The Sovereign was one of the last calculators to be released by Sinclair Radionics before the company was split up and sold off by the National Enterprise Board. It was released in 1976 and can display eight digits in its red LED display. It has a Mostek MK50321N main integrated circuit, and features the usual four arithmetic functions plus square, square root, percentage, and memory. As the case was made of pressed steel instead of plastic it was available in a variety of styles, including black painted, chrome plated, silver plated, and gold plated.

Sinclair won a Design Council Award in 1977 for the Sovereign calculator, which was designed by John Pemberton.

We have 12 examples in our collection which are pre-production models which were donated by Chris Wilding, a former employee of Sinclair Radionics and Sinclair Electronics. They are a mixture of the chrome and silver-plated finish versions. Seven of them are missing the memory function markings, one of them has the memory function marked etched into the casing, and one of them is an example of the Jubilee Special Edition version, but the finish on it does not seem to be proper silver plating.

Manufacturer: Sinclair Radionics
Date: 1976

This exhibit has a reference ID of CH70739. Please quote this reference ID in any communication with the Centre for Computing History.

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