing • • • • • • 4-26
Advanced Floppy Co ntr o ll er (AFC) Tr oubleshooting
Aid • • • • • •
4-27
Advanced Floppy Contro ll er Test Procedure
••• 4- 28
••• 4- 29
• • • • • • 4-35
Troubleshooting Chart • • • •
Disk Drive Trouble Ana l ysis ••••••
Preliminary Troubleshooting Steps ••
Drive Won 't Step Or Steps Er ra ti cal l y ••
H ead/Carriage Osci ll ates At Track 00.
Drive Motor Won't Rotate •• •• ••••••
Head Will Not Load.
Bad Index Output •••••
• 4- 36
• • 4 -3 6
• 4-36
••• 4- 36
• • 4-38
• •• 4- 38
v

BFISD 8072
SECTION
IV
4. 6.8 .7
4 .6. 8.8
4.6 . 8 .9
4. 6. 8.10
4.6.8.11
4 .6. 8. 12
4.6. 8.13
4.6.8.14
4.6.8.15
4.7
4.7 .1
4.7.2
4.7.3
4.7.3.1
4.7.3.2
4.7.3.3
4. 7.3.4
4.7.4
4.7.5
4. 7. 6
4 .7 .6.1
4.7 . 6. 2
4. 7.6.3
4. 7.7
4. 7.8
4.7.9
4.7. 10
SECTION v
5 .1
5.2
5.3
5.4
5 .5
5.6
5.7
5.8
5 .9
5 .1 0
5 .11
5 .1 2
5.13
5 .1 3 .1
5.13.2
5. 13.3
5 .1 3.4
5 .1 3. 5
vi
TABLE OF CO N TE N TS (continued)
MAIN TE NANCE (cont'd)
Light
Page
• • 4- 39
• • 4-39
4-39
Bad Write Protect O ut put • •
Activity Indicator Does No t
Read Erro r s - All Tracks ••
Read Errors -Random Tracks
Read Errors - Inside Tr acks
• • • • • 4 -39
•• 4- 41
Cannot Read Prewrit ten Data: Can Read Sel f-
Written D ata . • • • •• 4- 41
Cannot Wr ite Data • • • • • • • 4- 41
Erase Bad • • • • • • 4- 41
Drive Speed Uns tabl e . • 4- 41
Performance Tests • • • • • • • 4-43
ODT Terminal Integrity And Confidence Tests •••• 4- 43
Display Attribute Tes t s • • • • • • • • 4- 44
Key Funct ion Tests. • • • • • • • • •• 4-45
Tabst ops. • • • • • • • • • • • • • . • 4-45
Status, Keyclick, And Margin Be ll • • •• 4-45
Au t o Repeat And Scroll Rate • • • 4-46
Screen, Column Width, Cu r sor, And Reset •• • •• 4-46
Saving Set - Up Features ••• , • • • • • • 4-47
Screen Linearity And Focus Test • • • • • 4-47
S/10 Memory , EPROMs, And Disk Drive Tests ••••• 4- 48
Power Up Test • • • • • • • • • • • • • • • • 4-48
Verifying Data From The Diskette. • 4-49
Check The Other Dis k Drive . • • 4-5 0
S/ 10 Display Attribute Tests. • • 4- 50
S/10 Key Funct ion Tests • • 4-50
S/ 10 Screen Linearity and Focus Test . • • 4- 50
Testing Serial Por t s . • • • • • • • •• 4-50
REMOVAL/REPLACEMENT
Int r oduction. • • • • • • • • • • • • • • •
5- 1
. . . . . . . . 5- 1
Rep l acin8 The AVP And AFC Boards •••
Power Supply/Regulator Replacement.
Video Electronics Assembly Replacement .
Fl y back Transformer Replaceme nt • • • •
. . . . . . . 5 -1
• 5-3
• 5- 5
Power Socket _ And Switch Assembly Rep l acement.
• 5 -6
CRT Rep laceme nt • • • • • • • • 5- 6
Keyboard Replacement •••••••••
Keyboard Hinge Replacement •••••••
Speaker Replacement • • • • • • • • •
. . . . . 5- 8
Disk Dr ive Replacement ••••
Replacing The Disk Drive Fan.
Disk Drive Assembly • • ••
Printed Ci rcuit Board Assembly.
Shield Assembly • • • • • • • • • • • • • •
Rig ht-H and Gui de/Writ e Protect Assembly
Left-Hand Guide Assembly •••• , •
Front Panel Be ze l And Activity LED ••••
• 5 -9
•• 5- 10
• 5 -10
• 5 -12
• • 5 -1 2
. . 5- 16
• 5- 17
• • 5-17
•• • • 5- 18
. 5 -1 8

