Christopher Strachey

Christopher Strachey was born on 16 November 1916 to Oliver Strachey and Rachel (Ray) Costelloe in Hampstead, England. Oliver Strachey was the son of Richard Strachey and the great-grandson of Sir Henry Strachey, 1st Baronet. His elder sister was the writer Barbara Strachey. In 1919, the family moved to 51 Gordon Square. The Stracheys belonged to the Bloomsbury Group whose members included Virginia Woolf, John Maynard Keynes and Strachey's uncle Lytton Strachey. At 13, Strachey went to Gresham's School, Holt where he showed signs of brilliance but in general performed poorly. He was admitted to King's College, Cambridge (the same college as Alan Turing) in 1935 where he continued to neglect his studies. Strachey studied mathematics and then transferred to physics. At the end of his third year at Cambridge, Strachey suffered a nervous breakdown, possibly related to coming to terms with his homosexuality. He returned to Cambridge but managed only a "lower second" in the Natural Sciences Tripos.{{cite journal | first=M. | last=Campbell-Kelly | title=Christopher Strachey, 1916–1975: A Biographical Note | journal=IEEE Annals of the History of Computing | volume=7 | issue=1 | pages=21 | date=January 1985 | doi=10.1109/mahc.1985.10001| s2cid=17188378 }}

Unable to continue his education, Strachey joined Standard Telephones and Cables (STC) as a research physicist. His first job was providing mathematical analysis for the design of electron tubes used in radar. The complexity of the calculations required the use of a differential analyser. This initial experience with a computing machine sparked Strachey's interest and he began to research the topic. An application for a research degree at the University of Cambridge was rejected and Strachey continued to work at STC throughout the Second World War. After the war he fulfilled a long-standing ambition by becoming a schoolmaster at St Edmund's School, Canterbury, teaching mathematics and physics. Three years later he was able to move to the more prestigious Harrow School in 1949, where he stayed for three years.

File:Christopher Strachey's Draughts Program.png

In January 1951, a friend introduced him to Mike Woodger of the National Physical Laboratory (NPL). The lab had successfully built a reduced version of Alan Turing's Automatic Computing Engine (ACE) the concept of which dated from 1945: the Pilot ACE. In his spare time, Strachey developed a preliminary version of a program for the game of draughts ("checkers" in American English) in May 1951. This may have been the first video game. The game completely exhausted the Pilot ACE's memory. The draughts program failed due to program errors when it first ran at NPL on 30 July 1951.{{cite web|title=The Priesthood at Play: Computer Games in the 1950s|url=https://videogamehistorian.wordpress.com/2014/01/22/the-priesthood-at-play-computer-games-in-the-1950s/|work=They Create Worlds |access-date=28 August 2017 |date=22 January 2014}} When Strachey heard about the Manchester Mark 1, which had a much bigger memory, he asked his former fellow-student Alan Turing for the manual and transcribed his program into the operation codes of that machine by around October 1951. By the summer of 1952, the program could "play a complete game of Draughts at a reasonable speed".{{cite web|title=What is Artificial Intelligence|url=http://www.alanturing.net/turing_archive/pages/Reference%20Articles/what_is_AI/What%20is%20AI04.html|work=AlanTuring.net|access-date=28 August 2017 |date=May 2000}}{{cite conference | first=C. S. | last=Strachey | title=Logical or non-mathematical programmes | conference=ACM '52: Proceedings of the 1952 ACM National Meeting (Toronto) | page=47 | date=September 1952 | doi=10.1145/800259.808992 | url=https://books.google.com/books?id=pfgUAQAAMAAJ&q=%22play+a+complete+game+of+draughts+at+a+reasonable+speed%22| url-access=subscription }} While he did not give this game a name, Noah Wardrip-Fruin named it "M. U. C. Draughts."{{cite book |last1=Wardrip-Fruin |first1=Noah |title=How Pac-Man Eats |date=December 2020 |publisher=The MIT Press |location=Cambridge, MA |isbn=9780262044653 |page=121 |edition=1 |url=https://mitpress.mit.edu/books/how-pac-man-eats}}

