SEAC (computer)
{{Short description|First-generation electronic computer built in 1950}}
{{Infobox information appliance
| name = SEAC
| image = SEACComputer 020.jpg
| image_size =
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| caption = SEAC in 1950
| aka =
| developer = Samuel N. Alexander and team
| manufacturer = U.S. National Bureau of Standards (NBS)
| type =
| releasedate = {{Start date and age|1950}}
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| unitssold = 1
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| cpu =
| CPUspeed = 1 MHz
| storage =
| memory = 512 words, with each being 45 bits in size
| RAMtype = 64 acoustic delay lines
| display =
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| dimensions =
| weight = {{Convert|3,000|lb|ST MT}} (Central Machine)
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SEAC (Standards Eastern Automatic Computer{{Cite web | url=http://www.computerhistory.org/timeline/?year=1950 | title=1950 | Timeline of Computer History | Computer History Museum | access-date=2010-06-29 | archive-date=2010-04-24 | archive-url=https://web.archive.org/web/20100424235033/http://www.computerhistory.org/timeline/?year=1950 | url-status=live }} or Standards Electronic Automatic Computer){{Cite web |url=http://ed-thelen.org/comp-hist/BRL-o-s.html#SEAC |title=1955 BRL report |access-date=2016-01-14 |archive-date=2016-03-04 |archive-url=https://web.archive.org/web/20160304114130/http://ed-thelen.org/comp-hist/BRL-o-s.html#SEAC |url-status=live }} was a first-generation electronic computer, built in 1950 by the U.S. National Bureau of Standards (NBS) and was initially called the National Bureau of Standards Interim Computer, because it was a small-scale computer designed to be built quickly and put into operation while the NBS waited for more powerful computers to be completed (the DYSEAC). The team that developed SEAC was led by Samuel N. Alexander and Ralph J. Slutz.{{Cite web |title=Ralph J. Slutz {{!}} IT History Society |url=https://www.ithistory.org/honor-roll/ralph-j-slutz |access-date=2025-03-21 |website=www.ithistory.org}}{{cite journal|title=Obituary: Samuel Alexander, NBS Senior Research Fellow|journal=Physics Today|date=April 1968|volume=21|issue=4|pages=131|url=http://www.physicstoday.org/resource/1/phtoad/v21/i4/p131_s3?bypassSSO=1|archive-url=https://web.archive.org/web/20141024062049/http://www.physicstoday.org/resource/1/phtoad/v21/i4/p131_s3?bypassSSO=1|url-status=dead|archive-date=2014-10-24|doi=10.1063/1.3034910|url-access=subscription}} SEAC was demonstrated in April 1950 and was dedicated in June 1950;{{Cite book|url=https://books.google.com/books?id=ocx4Jc12mkgC&q=seac+1950&pg=PA237|title=International Biographical Dictionary of Computer Pioneers|last1=Lee|first1=John A. N.|last2=Lee|first2=J. A. N.|date=1995|publisher=Taylor & Francis|isbn=9781884964473|pages=237|language=en}}{{Cite journal|date=1950-08-01|title=3. SEAC (Formerly called NBS Interim Computer)|url=https://apps.dtic.mil/sti/citations/AD0694598|journal=Digital Computer Newsletter|language=en|volume=2|issue=3|pages=1–2|access-date=2022-06-02|archive-date=2022-11-12|archive-url=https://web.archive.org/web/20221112140530/https://apps.dtic.mil/sti/citations/AD0694598|url-status=live}}{{sfn|News - National Bureau of Standards|1950|p=239}} it is claimed to be the first fully operational stored-program electronic computer in the US.{{cite journal|last1=Kirsch|first1=Russell|title=Computer Development at the National Bureau of Standards|journal=NIST Special Publication|date=1 Sep 2000|volume=958|pages=86–89|url=https://www.nist.gov/publications/computer-development-national-bureau-standards|access-date=23 May 2018}}
Description
Based on EDVAC, SEAC used only 747 vacuum tubes (a small number for the time) eventually expanded to 1,500 tubes. It had 10,500 germanium diodes which performed all of the logic functions (see the article diode–transistor logic for the working principles of diode logic), later expanded to 16,000 diodes. It was the first computer to do most of its logic with solid-state devices. The tubes were used for amplification, inversion and storing information in dynamic flip-flops.{{cite book
| title = Logic Design: A Review Of Theory And Practice
| author = Glen G. Jr. Langdon
| publisher = Elsevier
| year = 2012
| isbn = 978-0323160452
| page = 7
| url = https://books.google.com/books?id=sQwE8Gpsj5EC&pg=PA7
}}
The machine used 64 acoustic delay lines to store 512 words of memory, with each word being 45 bits in size. The clock rate was kept low (1 MHz).
