DIY Calculator

[Steve Simpkin]

Yes Clive Sinclair is a genius and was almost unparalleled at getting his engineers to extract functionality out of a bare minimum of parts. I loved his practicality too.
"Scientific calculators usually provide constants such as e and π but there was no space in the ROM for these constants. The Sinclair Scientific used the brilliant solution of printing the constants on the calculator's case - the user could enter the constant manually if needed."

I only owned one Sinclair product, the Sinclair Wrist Calculator which I built from a kit. At the time it was the smallest electronic circuitry I ever had to solder. It did work when I was finished but the case had interference problems with the slider and was fragile. I played with it until the batteries died (6 mercury cells) and did not replace them as they cost almost as much as the calculator.
https://en.wikipedia.org/wiki/Sinclair_Wrist_Calculator
http://www.vintagecalculators.com/html/w...lator.html

If you get a chance to see the drama Micro Men, it is a very entertaining (if not super accurate) TV movie about the rise of the British home computer market. It focuses on the rivalry between Sir Clive Sinclair, who developed the ZX Spectrum, and Chris Curry the man behind the BBC Micro. I believe it is viewable on Youtube.
https://en.wikipedia.org/wiki/Micro_Men