Editing APEXC

{{More citations needed|date=March 2010}}

The '''APE(X)C''', or  '''All Purpose Electronic (X) Computer'''  series was designed by [[Andrew Donald Booth]] at [[Birkbeck, University of London|Birkbeck College]], [[London]] in the early 1950s. His work on the APE(X)C series was sponsored by the [[British Rayon Research Association]].<ref>The British computer industry: crisis and development By Tim Kelly, page 41</ref><ref name="earlybrit">Early British computers, Simon Hugh Lavington 1980</ref> Although the naming conventions are slightly unclear, it seems the first model belonged to the BRRA.<ref name="histcomp">History of Computing:Learning from the Past, Arthur Tatnall Springer, 2010</ref> According to Booth, the X stood for X-company.<ref>Book 495 in Origins of cyberspace: a library on the history of computing, Diana H. Hook, [[Jeremy M. Norman]], Michael R. Williams. Norman Publishing, 2002</ref>

One of the series was also known as the APE(X)C or '''All Purpose Electronic X-Ray Computer''' and was sited at Birkbeck.

==Background==
From 1943 on, Booth started working on the determination of [[crystal]] structures using [[X-ray diffraction]] data.  The computations involved were extremely tedious and there was ample incentive for automating the process. He developed an analogue computer to compute the reciprocal spacings of the diffraction pattern.<ref>
{{cite book|author=Andrew Brown|title=J.D. Bernal, The Sage of Science|page=276|publisher=Oxford U.P.|year=2005}}
</ref>
==ARC and SEC==
Booth designed an electromechanical computer, the [[Automatic Relay Computer|ARC]] (Automatic Relay Computer), in the late 1940s (1947-1948).<ref>{{Cite book|url=https://books.google.com/books?id=AU28AAAAIAAJ&q=%22Automatic+Relay+Computer%22+booth&pg=PA62|title=Early British Computers: The Story of Vintage Computers and the People who Built Them|last=Lavington|first=Simon Hugh|date=1980|publisher=Manchester University Press|isbn=9780719008108|pages=62|language=en}}</ref> Later on, they built an experimental electronic computer named SEC ([[Simple Electronic Computer]], designed around 1948-1949) - and finally, the APE(X)C (All-Purpose Electronic Computer) series.<ref name=":0">{{cite web|url=http://www.dcs.bbk.ac.uk/site/assets/files/1029/50yearsofcomputing.pdf|title=School of Computer Science & Information Systems: A Short History|last1=Johnson|first1=Roger|date=April 2008|website=Birkbeck College|publisher=University of London|pages=5–8|access-date=22 November 2018}}</ref><ref>{{Cite journal|date=1950|title=Automatic Computing Machinery: Bibliography Z-XII; 3. Anon., ''Digital Computer Research at Birkbeck College'', Office of Naval Research (London Branch), ''Technical Report'' OANAR-50-49, 12 December 1949, 2 p.|journal=Mathematics of Computation|language=en-US|volume=4|issue=31|pages=171|doi=10.1090/S0025-5718-50-99462-2|issn=0025-5718|doi-access=free}}</ref><ref>{{Cite journal|date=1950-01-01|title=11. Digital Computers, Birkbeck College, University of London|url=https://apps.dtic.mil/sti/citations/AD0694596|archive-url=https://web.archive.org/web/20210311004157/http://www.dtic.mil/docs/citations/AD0694596|url-status=live|archive-date=March 11, 2021|journal=Digital Computer Newsletter|language=en|volume=2|issue=1|pages=4}}</ref> 

