Sinclair C5 computers like the hugely successful ZX81 and ZX Spectrum, an affordable electric vehicle could unleash pent-up demand for a market that did not previously exist. However, Sinclair performed no market research to ascertain whether there was actually a market for his electric vehicle; as the director of the Primary Contact advertising agency commented in January 1985, the project continued all the way to the prototype stage "purely on the convictions of Sir Clive". With Sinclair's new specifications in hand, Ogle worked on a three-wheeled design dubbed the C5, which bore similarities with the earlier three-wheeled Bond Bug – another Ogle
Sinclair Executive consumption, creating issues with the reliability. The Executive Memory was launched in November 1973, with the same physical dimensions as the original, but with the ability to memorise subtotals from any number of chain calculations. There were at least 3 versions, including the black and white Type 1, and the Type 2 with a gold keyboard. The Executive Memory sold at the lower price of . Sinclair Executive The Sinclair Executive was the world's first "slimline" pocket calculator, and the first to be produced by Clive Sinclair's company Sinclair Radionics. Introduced in 1972, there were at least two different versions