MAI Basic Four 4108 Desktop Computer Manuals

Manuals and User Guides for MAI Basic Four 4108 Desktop Computer. We have 1 MAI Basic Four 4108 Desktop Computer manual available for free PDF download: Service Manual

MAI Basic Four 4108 Service Manual (488 pages)

Desktop Computer System

Brand: MAI Basic Four | Category: Desktop | Size: 57.55 MB

Table of Contents
3
Location of Jumpers on Central Microprocessor Board
10
Central Microprocessor Board Cable Part Numbers
10
Location of Address Switches on Memory Array Module
10
Location of Switches on 4-Way Controller PCBA
10
Location of Switch on Magnetic Cartridge Streamer Controller PCBA
10
Location of Jumpers on the Winchester Drive Controller PCBA
11
Model 4108 Base Unit
16
Section I
17
General
17
System Description
17
Central Microprocessor Board (CMB)
18
1-2. Block Diagram of the Base Unit Hardware System
18
Memory Array Boards
19
1.2.3 Winchester Disk Controller Board
20
4-Way Controller Board
20
Magnetic Cartridge Streamer Controller Board
20
Local Area Network Controller Board
21
Specifications
21
Specifications, MAI 2000 Series Desktop Computer System
22
Installation and Operation
25
General
25
Unpacking and Inspecting the Base Unit
25
Installing the 2000 Series Computer System
25
Switch Settings, Jumper Placements, Cable Connections
31
Central Microprocessor Board
31
CMB Jumper Configuration
37
Memory Array PCBA
38
Winchester Disk (Single-Board) Controller
38
Connections
38
Winchester Disk Controller Jumper Connections
38
Memory Array Module Address Switch Settings
38
4-Way Controller PCBA
41
Board 1
41
4-Way Controller PCBA Switch Settings
41
Installing the Local Area Network (LAN)
44
Installing the LANG Board
44
Installing the Tap Box
48
2.5.3 Installing the Repeater
49
Connecting Network Segments
51
Connecting a Network Branch
51
Connecting Power to the Repeater
52
Installing the LANG Software
52
Use and Care of Floppy Diskette and Drive
53
2.6.1 Diskette Insertion
53
Write Protection
54
Functional Description
55
Introduction
55
Central Microprocessor Board (CMB) Description
55
Clock Generator
57
Function Code Decoder
57
Boot PROM
58
CMB Diagnostic Hardware
59
CMB Status Drivers
59
CMB Control Register
59
Main Memory Fault Detection Circuits
60
Central Microprocessor Board Status Bits
60
Central Microprocessor Board Control Register Bits
61
Parity Error Register
62
Status Register Parity Bit
62
Parity Error Interrupt Cycle
63
3.2.6 Interrupt Logic
63
Interrupt Control Logic
64
Interrupt Acknowledge Decoder
65
Reset and Power Fail Detection Logic
65
System I/O Bus Control Logic
66
Non-Volatile RAM
66
Data Transfer Acknowledge Generator
68
NVRAM Contents
69
Device Nybble Specifiers
70
Timing Generation
71
Timing Selection
71
Bus Error Generation
72
Bus Arbitration Logic
73
Timing Diagram, PDTACK- and Bus Error Generation
73
Bus Arbitration Cycle
74
Fast Bus Grant
75
Address Space Decoding Logic
76
Address Space Decoding
76
READ Cycle Decoding
78
3.2.12.2 WRITE Cycle Decoding
78
3.2.12.3 Memory Select Decoding
78
Local I/O Decoding
79
Byte Interface Control Logic
79
Memory Address Bus
79
Memory Array Board Selection
80
Dynamic Memory Support
81
RAM Chip
81
Memory Timing
82
Row Address Strobe
82
Column Address Strobes
82
Memory Refresh
84
Refresh Address and Request Generation
85
Memory Control Timing Diagram
85
3.2.15.6 Refresh Arbitration
86
Memory Management Unit
87
Segmentation
87
Refresh Timing Diagram
87
Swapping
88
Other MMU Functions
88
Supervisor and User Access of the MMU
90
MMU Address Translation
91
Segment Attributes
92
Segment Status
93
MMU Error Generation
94
Serial Ports
95
Serial/Parallel Conversion
95
Simplified Block Diagram, 8530 SCC Chip
97
Communications Protocol Selection
98
Electrical Configuration Selection
100
Addressing and Control
102
Parallel Port
104
Addressing and Control
104
Data Transmission to a Printer
105
Floppy Disk Controller
105
Soft Sectoring
105
Centronics Protocol
107
Simplified Block Diagram, CMB Floppy Disk Controller
108
Double-Density Recording
109
Signal Encoding and Derived Clock, Kansas City Standard
109
MFM Data Separation
111
Encoded Data for Modified FM (MFM) Recording
112
Simplified Block Diagram, Data Separator Phase Detector Logic
113
Bit-Shifting
116
Bit Shifting
116
Floppy Drive Disk Control
117
Register Layout, WD1793 Floppy Disk Controller Chip
118
Command List, WD1793 Floppy Disk Controller Chip
119
Buffered Data Transfer
120
State Machine States
123
Floppy Disk Controller Section Control
124
Memory Array Board Functional Description
126
Base Unit Power Supply Functional Description
126
Introduction
127
Special Tools
127
Preventative Maintenance
127
Preventive Maintenance Summary
127
Trouble Analysis
128
Base Unit Power Supply Voltage Adjustments
128
Removal/Replacement
129
Introduction
129
Replacing the Central Microprocessor Board (CMB)
129
CMB Jumper Configuration
