Mary Coombs and the Birth of Business Computers

In the early 1950s, one of the UK’s top catering and food manufacturing companies took a sharp left turn into software development and the manufacture and sales of the world’s first business computers.

In 1947, executives of J. Lyons and Co. came away from a meeting with one of the developers of ENIAC convinced that their company would benefit from computerizing its accounting and related operations. They also convinced their board that the quickest way to achieve that was to invest in EDSAC, and then build on its design for their own needs.

In November 1951, the Lyons Electronic Office (LEO) took over calculating job valuations for J. Lyons and Co.’s bakery operations. LEO soon took on inventory, invoicing, management reports, payroll, and more–not just for J. Lyons and Co., but for the UK’s meteorological service, Ford UK, and others. In 1954, the company formed LEO Computers Ltd. to handle this new business.

Mary Coombs was part of the LEO programming team from nearly the beginning, and she is recognized as the first woman to program a commercial computer. She developed programs for internal use and as part of the new company’s business services offerings, debugged the work of other programmers, and was in charge of rewriting LEO II programs for LEO III, which used a different language.

Coombs’ career eventually took a path that is all too familiar to many women–with the birth of a disabled child, Coombs cut back her work from full- to part-time. She eventually left the programming field, and her history-making first career, altogether, and became a teacher.

Mary Coombs, a light-skinned person in a pink jacket and white shirt, wearing glasses and a beaded necklace, from the chest up, facing slightly left.
Mary Coombs shares her story with computingheritage

Illustration of an analog numeric typewriter, superimposed on a paper chart of printed numbers.

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