SECTION V
5.13.6
5 .13.7
5 .13. 8
5 .13.9
5.13.10
5 .13.11
5 .1 3. 12
5. 13.13
5.13 . 14
5 .1 3. 15
5 .1 3.16
5 .13.17
5.13.18
5 .13.19
5.13 . 20
5.13.21
SECTION VI
S ECTION VII
7. 1
7 .1.1
7 .1. 2
7 .1. 3
7. 2
7.2.1
7.2.2
7. 2. 3
7. 2.4
7. 2 .5
7. 2. 6
7.3
7.3.1
7.3 .2
7. 3. 3
7 .3. 4
7. 3.4 .1
7. 3. 4. 2
7. 3.4 .3
7. 3.4.4
7. 3. 4.5
7. 4
7. 4. 1
7.4 .1.1
7.4.1.2
7. 4.1.3
TABLE OF CONTENTS (continued)
REMOVAL/REPLACEMENT (cont'd)
Activity LED Remova l ••••
Activi t y LED Rep l acement ••
Cone Assembly • •
Pa ge
• • • 5-19
• • • • • 5-19
• • • • 5-19
Car ri er Assembly. • • • • • •
Ca rrier / Ind ex LED •
Index/Load BOSS • • • • • •
. . . . .
••• 5-20
• 5-21
So le noid ••••• •
Drive Motor • •
Track 00 Sensor •
Door But ton Assembl y. • • • • •
Stepper Band ••••••
St epper Motor • • • • • • • •
Head/Carriage Assembly •••••
Spindle, Bearings And Pulley.
Head Load Pad Assembl y. • • • •
Harness Assembly. • • • • • • •
SPARE PARTS
5.25" FIXED DISK DRIVE
Introduction ••••••••••
General Description •
Functional Concept •••••
Equipment Specif i ca ti ons ••••
In s tallation And Opera ti on .
Unp acking • • • • • •
Eq uipment Placement
Sh ip p in g Lock • • • • •
Step Rate Selection •
• 5-21
• • • • • • 5-22
•• 5-22
• • • • • • • 5-22
• 5- 24
• 5 -2 5
• 5-26
• • • • 5-27
• • • • • • 5- 28
. . . . . . . . 5- 28
• • •••• 5 -29
...
..
. . . . . . 7 -1
. . . . . • 7 -1
. . . . . . 7-4
. . . . . . 7-5
• • • 7-8
7- 8
• 7-9
. . . . . . 7- 9
7 -9
System Installation •••••
• . . . . . • . . . . 7-9
Ope r ation •• ••••
• 7-14
Functional Descript ion.
. . . . . . . . . . . . . 7 -1 6
Basic Disk Princip l es
Control Lines • • • • • • •
Data Lines ••••••• ••• •
Disk Controller ••••
Signal Definitions .
Detail ed Description . ... . . . .
•• 7-16
•• 7 -1 8
• • 7- 20
• •••• 7-23
• 7-26
• •• 7-29
Programming Informa ti on •
Commands •••
. . . . . • • • . . 7-31
• 7 -3 2
Secto r Format • • • • • • • • • • •
7-46
Maintenan ce • • • •
Diagnostics ••••••••
Power-Up Diagnostics •••••
Operational E rror Check
Fault Diagnostics ••••
• • • • • 7-47
••• 7-47
• 7-47
7- 48
••• 7- 49
BFISD 8072
vii

BFISD 8072
SECTION VII
7.5
7.5.1
7.5.2
7.5.3
7.5.4
7.5.5
7.5.6
7.5.7
7.5.8
7.6
SECTION VIII
viii
TABLE OF CONTENTS (continued)
Page
5.25" FIXED DISK DRIVE (cont'd)
Removal And Replacement Procedures •••••••••• 7-51
Disk Assembly Top Cover Removal And Replacement • • 7-52
Disk Controller Board Removal And Replacement • 7-52
Power Supply Removal And Replacement •••••••• 7-52
Disk Drive Assembly Removal And Replacement •••• 7-55
Master Electronic Board Removal And Replacement •• 7-55
Brake Removal And Replacement • • • • • • • • • • • 7-58
Motor Control Board Removal • • • • • • • ••• 7-59
Preamplifier Board Removal/Replacement. • 7-59
Parts List. • • • • • • • • • • • • • • • • • •• 7-59
REFERENCE DATA

