Electronic Numerical Integrator and Computer

(ENIAC) The first ever general-purpose digital

electronic computer and the ancestor of most computers in use

today. ENIAC was developed by {John Mauchly} and {J. Presper

Eckert} during World War II at the Moore School of the

{University of Pennsylvania} and was 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.

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.

{(http://ftp.arl.mil/~mike/comphist/48eniac-coding)}].

[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.

{(http://ftp.arl.mil/~mike/comphist/61ordnance)}].

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

1961. {(http://ftp.arl.mil/~mike/comphist/eniac-story.html)}].

(1997-08-03)