The computers were programmed by Kathleen.<ref name=":0" />

==The APE(X) C series==
The APE(X)C series included the following machines:
* '''APE(X)C''': Birkbeck College, London, first time operated in May 1952,<ref name=":0" /> ready for use at the end of 1953<ref name=":1" />
* '''APE(N)C''': [[Board of Mathematical Machines]], [[Oslo]] ('N' likely stands for '[[Norway]]'), also known as [[NUSSE]]
* '''APE(H)C''': [[British Tabulating Machine Company]] (It is unclear what 'H' stands for - perhaps '[[Computing-Tabulating-Recording Company#Tabulating Machine Company|Hollerith]]' as the company sold Hollerith [[Unit record equipment]]
* '''APE(R)C''': [[British Rayon Research Association]] ('R' stands for 'Rayon'<ref name="earlybrit" />), ready for use in June 1952<ref name=":1">{{cite book|url=https://archive.org/details/bitsavers_onrASurveyomputers1953_8778395|title=A survey of automatic digital computers|last1=Research|first1=United States Office of Naval|date=1953|publisher=Office of Naval Research, Dept. of the Navy|pages=[https://archive.org/details/bitsavers_onrASurveyomputers1953_8778395/page/n11 4]–5|language=en}}</ref>
* '''UCC''': [[University College, London]] (circa January 1956)<ref name=":2">{{cite journal|title=COMPUTERS, OVERSEAS: 2. Birkbeck College Computer Laboratory (London, England)|journal=Digital Computer Newsletter|date=Jan 1956|volume=8|issue=1|pages=16–17|url=https://apps.dtic.mil/sti/citations/AD0694619|archive-url=https://web.archive.org/web/20190406120028/http://www.dtic.mil/docs/citations/AD0694619|url-status=live|archive-date=April 6, 2019|language=en}}</ref>
* '''MAC''' or '''MAGIC''' ('''Magnetic Automatic Calculator'''): "built by [[Wharf Engineering Laboratories]]" (February 1955)<ref name=":2" />
* The '''HEC''' ('''[[Hollerith Electronic Computer]]'''), built by the British Tabulating Machine Company (later to become [[International Computers and Tabulators]] (ICT), then [[International Computers Limited]] (ICL)), a commercial machine sold in several models and later known as the ICT200 series.  There were likely the derivatives '''HEC 1''', '''HEC 2''', '''HEC 2M''' - M for 'marketable' denoting the machine's orientation toward commercial rather than scientific customers, and '''HEC 4''' (before 1955)

Only one of each of these machines was built, with the exception of HEC (and possibly MAC) which were commercial machines produced in quite large numbers for the time, around 150. They were similar in design, with various small differences, mostly in I/O equipment.  The APEHC was a [[punched card]] machine while the  APEXC, APERC and APENC were [[Teleprinter|teletype]]rs ([[alphanumeric keyboard|keyboard]] and [[Computer printer|printer]], plus [[paper tape]] reader and puncher).  Also, the UCC had 8k words of storage, instead of 1k word for other machines, and the MAC used germanium diodes in replacement of many valves.

==British Tabulating Machine Company machines==

[[File:Hollerith Electronic Computer1 Prototype.jpg|thumb|right|BTM Hollerith Electronic Computer 1 Prototype]]
In March 1951, the British Tabulating Machine Company (BTM) sent a team to Andrew Booth's workshop. They then used his design to create the Hollerith Electronic Computer 1 (HEC 1) before the end of 1951. The computer was a direct copy of Andrew Booth's circuits with extra Input/output interfaces. The HEC 2 was the HEC 1 with smarter metal casings and was built for the [[Business Efficiency Exhibition]] in 1953. A slightly modified version of the HEC 2 was then marketed as HEC2M and 8 were sold. The HEC2M was succeeded by the HEC4. Around 100 HEC4s were sold in the late 1950s.<ref name=bbk>{{cite web |url=http://www.dcs.bbk.ac.uk/50years/50yearsofcomputing.pdf |title=School of Computer Science & Information Systems A Short History  |date=2008 |website=Birkbeck, University of London |publisher=Department of Computer Science and Information Systems |access-date=2015-06-02 }}</ref>

==Further reading==
* Andrew D. Booth Technical Developments: The Development of A.P.E.(X).C. (in [https://doi.org/10.1090/S0025-5718-54-99336-9 Automatic Computing Machinery]), Mathematical Tables and Other Aids to Computation (MTAC) Volume 8, Number 46, April, 1954

==References==
{{reflist}}

[[Category:1940s computers]]
[[Category:1950s computers]]
[[Category:Computer-related introductions in 1948]]
[[Category:32-bit computers]]
[[Category:Crystallography]]
[[Category:Early British computers]]
[[Category:One-of-a-kind computers]]