Diff — Kay McNulty

**Kay McNulty** — born **Kathleen Rita McNulty** (12 February 1921 – 20 April 2006), later **Antonelli** and **Mauchly** — was an Irish-born American mathematician and one of the six original programmers of ENIAC.

McNulty was born in **Creeslough, County Donegal, Ireland**, and emigrated to Philadelphia as an infant on the night she was baptized — the family left so quickly the story became family legend. Raised in Chestnut Hill, she excelled in mathematics at **Chestnut Hill College**, graduating in 1942 — one of only a handful of math majors in her class.

Like most of the ENIAC six, she was recruited as a human "**computer**" by the Army's Ballistic Research Laboratory, grinding out artillery firing tables by hand — work she later described as mind-numbing. When the Army called for volunteers for a secret machine project in 1945, McNulty said yes without being told what the machine was. It was ENIAC.

On ENIAC, McNulty worked on the machine's function tables and program structure — she was particularly influential in developing **subroutines**: the idea that a block of wiring-and-switch logic could be invoked, reused, and checked as a unit. Debugging ENIAC's timing quirks — where a signal arriving a microsecond off produced garbage — was largely her territory.

In **1948** she married ENIAC's co-inventor **John Mauchly** (his second marriage; they had five children together) and continued working alongside him on the BINAC and [[UNIVAC_I|UNIVAC]] projects in a programming capacity — then later took up software for the next generation of Mauchly machines and taught programming at her own kitchen table.

- Inducted into the **Women in Technology International Hall of Fame** with the other five ENIAC programmers in **1997**.

- The digital-computer learning center at her Irish hometown's college is named for her — Donegal claims her back.

- She lived to see the ENIAC six publicly recognized, appearing in interviews and the documentary *The Computers* before her death in 2006.

- [[The first programmers]]

- [[History of Programming]]

1. Kleiman, Kathy. *Proving Ground: The Untold Story of the Six Women Who Programmed the World's First Modern Computer* (Grand Central, 2022).

2. Haigh, Thomas, Mark Priestley, and Crispin Rope. *ENIAC in Action: Making and Remaking the Modern Computer* (MIT Press, 2016).

3. Evans, Claire L. *Broad Band: The Untold Story of the Women Who Made the Internet* (Portfolio, 2018).

4. *Honeywell v. Sperry Rand*, 180 U.S.P.Q. 673 (D. Minn. 1973) — the ENIAC patent trial.

[[Category:History]]

[[Category:People]]