Figure
1-1
1-2
1-3
1-4
2-1
2-2
2-3
2-4
2-5
3-1
3-2
3-3
3-4
3-5
3-6
3-7
3-8
3-9
3-10
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
4-10
5-1
5-2
5-3
5-4
5-5
5-6
5-7
5-8
5-9
5-10
5-11
6-1
6-2
6-3
6-4
6-5
6-6
6-7
6-8
LIST OF ILLUSTRATIONS
Page
System S/10 and Office Display Terminal • • xiv
S/10-0DT Internal Components. • •••••••• 1-6
Keyboard Assembly • • • • • • • • • 1-6
S/10 Conceptual Diagram • • • • • ••••• 1-7
Left Rear View. • • • • • • • • • • • • • • • • • 2-4
Right Rear View • • • • • • • • • • • 2-5
ODT and S/10 Keyboard • • ••••••• 2-10
ODT - S/10 Keyboard • • • • • • • 2-15
Proper Disk Insertion • • ••••••• 2-22
80 Column Format. • • • • • • • • • • • 3-2
Special Graphics In The 80 Column Mode. • ••• 3-3
The 132 Column Font • • • • • • • • • • • • • • • • • 3-4
Address Assignments for 80 and 132 Column Fonts ••• 3-4
System Block Diagram. • • • • • • • • ••• 3-10
Disk Drive Functional Block Diagram • • 3-26
Basic Recording Technique • • • • • • • • 3-29
Wave Forms in Read Sequence • • 3-30
Video Amplifier Block Diagram • • • • • • • • • • 3-31
Horizontal Drive Signal • • • • • • • • • • • 3-32
Cabinet Rear Lower Left Corner. • • • • • ••• 4-4
Cabinet Cover Latch • • • • • • • • • • • • • • • • • 4-4
+5VDC Adjustment. • • • • • • • • ••• 4-6
Radial Track Alignment Patterns • • • • • •••• 4-8
Index-To-Data Alignment Pattern • • • • • • • • • • • 4-9
E Test Pattern. • • • • • • • • • • • • • 4-15
Stepper Motor Control Timing. • • • • • • • ••• 4-37
Motor Control Timing. • • • • • ••••••• 4-38
Read Timing • • • • • • • • • 4-40
Write Timing. • • • • • • • • • • • 4-42
Video Electronics Assembly. • •••••••••• 5-4
CRT Connector • • • • • • • • 5-4
Removing The CRT High Voltage Anode Lead ••••••• 5-5
Chassis Top Securing Screws • • • • • • • 5-8
Drive Securing Screws • • • • • • • 5-11
Front Panel Securing Screws • • • • • • • • ••• 5-11
Disk Drive, Top View. • • • • ••• 5-13
Disk Drive, Bottom View • • • • • • • • • • 5-14
Activity Indicator Assembly ••••••• 5-18
Door Button Assembly. • • ••• 5-24
Stepper Band. • • • • • • • • • • • • • 5-26
ODT - S/10 Keyboard and Cabinet Assembly ••••••• 6-2
ODT - S/10 CRT Assembly • • • 6-5
S/10 Disk Drive Assembly. • • • • •••••••• 6-7
Disk Drive, Exploded View • • • • • • • • • • 6-9
Disk Drive PCBA Component Layout. • • • • • • • • 6-12
Disk Drive Ready PCBA Component Layout. • 6-14
Advanced Video Processor Circuit Board Assembly
Diagram AVP - (ODT Only) •••••••••••••• 6-16
Advanced Video Processor Circuit Board Assembly
Diagram AVP - (S/10 Only) • • • • • • • • • • • 6-22
BFISD 8072
ix

