Sinclair ZX81

Dimensions : Width=167mm (6.32in), depth=175mm (6.80in), height=40mm (1.57in), weight 350 gms (12.15oz) 

  • Microprocessor : Z80A 3.25 MHz clock.
  • ROM : Containing 8K BASIC interpreter
  • RAM : 1K bytes internal, externally expandable to 16K bytes.
  • Serial number 10002.
Requires an ordinary domestic black and white TV. The display is organised as 24 lines of 32 characters with black characters on a white background. 

March 1981, Sinclair unveils the ZX81, based on the Z80A microprocessor, for under US$200. 

Oct. 1981, The ZX81 is introduced to the American market, for US$150. 

September 1981, Sinclair Research and W H Smith sign an agreement for W H Smith to sell the ZX-81 in its retail stores in England, for a trial 1-year period. 

Jan. 1981, In the first 10 months of sale, 250,000 Sinclair ZX81 microcomputers have been delivered. 

In may 1982, Timex Computer Corp. and Sinclair Research Ltd. announce an agreement for Timex to market a 2KB version of the ZX-81 as the Timex/Sinclair 1000.
The back of the ZX81


For more on the ZX81 please go to ZX81 HOME PAGE