Christopher Strachey

Christopher S. Strachey (16 November 1916 – 18 May 1975) was a British computer scientist.

He was one of the founders of denotational semantics, and a pioneer in programming language design and computer time-sharing.

He has also been credited as possibly being the first developer of a video game.

He was a member of the Strachey family, prominent in government, arts, administration, and academia.

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 Christopher's uncle Lytton Strachey.

At 13, Christopher 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.

Unable to continue his education, Christopher 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.

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.

Three years later he was able to move to the more prestigious Harrow School in 1949, where he stayed for three years.

In January 1951, a friend introduced him to Mike Woodger of the National Physical Laboratory (NPL).

In his spare time, Strachey developed a preliminary version of a program for the game of draughts ("checkers" in American English) in May 1951.

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.

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.

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".

By the summer of 1952, the program could "play a complete game of Draughts at a reasonable speed".

While he did not give this game – which may have been the first video game – a name, Noah Wardrip-Fruin named it "M. U. C. Draughts."

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.

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.

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.

Researchers at the University of Canterbury, Christchurch restored the acetate master disc in 2016 and the results may be heard on SoundCloud.