BFISD 8072
Figu re
6 -9
7-1
7-2
7-3
7-4
7-5
7-6
7-7
7-8
7 -9
7-10
7 -11
7 -1 2
7-13
7 -14
7-15
7-16
7 -17
7 -1 8
7-19
7-20
7-21
7-22
7-23
7- 24
x
LIST OF ILLUSTRAT I ONS (continue d)
Page
Advanced Floppy Disk Con tr o ll er Circuit Board
Assembly Diagram AFC. • • • • • • • 6- 28
Major Component L ocation ••••••••••••••• 7- 2
Head Disk Assembly. • • • • ••••••• 7-3
Simplified Block Diagram. • • • • • • • • • • • 7-4
Cable Clamp Bracket and Plate • • • • 7- 11
Cable Cl amp Bracket Installation. • • • • • 7-12
Cable Routin g and Fold. • • • • • • 7 -1 2
Interface PCBA and Bracket Mounting ••••••••• 7 -1 3
Disk Drive Block Diagram. • • • • • • • ••••• 7 -1 7
Surface and Head G eometry • • • • • • 7 -1 7
Differential Read Data Line Driver. • • • • 7-21
Differential Write Data Line Receiver • • 7- 21
Read/Write Timing • • • • • • • • • • •• 7-22
Write Data Precompensation •••••••••••••• 7- 24
Con tr olle r, Functional Or ganization ••••••••• 7-25
Controller Select Timing. • • • • • •••••• 7- 29
Data Transfer to Host, Timing • • •••••• 7 -3 0
Data Transfer from Host, Timing • • • • • • • • 7- 31
Device Control Block (DCB) Format • • • 7- 32
Comp l etion Status Bytes • • • • • • • • • • • 7-33
Sec tor Format • • • • • • • • • • ••• 7-46
Disk Drive Disassembl y. • • • • • •• 7- 53
Controller PCBA Removal • • • • • • • • • • • • • 7-54
Head Drive Assembly Removal • • • • • • ••• 7-56
Head Drive Disassembl y. • • • • • • • • 7-57

Table
1-1
2-1
2-2
3-1
3-2
4-1
4-2
5-1
5-2
6-1
6-2
6-3
6-4
6-5
6-6
6-7
6-8
6-9
6-10
6-11
6-12
7-1
7-2
7-3
7-4
7-5
7-6
7-7
7-8
7-9
7-10
7-11
7-12
7-13
7-14
7-15
7-16
7-17
7-18
7-19
7-20
LIST OF TABLES
Page
Specifications. • • • • . • . . . • •••.••• 1-8
Main Serial Port Pin Assignments. • ••• 2-6
Auxiliary Port Pin Assignments. • • • • • • ••• 2-7
Z80-l Control Signals • • • • • • • ••••• 3-14
I/O Port Input/Output Signals • • • • • • • 3-16
System S/10 Troubleshooting Chart • • • ••••• 4-29
Disk Drive Trouble Symptoms • • • • ••••••• 4-35
Removal/Replacement Procedures. • • 5-15
Removal/Replacement Adjustment Check List •••••• 5-16
ODT - S/10 Keyboard and Cabinet Assembly ••••••• 6-3
ODT - S/10 CRT Assembly • • • • • • • • • • •• 6-6
S/10 Disk Drive Assembly. • • • • • • • • • • •• 6-8
Disk Drive Model 915/925 Recommended Spare Parts
List • • • • • • • • • • • • • • • • • • • • 6-10
Disk Drive PCBA Component Layout. • • • • • • 6-13
Disk Drive Ready PCBA Component Layout. • • • 6-15
Advanced Video Processor, (16K) Parts List. • 6-17
Advanced Video Processor, (64K) Parts List. • 6-23
Advanced Floppy Controller Parts List •••••••• 6-29
S/10 Power Supply Parts List Phase lB • • • • 6-33
ODT Power Supply Parts List Phase lB. • • • • • • 6-36
Motherboard Parts List. • • • • • • • • • • ••• 6-39
Specifications. • • • • • • • • • • • • • • • 7-5
Interface Cable Pin Assignment. • • • • • 7-10
Diagnostic and Failure Code Indicators •••••••• 7-15
Power Requirements. • • • • • • ••••••••• 7-16
Head Select Decode Matrix • • • 7-19
Write Data Precompensation. • • • • • • • • • • • 7-23
Host Bus Status Signals • • • • • • • • • • • • 7-26
Summary of Host Bus Status Signals. • • • • • •• 7-27
Controller - Host Handshaking • • • • • • • • • • • • 7-27
Host Bus Control Signals. • • • • • . • • . 7-28
Host Bus Data Signals • • • • • • • ••••••• 7-28
Type 0 Error Codes, Disk Drive. • • • • • • • • • • • 7-36
Type 1 Error Codes , Controller. • • • • • • • • • • • 7-36
Types 2 and 3 Error Codes, Command and Miscellaneous. 7-37
Request Sense Status Error Codes. • • 7-37
Sector Field Description. • • • • • • • • • • • • • • 7-46
Power-Up Sequence Error Codes • • • • • • • 7-47
Operational Error Codes •••••••••••• 7-49
Fault Diagnostics • • • • • • • • • • • • • • 7-50
Parts List. • • • • • • • • • • • • • • • 7-59
BFISD 8072
xi/xii

