Analog Computers
A good summary of analog computers can be found on the wikipedia article:<p><a href="https://en.wikipedia.org/wiki/Analog_computer" rel="nofollow">https://en.wikipedia.org/wiki/Analog_computer</a><p>Takeaway: Analog computers are limited in precision and by "analog noise"; the precision of the components used determine the precision of the output. Usually no more than 3 or 4 decimal places are possible, at least with the tech that was used in their heydey. I would say that is still close to the case even today. Of course, one could do things like cryogenic cooling or such, but it becomes a cost factor at that point.<p>Something else that wasn't mentioned:<p>The ADALINE/MADALINE memister technology is an analog component, and is a hardware component equivalent to a McCulloch–Pitts neuron model (perceptron).<p>The memister is NOT to be confused with the memristor, which is a different technology; the memister was a 3-terminal device (memory transistor):<p><a href="https://en.wikipedia.org/wiki/ADALINE" rel="nofollow">https://en.wikipedia.org/wiki/ADALINE</a><p>...whereas a memristor is a two terminal device ("memory resistor"):<p><a href="https://en.wikipedia.org/wiki/Memristor" rel="nofollow">https://en.wikipedia.org/wiki/Memristor</a>