Stored-program computer: Difference between revisions

Revision as of 19:31, 22 December 2022

Revision as of 18:42, 22 February 2023

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{{see also|Universal Turing machine#Stored-program computer|l1=Universal Turing machine: Stored-program computer}}

{{Use dmy dates|date=June 2020}}

{{short description|Computer that stores program instructions in electronically or optically accessible memory}}

{{Use dmy dates|date=JuneFebruary 20202023}}

A '''stored-program computer''' is a [[computer]] that stores [[Instruction (computer science)|program instructions]] in electronically or optically accessible memory.<ref>{{Citation | last = Allison | first = Joanne | title = Stored-program Computers | year = 1997 | url = http://www.computer50.org/mark1/stored.html | access-date = 24 August 2011 | url-status = dead | archive-url = https://web.archive.org/web/20110927012816/http://www.computer50.org/mark1/stored.html | archive-date = 27 September 2011}}</ref> This contrasts with systems that stored the program instructions with [[plugboard]]s or similar mechanisms.

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Several computers could be considered the first stored-program computer, depending on the criteria.<ref>Edwin D. Reilly (2003). ''Milestones in Computer Science and Information Technology'', p. 245.</ref>

* [[IBM SSEC]], became operational in January 1948 but was [[electromechanical]]<ref>{{cite book|author=Emerson W. Pugh|author2=Lyle R. Johnson|author3=John H. Palmer|title=''IBM's 360 and Early 370 Systems''|url=https://archive.org/details/ibms360early370s0000pugh|url-access=registration|date=1991|publisher=MIT Press|isbn=978-0-262-51720-1|page=[https://archive.org/details/ibms360early370s0000pugh/page/15 15]}}</ref>

* In April 1948, modifications were completed to [[ENIAC]] to function as a stored-program computer, with the program stored by setting dials in its function tables, which could store 3,600 decimal digits for instructions. It ran its first stored program on April 12, April 1948 and its first production program on April 17 April<ref>{{cite book|author1=Thomas Haigh|author2=Mark Priestley|author3=Crispen Rope

|title=ENIAC in Action:Making and Remaking the Modern Computer

|year=2016

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===Telecommunication===

The concept of using a stored-program computer for switching of telecommunication circuits is called [[stored program control]] (SPC). It was instrumental to the development of the first [[electronic switching system]]s by [[American Telephone and Telegraph]] (AT&T) in the [[Bell System]],<ref>D.H. Carbaugh and N.L. Marselos, ''Switching System Software'', in ''Fundamentals of Digital Switching Systems'', J. C. McDonald (ed.), Plenum Press (1983), {{ISBN|0-306-41224-1}}</ref> a development that started in earnest by c. 1954 with initial concept designs by [[Erna Schneider Hoover]] at [[Bell Labs]]. The first of such systems was installed on a trial basis in [[Morris, Illinois]] in 1960.<ref>{{cite journal |last1=Joel |first1=A. E. |title=An Experimental Electronic Switching System |journal=[[Bell Laboratories Record]] |date=October 1958 |volume=36 |issue=10 |pages=359–363 |url=https://worldradiohistory.com/Archive-Bell-Laboratories-Record/50s/Bell-Laboratories-Record-1958-10.pdf#page=5 |access-date=October 13, October 2022}}</ref> The storage medium for the program instructions was the [[flying-spot store]], a [[photographic plate]] read by an optical scanner that had a speed of about one microsecond access time.<ref>''Electronic Central Office'', Long Lines 40(5) p16 (1960)</ref> For temporary data, the system used a barrier-grid electrostatic [[storage tube]].

==See also==