> "But he did not make personal use of his own inventions. His daughter said he never had a pocket calculator as far as she knew, instead carrying a slide-rule around with him at all times. And he told interviewers he used neither a computer nor email."
That doesn't particularly surprise me. His computers weren't aimed at middle aged adult engineers. The early calculators weren't all that sophisticated. They were convenience devices rather than serious tools. There's nothing wrong with designing products aimed at people other than yourself.
> His computers weren't aimed at middle aged adult engineers.
Maybe not Clive Sinclair's products specifically, but you'd be surprised with what professional engineers could use these 'toys' for. Keep in mind that machines with comparable featuresets could sell for huge prices well into the early and even the mid-1960s, and were used for real, sometimes critically important work.
Turing's Pilot ACE, that Turing considered didn't have enough memory for real work, had 32 mercury delay lines with 1024 bits each: that's four times as much memory as the ZX81.