The computer's instruction set consisted of only 11 types of instructions: fixed-point addition, subtraction, multiplication, and division; comparison, and input & output. It eventually expanded to 16 instructions.
The addition time was 864 microseconds and the multiplication time was 2,980 microseconds (i.e. close to 3 milliseconds).
Applications
On some occasions SEAC was used by a remote teletype. This makes it one of the first computers to be used remotely. With many modifications, it was used until 1964.{{cite journal|title=COMPUTING CENTERS: 2. National Bureau of Standards, SEAC Retirement, Washington, D. C. 20234|journal=Digital Computer Newsletter|date=Jul 1964|volume=16|issue=3|pages=3–4|url=https://apps.dtic.mil/sti/citations/AD0694641|archive-url=https://web.archive.org/web/20180602102444/http://www.dtic.mil/docs/citations/AD0694641|url-status=live|archive-date=June 2, 2018|language=en}} Some of the problems run on it dealt with:
- digital imaging, led by Russell A. Kirsch
- computer animation of the city traffic simulation{{cite journal|title=ARTICLES: City Traffic Simulated by Computer|journal=Computers and Automation|date=May 1962|volume=XI|issue=5|pages=23–26|url=http://www.bitsavers.org/magazines/Computers_And_Automation/196205.pdf|access-date=2020-09-05|archive-date=2022-03-08|archive-url=https://web.archive.org/web/20220308232105/http://bitsavers.org/magazines/Computers_And_Automation/196205.pdf|url-status=live}}{{Citation |last=Stark |first=Martin C. |date=1961 |title=Computer Simulation of Street Traffic |pages=1, 5, 10–11 |url=https://www.gpo.gov/fdsys/pkg/GOVPUB-C13-39faaf349d16e2712bd2ac27a9f05fbc/content-detail.html |series=NBS Technical Notes |publisher=United States Department of Commerce, National Institute of Standards and Technology |language=en |access-date=2018-09-21 |archive-date=2018-09-21 |archive-url=https://web.archive.org/web/20180921230212/https://www.gpo.gov/fdsys/pkg/GOVPUB-C13-39faaf349d16e2712bd2ac27a9f05fbc/content-detail.html |url-status=live }}
- meteorology
- linear programming
- optical lenses
- a program for Los Alamos National Laboratory
- tables for LORAN navigation
- statistical sampling plans
- wave function of the helium atom
- designing a proton synchrotron
File:SEACComputer 008.jpg|SEAC block diagram
File:SEACComputer 011.jpg|SEAC input/output diagram
File:SEACComputer 030.jpg|Magnetic wire drives and cartridges
File:SEACComputer 025.jpg|Offline magnetic wire to paper tape & print station
File:SEACComputer 031.jpg|SEAC scanner
File:NBSFirstScanImageRestored.jpg|First image scanned into SEAC, son of Russell A. Kirsch
File:SEACComputer 018.jpg|Samuel N. Alexander with SEAC
File:SEACComputer 047.jpg|Horace Joseph and George A. Moore using the SEAC image scanner to analyze metallurgical photographs in 1960. Moore was legally blind.{{Cite book |last=Vander Voort |first=George F. |date=June 1993 |title=Metallography--Past, Present, and Future: 75th Anniversary Volume |url=https://books.google.com/books?id=d2R5dvk9vX4C&dq=George+moore+NBS&pg=PA14 |location=Baltimore |issue=1165 |page=14 |via=Google Books |access-date=2023-03-17 |archive-date=2024-07-13 |archive-url=https://web.archive.org/web/20240713055940/https://books.google.com/books?id=d2R5dvk9vX4C&dq=George+moore+NBS&pg=PA14#v=onepage&q=George%20moore%20NBS&f=false |url-status=live }}
File:SEACComputer 039.jpg|SEAC wiring
File:SEACComputer 024.jpg|Ethel Marden at the control console of SEAC in 1959
See also
- SWAC (Standards Western Automatic Computer)
- List of vacuum-tube computers
- Manchester Baby
References
- Williams, Michael R. (1997). A History of Computing Technology. IEEE Computer Society.
