Fighter planes in the 1950s used the Bendix Central Air Data Computer to determine air speed, mach number, altitude and so forth from pressure. It is electromechanical, using gears and synchros for its computations. Amazingly, it is modular and can be easily disassembled.
We separated the top layer from the rest for testing. The “interface” between the layers is two gears and an electrical connection. The electronic servo amplifier blocks come off too.
(3 photos in link)
Yup. It just amazes me how clever some of those engineers were to solve these kinds of issues with the technology available to them at the time.