Panel meter calculator with floating point

I didn’t actually know about the Casio 14-A until now. I almost thought the picture was AI-generated. Four functions squeezed into that compact desktop unit in 1957? Impossible with the technology of the time…

The Casio 14-A was indeed the world’s first all-electric desk calculator. But by “desk calculator,” they literally mean “a desk that is a calculator.” The display/keyboard pictured was literally attached to a desk filled with hundreds of relays and weighed 140 kg. [0]

The “all-electric” claim is interesting. There had been scores of electric calculators for decades (Friden, Marchant, etc.) but were merely driven by an electric motor. The calculations were still performed by gears and cams and linkages.

https://www.casioeducation.com/primary-calculators/14-a

Today I learned you can use generic GPIO PWM to fake an analog voltage.

https://ww1.microchip.com/downloads/en/Appnotes/90003250A.pd...

Awesome project. The video moves a little fast to fully appreciate it, but I did like how it was short & to the point.

It could be fun to implement a scientific notation result display for answers that would otherwise overflow, although off the top of my head I'm not sure what the cleanest way to do that is.