Mary Coombs, who has died aged 93, was the first woman in the world trained to program a computer for business applications. She worked on the Lyons Electronic Office – Leo – the computer built in the early 1950s by the catering company J Lyons & Co to automate the back office for its national chain of 250 teashops, three vast Corner Houses in London, and sales of cakes, tea and ice-cream.
In 2001, old Leo hands celebrated the 50th anniversary of the world’s first computerised office job, Bakery Valuations, which ran on Leo as a routine application starting in November 1951. The anniversary brought Coombs’ role into the public eye for the first time. With her astonishingly detailed memory, sharp mind and engaging personality, she found herself frequently called upon to give interviews for print, radio and television, helping to bring back to life a largely forgotten episode in the history of British computing.
Leo was the brainchild of a Lyons manager, John Simmons, who persuaded the board to fund a computer for the company soon after the second world war. At the time, computers were seen as scientific tools – it was revolutionary to imagine that they could take on stock control, distribution, payroll, even tea blending, previously carried out by hand. Lyons bought the technology from Cambridge University by funding the development of Edsac (Electronic Delay Storage Automatic Calculator), one of the first British scientific computers, building its own machine and developing business applications.
Coombs’ father was a medical officer at Lyons. She was a management trainee in the statistical office when a memo came round inviting staff to sign up for a “computer appreciation course”. She was intrigued, attended the intensive programme of lectures and assignments, and was almost immediately offered a job as a programmer. Only one of the other 10 participants, Frank Land, passed muster, starting a few months after Coombs.
The room-sized computer, based on thermionic valves and inherently unreliable, was not fully ready until December 1953. Coombs spent her first months writing test programs, often working with the engineers until well after midnight to solve problems (one turned out to be because of interference from the managers’ lift).
Payroll for Lyons’ 10,000 employees was the next big task. The program, written in a simple alphanumeric code, had to produce payslips in pre-decimal currency, taking into account tax deductions, loans to the employee, holiday and sick pay, and calculating the denominations of cash needed to go into pay packets. Coombs later did the same for the Ford motor company, one of many queueing up to use Leo.
In 1954 Lyons set up Leo Computers Ltd and started making computers for sale. The senior systems analysts became “consultants” responsible for designing systems for customers as well as for making sales. Her former classmate on the appreciation course, Land, became one of them, but Coombs was never offered a management position. “I always had a shrewd suspicion that I was too useful to be promoted to management,” she told an interviewer from the British Library’s Voices of Science project.
Training and supervising a pool of programmers, she specified payroll programs for a consortium of London local authorities, and spent time in the offices of British Oxygen, valiantly trying to produce programs to a specification (drawn up by the company’s planners, who knew nothing about computers) that she had said from the start was far too complicated.
When Leo produced its first transistor machine, Leo III, Coombs translated programs from machine code into the English-based programming language then in use. She loved the job. It was “wildly exciting”, she recalled. “If I hadn’t enjoyed myself so much … I would have balked at the relatively low pay, you know … It was really great fun.”
Born in Muswell Hill, north London, Mary was the elder daughter of Ruth (nee Petri) and William Blood, then a GP. She had a sister, also named Ruth. Mary attended Putney high school and St Paul’s girls’ school in Hammersmith. Although she had excelled at maths, she chose to read French and history at the then Queen Mary College, London.
After graduating, she taught English and took secretarial courses in Lausanne, Switzerland, for a year, returning to England in August 1952 intending to teach French. All the teaching posts had been filled, so she took the “temporary” job at Lyons that led to Leo.
She married John Coombs, a fellow programmer, in 1955. Their daughter, Anne, was born in 1961, and they adopted three further children, Andrew, Paul and Gillian. Leo Computers eventually became part of ICL, and Coombs continued to be employed by the company part-time until 1969, working at home editing computer manuals.
Anne had been born with a developmental disorder, and she died of pneumonia at only six. After stopping work for three years Coombs returned to her original ambition, qualifying to work as a primary school teacher until her post was axed in a round of cuts. Versatile, quick to learn and hating to be out of a job, she then worked as an equipment buyer for a water treatment company until she retired at 64.
At different times Coombs ran a cub scouts troop, taught music, played the church organ, took Sunday school classes, and volunteered for the Spastics Society (now Scope). “I was always worried about running out of things to do,” she told the British Library interviewer.
John died in 2012. Mary is survived by Andrew, Paul and Gillian, by three grandchildren, Grace, Jemma and John, and by Ruth.
• Mary Clare Coombs, computer programmer, born 4 February 1929; died 28 February 2022
