Texas Instruments 990 User Manual

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Appendix
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B
TABLE OF CONTENTS (Continued)
Title
Page
VDT Controller ..................................................... 144
CRT Interface Logic ............................................... 145
Built-in Test Logic ................................................. 146
Keyboard Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 7
CRU Interface Logic .............................................. .1-52
Refresh Memory and Control Logic ................ · .................... .1-59
Video Output Logic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-61
Alarm Logic ..................................................... 1-61
Time Base Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-62
SECTION II. MAINTENANCE
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Maintenance Philosophy ................................................. 2-1
Special Test Equipment ................................................. 2-1
Hot Mock-Up System ................................................. 24
Diagnostic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Loading the Diagnostic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Using the Diagnostic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Special Verbs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
General Maintenance Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
PWB Preliminary Checkout ............................................. 2-8
General Fault Isolation Procedures ........................................ 2-8
Scoping Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
Keyboard Maintenance Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
Keyboard Preliminary Checkout. ......................................... 2-8
Keyboard Fault Isolation Procedures ....................................... 2-9
Keyboard Operational Checkout ........................................ .2-12
Power/Logic PWB Maintenance Procedures ..................................... 2-12
Power/Logic PWB Preliminary Checkout .................................... 2-13
Power/Logic PWB Fault Isolation Procedures ................................ .2-13
VDT Controller Maintenance Procedures ...................................... 2-13
VDT Controller Preliminary Checkout. ..................................... 2-16
VDT Controller Fault Isolation Procedures .................................. .2-16
CRT Monitor Maintenance Procedures ....................................... .2-16
CRT Monitor Preliminary Checkout ....................................... 2-16
CRT Monitor Fault Isolation Procedures .................................... 2-16
APPENDIXES
Title
Page
United Kingdom Model 911 VDT Keyboard Arrangement, Hexadecimal Codes,
Mode Character Positions, ASCII, Special Character Set, and Matrix Chart .............. A-1
French Model 911 VDT Keyboard Arrangement, Hexadecimal Codes, Mode
Character Positions, ASCII, Special Character Set, and Matrix Chart .................. B-1
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Digital Systems Division

Texas Instruments 990 Specifications

General

Brand	Texas Instruments
Model	990
Category	Desktop
Language	English