Cicely Mary Williams (née Popplewell) 29 October 1920 – 20 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. Turing was highly influential in the development of theoretical c ...

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 29 October 1920 in Stockport, 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 in Lancashire, England, built in a Tudorbethan style for Thomas Talbot Leyland Scarisbrick in 1900. History Thomas Scarisbrick born in 1874, built Greaves Hall in 1900 on a 124-acre (0.5 ...

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

. She studied the

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

at the

University of Cambridge , mottoeng = Literal: From here, light and sacred draughts. Non literal: From this place, we gain enlightenment and precious knowledge. , established = , other_name = The Chancellor, Masters and Schola ...

where she worked with statistics in the form of

punched card A punched card (also punch card or punched-card) is a piece of stiff paper that holds digital data represented by the presence or absence of holes in predefined positions. Punched cards were once common in data processing applications or to di ...

s. She was considered an expert in the

Brunsviga The Odhner Arithmometer was a very successful pinwheel calculator invented in Russia in 1873 by W. T. Odhner, a Swedish immigrant. Its industrial production officiallyTrogemann G., Nitussov A.: ''Computing in Russia'', page 39-45, GWV-Vieweg, ...

desk calculator. She graduated with a

Bachelor of Arts Bachelor of arts (BA or AB; from the Latin ', ', or ') is a bachelor's degree awarded for an undergraduate program in the arts, or, in some cases, other disciplines. A Bachelor of Arts degree course is generally completed in three or four yea ...

degree in 1942, which was converted to a

Master of Arts A Master of Arts ( la, Magister Artium or ''Artium Magister''; abbreviated MA, M.A., AM, or A.M.) 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. ...

degree in 1949 from

Girton College, Cambridge Girton College is one of the 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 1948, it was granted full college statu ...

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 ...

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 owns and operates majo ...

to help with the programming of a prototype computer. At first she shared an office with Turing and Audrey Bates, 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. 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, software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ef ...

, 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 ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, t ...

at the

University of Buenos Aires The University of Buenos Aires ( es, Universidad de Buenos Aires, UBA) is a public research university in Buenos Aires, Argentina. Established in 1821, it is the premier institution of higher learning in the country and one of the most prestigi ...

in 1961. Her class there included the computer scientist

Cecilia Berdichevsky Cecilia Berdichevsky or Berdichevski (née Tuwjasz) (1925 – 2010) was a pioneering Argentinian computer scientist and 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 la ...

. Popplewell published the textbook ''Information Processing'' in 1962. Her life was documented in

Jonathan Swinton Jonathan may refer to: * Jonathan (name), a masculine given name Media * ''Jonathan'' (1970 film), a German film directed by Hans W. Geißendörfer * ''Jonathan'' (2016 film), a German film directed by Piotr J. Lewandowski * ''Jonathan'' (2018 ...

'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 in Derbyshire, England. It has been dubbed the "Capital of the Peak", in reference to the Peak District, historically the upperland areas between the Saxon lands (bel ...

. She died in 1995 in

Buxton Buxton is a spa town in the High Peak, Derbyshire, Borough of High Peak, Derbyshire, England. It is England's highest market town, sited at some above sea level.British women computer scientists Alumni of Girton College, Cambridge Academics of the University of Manchester 1920 births 1995 deaths People from Stockton-on-Tees British mathematicians British computer scientists Women's Engineering Society