The Relay Interpolator

Abstract

As a part of the development of the M-9 gun director, it was necessary to provide accurate test equipment which would move the input knobs of the director exactly as an operator would move them in tracking a hostile airplane, and then check whether the orders given by the director would keep the gun properly pointed. The design of this test equipment required an enormous number of computations-so many, in fact, that even if all the computing facilities of the Research Department had been continuously devoted to this one job, it would have taken nearly a year to carry them out. Since the equipment had to be built in less time than that, some way of speeding up these computations was required. G. R. Stibitz, who was then employed by the National Defense Research Committee, suggested that an all-relay digital computer might be designed to do the job.