<img width="528" height="375" data-tf-not-load src="https://dayintechhistory.com/wp-content/uploads/2019/03/ZX81_Sinclair_Research_advert1.jpg" class="attachment-full size-full wp-post-image" alt="Sinclair ZX81" decoding="async" srcset="https://dayintechhistory.com/wp-content/uploads/2019/03/ZX81_Sinclair_Research_advert1.jpg 528w, https://dayintechhistory.com/wp-content/uploads/2019/03/ZX81_Sinclair_Research_advert1-300x213.jpg 300w" sizes="(max-width: 528px) 100vw, 528px" />

1981 – The successor to the Sinclair ZX80, Britain’s most popular home computer – the Sinclair ZX81 was launched by Sinclair Research – a Timex Corporation. It was a popular computer mostly because of the price – £69.95 ($99) or £49.95 in kit form.

The cheap computer had only a fraction of components that an Apple II did. Yet the Apple II was around £699. The Sinclair ZX81 only had 1 kB RAM with option to upgrade to 16 kB. The graphics were only in monochrome and the Z80 CPU ran at 3.25 MHz – 8-bit. This was actually faster than the Apple II processor (1.08 MHz) and only outbested by the IBM PC (4.77 MHz at 16-bit). The TI99/4A procesor was a 3Mhz 16-bit chip.

You could get a tape drive and printer, bringing the system up to about £160 ($250). The computer was succeeded by the ZX Spectrum.