What (who) is analog computer - definition

An analog computer or analogue computer is a type of computer that uses the continuous variation aspect of physical phenomena such as electrical, mechanical, or hydraulic quantities (analog signals) to model the problem being solved. In contrast, digital computers represent varying quantities symbolically and by discrete values of both time and amplitude (digital signals).

<computer, hardware> A machine or electronic circuit designed to work on numerical data represented by some physical quantity (e.g. rotation or displacement) or electrical quantity (e.g. voltage or charge) which varies continuously, in contrast to digital signals which are either 0 or 1. For example, the turning of a wheel or changes in voltage can be used as input. Analogue computers are said to operate in real time and are used for research in design where many different shapes and speeds can be tried out quickly. A computer model of a car suspension allows the designer to see the effects of changing size, stiffness and damping. (1995-05-01)

The general purpose analog computer (GPAC) is a mathematical model of analog computers first introduced in 1941 by Claude Shannon. This model consists of circuits where several basic units are interconnected in order to compute some function.