PROVING GROUND: The untold story of the six women who programmed the world’s first supercomputer. By Kathy Kleiman. Grand Central Editions. 320 pages. $30.
When the world’s first general-purpose programmable electronic computer, known as the ENIAC, made its debut in 1946, great fanfare was given to the men who created it, John Mauchly and J. Presper Eckert Jr., between others.
But little attention has been paid to six women who played big roles behind the scenes, spending months figuring out how to program the computer with little more than schematics of the huge, complicated machine.
In “Proving Ground,” author Kleiman sets out to rectify that, tracking down four of the six women for interviews and restoring them all to their rightful place in history. She tells how six young women from different walks of life and parts of the United States – Kathleen McNulty, Frances Bilas, Frances Elizabeth Synder, Marlyn Wescoff, Ruth Lichterman and Betty Jean Jennings – were enlisted to create the first computer program for ENIAC.
The women came together after a shortage of male mathematicians during World War II prompted the military to seek women, publishing a notice in the newspapers: ‘Looking for female math majors’ and s’ addressing university campuses.
Mathematicians were needed to calculate ballistic trajectories at a Philadelphia branch of the Army Ballistics Research Laboratory based at Aberdeen Proving Ground in Aberdeen, Maryland.
The women used mechanical desktop computers – large machines with raised knobs and gears – to perform analog calculations for ballistic trajectories that took into account variables such as distance, humidity, shell weight and d other factors. Computing a trajectory can take 30 to 40 hours.
In their spare time, the women became close friends, exploring Philadelphia’s movie theaters and parks and attending dances held for soldiers stationed nearby.
Meanwhile, the military was building a top-secret electronic computer aimed at speeding up calculations, called the Electronic Numerical Integrator and Computer, or ENIAC. When completed, it was 8 feet high, 80 feet wide, laid out in a U-shape, and filled with vacuum tubes, cables, wires, and switches.
As experts in ballistic trajectories, the “ENIAC 6” were tasked with creating a program allowing the ENIAC to perform the same calculations that they had performed with the desk calculators. But without an instruction manual for ENIAC or existing programming languages, they had to invent the program on their own. They succeeded in creating an ENIAC program that reduced the speed of calculating trajectories from 30 to 40 hours to a lightning speed of 20 seconds.
While early female programming pioneers Ada Lovelace and Grace Hopper took their place in the annals of computer history, Kleiman shows us that there were other female programmers – like ENIAC 6 – who also deserve recognition.