Strachey programmed the first Computer music in England – the earliest recording of music played by a computer: a rendition of the British National Anthem "God Save the King" on the University of Manchester's Ferranti Mark 1 computer, in 1951. Later that year, short extracts of three pieces were recorded there by a BBC outside broadcasting unit: "God Save the King", "Baa, Baa, Black Sheep", and "In the Mood". Researchers at the University of Canterbury, Christchurch restored the acetate master disc in 2016 and the results may be heard on SoundCloud.{{cite web|title=First recording of computer-generated music – created by Alan Turing – restored |url=https://www.theguardian.com/science/2016/sep/26/first-recording-computer-generated-music-created-alan-turing-restored-enigma-code |work=The Guardian |access-date=28 August 2017 |date=26 September 2016}}{{cite web|title=Restoring the first recording of computer music – Sound and vision blog|url=http://blogs.bl.uk/sound-and-vision/2016/09/restoring-the-first-recording-of-computer-music.html|publisher=British Library|access-date=28 August 2017|date=13 September 2016}}

During the summer of 1952, Strachey programmed a love letter generator for the Ferranti Mark 1 that is known as the first example of computer-generated literature.{{Cite journal |last=Rettberg |first=Jill Walker |date=October 3, 2021 |title=Speculative Interfaces: How Electronic Literature Uses the Interface to Make Us Think about Technology |url=https://electronicbookreview.com/essay/speculative-interfaces-how-electronic-literature-uses-the-interface-to-make-us-think-about-technology/ |journal=Electronic Book Review |language=en |doi=10.7273/1XSG-NV26}}

In May 1952, Strachey gave a two-part talk on "the study of control in animals and machines" ("cybernetics") for the BBC Home Service's Science Survey programme.{{cite web|title=Science Survey – BBC Home Service Basic – 1 May 1952 | work=BBC Genome|date=May 1952 |url=http://genome.ch.bbc.co.uk/f6aaf5636e1645fdbd6aec1d09457dd2|publisher=BBC|access-date=28 August 2017}}{{cite web|title=Science Survey – BBC Home Service Basic – 8 May 1952 | work=BBC Genome|date=8 May 1952 |url=http://genome.ch.bbc.co.uk/fc726824fbdb45aeaca5173a18211e31|publisher=BBC|access-date=28 August 2017}}

Strachey worked for the National Research Development Corporation (NRDC) from 1952 to 1959. While working on the St. Lawrence Seaway project, he was able to visit several computer centres in the United States and catalogue their instruction sets. Later, he worked on programming both the Elliott 401 computer and the Ferranti Pegasus computer. Together with Donald B. Gillies, he filed three patents in computing design, including the design of base registers for program relocation. He also worked on the analysis of vibration in aircraft, working briefly with Roger Penrose.

In 1959, Strachey left NRDC to become a computer consultant working for NRDC, EMI, Ferranti, and other organisations on several wide-ranging projects. This work included logical design for computers, providing autocode and, later, the design of high-level programming languages. For a contract to produce the autocode for the Ferranti Orion computer, Strachey hired Peter Landin who became his one assistant for the duration of Strachey's consulting period.

Strachey developed the concept of time-sharing in 1959.{{Cite web |title=Computer Pioneers – Christopher Strachey |url=https://history.computer.org/pioneers/strachey.html |access-date=2020-01-23 |website=history.computer.org |quote=What Strachey proposed in his concept of time-sharing was an arrangement that would preserve the direct contact between programmer and machine, while still achieving the economy of multiprogramming.}}{{Cite web |title=Computer – Time-sharing and minicomputers |url=https://www.britannica.com/technology/computer/Time-sharing-and-minicomputers |access-date=2020-01-23 |website=Encyclopedia Britannica |language=en |quote=In 1959 Christopher Strachey in the United Kingdom and John McCarthy in the United States independently described something they called time-sharing.}} He filed a patent application in February that year and gave a paper entitled "Time Sharing in Large Fast Computers" at the inaugural UNESCO Information Processing Conference in Paris where he passed the concept on to J. C. R. Licklider.{{Cite book |last1=Gillies |first1=James M. |url=https://archive.org/details/howwebwasbornsto00gill/page/12/mode/2up?q=strachey |title=How the Web was Born: The Story of the World Wide Web |last2=Gillies |first2=James |last3=Gillies |first3=James and Cailliau Robert |last4=Cailliau |first4=R. |date=2000 |publisher=Oxford University Press |isbn=978-0-19-286207-5 |pages=[https://archive.org/details/howwebwasbornsto00gill/page/13 13] |language=en |url-access=registration}}{{Cite web |title=Reminiscences on the Theory of Time-Sharing |url=http://jmc.stanford.edu/computing-science/timesharing.html |access-date=2020-01-23 |website=jmc.stanford.edu |quote=in 1960 'time-sharing' as a phrase was much in the air. It was, however, generally used in my sense rather than in John McCarthy's sense of a CTSS-like object.}} This paper is credited by the MIT Computation Center in 1963 as "the first paper on time-shared computers".