BFISD 8072
PREFACE
This manual contains the necessary information to install , repair and maintain
the System S/10 and Office Display Terminal. The information in this manual is
directed primarily toward the System S/10. For purpose of maintenance, the
Office Display Terminal is the same unit without the Disk Drive assembly and
Floppy Controller that supports the Disk Drive interface. The instructions and
information are presented to aid maintenance personnel in the installation,
operation and care of this system. All controls are described and operational
considerations are presented in sufficient detail to enable field service
personnel to operate and maintain the equipment.
The major topics described in this manual are:
Section I
Section
II
Section
III
Section
IV
Section v
Section VI
Section VII
Section VIII
I ntroduction
Installation
Functional Description
Maintenance
Removal/Replacement
Spare Parts
5.25 Fixed Disk
Drive (optional)
Reference Data
WARNING
This equipment generates, uses, and can radiate
radio frequency energy and if not installed and
used in accordance with the instructions manual,
may cause interference to radio communications,
as temporarily permitted by regulation. It has
not been tested for compliance with the limits
for Class A Computing Devices pursuant to Subpart
J of Part 15 of FCC Rules, which are designed to
provide reasonable protection against such
interference. Operation of this equipment in a
residential area is likely to cause interference,
in which case the User at his own expense will be
required to take whatever measures may be
requir ed to correct the interference.
xiii

BFISD 8072
I I
~ ;
SYSTEM S/10
OFFICE DISPLAY TERMINAL
8072-01
Figur e 1-1. System S/ 10 and Office Display Terminal
x iv

BFISD 8072
SECTION I
INTRODUCTION
1.1 PURPOSE
This manual is a reference guide for the service technician. The information
in this manual enables a service technician to maintain the S/10 System (S/10)
or Office Display Terminal (ODT). See figure 1- 1. It includes information
and procedures needed to troubleshoot and maintain the S/10 or Office Display
Terminal to the replaceable assembly level. All references to the System S/10
are applicable to the Office Display Terminal except where noted.
1.2 RELATED DOCUMENTS
This manual provides only the information necessary fpr a technician to
service the S/10 or Office Display Terminal. Other documents that may be
helpful to the service technician include the following:
• System S/10 Users Guide (BFBPC 4410)
• Office Display Terminal Users Guide (BFBPC 4400)
1.3 SAFETY PRECAUTIONS
As with any electronic equipment, precautions consistent with all standard
industrial safety practices must be taken while servicing the S/10-0DT. The
cabinet contains potentially dangerous voltages. An y servicing that requires
removing cabinet covers must be performed by qualified service personnel.
Before inspecting or servicing the S/10-0DT, disconnect power.
Notices are included throughout this manual to alert you to problem areas or
situations that could cause personal injury, loss of data, or hardware damage.
A WARNING precedes the text of procedures; if not strictly followed could
result in serious injury to the service technician.
A CAUTION precedes the text of procedures; if not strictly followed could
result in the loss of data or damage to or the destruction of equipment.
A NOTE highlights essential procedures, conditions, or clarifying facts.
NOTEs also provide information that helps the reader understand a concept or
the completion of a procedure.
1-1

