Tubes and tube computers

Summary

A relay has only a limited speed as a mechanical construct. Only the introduction of the electron tube accelerates the switching processes by a thousand times. The required components have already existed since the beginning of the 20th century. A tube consists of electrodes in a glass flask.

Finally, this technique is also used in the early computer construction: in 1946 the University of Pennsylvania/USA presents the ENIAC, one of the first tube calculators. The development takes four years. From then on, the U.S. military uses the computer to calculate ballistic tables. For this purpose 17,468 tubes are used on 170 sqm, with 27 tons of weight with a total power requirement of 150 kW. Although tubes have an average operating time of two years, each hour a tube in the ENIAC breaks down. Accordingly, mechanics must continuously maintain the computer.

Other notable tube calculators are the British Colossus (1943) and the German Z22 (1955).