In 1962, while remaining a consultant, he accepted a position at the University of Cambridge.

In 1965, Strachey accepted a position at the University of Oxford as the first director of the Programming Research Group and later the university's first professor of computer science and fellow of Wolfson College, Oxford. He collaborated with Dana Scott.

Strachey was elected as a distinguished fellow of the British Computer Society in 1971 for his pioneering work in computer science.

In 1973, Strachey (along with Robert Milne) began to write an essay submitted to the Adams Prize competition, after which they continued work to revising it into book form. Strachey can be seen and heard in the recorded Lighthill debate on AI{{Citation|last=bilkable|title=The Lighthill Debate (1973) – part 6 of 6|date=12 September 2010|url=https://www.youtube.com/watch?v=3GZWFnWOqkA|access-date=27 October 2017}} (see Lighthill report).

He developed the Combined Programming Language (CPL). His influential set of lecture notes Fundamental Concepts in Programming Languages formalised the distinction between L- and R- values (as seen in the C programming language). Strachey also coined the term currying,{{Citation needed|date=June 2019}} although he did not invent the underlying concept.

He was instrumental in the design of the Ferranti Pegasus computer.

The macro language m4 derives much from Strachey's GPM (General Purpose Macrogenerator), one of the earliest macro expansion languages.C. Strachey: "A General Purpose Macrogenerator", The Computer Journal, 8(3):225–241, 1965.

Strachey contracted an illness diagnosed as jaundice, which after a period of seeming recovery returned, and he died of infectious hepatitis on 18 May 1975. After his death, Strachey was succeeded by Sir Tony Hoare as Head of the Programming Research Group at Oxford, starting in 1977.

The Department of Computer Science at the University of Oxford has a Christopher Strachey Professorship of Computing,{{cite web| url=https://www.cs.ox.ac.uk/news/1988-full.html | title=Christopher Strachey Professorship of Computing | publisher=Department of Computer Science, University of Oxford | date=5 November 2021 | access-date=18 January 2024 }}{{cite web| url=https://governance.admin.ox.ac.uk/legislation/christopher-strachey-professor-of-computing | title=Christopher Strachey Professor of Computing | publisher=University of Oxford | date=28 October 2021 | access-date=18 January 2024 }} which has been held by the following:

• Sir Tony Hoare FRS (1988–2000)
• Samson Abramsky FRS (2000–2021){{cite web| url=http://www.cs.ox.ac.uk/people/samson.abramsky/ | title=Samson Abramsky | publisher=Department of Computer Science, University of Oxford | location=UK | access-date=18 January 2017 }}
• Nobuko Yoshida (2022 onwards){{cite web| url=https://www.cs.ox.ac.uk/news/2070-full.html | title=Welcome to our new Strachey Chair, Professor Nobuko Yoshida | publisher=Department of Computer Science, University of Oxford | date=29 June 2022 | access-date=18 January 2024 }}

In November 2016, a Strachey 100 event was held at Oxford University to celebrate the centenary of Strachey's birth,{{cite web| url=https://www.cs.ox.ac.uk/strachey100/ | title=Strachey 100: Celebrating the life and research of Christopher Strachey | publisher=Department of Computer Science, University of Oxford | location=UK |year=2016 | access-date=18 January 2017 }} including a viewing at the Weston Library in Oxford of the Christopher Strachey archive held in the Bodleian Library collection.{{cite journal| url=https://www.bcs.org/media/3084/facs-dec16.pdf | last=Bowen | first=Jonathan P. | author-link=Jonathan Bowen | title=Strachey 100 Centenary Conference: Photographs of Strachey 100 | journal=FACS FACTS | publisher=BCS-FACS | location=UK | volume=2 | year=2016 | pages=44–52 | access-date=18 January 2017 }} (Also [https://www.cs.ox.ac.uk/strachey100/photos/Bowen-photos.pdf here].)

