The ENIAC women: the first programmers history forgot
Six mathematicians wired the first general-purpose electronic computer, were left out of the celebration dinner, and waited fifty years for their names.
On February 14, 1946, the United States Army unveiled a machine the newspapers called a giant brain: ENIAC, the first general-purpose electronic computer — thirty tons, eighteen thousand vacuum tubes, a room-sized monster that could calculate a shell's trajectory faster than the shell flew. The demonstration dazzled the press: problems that took human calculators days ran in seconds. That night there was a celebratory dinner for the engineers and the brass.
The six people who had actually programmed the demonstration were not invited. Reporters who saw them working the machine assumed they were models posing for photos, and captions did not bother with their names. They were women — and for nearly half a century, the story of the first programmers of the first computer was simply left out of the story of the computer.
Who were they?
Kathleen McNulty, Frances Bilas, Betty Jean Jennings, Marlyn Wescoff, Ruth Lichterman, and Betty Snyder. They came to the job through a wartime door: with men drafted, the Army hired women mathematicians as human computers at the University of Pennsylvania, calculating artillery firing tables by hand and by desk calculator — one trajectory could take thirty hours of grinding arithmetic. Around eighty to a hundred women worked these calculations; the work was considered clerical, which tells you the era's opinion of it.
When the Army's secret electronic machine neared completion in 1945, six of the computers were picked to make it actually compute. The engineers, Presper Eckert and John Mauchly, had built the hardware. Turning a real problem into something the hardware could execute — that job had no name yet, no manuals, and no prestige. It would eventually be called programming.
What did programming the first computer actually involve?
Nothing like typing. ENIAC had no stored programs, no keyboard, no screens. Programming it meant physically rewiring the machine: setting thousands of switches and plugging hundreds of cables so that pulses flowed through the right units in the right order — closer to configuring a telephone exchange than writing code. The six were handed wiring diagrams, denied access to the classified hardware at first, and told to figure it out from blueprints. They did, teaching themselves the machine's logic so thoroughly that engineers came to them to locate failed vacuum tubes down to the individual tube.
They invented working methods programmers still recognize: breaking problems into steps, tracing execution by hand, and debugging — Betty Snyder among the first to hunt a program fault by halving the search space. The famous February demonstration ran a hydrogen-bomb-related calculation and a trajectory display finished by Snyder and Jennings the night before; the machine performed flawlessly, the engineers took the bows, and the women went home to make their own dinner while the celebration ran without them.
How were they forgotten — and found?
They stayed in the field, mostly, and kept building it. Betty Snyder Holberton wrote the input-output system for UNIVAC, the first commercial computer, helped design the instruction set, and created one of the first tools that translated code for humans — an ancestor of every programming environment since. Jean Jennings Bartik led hardware conversion of ENIAC to stored-program operation. Several worked on the languages that became COBOL and FORTRAN alongside Grace Hopper, the naval officer whose compilers taught computers to accept something like English.
Then the profession they founded changed gender. As programming gained status and salaries through the 1960s and 70s, it was redefined as men's work; the pioneers' names slid out of the textbooks. The photographs of women at ENIAC's panels were assumed, for decades, to show refrigerator ladies — models decorating the machine.
The rediscovery came embarrassingly late. A young researcher named Kathy Kleiman, told in the 1980s that the women in the photos were models, went and found them alive and unfamous. The six were finally inducted into Women in Technology's hall of fame in 1997 — more than fifty years after the demonstration. Jean Bartik, near the end of her life, put the whole story in one dry sentence: if the ENIAC's administrators had known how crucial programming would be, she said, they might have been more reluctant to give such an important role to women.
The machine got a museum. The engineers got the patents and the fame. The women got, eventually, the last word: every person who has ever debugged code at midnight is working a trade six uninvited women invented in a hot room in Philadelphia, one cable at a time.