BFISD 8072
The following are general safety precautions that are not related to any
specific procedure and therefore do not appear elsewhere in this manual.
Personnel must heed these warnings during routine service and repair.
WARNING
Keep Away From Live Circuits.
Always observe safety precautions. Observe all
the CAUTIONS and WARNINGS in this manual when
working inside the e quipment cabinet. Under
certain conditions, dangerous potentials can
exist when the power is off because of charges
retained by capacitors or the cathode ray tube
(CRT). To avoid injury, alwa ys remove power
and discharge a c ircuit to ground before
touching it.
The following WARNING applies to any service inside the equipment cabinet. It
appears elsewhere in the text of this manual and is introduced here for
emp hasis:
WARNING
Hazardous voltages are exposed in the ca binet.
Be extremely careful when servicing eit her th e
power supply or any area where power terminals
are exposed.
1.4 S/10 OVERVIEW
The S/10 is a software based video display information sta tion that com bin es
state -of-th e-ar t hardware and software technology with a design oriented to
the user and his environment. The unit functions both as a stand alone pro-
cessor and as a remote terminal for communication with a host computer. The
Office Display Terminal (ODT) functions only as a remote terminal for
com mun ica ti ons with a host computer.
The keyboard has been designed to accommodate touch typing techniqu es using
the layout an d touch of a sculptured keyboard similar to that of popular
office typewrit ers . Th e eye -ea sing high resolution display maximizes user
productivity. From the keyboard the operator can control nearly all of the
user convenience features inclu din g margin bell, audible keyclick, scroll
rate, auto r epeat , line width and screen intensity. Combined with a detach-
able, fold-up keyboard and an aesthetic, low profile d esign, the S/10 is a
unique and flexible product for the modern office.
1 -2

BFISD 8072
As a stand alone computer system, the S/10 provides ample local storage and
ease of operation. The unit operates using the (BBM/CPM) operating system,
for which a large body of application software exists. In this mode the unit
can be used for word processing, accounting, inventory, data entry, and a
variety of other applications.
The S/10 can also operate as a remote terminal. A variety of terminal per-
sonalities are available or planned which facilitate communication with
different host com put er systems. These personalities are stored on disk and
loaded into the unit as needed.
The S/10 allows configuration of the operating characteristics of the system
via software control, including definition and downloading of character fonts.
User defined character fonts can be configured to provide unique characters for
word processing and multi-lingual applications as well as line drawing and
special graphic symbols. A dynamic memory manager efficiently allocates
display memory on an as needed basis, providing the user with the optimum
number of pages of data storage. The S/10 features and adaptability make it
the ideal solution for a wide variety of applications and developmental needs.
1.5 PHYSICAL DESCRIPTION
1.5.l Office Display Terminal (ODT)
The ODT Terminal is designed to work interactively with a host computer using
either ANSI standards or a specific personality or protocol for the communica-
tions link. The personality is stored in the terminal in a Read-Only-Memory
to enable it to interfa ce with the host computer.
The ODT includes the following components:
a . Keyboard -The terminal has a unique hinged detachable keyboard that
folds up out of the way when not in use, and also protects the face
of the CRT. The keyboard, which is laid out like an office type-
writer, is designed for the touch typist. It has sculptured keys, a
10-key numeric pad, and eight function keys (PF! -PF8) which can be
programmed by the user.
b. Display Monitor -The terminal features a P-4 white phosphor or a
P-31 green phosphor screen as standard. (A green phosphor eases eye
strain during extended periods of viewing.) The s cr een measures 12
inches diagonally.
c . Video Moni t or Board - Th is c ircuit board performs the final
stage of the video processing for the CRT screen display. It is
mounted on the mother board.
d. Mother Board - This board is placed horizontally on the bottom of
the console . All circuit boards are plugged into this board, which
eliminates the need for interconnect cables and greatly improves the
reliability of the unit. The speaker is mounted on this bo ard.
1-3