• {{cite conference |last1=Strachey |first1=Christopher |date=1952 |title=Logical or Non-Mathematical Programmes |url=https://dl.acm.org/doi/10.1145/800259.808992 |book-title=Proceedings of the 1952 ACM national meeting |location=Toronto |publisher=ACM |pages=46–49 |doi=10.1145/800259.808992 |doi-access=|url-access=subscription }}
• {{cite magazine |last1=Strachey |first1=Christopher |date=1954 |title=The "Thinking" Machine |magazine=Encounter |pages=25–31}}
• {{cite journal |last1=Strachey |first1=Christopher |date=1959 |title=Programme-Controlled Time Sharing |journal=Proceedings of the IEE - Part B: Electronic and Communication Engineering |volume=106 |issue=29 |pages=462 |doi=10.1049/pi-b-2.1959.0311 |doi-access=free}}
• {{cite journal |last1=Strachey |first1=Christopher |date=1959 |title=On Taking the Square Root of a Complex Number |url=https://academic.oup.com/comjnl/article/2/2/89/443682 |journal=The Computer Journal |volume=2 |issue=2 |pages=89 |doi=10.1093/comjnl/2.2.89 |doi-access=free}}
• {{cite conference |last1=Strachey |first1=Christopher |date=1959 |title=Time Sharing in Large, Fast Computers |url=https://dblp.uni-trier.de/db/conf/ifip/ifip1959.html |book-title=Proceedings of the 1st International Conference on Information Processing |location=Paris |publisher=UNESCO |pages=336–341 |doi= |doi-access=}}
• {{cite journal |last1=Strachey |first1=Christopher |date=1960 |title=Two Contributions to the Techniques of Queuing Problems |url=https://academic.oup.com/comjnl/article/3/2/114/504851 |journal=The Computer Journal |volume=3 |issue=2 |pages=114–116 |doi=10.1093/comjnl/3.2.114 |doi-access=free}}
• {{cite journal |last1=Strachey |first1=Christopher |date=1961 |title=Bitwise Operations |journal=Communications of the ACM |volume=4 |issue=3 |pages=146 |doi=10.1145/366199.366254 |s2cid=7359297 |doi-access=free}}
• {{cite journal |last1=Strachey |first1=Christopher |last2=Wilkes |first2=Maurice |date=1961 |title=Some Proposals for Improving the Efficiency of ALGOL 60 |journal=Communications of the ACM |volume=4 |issue=11 |pages=488–491 |doi=10.1145/366813.366816 |s2cid=8757176 |doi-access=free}}
• {{cite journal |last1=Strachey |first1=Christopher |last2=Francis |first2=John |date=1961 |title=The Reduction of a Matrix to Codiagonal Form by Eliminations |url=https://academic.oup.com/comjnl/article/4/2/168/383464 |journal=The Computer Journal |volume=4 |issue=2 |pages=168–176 |doi=10.1093/comjnl/4.2.168 |doi-access=free}}
• {{cite journal |last1=Strachey |first1=Christopher |date=1962 |title=Book Reviews |url=https://academic.oup.com/comjnl/article/5/2/152/340910 |journal=The Computer Journal |volume=5 |issue=2 |pages=152–153 |doi=10.1093/comjnl/5.2.152 |doi-access=free}}
• {{cite journal |last1=Barron |first1=David |last2=Buxton |first2=John |last3=Hartley |first3=David |last4=Nixon |first4=Eric |last5=Strachey |first5=Christopher |date=1963 |title=The Main Features of CPL |url=https://academic.oup.com/comjnl/article/6/2/134/364746 |journal=The Computer Journal |volume=6 |issue=2 |pages=134–143 |doi=10.1093/comjnl/6.2.134 |doi-access=free}}
• {{cite journal |last1=Strachey |first1=Christopher |date=1965 |title=An Impossible Program |url=https://academic.oup.com/comjnl/article/7/4/313/354243 |journal=The Computer Journal |volume=7 |issue=4 |pages=313 |doi=10.1093/comjnl/7.4.313 |doi-access=free}}
• {{cite journal |last1=Strachey |first1=Christopher |date=1965 |title=A General Purpose Macrogenerator |url=https://academic.oup.com/comjnl/article/8/3/225/336044 |journal=The Computer Journal |volume=8 |issue=3 |pages=225–241 |doi=10.1093/comjnl/8.3.225 |doi-access=free}}
• {{cite magazine |last1=Strachey |first1=Christopher |date=1966 |title=System Analysis and Programming |url=https://www.scientificamerican.com/article/system-analysis-and-programming/ |magazine=Scientific American |volume=215 |issue=3 |pages=112–127 |doi= |doi-access=}}
