Service manual

CONTENTS
Page
Overall Description...................................1
Internal Expansions compatibility.....................4
Z80 CPU...............................................6
Z80 Pin Description.................................7
Z80 CTC..............................................10
Z80 CTC Pin Description............................11
Z80 DART.............................................13
Z80 DART Pin Description...........................14
TMS 9929 VDP.........................................17
PAL VDP Horizontal Timing..........................18
9929 Signal Waveforms..............................19
MTX Series System Bus................................20
System Block Diagram...............................21
MTX Disassembly Instructions.........................22
Trouble Shooting Guide...............................25
Symptom 1
No Display/Black and white display............26
Symptom 2
Blank screen/no humming/power on..............28
Symptom 3
Corrupt Video Display or characters...........30
Symptom 4
Bad hum bars..................................31
Symptom 5
Green screen and hum..........................32
Symptom 6
Load and save problems........................35
Symptom 7
Sound problems................................37
Symptom 8
Keyboard......................................38
Symptom 9
Memory Exps, ROM Exps, RS232, Printer.........40
UM1286 Modulator.....................................42
Testing and Setting up........................43
Mother board Links and PAL Colour coding.............44
PROM Codes for memory expansion boards...............45
MTX Service Manual