Tom Kilburn was born in Earlseaton near Dewsbury, Yorkshire, on 11 August 1921,[7] the only son of John William Kilburn, a wool mill clerk who later became a company secretary, and his wife, Ivy Mortimer. From 1932 to 1940,[8] he attended the Wheelwright Grammar School for Boys, where the headmaster encouraged his aptitude for mathematics.[9] He also played sports, notably running.[8]
In 1940, Kilburn entered Sidney Sussex College, Cambridge, with a state scholarship, a county major scholarship, and a minor open scholarship,[8] where he studied mathematics. Although many university dons were absent performing war work at places like Bletchley Park, the University of Cambridge maintained a vigorous mathematical community, and Kilburn became the Sidney Sussex College representative in the New Pythagoreans, a clique with the Cambridge University Mathematical Society that also numbered Gordon Welchman and Geoff Tootill among its members. Due to the outbreak of the Second World War, courses were compressed to two years, and he graduated in 1942 with First Class Honours in Part I of the Mathematical Tripos and preliminary examinations for Part II.[9]
Career and research
On graduation, Kilburn was recruited by C.P. Snow.[10] He was given a quick course in electronics, and was posted to the Telecommunications Research Establishment (TRE) in Malvern, where he worked on radar in Group 19 under Frederic Calland Williams. The group was responsible for designing and debugging electronic circuitry. Although Williams was initially disappointed at being given someone with so little practical experience, Kilburn became a valued member of the team.[9] On 14 August 1943, he married Irene Marsden, a shop assistant. They went on to raise a son, John, and a daughter, Anne.[8]
Kilburn's wartime work inspired his enthusiasm for some form of electronic computer. The principal technical barrier to such a development at that time was the lack of any practical means of storage for data and instructions. In July 1946, Kilburn and Williams collaboratively developed a storage device based on a cathode ray tube (CRT) called the Williams–Kilburn tube. A patent was filed in 1946.[11] Initially they used it to store a single bit. The CRT image soon faded, so they devised a scheme by which it was read and refreshed continually, effectively making the data storage permanent. By December 1947, they were able to store 2,048 bits on one 6-inch (150 mm) diameter CRT.[12][13]
In December 1946, Williams took up the Edward Stocks Massey Chair of Electrotechnics at the University of Manchester, and recruited Kilburn on secondment from Malvern.[9] The two developed their storage technology and, in 1948, Kilburn put it to a practical test in constructing the Manchester Baby, which became the first stored-program computer to run a program, on 21 June 1948.[8] He received the degree of PhD in 1948 for his work at Manchester, writing his thesis on A storage system for use with binary digital computing machines under Williams's supervision.[14]
Manchester computers
Kilburn anticipated a return to Malvern but Williams persuaded him to stay to work on the university's collaborative project developing the Ferranti Mark 1, the world's first commercial computer.[15][16][17]Max Newman withdrew from the project, believing that the development of computers required engineers and not mathematicians at this point, but Williams preferred to return to electrotechnics, leaving Kilburn in charge.[9] He was assisted by Alan Turing, who arrived at Manchester in 1948.[12][18] The Mark I incorporated innovations such as index registers, and combined CRTs with magnetic drum storage.[8][19] Nine Mark I computers were sold by between 1951 and 1957.[9]
Over the next three decades, Kilburn led the development of a succession of innovative Manchester computers.[15] The first, commenced in 1951, was a development of the Mark I known as the megacycle machine or Meg, that replaced the vacuum tubediodes with solid state ones. This permitted an order of magnitude increase in the clock rate. To add further speed, Kilburn provided for 10-bit parallel CRT memory.[9] It was also one of the first computers, if not the first, to have floating point arithmetic.[8] Meg operated for the first time in 1954, and nineteen were sold by Ferranti under the name 'Mercury', six of them to customers overseas.[9]
While Kilburn led one design team working on Meg, he led another with Dick Grimsdale and Douglas Webb, on a research project examining what he believed would be the next step forward in computer design: the use of transistors. The 48-bit machine they completed in November 1953 was the world's first transistor computer, with 550 diodes and 92 transistors, and was manufactured by STC. An improved version completed in April 1955 had 1,300 diodes and 200 transistors, and was sold by Metropolitan-Vickers as the Metrovick 950.[9]
Kilburn became a professor of computing engineering in the Department of Electrical Engineering at Manchester in 1960. He was instrumental in forming the Department of Computer Science in 1964, becoming the first head of the department, and served as Dean of the Faculty of Science from 1970 to 1972, and pro-vice-chancellor of the university from 1976 to 1979.[9] His final computer project was the MU5, which was designed to facilitate the running of programs in high-level programming languages. An analysis of code written for the Atlas gave an insight into the frequency of different operands and control structures. The project was assisted by a £630,000 Science Research Council (SRC) grant awarded over five-years. The design heavily influenced the successful ICL 2900 Series.[9][20]
Professor of Computer Engineering in the University of Manchester. He was a pioneer in the engineering realisation of the general purpose electronic digital computer and has made major contributions to the rapid rate of development that has occurred in this field over the past 15 years. His contributions cover the whole range from overall system design to the invention of high speed circuits to meet particular needs. His latest machine, 'Atlas' may well be the most advanced machine currently under construction anywhere in the World.[30]
Personal life
Kilburn married Irene Marsden in 1943 and had two children, one daughter and one son.[1] Kilburn habitually holidayed with his family in Blackpool but was always back in time for Manchester United F.C.'s first match of the football season. He claimed that watching Manchester United win the 1968 European Cup Final at Wembley stadium was the best day of his life.[8] He took early retirement in 1981 to care for his ailing wife,[12] who was suffering from chronic bronchitis, but she died on 3 August 1981, two weeks before his retirement.[8][9][1]
^Anderson, D. P. (2009). "Biographies: Tom Kilburn: A Pioneer of Computer Design". IEEE Annals of the History of Computing. 31 (2): 82–86. doi:10.1109/MAHC.2009.32.
^Kilburn, Tom (1948). A storage system for use with binary digital computing machines. manchester.ac.uk (PhD thesis). University of Manchester. OCLC841848118. EThOSuk.bl.ethos.488439. A first version of this thesis was written by Kilburn with the same title, as a personal report to the Telecommunications Research Establishment (TRE) to obtain a second year of secondment to the University of Manchester. Kilburn has stated that whilst he was writing it, requests for copies came in. Twenty copies were therefore made, and the document was circulated as an Internal Report by the Department of Electrotechnics, University of Manchester, dated 1st December 1947. Due to demand, a further 30 copies were made. It is known that several copies were taken to the USA by Douglas Hartree, Harry Huskey and A. M. Utley (TRE) in the Spring of 1948
^ abShelburne, B. J.; Burton, C. P. (1998). "Early programs on the Manchester Mark I Prototype". IEEE Annals of the History of Computing. 20 (3): 4. doi:10.1109/85.707570.
^Kilburn, T.; Edwards, D. B. G.; Lanigan, M. J.; Sumner, F. H. (1962). "One-Level Storage System". IEEE Transactions on Electronic Computers (2): 223–235. doi:10.1109/TEC.1962.5219356.
