Keith Lonsdale

Co-developer of the Ferranti Mark I, believed to be the world's first commercially available computer, Lonsdale worked alongside Brian Pollard and Tom Kilburn to construct the machine, a production version of the University prototype delivered in February 1951.

Born in 1923 and a graduate of the College of Technology, University of Manchester, in 1945, Lonsdale worked at Salford Electrical Instruments as development engineer, then AC Cossor, and joined Ferranti in September 1948 as computer development engineer. He was appointed Senior Engineer in 1950 and Chief Engineer of the newly formed Computer Department in 1953.

In 1961 he was appointed Manager of the Technical Services Department and Manager of West Gorton Factories in 1963. In September 1963 the Ferranti Computer Department was sold to ICT, and Lonsdale transferred to Letchworth, where he remained as Manager of the Computer Division of the Engineering Services Organisation until 1971, when he left to move to Scotland. In "Turing's Cathedral" by George Dyson, he appeared in a photo with Alan Turing and Brian Pollard at the console of the Ferranti Mark 1 computer at the University of Manchester in 1951.