Just found the Clockuator... old but still fun

[Ren]

Totally unrelated to your post...
(but that's what this subforum is all about, right?)
During the early 1980s, Radio-Electronics magazine had an article about turning an old calculator into a capacitance meter. Back then the idea of an old calculator was foreign to me. And a used capacitance meter (if available) was expensive.
I wish I had kept the issue.
IIRC, it used the "clock" (oscillator) of the calculator to measure the time it took the capacitor to charge and displayed the capacitance on the calculator display.