Editing ILLIAC I

{{short description|Vacuum tube computer built in 1952 by the University of Illinois}}
[[File:Illiac memory drum IMG 1108.jpg|thumb|Memory drum of ILLIAC I, on display at the [[Spurlock Museum]].]]
[[File:Donald Betsy Gillies Illiac I.jpg|thumb|Alice (Betsy) E. D. Gillies and Donald B. Gillies with the ILLIAC I at the Digital Computer Lab, [[University of Illinois Urbana–Champaign|Urbana Illinois]], circa 1958.]]
The '''ILLIAC I''' ('''Illinois Automatic Computer'''), a pioneering [[computer]] in the [[ILLIAC]] series of computers built in 1952 by the [[University of Illinois Urbana–Champaign|University of Illinois]], 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.<ref>{{Cite book|url=https://books.google.com/books?id=3FvELn2KiUYC&dq=ILLIAC+1952&pg=PA307|title=The Computer from Pascal to Von Neumann|last=Goldstine|first=Herman H.|date=1980-10-21|publisher=Princeton University Press|isbn=0691023670|pages=307|language=en}}</ref><ref>{{Cite book|url=https://books.google.com/books?id=AsvSBQAAQBAJ&dq=ILLIAC+1952&pg=PA360|title=History of Computing in the Twentieth Century | last=Metropolis | first=Nicholas|date=2014-06-28|publisher=Elsevier|isbn=9781483296685|pages=360|language=en}}</ref> 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]] [[Von Neumann architecture]] as described by mathematician [[John von Neumann]] in his influential ''[[First Draft of a Report on the EDVAC]]''. 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]]s, measured 10&nbsp;ft (3 m) by 2&nbsp;ft (0.6 m) by 8½ ft (2.6 m) (L×B×H), and weighed {{convert|4000|lb|ST MT}}.<ref>{{cite web|last1=Weik|first1=Martin H.|title=ILLIAC|url=http://www.ed-thelen.org/comp-hist/BRL61-ibm7070.html#ILLIAC|website=www.ed-thelen.org|date=March 1961|series=A Third Survey of Domestic Electronic Digital Computing Systems}}</ref> ILLIAC I was very powerful for its time; in 1956, it had more computing power than all of [[Bell Labs|Bell Telephone Laboratories]].

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]] 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 [[University of Illinois at Urbana–Champaign|University of Illinois]] used the ILLIAC I computer to calculate the orbit of the [[Sputnik 1]] satellite within two days of its launch.
* 1960 – The first version of the [[PLATO (computer system)|PLATO]] computer-based education system was implemented on the ILLIAC I by a team led by [[Donald Bitzer]]. It serviced a single user. In early 1961, version 2 of PLATO serviced two simultaneous users.

==See also==
* [[ILLIAC II]]
* [[ILLIAC III]]
* [[ILLIAC IV]]
* [[MISTIC]] – Similar computer specifically inspired by ILLIAC I
* [[SILLIAC]] - Sydney version of the Illinois Automatic Computer, built by the University of Sydney
* [[List of vacuum-tube computers]]

==References==
{{Reflist}}

==External links==
{{Commons category|ILLIAC I}}
* [https://web.archive.org/web/20120414203023/http://ems.music.uiuc.edu/history/illiac.html ILLIAC I history including computer music]
* [http://www.bitsavers.org/pdf/univOfIllinoisUrbana/illiac/ILLIAC 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 (journal)|Nature]]'', No. 4593, November 9, 1957, p.&nbsp;943.
* Digital Computer, 'electronic brain' at the University of Illinois. Digital Public Library of America [https://web.archive.org/web/20150403020954/http://dp.la/item/e519e357ac38fff007f7ca53b45a7c10]
* [https://www.google.com/search?q=&tbm=isch&tbs=rimg:CZkQHxsQTpVCIjhDO3odQy9-dixaUBf8FG9LWExJkN4Cy1sigm4RarnVeZ4S1uShmwLBufjDwq3msbLNgKjXbrYttCoSCUM7eh1DL352EW9ODJCcC3edKhIJLFpQF_1wUb0sRwRKxmskNSi8qEglYTEmQ3gLLWxEIm1alQnGK_1CoSCSKCbhFqudV5ESQMhjnKjIKEKhIJnhLW5KGbAsERMzj1OoAWysoqEgm5-MPCreaxshFYM7kaNQ_1I9CoSCc2AqNduti20EbTuwj77CfGB&tbo=u&sa=X&ved=2ahUKEwj91Liw4oXaAhVIuVMKHe08DPcQ9C96BAgAEBs&biw=1446&bih=686&dpr=1.2 Photos from University of Illinois archives]
{{Mainframes}}
[[Category:IAS architecture computers]]
[[Category:40-bit computers]]
[[Category:Vacuum tube computers]]
[[Category:Computer-related introductions in 1952]]