In part one, we saw how the young Clive Sinclair created Sinclair Radionics — twice — and built it into a successful business that launched hi-fi products in the 1960s and the first ever pocket calculator in 1972, but soon suffered badly as its digital watch efforts foundered and competition crushed its calculator sales. Read on to learn how Radionics met its end, but (almost) gave birth to a new microcomputer…