Go figure – Brian Maye on Donegal computer pioneer Kay McNulty

An Irishman’s Diary

A young woman from the Donegal Gaeltacht was at the centre of the development of computer technology but her major contribution was sadly not recognised until much later in her life. Her name was Kay McNulty and she was born 100 years ago on February 12th.

Her birthplace was Feymore, near Creeslough, and she was the third of six children of James McNulty and Anne Nelis.

Her father, who was active in the independence struggle and suffered imprisonment, rejected the Anglo-Irish Treaty and took his family to Philadelphia, where he established a successful construction business, working with John B Kelly, father of Grace, the future actress and princess.

Kay had to learn English in America before attending school as her family had been Irish speaking (she remembered her prayers in Irish for the rest of her life).


She shone at school, especially at maths, and won a scholarship to Chestnut Hill College, from where she graduated, majoring in maths.

America was by then involved in the second World War; with the army greatly needing mathematicians to do ballistics calculations and due to a shortage of men, McNulty was among a group of women recruited to work at the University of Pennsylvania. Working with hand-operated calculators and whatever tables were available, they were given the title "computers".

It is well known that war greatly accelerates technology and McNulty and a colleague were trained to use a newly developed differential analyser machine, which could do quicker calculations.

Meanwhile, the army was rapidly working on a much more sophisticated machine, which could use electrical circuits to do calculations, and in June 1945 McNulty and four other women were selected to work on this room-sized Electronic Numerical Integrator and Computer (ENIAC). Her future husband, the physicist John Mauchly, was one of the machine's creators.

McNulty and her colleagues were employed to write a programme for the new machine.

Essentially, they had to teach themselves how to do it; as her entry in the Dictionary of Irish Biography explains, the women “devised the processing routines that enabled the machine to carry out calculations, more or less establishing the ways in which artificial intelligence subsequently developed”. They were enormously successful, cutting the time of calculating trajectories from 30 or 40 hours to four calculations per minute.

When the ENIAC was launched as the first general-purpose electronic digital computer in February 1946, making business and scientific interests greatly excited about its potentialities, the women programmers were treated as mere hostesses, and it would be 40 years or more before their vital role received recognition.

A year later, McNulty married Mauchly, much to the upset of her absent parents because he was non-Catholic, 14 years her senior and with two children from his first marriage (his first wife had drowned in 1946). She became stepmother to them and had five children of her own, four of whom suffered from a chronic hereditary illness from which her husband suffered.

Her paid scientific work ended on her marriage and it’s hard to be definite about her subsequent contributions to advancements in computer technology. Her husband’s company pioneered the development of the first commercial computer, and she no doubt assisted him in many ways, but there were many legal disputes over patents and with business partners; McNulty felt bitter about how Mauchly was treated and always strongly defended his central role in computer development.

He died in 1980 and in 1985 she married Severo Antonelli, a photographer, with whom she enjoyed travel and socialising. He died in 1995.

By this time, her contributions and achievements had come to be finally recognised and she was in widespread demand to address events and conferences to explain the role women had played in the birth of information technology, which she did very skilfully and effectively. She did a lecture tour of Ireland in 1999, during which a film documentary called "Oh Kay Computer" was made about her. She returned to Creeslough and met many of her relatives there. Letterkenny Institute of Technology introduced the Kay McNulty Mauchly Antonelli Medal as an annual award to a computer-science student.

In 1997, she and the women who programmed the ENIAC were inducted into the Women in Technology International Hall of Fame. She died in Pennsylvania on April 20th, 2006, at the age of 85. Dublin City University named a computer-science building after her in 2017.

The little three-year-old native Irish speaker from the tiny townland in the Donegal Gaeltacht had travelled a remarkable journey to be at the cutting edge of a technology that has transformed all our lives.