in the United Kingdom, in 1943. Although it was designed and employed to break a specific German cipher system, this machine was in fact a true electronic computer and could be used, in principle, on a range of problems. The existence of this machine was classified until the 1970s.

U.S. personnel working with Bletchley Park during World War II played a major role in creating the early U.S. computer industry in the decade following the war. In particular, U.S. engineers at the Naval Computing Machinery Laboratory (a National Cash Register plant in Dayton, Ohio, deputized into the war effort) were building copies or improved versions of Bletchley Park electronic cryptanalysis machines, as well as computers of their own design. American engineers involved in this effort included William Norris and Howard Engstrom—Norris later founded Engineering Research Associates (ERA), then Control Data; Engstrom was later deputy director of the National Security Agency (NSA)—and Ralph Palmer who was principal technical architect of IBM’s move into electronic computers in the 1950s. Of the 55 people in the founding technical group at ERA, where Seymour Cray had his first design job in computers, 40 came from Navy communications intelligence in Washington, 5 from the Navy lab in Dayton, and 3 from the Naval Ordnance Laboratory.3

The ENIAC, built in 1945 at the University of Pennsylvania and often credited as the first functioning electronic computer, was a larger, plug-programmable computer designed to compute artillery ballistics tables.4 Ironically, it came into existence, indirectly, as a result of the code-breaking efforts of the U.S. intelligence community. The U.S. Army’s Ballistic Research Laboratory (BRL) had originally funded a ballistics computer project at National Cash Register and had turned down a competing proposal from J. Presper Eckert and John Mauchly at the University of Pennsylvania. BRL reconsidered this decision after the National Cash Register Dayton group was drafted into producing cryptanalysis machines for the Navy and finally decided to fund the ENIAC project.


See Flamm, 1988, pp. 36-41, 43-45.


As is the case for many other technologies, there has been a heated debate about who should be credited as the inventor of the first digital computer. In addition to the Colossus and the ENIAC, the following are worth mentioning: Konrad Zuse, working in Germany, built a relay-based automatic digital computer in Germany in 1939-1941. A similar system, the Automatic Sequence Controlled Calculator (ASCC), also called the Mark I, was conceived by Howard Aiken and designed and built by IBM in 1939-1944. John Vincent Atanasoff and Clifford Berry started building an electronic digital computer at Iowa State University in 1937-1942. Although the project was not completed, Atanasoff and Berry won a patent case against Eckert and Mauchly in 1973, invalidating the patent of the latter on ENIAC as the first automatic electronic computer.

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