Royal Radar Establishment Automatic Computer

The Royal Radar Establishment Automatic Computer, or the RREAC, was an early solid-state computer in 1962. It was made with transistors; many of Britain's previous experimental computers used the thermionic valve, also known as a vacuum tube.

Britain had built the world's first electronic computer, the Colossus computer, during the war at Bletchley Park in late 1943 and early 1944, and the world's first stored-program computer, the Manchester Small-Scale Experimental Machine, on 21 June 1948. The Germans had built the electro-mechanical Z3 in 1941 in Berlin, which used relays. The world's first digital computing device was the Atanasoff–Berry Computer in 1942. ENIAC was built in 1946 at the Moore School of Electrical Engineering at the University of Pennsylvania. ENIAC and Colossus both claim to be the world's first electronic computer. Electronic Delay Storage Automatic Calculator (EDSAC) ran its first programs on 6 May 1949 at the University of Cambridge Mathematical Laboratory about a month after the Manchester Mark 1 was put to research work at the University of Manchester. In May 1952 Geoffrey Dummer thought up the idea of the integrated circuit at the TRE, the former name of the RRE.

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