Fuzzy logic for one thing, but usually you do not user analogue computers for digital tasks, since that's a very inefficient use of their capabilities. Instead,

Fuzzy logic for one thing, but usually you do not user analogue computers for digital tasks, since that's a very inefficient use of their capabilities. Instead, they can be used to directly calculate differential and integral equations, "simulate" analogue filters of all kinds and so on. This works by recreating the system in question using analogue integrators, differentiators , amplifiers, log converters etc. Input variables and output variables become voltages. This is very different from digital, quantified computers. It's also extremely useful, because a whole lot of things can be described by differential equations, and since analogue computers have no FLOPS limit, but only noise (also dynamic range) and bandwidth limits. PS: There were also mechanical analogue computers (using gears but also more complex constructions) and hydraulics based computers (but I think these were not used practically, just for demonstration).