Sinclair ZX80

The Sinclair ZX80 was a compact monochrome home computer designed to bring programming below the £100 barrier. Its Z80-compatible processor, 1KB of RAM and 4KB BASIC ROM were housed beneath a distinctive white vacuum-formed case with a flat membrane keyboard.

To reduce hardware, the processor generated the television display and normally blanked the screen while executing a program. Despite severe limitations, the ZX80's accessible price and clear manual helped ignite the British home-computer boom.

Notable Features

• Processor generated much of the display in software, causing the screen to disappear during normal computation.
• Available either as a kit or fully assembled computer.
• Rear bus accepted the 16KB RAM pack and other expansions.

Historical Significance

• Among the first complete British personal computers sold for less than £100.
• Its commercial success established the design approach developed further in the ZX81.

Collector’s Notes

• The thin vacuum-formed case and membrane keyboard are easily damaged.
• Original 4KB ROM machines differ from ZX80s upgraded with the later 8KB ROM.

Specifications

Technical Information
Name	Sinclair ZX80
Manufacturer	Sinclair Research Ltd
Launched	Tuesday, January 29, 1980
Discontinued	10/3/1981
Launch Price	£79.95 kit; £99.95 assembled
Country	United Kingdom
CPU	NEC µPD780C-1 or Zilog Z80 at approximately 3.25 MHz
Units Sold	Approximately 100,000
CPU Speed	Approximately 3.25 MHz
RAM	1KB; expandable to 16KB
ROM	4KB containing Sinclair BASIC
Display	32 x 24 monochrome characters
Graphics	64 x 48 block graphics
Sound	No built-in sound
Storage	External cassette recorder
Keyboard	Integrated 40-key membrane keyboard
I/O	RF television, cassette EAR/MIC and rear expansion bus
Operating System	Sinclair 4K BASIC