analog computers

Analog computers process information using continuously variable physical quantities—voltage, fluid pressure, mechanical position—rather than discrete digital values.

They model problems directly: a voltage might represent velocity, a spinning disc might represent an integral.

Before digital computers dominated, analog machines solved differential equations for artillery trajectories, weather prediction, and flight simulation.

The old analog computer filled an entire room.

They've largely been replaced by digital systems but persist in specialized applications where continuous signals matter.