The ILLIAC I (Illinois Automatic Computer), a pioneering

computer A computer is a machine that can be Computer programming, programmed to automatically Execution (computing), carry out sequences of arithmetic or logical operations (''computation''). Modern digital electronic computers can perform generic set ...

in the ILLIAC series of computers built in 1952 by the

University of Illinois The University of Illinois Urbana-Champaign (UIUC, U of I, Illinois, or University of Illinois) is a public university, public land-grant university, land-grant research university in the Champaign–Urbana metropolitan area, Illinois, United ...

, was the first computer built and owned entirely by a United States educational institution.

Computer

The project was the brainchild of Ralph Meagher and Abraham H. Taub, who both were associated with Princeton's Institute for Advanced Study before coming to the University of Illinois. The ILLIAC I became operational on September 1, 1952. It was the second of two identical computers, the first of which was ORDVAC, also built at the University of Illinois. These two machines were the first pair of machines to run the same instruction set. ILLIAC I was based on the

IAS machine The IAS machine was the first electronic computer built at the Institute for Advanced Study (IAS) in Princeton, New Jersey. It is sometimes called the von Neumann machine, since the paper describing its design was edited by John von Neumann, a ...

Von Neumann architecture The von Neumann architecture—also known as the von Neumann model or Princeton architecture—is a computer architecture based on the '' First Draft of a Report on the EDVAC'', written by John von Neumann in 1945, describing designs discus ...

as described by mathematician

John von Neumann John von Neumann ( ; ; December 28, 1903 – February 8, 1957) was a Hungarian and American mathematician, physicist, computer scientist and engineer. Von Neumann had perhaps the widest coverage of any mathematician of his time, in ...

in his influential ''

First Draft of a Report on the EDVAC The ''First Draft of a Report on the EDVAC'' (commonly shortened to ''First Draft'') is an incomplete 101-page document written by John von Neumann and distributed on June 30, 1945 by Herman Goldstine, security officer on the classified ENIAC pr ...

''. Unlike most computers of its era, the ILLIAC I and ORDVAC computers were twin copies of the same design, with software compatibility. The computer had 2,800

vacuum tube A vacuum tube, electron tube, thermionic valve (British usage), or tube (North America) is a device that controls electric current flow in a high vacuum between electrodes to which an electric voltage, potential difference has been applied. It ...

s, measured 10 ft (3 m) by 2 ft (0.6 m) by 8½ ft (2.6 m) (L×B×H), and weighed . ILLIAC I was very powerful for its time; in 1956, it had more computing power than all of

Bell Telephone Laboratories Nokia Bell Labs, commonly referred to as ''Bell Labs'', is an American industrial research and development company owned by Finnish technology company Nokia. With headquarters located in Murray Hill, New Jersey, Murray Hill, New Jersey, the compa ...

. Because the lifetime of the tubes within ILLIAC was about a year, the machine was shut down every day for "preventive maintenance" when older vacuum tubes would be replaced in order to increase reliability. Visiting scholars from Japan assisted in the design of the ILLIAC series of computers, and later developed the MUSASINO-1 computer in Japan. ILLIAC I was retired in 1962, when the

ILLIAC II The ILLIAC II was a revolutionary super-computer built by the University of Illinois Urbana–Champaign, University of Illinois that became operational in 1962. Description The concept, proposed in 1958, pioneered Emitter-coupled logic (ECL) ...

became operational.

Innovations

* 1955 – Lejaren Hiller and Leonard Isaacson used ILLIAC I to compose the '' Illiac Suite'' which was one of the first pieces of music to be written with the aid of a computer. * 1957 – Mathematician Donald B. Gillies, physicist James E. Snyder, and astronomers George C. McVittie, S. P. Wyatt, Ivan R. King and George W. Swenson of the

used the ILLIAC I computer to calculate the orbit of the

Sputnik 1 Sputnik 1 (, , ''Satellite 1''), sometimes referred to as simply Sputnik, was the first artificial Earth satellite. It was launched into an elliptical low Earth orbit by the Soviet Union on 4 October 1957 as part of the Soviet space program ...

satellite within two days of its launch. * 1960 – The first version of the

PLATO Plato ( ; Greek language, Greek: , ; born BC, died 348/347 BC) was an ancient Greek philosopher of the Classical Greece, Classical period who is considered a foundational thinker in Western philosophy and an innovator of the writte ...

computer-based education system was implemented on the ILLIAC I by a team led by

Donald Bitzer Donald Lester Bitzer (January 1, 1934 – December 10, 2024) was an American electrical engineer and computer scientist. He was the co-inventor of the plasma display and was widely regarded as the "father of PLATO". Life and career Donald Leste ...

. It serviced a single user. In early 1961, version 2 of PLATO serviced two simultaneous users.

References

External links

ILLIAC I history including computer music

ILLIAC I documentation
at bitsavers.org * I. R. King, G. C. McVittie, G. W. Swenson, Jr., and S. P. Wyatt, Jr., "Further observations of the first satellite," ''

Nature Nature is an inherent character or constitution, particularly of the Ecosphere (planetary), ecosphere or the universe as a whole. In this general sense nature refers to the Scientific law, laws, elements and phenomenon, phenomena of the physic ...

'', No. 4593, November 9, 1957, p. 943. * Digital Computer, 'electronic brain' at the University of Illinois. Digital Public Library of Americ

Photos from University of Illinois archives
{{Mainframes IAS architecture computers 40-bit computers Vacuum tube computers Computer-related introductions in 1952

Computer

Innovations

See also

References

External links