Margaret Marrs (née Lewin; born 1929) is an English computer programmer who was the Senior Operator of the original Electronic delay storage automatic computer (EDSAC). EDSAC was an early British computer constructed at the

University of Cambridge Mathematical Laboratory The Department of Computer Science and Technology, formerly the Computer Laboratory, is the computer science department of the University of Cambridge. it employed 35 academic staff, 25 support staff, 35 affiliated research staff, and about 15 ...

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

, and the second electronic digital

stored-program computer A stored-program computer is a computer that stores program instructions in electronically or optically accessible memory. This contrasts with systems that stored the program instructions with plugboards or similar mechanisms. The definition i ...

to go into regular service.

Education

Born in

Lancashire Lancashire ( , ; abbreviated Lancs) is the name of a historic county, ceremonial county, and non-metropolitan county in North West England. The boundaries of these three areas differ significantly. The non-metropolitan county of Lancashi ...

, Marrs grew up in a village called Simonstone. She attended the

Clitheroe Royal Grammar School ; "Founded on Rock" , established = , closed = , type = Grammar school;Academy , religious_affiliation = , president = , head_label = Headteacher , head = James Keulemans , r_head_label = Deputy He ...

where she completed maths, Latin, and French as her Higher School Certificate subjects. She studied maths at the

Girton College Girton College is one of the Colleges of the University of Cambridge, 31 constituent colleges of the University of Cambridge. The college was established in 1869 by Emily Davies and Barbara Bodichon as the first women's college in Cambridge. In 1 ...

Cambridge Cambridge ( ) is a university city and the county town in Cambridgeshire, England. It is located on the River Cam approximately north of London. As of the 2021 United Kingdom census, the population of Cambridge was 145,700. Cambridge bec ...

, graduating in 1948.

Career

In 1951, Marrs worked as a computer programmer for

Ferranti Ferranti or Ferranti International plc was a UK electrical engineering and equipment firm that operated for over a century from 1885 until it went bankrupt in 1993. The company was once a constituent of the FTSE 100 Index. The firm was known ...

, a UK

electrical engineering Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems which use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the l ...

and equipment firm based in

Manchester Manchester () is a city in Greater Manchester, England. It had a population of 552,000 in 2021. It is bordered by the Cheshire Plain to the south, the Pennines to the north and east, and the neighbouring city of Salford to the west. The t ...

. Her work focused on adapting 39

differential equation In mathematics, a differential equation is an equation that relates one or more unknown functions and their derivatives. In applications, the functions generally represent physical quantities, the derivatives represent their rates of change, an ...

s for automatic computers. She accomplished this by working from a paper published in the late 1940s by

Stanley Gill Professor Stanley J. Gill (26 March 1926 – 1975) was a British computer scientist credited, along with Maurice Wilkes and David Wheeler, with the invention of the first computer subroutine. Early life, education and career Stanley Gill was bor ...

, adapting the Runge–Kutta method of solving differential equations for automatic computers. In 1952, Marrs returned to

where she was employed by

as the Senior Operator for EDSAC. Her job included punching tape into the computer to run programs. In 2016, Marrs and other former EDSAC computer scientists, including Joyce Wheeler and Liz Howe, assisted the

National Museum of Computing The National Museum of Computing is a museum in the United Kingdom dedicated to collecting and restoring History of computing hardware, historic computer systems. The museum is based in rented premises at Bletchley Park in Milton Keynes, Bucki ...

's efforts to recreate the EDSAC by providing information on the EDSAC's machinery. Marrs and other EDSAC veterans visited the reconstruction team to celebrate the 70th anniversary of EDSAC.

References

{{DEFAULTSORT:Marrs, Margaret 1929 births Living people People educated at Clitheroe Royal Grammar School Alumni of Girton College, Cambridge British women computer scientists 20th-century British women scientists