Cicely Mary Williams (; 29 October 192020 June 1995) was a British software engineer who worked with

Alan Turing Alan Mathison Turing (; 23 June 1912 – 7 June 1954) was an English mathematician, computer scientist, logician, cryptanalyst, philosopher and theoretical biologist. He was highly influential in the development of theoretical computer ...

on the

Manchester Mark 1 The Manchester Mark 1 was one of the earliest stored-program computers, developed at the Victoria University of Manchester, England from the Manchester Baby (operational in June 1948). Work began in August 1948, and the first version was operat ...

computer.

Early life and education

Popplewell was born on 29October 1920 in

Bramhall Bramhall is a large village in the Metropolitan Borough of Stockport, Greater Manchester, England. At the 2021 census, the built-up area as defined by the Office for National Statistics had a population of 17,195. Bramhall was formerly a civi ...

Stockport Stockport is a town in Greater Manchester, England, south-east of Manchester, south-west of Ashton-under-Lyne and north of Macclesfield. The River Goyt, Rivers Goyt and River Tame, Greater Manchester, Tame merge to create the River Mersey he ...

, England. Her parents were Bessie (née Fazakerley) and Alfred Popplewell, a chartered accountant. She attended Sherbrook Private Girls School at

Greaves Hall Greaves Hall was a country house on the outskirts of Banks, Lancashire, Banks in Lancashire, England, built in a Tudorbethan style for Sir Thomas Scarisbrick, 1st Baronet, Thomas Talbot Leyland Scarisbrick in 1900. History Thomas Scarisbrick born ...

Lancashire Lancashire ( , ; abbreviated ''Lancs'') is a ceremonial county in North West England. It is bordered by Cumbria to the north, North Yorkshire and West Yorkshire to the east, Greater Manchester and Merseyside to the south, and the Irish Sea to ...

. She studied the

Mathematical Tripos The Mathematical Tripos is the mathematics course that is taught in the Faculty of Mathematics, University of Cambridge, Faculty of Mathematics at the University of Cambridge. Origin In its classical nineteenth-century form, the tripos was a di ...

at the

University of Cambridge The University of Cambridge is a Public university, public collegiate university, collegiate research university in Cambridge, England. Founded in 1209, the University of Cambridge is the List of oldest universities in continuous operation, wo ...

where she worked with statistics in the form of

punched card A punched card (also punch card or punched-card) is a stiff paper-based medium used to store digital information via the presence or absence of holes in predefined positions. Developed over the 18th to 20th centuries, punched cards were widel ...

s. She was considered an expert in the

Brunsviga Brunsviga was a calculating machine company whose history goes back to 1892. They produced mechanical calculators, hand operated but later also electrically driven. The firm Grimme, Natalis & Co that manufactured the machines changed their name ...

desk calculator. She graduated with a

Bachelor of Arts A Bachelor of Arts (abbreviated B.A., BA, A.B. or AB; from the Latin ', ', or ') is the holder of a bachelor's degree awarded for an undergraduate program in the liberal arts, or, in some cases, other disciplines. A Bachelor of Arts deg ...

degree in 1942, which was converted to a

Master of Arts A Master of Arts ( or ''Artium Magister''; abbreviated MA or AM) is the holder of a master's degree awarded by universities in many countries. The degree is usually contrasted with that of Master of Science. Those admitted to the degree have ...

degree in 1949 from

Girton College, Cambridge Girton College is a constituent college of the University of Cambridge. The college was established in 1869 by Emily Davies and Barbara Bodichon as the first women's college at Cambridge. In 1948, it was granted full college status by the un ...

Career

In 1943 she was a Technical Assistant in the Experimental Department at

Rolls-Royce Rolls-Royce (always hyphenated) may refer to: * Rolls-Royce Limited, a British manufacturer of cars and later aero engines, founded in 1906, now defunct Automobiles * Rolls-Royce Motor Cars, the current car manufacturing company incorporated in ...

Ltd. and joined the

Women's Engineering Society The Women's Engineering Society is a United Kingdom professional learned society and networking body for women engineers, scientists and technologists. It was the first professional body set up for women working in all areas of engineering, pred ...

. In 1949 Popplewell joined

in the Computer Machine Learning department at the

University of Manchester The University of Manchester is a public university, public research university in Manchester, England. The main campus is south of Manchester city centre, Manchester City Centre on Wilmslow Road, Oxford Road. The University of Manchester is c ...

to help with the programming of a prototype computer. At first she shared an office with Turing and

Audrey Bates Audrey Glenys Bates (4 April 1922 – 21 November 2001) was a Welsh international athlete in four sports for Wales: table tennis, tennis, squash and lacrosse. She as inducted into the Welsh Sports Hall of Fame posthumously in 2002. Biograph ...

, a

mathematics graduate. Her first role was to create a library for the prototype

. This included input/output routines and mathematical functions, and a reciprocal square root routine. She worked on ray tracing. She wrote the first versions of sections of the subroutines for functions like

COSINE In mathematics, sine and cosine are trigonometric functions of an angle. The sine and cosine of an acute angle are defined in the context of a right triangle: for the specified angle, its sine is the ratio of the length of the side opposite that ...

. Together they designed the programming language for the

Ferranti Mark 1 The Ferranti Mark 1, also known as the Manchester Electronic Computer in its sales literature, and thus sometimes called the Manchester Ferranti, was produced by British electrical engineering firm Ferranti Ltd. It was the world's first commer ...

. She wrote the ''Programmers Handbook'' for the

in 1951, reworking Turing's programming manual to make it comprehensible. Whilst Turing worked on Scheme A, an early

operating system An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ...

, Popplewell proposed Scheme B, which allowed for decimal numbers, in 1952. Popplewell went on to become an advisor and administrator in the newly formed University of Manchester Computing Service where she was remembered as a 'universally liked' mother-figure. She left the Service in the late 1960s shortly before her marriage. Popplewell taught the first ever programming class in

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

at the

University of Buenos Aires The University of Buenos Aires (, UBA) is a public university, public research university in Buenos Aires, Argentina. It is the second-oldest university in the country, and the largest university of the country by enrollment. Established in 1821 ...

in 1961. Her class there included the computer scientist

Cecilia Berdichevsky Cecilia Berdichevsky or Berdichevski (; 30 March 1925 – 20 February 2010) was an Argentine computer scientist. She began her work in 1961 using the first Ferranti Mercury computer in that country. Biography She was born Mirjam Tuwjasz

. She was supported by the

British Council The British Council is a British organisation specialising in international cultural and educational opportunities. It works in over 100 countries: promoting a wider knowledge of the United Kingdom and the English language (and the Welsh lang ...

. Popplewell published the textbook ''Information Processing'' in 1962. Her life was documented in Jonathan Swinton's 2019 book ''Alan Turing’s Manchester.''

Personal life

In 1969 Popplewell married George Keith Williams in

Chapel-en-le-Frith Chapel-en-le-Frith () is a town and civil parish, in the Borough of High Peak, Derbyshire, England. It has been dubbed the "Capital of the Peak", in reference to the Peak District, historically the highland areas between the Saxon lands (below ...

. She died on 20June 1995 at Stockport Infirmary, Stockport. The funeral service was held on 27June 1995 at St John's church, Buxton, followed by a private cremation.

References

{{DEFAULTSORT:Popplewell, Cicely 1920 births 1995 deaths Academics of the University of Manchester Alumni of Girton College, Cambridge British computer scientists British mathematicians British women computer scientists People from Bramhall Women's Engineering Society Academic staff of the University of Buenos Aires