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.
Draughts on a storage CRT, 1952
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.[8] 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".[9][10] While he did not give this game a name, Noah Wardrip-Fruin named it "M. U. C. Draughts."[11]
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.[12][13]
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.[15][16]
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 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[21] (see Lighthill report).
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.[17] After his death, Strachey was succeeded by Sir Tony Hoare as Head of the Programming Research Group at Oxford, starting in 1977.
In November 2016, a Strachey 100 event was held at Oxford University to celebrate the centenary of Strachey's birth,[27] including a viewing at the Weston Library in Oxford of the Christopher Strachey archive held in the Bodleian Library collection.[28]
Strachey, Christopher (1966). "Towards a Formal Semantics". Proceedings of the IFIP Working Conference on Formal Language Description Languages. Amsterdam: North Holland. pp. 198–220.
Strachey, Christopher (1967). Fundamental Concepts in Programming Languages (Technical report). Lecture notes for the International Summer School in Computer Programming at Copenhagen. Also: Strachey, Christopher (2000). "Fundamental Concepts in Programming Languages". Higher-Order and Symbolic Computation. 13 (1–2): 11–49. doi:10.1023/A:1010000313106. S2CID14124601.
Scott, Dana; Strachey, Christopher (1971). Toward a Mathematical Semantics for Computer Languages (Technical report). Oxford University Computing Laboratory, Programming Research Group. PRG06. Also: Scott, Dana; Strachey, Christopher (1971). "Toward a Mathematical Semantics for Computer Languages". Proceedings of the Symposium on Computers and Automata. New York: Polytechnic Institute of Brooklyn. pp. 19–46.
Strachey, Christopher (1972). "Varieties of Programming Language". Proceedings of the International Computing Symposium. Venice: Cini Foundation. pp. 222–233. Also: Strachey, Christopher (1973). The Varieties of Programming Language (Technical report). Oxford University Computing Laboratory, Programming Research Group. PRG10.
Strachey, Christopher; Stoy, Joseph (1972). The Text of OSPub (Technical report). Oxford University Computing Laboratory, Programming Research Group. PRG09.
^Strachey, Christopher (1967). Fundamental Concepts in Programming Languages (Technical report). Lecture notes for the International Summer School in Computer Programming at Copenhagen.
^ ab"Computer Pioneers – Christopher Strachey". history.computer.org. Retrieved 23 January 2020. 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.
^"Computer – Time-sharing and minicomputers". Encyclopedia Britannica. Retrieved 23 January 2020. In 1959 Christopher Strachey in the United Kingdom and John McCarthy in the United States independently described something they called time-sharing.
^"Reminiscences on the Theory of Time-Sharing". jmc.stanford.edu. Retrieved 23 January 2020. 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.