- Metropolis, N; Howlett, J.; Rota, Gian-Carlo (editors) (1980). A History of Computing in the Twentieth Century. Academic Press. (The chapter "Memories of the Bureau of Standards' SEAC", by Ralph J. Slutz.)
- Astin, A. V. (1955), [http://catalog.hathitrust.org/Record/000425518 Computer Development (SEAC and DYSEAC) at the National Bureau of Standards, Washington D.C.], National Bureau of Standards Circular 551, Issued January 25, 1955, U.S. Government Printing Office. Includes several papers describing SEAC, its technical details, and its operation. In particular, see "SEAC", by S. Greenwald, S. N. Alexander, and Ruth C. Haueter, on pp. 5–26, for an overview of the SEAC system.
Further reading
- {{cite book |title=National Institute of Standards and Technology Special Publication |date=1988 |publisher=The Institute |pages=86–89 |chapter-url=https://books.google.com/books?id=5AdRAAAAMAAJ&q=%22Computer+Development+at+the+National+Bureau+of+Standards%22&pg=PA86 |language=en |chapter=Computer Development at the National Bureau of Standards}}
- {{Cite journal|date=1950|title=The incorporation of subroutines into a complete problem on the NBS Eastern Automatic Computer|journal=Mathematics of Computation|language=en-US|volume=4|issue=31|pages=164–168|doi=10.1090/S0025-5718-1950-0037593-9|issn=0025-5718|doi-access=free}}
- {{Cite journal|date=1950|title=Automatic Computing Machinery: The Operating Characteristics of the SEAC; News - National Bureau of Standards|journal=Mathematics of Computation|language=en-US|volume=4|issue=32|pages=229–230; 239|doi=10.1090/S0025-5718-50-99453-1|issn=0025-5718|ref={{harvid|News - National Bureau of Standards|1950}}|doi-access=free}}
- {{cite journal|title=Automatic Computing Machinery: Technical Developments - Provision for Expansion in the SEAC|journal=Mathematics of Computation|date=1951|volume=5|issue=36|pages=232–237|doi=10.1090/S0025-5718-51-99416-1|issn=0025-5718|doi-access=free}}
External links
- [http://museum.nist.gov/panels/seac/SEACOVER.HTM SEAC and the Start of Image Processing at the National Bureau of Standards], [https://web.archive.org/web/20160920230327/http://museum.nist.gov:80/panels/seac/SEACOVER.HTM (Archived)] – At the NIST virtual museum
- [http://purl.umn.edu/41420 Margaret R. Fox Papers, 1935-1976], Charles Babbage Institute, University of Minnesota. collection contains reports, including the original report on the ENIAC, UNIVAC, and many early in-house National Bureau of Standards (NBS) activity reports; memoranda on and histories of SEAC, SWAC, and DYSEAC; programming instructions for the UNIVAC, LARC, and MIDAC; patent evaluations and disclosures; system descriptions; speeches and articles written by Margaret Fox's colleagues; and correspondence of Samuel Alexander, Margaret Fox, and Samuel Williams. Boxes 6-8 of the Fox papers contain documents, reports, and analysis of the NBS's SEAC.
- [http://csrc.lse.ac.uk/history/SEAC-1950.htm SEAC ("Standards Eastern Automatic Computer") (1950)] [https://web.archive.org/web/20070723040312/http://csrc.lse.ac.uk/history/SEAC-1950.htm (Archived)], from History of Computing: An Encyclopedia of the People and Machines that Made Computer History, Lexikon Services Publishing
- [http://www.computerhistory.org/timeline/?year=1950 Timeline of Computer History at CHM]
{{Commons category|position=left|SEAC computer}}
Category:One-of-a-kind computers
Category:Vacuum tube computers