 The spacistor was a type of transistor developed in the 1950s as an improvement over the point-contact transistor and the later alloy junction transistor.In 1953, Philco had developed the world's first high frequency surface-barrier transistor, which was also the first transistor that was suitable for high speed computers.The world's first all-transistor car radio, manufactured by Philco in 1955, used surface-barrier transistors in its circuitry design.