Sinclair Instrument Wrist Calculator

The Sinclair Instrument Wrist Calculator was a simple 8-digit calculator, that was only sold as a kit. It was released in February 1977 by Sinclair Instruments, a company ran in parallel with Sinclair Radionics.

It ran off of six mercury batteries, which lasted only about an hour and a half, and required the user to disassemble the unit to change them.

The calculator had a three position button to access extra functions, such as memory and square root. It originally sold for £9.95 (plus VAT). Sales were not great, only around 10,000 were reported sold.

Reliability meant that a great many were returned to Sinclair, as was the case with the Sinclair digital watches.

Manufacturer: Sinclair Radionics
Date: February 1977

This exhibit has a reference ID of CH52845. Please quote this reference ID in any communication with the Centre for Computing History.


Sinclair Instrument Wrist Calculator

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