Analog computers are from the 19th century; they were used to decompose signals using the Fourier transform, since it's easy(ish) to get a bunch of different fr

Analog computers are from the 19th century; they were used to decompose signals using the Fourier transform, since it's easy(ish) to get a bunch of different frequency oscillators. They used them for tides and differential equations. https://en.m.wikipedia.org/wiki/Analog_computer https://en.m.wikipedia.org/wiki/Analog_computer