BFISD 8072
e. Power Supply - This unit plugs into the Mother board, and supplies
+5 volts, and +12 volts. There is one adjustment on this unit to set
the +5 volt level. The Power Supply for the System S/10 is of
different current rating.
f . Advanced Processor (AVP) Board - This board plugs into the Mother
board and carries all of the electronics required for the terminal.
This includes the Z80 microprocessor, memory, NVR (Non-Volatile RAM),
video processors, timing circuits, and circuits to support the serial
data ports. The AVP Board for the System S/10 has slight differences
in IC component configuration.
1.5.2 System S/10
The System S/10 is a stand-alone computer, which provides two diskette drives
with controller, and the necessary Z80 micropocessor and memories to enable
text and data processing. The computer is CP/M or BB/M based, giving a wealth
of software which can be used with the computer.
The System S/10 is built with modular construction, using the same terminal
assemblies listed for the ODT, but adding the following assemblies to turn the
terminal into a computerized system. The exceptions are the power supply,
which is bigger to provide more power for the additional circuits, disk drives
for program storage, different configuration of the Advanced Processor (AVP)
Board, and a controller board for control and data handling of the disk drives.
a. Advanced Floppy Controller Board (AFC) - This board plugs into the
Mother board adjacent to the Advanced Processor board. It contains
a second Z80 microprocessor, with 64K Random-Access Memory (RAM) and a
Read-Only Memory (ROM) which "boots" the computer part of the system
and loads the operating system. It also has the controller and other
circuits for control and data handling for th e diskette drive.
b. Diskette Drives - These a re MPI drives which are double-sided
double density 96tpi. These drives are shrouded in an aluminum
box for screenin g.
c. Advanced Video Processor Board (AVP) -The AVP Board for the S/10 is
the same as in the ODT except in the S/10 it contains 64K RAM, while
the ODT AVP Board has 1 6K of RAM.
1.5.3 Main Console
The assemblies are contained in a high-impact plastic cabinet . The same
cabinet is used for both the ODT terminal and the System S/10; only the blank
panel to the right of the displa y is replaced with one with slots when diskette
drives are installed. (See figure 1-2.)
The Power Supply, the Advanced Processor board, and the Advanced Floppy
Controller board are held in place by the clamsh ell lid when it is lowered and
locked in place.
1-4

BFISD 8072
1.5.4 Keyboard Assembly
The keyboard assembly is an integral unit consisting of a regulator, and the
keypad assembly which are mounted on a printed circuit board. The keyboard
is connected to the main console with a standard 4-wire coiled telephone cable
allowing the keyboa rd to be detached and operated away from the display in a
position to suit the operator. (See figure 1-3.)
Data to the keyboard is transmitted to the main unit via a USART (universal
synchronous-asynchronous receiver-transmitter) located on the AVP board. The
same keyboard is used for both the ODT and System S/ 10.
1.6 OPERATIONAL DESCRIPTION
The S/10 is an easy to operate data processing workstation and remote
termin a l. The unit can be considered · as a typewriter that uses a video screen
inst ea d of paper and is a vehicle thr ough which the operator i s able to
manipulate information and communicate with a computer. When a paper copy of
information is needed, the inform a tion is sent to a separate printer unit.
The unit has several components which work together to form a self-contained
system. The heart of the system is the central processing unit or CPU, which
monitors and controls the other parts, and the main memory, which stores both
instructions (programs) and information (data) used by the CPU. The main
memory's content changes con stantly wh en the unit is in use, and the co ntent
is lost when the unit is powered down; when the unit is turned on, it takes
several seconds to load th e instructions the unit needs to operate into main
memory.
The keyboa rd, screen and disk drives are all devices which exchange programs
and data with the CPU and main memory. The keyboard is the primary means for
the user to communicate with the system. The screen displays the result of
the user's commands and the actions of the other components. The disk drives
provide a permanent form of storage, as opposed to the temporary storage in
the main memory. The drives write data from the main memor y onto the ma g netic
surface of th e floppy disks to make a permanent record . The drives also read
data written on the disks into the main memory for use by the other
components. In this way the user can store and manipulate large quantities of
data.
When the S/10 is used by itself, the screen and keyboard provide the functions
of a terminal. A terminal is a device which receives and displays data from a
computer and also prepares and sends data back to the computer. The S/ 10 CPU
and main memory act as an independent com put e r. A second section of memory,
display memory, keeps a record of these transactions betwe en the terminal part
of th e S/10 and the computer part of the S/10. This mem ory is co mpl ete l y
separate from the S/10 m ai n memory. Lik e the main memory, its con t ents change
constantly and are lost wh en the unit is turn ed off.
A second way to u se the S/10 terminal is to communicate with a host computer.
Wh en used in this way, the host co mputer provides CPU, main memory and per-
manent storage . The S/10 provides the screen, keyboard, and display memory.
, c

BFISD 8072
8072-02
POWER
SUPPLY
VIDEO
AMPLIFIER MOTHERBOARD
CA TH ODE RAY
TUBE (C RT)
ADVANCED VIDEO
P ROCESS OR
BOARD NO . l
(S/10 O NLY)
Figure 1-2. S/10-0DT Internal Components
KEYBOARD C IR CU IT ASSEMBLY
AN D KEY MATR IX
8072-03
1-6
COVER PANEL
SECURING PADS
LA TCH
Figure 1-3. Keyboard Assembl y
KEYBOARD
CO NNECTOR KEYBOARD CABLE
CONNECTOR