Designer: John Pemberton
Manufacturer: Sinclair Radionics, LTD
Made in: England
Dimensions: 36 × 12 × 141 mm
Materials: pressed steel case with LED screen
The Sinclair Sovereign was a high-end calculator introduced by Clive Sinclair's company Sinclair Radionics in 1976. It was an attempt to escape from the unprofitable low end of the market, and one of the last calculators Sinclair produced. Made with a case of pressed steel that a variety of finishes, it cost between GB£30 and GB£60 at a time when other calculators could be purchased for under GB£5. A number of factors meant that the Sovereign was not a commercial success, including the cost, high import levies on components, competition from cheaper calculators manufactured abroad, and the development of more power-efficient designs using liquid-crystal displays. Though it came with a five-year guarantee, issues such as short battery life limited its usefulness. The company moved on to producing computers soon afterwards. The design by John Pemberton won a Design Council award, and there are examples of the Sovereign in the Museum of Modern Art in New York. It had a Mostek MK50321N main integrated circuit and a small memory register, a LED display, and could perform a variety of a number of basic mathematical operations besides four-function arithmetic.