The Free On-line Dictionary of Computing (30 December 2018):

ZX-80

    Sinclair's cheap personal computer with
   built-in BASIC, launched at the end of January 1980 at a
   computer fair in Wembley, UK.  The processor was an NEC
   780-C running at 3.25 MHz.  It had 1KB of RAM, externally
   expandable to 16KB, and 4KB of ROM.  It had RF video output to
   a TV, displaying 24 lines by 32 characters of monochrome text.
   An audio cassette recorder was used to save programs.

   The ZX-80 was sold in kit form for £79.95 or ready-built for
   £99.95.  It was used by many UK hobbyists as a means of learning
   the basics of computing.  Some remember the 1KB ZX-80 for the
   claim in its advertising that you could control a nuclear power
   station with it.

   The ZX-80 was succeeded by the ZX-81.

   (http://home.t-online.de/home/p.liebert/zx80_eng.htm).

   Planet Sinclair (http://nvg.ntnu.no/sinclair/).

   The Sinclair Story
   (http://sincuser.f9.co.uk/046/sstory.htm).

   (2002-08-30)