Clive Sinclair 1985 owing to Sinclair's financial troubles.) The following year, he received a knighthood and formed Sinclair Vehicles Ltd. to develop electric vehicles, which resulted in the unsuccessful Sinclair C5 in 1985. In 1984, Sinclair launched the Sinclair QL computer, intended for professional users. Development of the ZX Spectrum continued with the enhanced ZX Spectrum 128 in 1985. In April 1986, Sinclair Research sold the Sinclair trademark and computer business to Amstrad for £5 million. Sinclair Research Ltd. was reduced to an R&D business and holding company, with shareholdings in several spin-off companies, formed to exploit technologies developed by the company.
Sinclair Scientific fraction of the cost of competing calculators. In 1972, Hewlett-Packard launched the HP-35, the world's first handheld scientific calculator. Despite market research suggesting that it was too expensive for there to be any real demand, production went ahead. It cost (about ), but despite the price, over 300,000 were sold in the three and a half years for which it was produced. From 1971 Texas Instruments had been making available the building block for a simple calculator on a single chip and the TMS0803 chipset appeared in a number of Sinclair calculators. Clive Sinclair wanted to design a calculator to