• {{cite conference |last1=Strachey |first1=Christopher |date=1966 |title=Towards a Formal Semantics |url= |book-title=Proceedings of the IFIP Working Conference on Formal Language Description Languages |location=Amsterdam |publisher=North Holland |pages=198–220 |doi= |doi-access=}}
• {{cite tech report |last1=Strachey |first1=Christopher |date=1967 |title=Fundamental Concepts in Programming Languages |url= |institution=Lecture notes for the International Summer School in Computer Programming at Copenhagen |number=}} Also: {{cite journal |last1=Strachey |first1=Christopher |date=2000 |title=Fundamental Concepts in Programming Languages |url=https://link.springer.com/article/10.1023%2FA%3A1010000313106 |journal=Higher-Order and Symbolic Computation |volume=13 |issue=1–2 |pages=11–49 |doi=10.1023/A:1010000313106 |s2cid=14124601 |doi-access=|url-access=subscription }}
• {{cite tech report |last1=Scott |first1=Dana |last2=Strachey |first2=Christopher |date=1971 |title=Toward a Mathematical Semantics for Computer Languages |url=https://www.cs.ox.ac.uk/publications/publication3723-abstract.html |institution=Oxford University Computing Laboratory, Programming Research Group |number=PRG06}} Also: {{cite conference |last1=Scott |first1=Dana |last2=Strachey |first2=Christopher |date=1971 |title=Toward a Mathematical Semantics for Computer Languages |url= |book-title=Proceedings of the Symposium on Computers and Automata |location=New York |publisher=Polytechnic Institute of Brooklyn |pages=19–46 |doi= |doi-access=}}
• {{cite conference |last1=Strachey |first1=Christopher |date=1972 |title=Varieties of Programming Language |url= |book-title=Proceedings of the International Computing Symposium |location=Venice |publisher=Cini Foundation |pages=222–233 |doi= |doi-access=}} Also: {{cite tech report |last1=Strachey |first1=Christopher |date=1973 |title=The Varieties of Programming Language |url=http://www.cs.ox.ac.uk/publications/publication3727-abstract.html |institution=Oxford University Computing Laboratory, Programming Research Group |number=PRG10}}
• {{cite journal |last1=Stoy |first1=Joseph |last2=Strachey |first2=Christopher |date=1972 |title=OS6—An Experimental Operating System for a Small Computer. Part 1: General Principles and Structure |url=https://academic.oup.com/comjnl/article/15/2/117/350018 |journal=The Computer Journal |volume=15 |issue=2 |pages=117–124 |doi=10.1093/comjnl/15.2.117 |doi-access=free}}
• {{cite journal |last1=Stoy |first1=Joseph |last2=Strachey |first2=Christopher |date=1972 |title=OS6—An Experimental Operating System for a Small Computer. Part 2: Input/Output and Filing System |url=https://academic.oup.com/comjnl/article/15/3/195/480542 |journal=The Computer Journal |volume=15 |issue=3 |pages=195–203 |doi=10.1093/comjnl/15.3.195 |doi-access=free|url-access=subscription }}
• {{cite tech report |last1=Strachey |first1=Christopher |last2=Stoy |first2=Joseph |date=1972 |title=The Text of OSPub |url=https://www.cs.ox.ac.uk/publications/publication3726-abstract.html |institution=Oxford University Computing Laboratory, Programming Research Group |number=PRG09}}
• {{cite tech report |last1=Strachey |first1=Christopher |last2=Wadsworth |first2=Christopher |date=1974 |title=Continuations: A Mathematical Semantics for Handling Full Jumps |url=http://www.cs.ox.ac.uk/publications/publication3729-abstract.html |institution=Oxford University Computing Laboratory, Programming Research Group |number=PRG11}} Also: {{cite journal |last1=Strachey |first1=Christopher |last2=Wadsworth |first2=Christopher |date=2000 |title=Continuations: A Mathematical Semantics for Handling Full Jumps |url=https://link.springer.com/article/10.1023%2FA%3A1010026413531 |journal=Higher-Order and Symbolic Computation |volume=13 |issue=1–2 |pages=135–152 |doi=10.1023/A:1010026413531 |s2cid=10673265 |doi-access=|url-access=subscription }}
• {{cite book |last1=Milne |first1=Robert |last2=Strachey |first2=Christopher |date=1976 |title=A Theory of Programming Language Semantics |url=https://www.springer.com/gp/book/9781504128339 |location=New York |publisher=Springer |isbn=978-1-5041-2833-9}}

