Timex Sinclair 1000

The Timex Sinclair 1000 was the North American version of the Sinclair ZX81, manufactured and marketed by the Timex Sinclair partnership. It retained the Z80 processor, compact wedge-shaped case, membrane keyboard and monochrome display while doubling the built-in memory to 2KB.

Its launch price below $100 brought programmable computing to a broad American audience through mass-market retail outlets. Limited memory, slow cassette storage and the fragile external RAM expansion were conspicuous compromises, but the machine introduced hundreds of thousands of owners to computing.

Notable Features

• 2KB of built-in RAM doubled the standard capacity of the British ZX81.
• Membrane keyboard and character-based graphics allowed an exceptionally low component count.
• Compatible with much ZX81 software and many expansion devices.

Historical Significance

• Widely promoted as the first home computer sold in the United States for under $100.
• Rapid early sales helped establish a large North American Sinclair user community.

Collector’s Notes

• Original machines often show wear to the membrane keyboard and expansion connector.
• A period 16KB RAM pack makes the system far more usable but can cause crashes if disturbed.

Specifications

Technical Information
Name	Timex Sinclair 1000
Manufacturer	Timex
Launched	Thursday, July 1, 1982
Launch Price	$99.95
Country	United States
CPU	Zilog Z80A at 3.5 MHz
Units Sold
Operating System	Sinclair BASIC
I/O	RF television, cassette EAR/MIC, power and rear expansion bus
Keyboard	Integrated 40-key membrane keyboard
Storage	External cassette recorder at approximately 250 baud
Sound	BASIC BEEP through television speaker
Graphics	64 x 48 block graphics
Display	32 x 24 monochrome characters
ROM	8KB containing Sinclair BASIC
RAM	2KB; commonly expanded to 16KB or more
CPU Speed	3.25 MHz