A computer that processes analog data is known as an analog computer. Analog computers store information in physical quantities in a continuous format and use measurements to perform computation.

At one time a scientist or engineer trying to solve a tough problem with electronic computation had the choice of an analog computer, a digital computer, or both together in a hybrid configuration.

Today it seems that everything electronic is digital—a reasonable assumption considering it’s hard to find a turnable knob anywhere and values are displayed in digits everywhere. The underlying ...