国王街
Shortly after the NEB took control Sinclair encouraged Curry to leave Sinclair Radionics to get Sinclair Instruments off the ground. Curry borrowed some money and rented offices at 6 King's Parade, Cambridge. To raise cash, Sinclair Instruments released the Wrist Calculator, designed by John Pemberton, in February 1977. The product was successful, selling 15,000 units.