Sinclair Sovereign

Sinclair Sovereign

The Silver Sovereign was a high-end calculator introduced by Sinclair Research Ltd of the United Kingdom in 1976, it was one of the last Sinclair calculators. The Sovereign came in silver and gold plated models, with leather pouches and fitted wooden cases. The display can view 8 digits using red light-emitting diodes (LEDs), and includes four functions for percentage, memory, square root and square. It uses two 2.5 volt button cells and uses a Mostek MK50321N main integrated circuit (IC). Similar to other Sinclair products and calculators, the Sovereign was small and slim measuring 36 x 141 x 12 mm (1.4 x 5.6 x 0.5 inches).

The Sovereign was unusual because the casing was made from pressed steel. This allowed a variety of paint and plating options, including black painted, bright chrome plated, silver plated, and gold plated. A small number of solid gold ones were made. In 1976, the chrome plated version cost GB£30 (US$60) and the gold plated version cost twice as much. A limited edition silver plated version, inscribed to commemorate the Silver Jubilee of Queen Elizabeth II in 1977 was produced.