Sinclair QL

The Sinclair QL, short for Quantum Leap, was Sinclair Research's attempt to enter the professional and small-business market. Its Motorola 68008 processor ran the pre-emptive multitasking QDOS operating system, structured SuperBASIC language and a bundled Psion office suite.

Two built-in Microdrives provided inexpensive removable storage, but production and firmware delays damaged the launch and early reliability. The architecture nevertheless inspired a dedicated community and influenced later operating-system developers.

Notable Features

• QDOS supplied pre-emptive multitasking and device-independent I/O.
• Twin built-in Microdrives each stored approximately 100KB on loop-tape cartridges.
• Bundled Psion suite included Quill, Abacus, Archive and Easel.

Historical Significance

• Sinclair's only production computer based on the Motorola 68000 family.
• An ambitious effort to offer a complete business system below the price of contemporary 16-bit competitors.

Collector’s Notes

• Early ROM versions and machines fitted with the external ROM dongle document the troubled launch.
• Microdrive condition, keyboard membrane and power supply should be checked before use.

Specifications

Technical Information
Name	Sinclair QL
Manufacturer	Sinclair Research Ltd
Launched	Thursday, January 12, 1984
Launch Price	£399
Country	United Kingdom
CPU	Motorola MC68008 at 7.5 MHz
Units Sold	Approximately 150,000
Operating System	QDOS with SuperBASIC and bundled Psion office suite
I/O	RF, RGB, composite, two RS-232, two joystick, QLAN, ROM and expansion ports
Keyboard	Integrated 65-key full-size keyboard
Storage	Two internal approximately 100KB Microdrives; external Microdrives and third-party disks
Sound	Single-channel beeper
Graphics	512 x 256 in four colours or 256 x 256 in eight colours
Display	85 x 25 or 42 x 25 text
ROM	48KB containing QDOS and SuperBASIC
RAM	128KB; expandable to 640KB or more
CPU Speed	7.5 MHz