Irish Culture & Heritage

Kay McNulty – the Technological Warrior of WW11

When you think of computer legends, no doubt names like Bill Gates, Steve Jobs and Tim Berners-Lee come to mind, but an Irish woman, Kay McNulty was one of the very first computer programmers in the world long before they were born.

Kathleen (Kay) was born in County Donegal in 1921 and emigrated as a child with her parents to America in search of a better life. Kay lived and went to school in Philadelphia. In 1942, she graduated with a degree in mathematics and found a job with the US Army. Her job was to work out the ballistic trajectories for a range of weapons. America was involved in the second world war at the time. This proved very challenging work, but after much trial and error, Kay and the team learned how to make fairly accurate calculations.

Kay moved on to using a mechanical calculator, one of only six in the world, to work out the trajectories. This significantly reduced the time needed for the  calculations.

After the war, Kay was chosen as one of the first computer programmers to learn the binary code that directed early computers to carry out instructions in the correct sequence. Much of this work was top secret and it was only when a documentary called ‘Top Secret Rosies: The Female ‘Computers’ of WWII’, was released in 2010, that Kay’s contribution to the war effort was fully recognised.

In 2017, Dublin University honoured Kay McNulty by naming a new building after her. In 2019, the National University of Ireland in Galway named their supercomputer ‘Kay’ following a public poll – fitting tributes to a brilliant mathematician. Sadly, Kay died in 2006, never knowing that her achievements would receive such public acclaim.