Sinclair QL Service Manual

Keyboard and Bubble Mat
Keyboard Assembly Fixings
Adhesive Cable Clip
Double-sided Tape (0.5-in wide)
1/4-in self-tap - keyboard backplate
ROM Cartridge Bung
MDV Extension Bung
BUS Extension Bung
General Assembly Fixings
5/16-in self-tap (4 off)
Keyboard/Base
1 1/4-in self-tap (4 off)
TABLE 5.2 HEATSINK ASSEMBLY
Description Manufacturer/Type
Heatsink Wakefield Mk.2
+5V Regulator (IC35) 7805
3-pin connector Molex, 4025
Heatsink Fixings
M3 x 10 mm pan hd screw 1-off
M3 plain washer 1-off
M3 crinkle washer 1-off
TABLE 5.3 MICRODRIVE CHASSIS
Description Manufacturer/Type
Microdrive Cassette Chassis Assembly
Cassette Chassis
Motor Assembly
Microswitch Assembly
Drive Roller (parallel)
Plastic Roller
Cassette Chassis Fixings
M2.5 x 4 csk self-tap, motor fixings
2,28 x 3/5-in self-tap, microswitch fixing
Microdrive PCB Assembly - Table 5.4
PCB Fixings
No. 4 x 5/16-in self-tap (2 off)
Fibre Washers (2 off)
ULA Screen
TABLE 5.4 MICRODRIVE BOARD
Circuit Ref
ISSUE 5 ISSUE 6 Notes Rating/% Tol Manufacturer/Type
MDV1 MDV2
CAPACITORS (all axial types unless otherwise stated)
C5 C6 330 pF
As Issue 5
2.5% HS30, Suflex
C9 C10 0.47 F 35V ITT
C11 C12 0.22 F 35V ITT
C13 C14 330 pF 2.5% HS30, Suflex
C15 C16 220 pF 2.5% HS30, Suflex
C17 C18 220 pF 2.5% HS30, Suflex
C49 C50 47 nF 50V
C51 C52 47 nF 50V
DC28 DC29 100 F 50V, 10%+80%
RESISTORS
R34 R35 330R 5%, 1/4W
R36 R37 330R 5%, 1/4W
R38 R39 4K7 5%, 1/4W

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)