Clive Sinclair was very innovative in the field of consumer electronics and, for many years in Britain, was widely known as "the man who invented the pocket calculator".
This is not true since there were earlier calculators that would fit in a small pocket (for example the Busicom LE-120A "handy"). However, the Sinclair Executive, shown on the left, was the first slimline calculator and when launched in July 1972 it caused a sensation because it was the world's thinnest calculator by a long way.
The later Cambridge models were also very small and generally crammed many functions into their small size. However, the smart design of some of these, the "pregnant" models, was destroyed since they required a large bulge in the back of the case to take a 9v PP3 battery instead of the earlier AAA pen-light cells.
The Sinclair name is associated with several companies. Nearly all of the calculators were produced by Sinclair Radionics Ltd., though the Wristwatch calculator was produced by Sinclair Instruments Ltd. There is a brief history of Clive Sinclair, his companies, his calculators, and other products in the article Clive Sinclair and the pocket calculator in the Collecting Calculators section of this site.
Sinclair calculators are known for their innovative and often elegant designs. The dates of introduction of some of the notable models are listed below. All are from Sinclair Radionics Ltd., except where noted:
Source "Sinclair and the 'Sunrise' Technology"
Known Sinclair models :-
Sinclair models under other names :-
Thumbnail pictures are grouped here by case style.
Click on an image to go to a page with larger pictures and technical details -
Models by Sinclair under other names:
Sinclair digital multimeter in a calculator case:
© Text & photographs copyright Nigel Tout 2000-2019 except where noted otherwise.