ABSTRACT
The first half of this chapter is concerned with the prewar and wartime origins of electronic analogue devices and computing systems. Here we see that in the late 1930s and early 1940s pioneering work on the use of thermionic valve amplifiers and alternating current signal techniques to model and simulate dynamic systems was undertaken independently by G. A. Philbrick in the USA and H. Hoelzer in Germany. The dynamic systems being studied by Philbrick in the late 1930s were industrial process controllers. In wartime Germany, Hoelzer was a member of staff at the Peenemunde centre for rocket development,
where he worked on the development of guidance systems and the simulation of missiles. In wartime Britain, at the government-funded Telecommunications Research Establishment, Malvern, work on electronic analogue computing devices was carried out in connection with the development of anti-aircraft gun controllers, radar, aircraft and simulators. In the USA during the war, seminal work on the development of alternating and direct current amplifiers was carried out at the Bell Telephone Laboratories. At BTL these devices were developed for use in anti-aircraft gun controllers. Finally, we see that in the USA the first concrete steps to create a general-purpose electronic analogue computer were undertaken at Columbia University during the war.