136
Replacing the Base Unit Power Supply
138
Replacing the Memory Array Modules
139
Memory Array Module Address Switch Settings
140
Replacing the 4-Way Controller Boards
142
Replacing the Winchester Drive Controller (WDC) Board
145
Replacing the Magnetic Cartridge Streamer Controller (MCSC) Board
146
Replacing the Winchester Drive Controller Bus Adapter Board
148
5-6. Location of Switch on Magnetic Cartridge Streamer Controller PCBA
149
Replacing the Local Area Network (LAN) Board
151
Replacing the Winchester Drive
154
Replacing the Floppy Disk Drive
156
Illustrated Parts List
159
Introduction
159
Index of Assemblies
159
Controller PCBA
159
Memory Array PCBA
159
WDC Bus Adapter PCBA
159
4-Way Controller PCBA
159
MTCS Controller PCBA
159
LAN Controller PCBA
159
Floppy Disk Drive
195
Introduction
195
General Description
195
Spindle Mechanism
195
Positioning Mechanism
195
Head Load/Interlock Mechanism
196
Functional Concepts
196
Floppy Disk Drive
196
Functional Block Diagram
198
Stepper Motor Control
199
Stepper Motor Timing Diagram (96 TPI)
199
Drive Motor Control
200
Head Load Circuit
200
Motion Check LED
200
Track 00 Detection
200
Stepper Motor Phase Transfer Chart
200
Head Load Timing Diagram
200
Track 00 Detection Circuit
200
Write Protect Detector
201
Index Detector
201
Write Protect Detector Circuit
201
Ready Detector
203
Index Detection Circuit
203
Read/Write Heads
204
Write Start Timing Diagram
204
Write Circuit
205
Write Timing Diagram (FM)
205
Read Circuit
206
Read/Write Select Circuit
206
Erase Delay Timing Diagram
206
Read Amplifier Circuit and Filter Work
207
Active Differential Circuit and Comparator
207
Read Amplifier Circuit and Filter Network
207
Timed Main Filter and Crossover Detector
208
DC Control Circuit
211
Power-On Reset Circuit
211
Equipment Specifications
211
Power-On Reset Timing Diagram
211
Installation and Maintenance
214
Equipment Placement
214
Electrical Installation
214
Adjustment Procedures
214
Index Burst Position Adjustment
215
Track Position Adjustment
215
Track 00 Position Adjustment
216
Rotation Adjustment
217
0-1 Head Gap Adjustment
217
Reference Information
218
Interface
218
Signal Interface
218
Input Lines
219
Signal Interface Lines
220
Output Lines
221
Index Timing
221
Jumper Pin
222
Drive Timing Diagram
224
20 Megabyte Winchester Drive System
229
Introduction
229
General Description
229
Functional Concepts
232
Equipment Specifications
233
Installation and Operation
236
Unpacking
236
Equipment Placement
236
Shipping Lock (Read/Write Heads)
236
Step Rate Selection
236
System Installation
237
Operation
237
Functional Description
239
Basic Disk Principles
239
Control Lines
241
Winchester Drive Controller
242
Signal Definitions
244
Controller - Host Handshaking
245
SASI Bus Status Signals
245
Summary of SASI Bus Status Signals
245
Host Bus Control Signals
246
Host Bus Data Signals
246
Detailed Description (Handshaking and Timing)
247
Programming Information
249
Type 0 Error Codes, Disk Drive
254
Type 1 Error Codes, Controller
254
Type 2 Error Codes, Command and Miscellaneous
255
Request Sense Status Error Codes
255
Command
256
Mode Select Parameter List
261
Extent Descriptor List
261
Drive Parameter List
262
Search Command Argument
271
Maintenance
272
Diagnostics
272
Power-Up Diagnostics
272
Power-Up Sequence Error Codes
273
Operational Error Check
274
Fault Diagnostics
274
Operational Error Codes
274
Removal and Replacement Procedures
276
8.5.1 Master Electronics PCBA Removal and Replacement
276
Brack Removal and Replacement
279
Motor Control PCBA Removal and Replacement
280
Preamplifier PCBA Removal and Replacement
280
Parts List
280
50 Megabyte Winchester Drive System
289
Introduction
289
General Description
289
Head Disk Assembly
289
Functional Concepts
290
Equipment Specifications
291
Installation and Operation
294
Unpacking
294
Equipment Placement
294
Shipping Lock (Read/Write Heads)
294
System Installation
294
Power and Interface Cables and Connectors
295
Drive Addressing and Interface Termination
295
DC Power Connector J3 Pin Assignments
297
Installation of the Winchester Drive and the WDC PCBA
298
Operation
301
Power Requirements
301
Functional Description
302
Basic Disk Principles
302
Control Lines
304
Winchester Drive Controller
306
Controller, Functional Organization
306
Signal Definitions
307
Host Bus Control Signals
309
Detailed Description (Handshaking and Timing)
310
Winchester Drive Controller Select Timing
310
Data Transfer to Host, Timing
311
Programming Information
312
Data Transfer from Host, Timing
312
Commands
313
Type 0 Error Codes, Disk Drive
317
Type 1 Error Codes, Controller
317
Type 2 Error Codes, Command and Miscellaneous
318
Request Sense Status Error Codes
318
PCBA, Central Microprocessor Board
338
Logic Diagram, Central Microprocessor Board
360

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