{{Reflist}}

• {{cite journal |last=Barron |first=David |url=https://www.computerconservationsociety.org/resurrection/res43.htm#e |title=Pioneer Profiles – Christopher Strachey |journal=Resurrection |publisher=Computer Conservation Society |number=43 |date=Summer 2008 |issn=0958-7403}}
• {{cite web |last=Copeland |first=Jack |author-link=Jack Copeland |date=June 2000 |url=http://www.alanturing.net/turing_archive/pages/Reference%20Articles/BriefHistofComp.html |title=A Brief History of Computing |website=AlanTuring.net}}
• {{cite journal |editor1-first=Olivier |editor1-last=Danvy |editor2-first=Carolyn |editor2-last=Talcott |url=https://link.springer.com/journal/10990/volumes-and-issues/13-1 |journal=Higher-Order and Symbolic Computation |volume=13 |issue=1/2 |date=April 2000 |title=Special Issue in memory of Christopher Strachey}}
• {{cite book |last=Lavington |first=S. |title=The Pegasus Story |publisher=Science Museum |date=2000 |isbn=1-900747-40-5}}

• {{DBLP|name=Christopher Strachey}}
• {{webarchive |url=https://web.archive.org/web/20070926235419/http://vmoc.museophile.org/pioneers/strachey.html |date=26 September 2007 |title=Christopher Strachey (1916–1975) }} at the Virtual Museum of Computing
• [http://www.alpha60.de/art/love_letters/ A simulator of the Manchester Mark 1, executing Christopher Strachey's Love letter algorithm from 1952]
• [http://www.gingerbeardman.com/loveletter/ A web-based version of Christopher Strachey's Love letter algorithm showing word lists]
• [http://searcharchives.bl.uk/IAMS_VU2:IAMS032-001987657 Supplementary Strachey Papers] held at the British Library

{{Authority control}}

{{DEFAULTSORT:Strachey, Christopher}}

Category:1916 births

Category:1975 deaths

Category:People from Hampstead

Category:People educated at Gresham's School

Category:Alumni of King's College, Cambridge

Category:English computer scientists

Category:Members of the Department of Computer Science, University of Oxford

Category:Fellows of Wolfson College, Oxford

Category:Programming language researchers

Category:Programming language designers

Category:British computer programmers

Category:Schoolteachers from London

Category:Formal methods people

Category:Fellows of the British Computer Society

Category:British LGBTQ scientists

Category:British LGBTQ academics

Category:Deaths from hepatitis

Category:LGBTQ mathematicians

Category:20th-century English LGBTQ people

Category:Schoolteachers from Kent

Category:Strachey family

Category:History of computing in the United Kingdom