Sinclair QL Service Manual

Sinclair QL Service Manual
Prepared by THORN (EMI) DATATECH LTD for SINCLAIR RESEARCH LTD
OCTOBER 1985
© Sinclair Research Ltd.
SERVICE MANUAL X-1204
List of Contents
SECTION 1 SYSTEM DESCRIPTION
SECTION 2 DISASSEMBLY/ASSEMBLY
SECTION 3 SYSTEM TEST
SECTION 4 FAULT DIAGNOSIS AND REPAIR
Appendix A Known Bugs and their Remedies
Appendix B User Hints
Appendix C Mandatory Modifications
Appendix D Microdrive Fault Finding
SECTION 5 PARTS LISTS
List of Illustrations
RS 232 Link
Keyboard Matrix Interconnections
QL Block Diagram
QL Circuit Diagram (Issue 5)
QL Circuit Diagram (Issue 6)
Motor Location Jig
Keyboard Format
Head Chassis
Issue 5 Board - Component Side Modification
Issue 5 Board - Solder Side Modification
Issue 6 Board - Solder Side Modification
Microdrive Signals (100 kHz WRITE)
Microdrive Signals (100 kHz READ)
Microdrive Signals (100 kHz FORMAT READ)
ULA 2G007 - Internal Circuit
Printed Circuit Board (Issue 5) Component Layout
Printed Circuit Board (Issue 6) Component Layout
History Sheet
MANUAL ISSUE TEXT CIRCUIT/LAYOUT DIAGRAMS REMARKS
1 JANUARY 1985
2
JUNE 1985
Minor changes made to pages 1.5, 3.6, 4.1, 4.3, 4.4, 4.15, 4.17 and 5.7.
3
OCTOBER 1985
Appendices A, B, C and D added to Section 4.

Sinclair QL Specifications

General

Processor	Motorola 68008
Clock Speed	7.5 MHz
RAM	128 KB (expandable to 640 KB)
ROM	48 KB
Operating System	Sinclair QDOS
Release Year	1984
Storage	Microdrive tape loop
Graphics	256x256 pixels, 8 colors
Ports	RS-232, ROM cartridge
Sound	Beeper (internal speaker)