For context, the pre-existing larger mechanical calculators such as the 1936 Facit: https://www.youtube.com/watch?v=cRGu1OBFPrc https://www.youtube.com/watch?v

For context, the pre-existing larger mechanical calculators such as the 1936 Facit: https://www.youtube.com/watch?v=cRGu1OBFPrc https://www.youtube.com/watch?v=cRGu1OBFPrc I saw one of these still in use before the takeover by electronic calculators in the 1970s. I think it was replaced by a TI-58, which was programmable and was supplied by a manufacturer with several magnetic program cards for the specific field of use (industrial lab). P.S. text and photos of the Facit: https://mechanicalcalculators.wordpress.com/about/facit-calculators/ https://mechanicalcalculators.wordpress.com/about/facit-calc...