(ENIAC) The second general-purpose electronic digital computer and an ancestor of most computers in use today. ENIAC was developed by Dr. john w. mauchly and j. presper eckert during World War II at the Moore School of the university of pennsylvania.

In 1940 Dr. john vincent atanasoff attended a lecture by Mauchly and subsequently agreed to show him his computer, the atanasoff-berry computer (ABC), which was built between 1937-1942. Mauchly used ideas from the ABC in the design of ENIAC, which was started in June 1943 and released publicly in 1946.

ENIAC was underwritten and its development overseen by Lieutenant Herman Goldstine of the U.S. Army Ballistic Research Laboratory (BRL). While the prime motivation for constructing the machine was to automate the wartime production of firing and bombing tables, the very first program run on ENIAC was a highly classified computation for Los Alamos. Later applications included weather prediction, cosmic ray studies, wind tunnel design, petroleum exploration, and optics.

ENIAC had 20 registers made entirely from vacuum tubes. It had no other no memory as we currently understand it. The machine performed an addition in 200 microseconds, a multiplication in about three milliseconds, and a division in about 30 milliseconds.

john von neumann, a world-renowned mathematician serving on the BRL Scientific Advisory Committee, soon joined the developers of ENIAC and made some critical contributions. While Mauchly, Eckert and the Penn team continued on the technological problems, he, Goldstine, and others took up the logical problems. In 1947, while working on the design for the successor machine, EDVAC, von Neumann realized that ENIAC's lack of a centralized control unit could be overcome to obtain a rudimentary stored program computer. Modifications were undertaken, that eventually led to an instruction set of 92 "orders". von neumann also proposed the fetch-execute cycle.

[R. F. Clippinger, "A Logical Coding System Applied to the ENIAC", Ballistic Research Laboratory Report No. 673, Aberdeen Proving Ground, MD, September 1948. ].

[H. H. Goldstine, "The Computer from Pascal to von Neumann", Princeton University Press, 1972].

[K. Kempf, "Electronic Computers within the Ordnance Corps", Aberdeen Proving Ground, MD, 1961. ].

[M. H. Weik, "The ENIAC Story", J. American Ordnance Assoc., 1961. ].