Mary Coombs, first female business computer programmer, dies at 93
British programmer Mary Coombs (née Blood), the first woman to programme a computer for commercial use, died on 28th February 2022, at the age of 93.
Coombs was born on 4th February, 1929, in northwest London, to William and Ruth Blood.
She earned a BA Honors degree in French from Queen Mary University in London, and then took a temporary job at J. Lyons & Co, a tea shop operator and founder of the Wimpy burger chain.
Despite not having studied maths in school, her abilities led her to a job running a calculating machine at Lyons' Statistical Office.
Coombs excelled in Lyons' computer appreciation course - the only woman to take it - and earned a job offer in the company's nascent computer division.
There she worked with Frank Land on the Lyons Electronic Office (LEO) computer (the world's first computer designed solely for commercial use) from 1952 onwards.
The LEO occupied 5,000 square feet at the firm's headquarters at Cadby Hall in Hammersmith, and crunched its first numbers in November 1951.
The computer was built to automate the back office tasks for Lyons' national chain of 250 teashops and the sales of tea, cakes, and ice-cream. Its first job was to calculate the costs of the weekly bakery delivery run, which accounts clerks previously did manually.
Within two years, the machine was being used for the more sensitive task of payroll calculation.
Editor's note: I talked to Mary in September 2020 about her work with the LEO I. She said, "It wasn't calculating the hours worked, it was calculating the money due... But also there were bonuses to add on, there were deductions to take off like National Insurance and income tax, and you couldn't use the tax tables to take the income tax off because there wasn't room [in the computer's memory]... It was only 2 KB, that was the total storage for the LEO I.
"I think we got [the calculations] down to six seconds per employee... When you look at it the work was hours times rates, plus a bonus, which might have to be calculated as well, minus deductions and maybe something like sick pay or holiday pay to be added in- so we're talking several minutes per employee [to calculate it by hand]."
Coombs wrote test programmes for the LEO computer during her first months in Lyons' computer division. She worked on the LEO I, II and III and as a result of her expertise, she was given the task of rewriting the programmes from the LEO II for use on the LEO III.
She loved her work, describing it as "wildly exciting."
"If I hadn't enjoyed myself so much … I would have balked at the relatively low pay, you know … It was really great fun," she said.
She stopped her full-time programming role in 1964 due to family obligations, but continued to work part-time, editing computer manuals. She officially ended her association with the LEO team in 1969.
Along with programming the LEO, Coombs handled payroll at other firms, including the Ford Motor Company. She also worked on other projects, including Met Office work, tax tables for Inland Revenue, and the calculation of ballistics for the Army.
In 1955, she married programmer John Coombs, and they adopted Andrew, Paul and Gillian. John passed away in 2012, but he and Mary are survived by their children and three grandchildren.