The first programmers started out as "Computers." This was the name given by the Army to a group of over 80 women working at the University of Pennsylvania during World War II calculating ballistics trajectories - complex differential equations - by hand. When the Army agreed to fund an experimental project, the first all-electronic digital computer, six "Computers" were selected in 1945 to be its first programmers. They were Kathleen McNulty Mauchly Antonelli, Jean Jennings Bartik, Frances Snyder Holberton, Marlyn Wescoff Meltzer, Frances Bilas Spence and Ruth Lichterman Teitelbaum.
The ENIAC was the first all-electronic digital computer, a machine of approximately 18,000 vacuum tubes and forty black 8-foot panels. Because the ENIAC project was classified, the programmers were denied access to the machine they were supposed to tame into usefulness until they received their security clearances. As the first programmers, they had no programming manuals or courses, only the logical diagrams to help them figure out how to make the ENIAC work.
They had none of the programming tools of today. Instead, the programmers had to physically program the ballistics program by using the 3000 switches and dozens of cables and digit trays to physically route the data and program pulses through the machine. Therefore, the description for the first programming job might have read: "Requires physical effort, mental creativity, innovative spirit, and a high degree of patience."
On February 15, 1946, the ENIAC Computer was unveiled to the public and press. It ran the ballistics trajectory programmed by the six programmers and captured the world's imagination.
In 1947, the ENIAC was turned into a "stored program" computer, the world's first. Thus, these six programmers were the only generation of programmers to program it at the machine level.
All six women contributed to the programming the ENIAC. Many of these pioneer programmers went on to develop innovative tools for future software engineers and to teach others early programming techniques.
Marlyn Meltzer and Ruth Teitelbaum were a special team of ENIAC programmers. As "Computers" for the Army, they calculated ballistics trajectory equations painstakingly using desktop calculators, an analog technology of the time. Chosen to be ENIAC programmers, they taught themselves and others certain functions of the ENIAC and helped prepare the ballistics program. After the war, Ruth relocated with the ENIAC to Aberdeen, Maryland, where she taught the next generation of ENIAC programmers how to use the unique new computing tool.
Frances Spence and Kathleen Antonelli were a second ENIAC team. Both mathematics majors in the class of 1942 of Chestnut Hill College in Philadelphia, they responded to the Army's call for mathematicians and were assigned to operate the Differential Analyzer, a huge analog machine of which there were only a few in the world. Fran and Kay led the teams of women who used this machine to calculate the ballistics equations. After the war, both Fran and Kay continued with the ENIAC to program equations for some of the world's foremost mathematicians. Kay married Dr. John Mauchly who, together with J. Presper Eckert, invented the ENIAC and UNIVAC computers, and Kay worked with John on program designs and techniques for many years.
The third ENIAC programming team was comprised of Jean Bartik and Betty Holberton. As ENIAC programmers, they took on the challenging task of learning the Master Programmer that directed the performance of all program sequences of the ENIAC. They led the entire group in programming the ballistics trajectory for the February 14, 1946 demonstration, but that was only the beginning.
After the War, Jean Bartik worked on the team that converted the ENIAC into a stored program machine, making it easier and faster to program larger and more sophisticated problems. Jean then programmed the BINAC, designed logic for UNIVAC I, designed an electrostatic memory backup system for UNIVAC I, and later, developed reports to help businesses understand a powerful new class of computers, the microcomputer. She worked tirelessly to make computers easier to use.
After programming the ENIAC, Betty Holberton joined the company founded by Eckert and Mauchly and worked on the first commercial computers. She wrote the C-10 instruction code for UNIVAC I, forever making programming easier and faster for programmers. She designed the control console for UNIVAC I and its computer keyboards and numeric keypad. In 1952, she designed the first sort merge generator for UNIVAC I. She served on the COBOL committee to design the first business language to operate across computer platforms, wrote standards for FORTRAN and served on national and international computer standards committees for decades.
ENIAC Programmers @ WITI New York Network Meeting
Women in Technology Hall of Fame Induction Ceremony