ZX80 - Vintage Sinclair

The ZX80, launched in 1980, brought computing to the masses and founded the British computer market. Previously, computing was either very expensive, or only for hobbyists who tinkered with circuit boards (see Sinclair's MK14 from 1977).

The ZX80 broke the sub-100 pound barrier (£99.95 or £79.95 in kit form) and could be purchased from a shop and simply plugged in at home and was ready to go. There was nothing else remotely similar at the time.

The advertising made bold claims for the ZX80, famously saying it could be used to run a power station...however, the reality was somewhat different.
Due to cost constraints, the keyboard was a small touch sensitive type and fiddly to use. To save memory (there was only 1K in total), the BASIC language keywords were not typed-in but entered by pressing certain combinations of keys. It's abilities were limited but it was but useful in getting the public interested in consumer friendly computing. It paved the way for mass-market home computers. Approx 100,000 were sold before it was discontinued in 1981.

Technical details:
Power : 9.5V DC
Video : Built in RF modulator, monochrome output to a household TV
Display : 22 X 32
Data storage : Cassette recorder
Memory : 1K expandable to 16K
Processor : Z80, 3.25MHz
Operating system : Sinclair Basic
Dimensions : 7 X 8.5 inches

Membrane-type keyboard

Rear, showing:
left - connections for cassette recorder and mains adapter
center - TV output
right - memory expansion.

An 8-line program in Sinclair BASIC.
The key words are entered in a single keystroke.
Lines of code are typed at the bottom of the screen and are then displayed at the top after syntax checks.
The cursor changes for the different entry modes:
K for Keyword.
L for Line entry.

Program output after <RUN>.