Programming Pioneers
In 1943, the U.S. Army funded a team at the University of Pennsylvania in Philadelphia to build an electronic computer that could overcome existing technological barriers to perform firing table calculations needed during World War II. The computer was called the Electronic Numerical Integrator and Computer, or ENIAC for short.
Left side of the ENIAC, U.S. Army Research Laboratory.
Close-up view of the ENIAC, 1947, Fortune Magazine.
The ENIAC Programmers
The ENIAC could not store equations and required physical programming to work. In June 1945, Kathleen Antonelli, Jean Bartik, Betty Holberton, Marlyn Meltzer, Frances Spence, and Ruth Teitelbaum were selected to program the ENIAC. They became known as the ENIAC Six.
ENIAC programming chart showing the wiring required to set up a ballistic equation, Columbia University.
Programming Breakthrough
Programming the ENIAC was complicated and required great innovation. The ENIAC Six figured out how to break down mathematical calculations into steps and convert them into programs. They discovered how to manually adjust the ENIAC's switches and cables to execute these programs, which allowed the ENIAC to be rewired for each new program. Through their pioneering contributions, the ENIAC became the world's first re-programmable electronic computer when it was introduced to the public in February 1946.
Excerpt of 2008 interview with Jean Bartik regarding the process for programming the ENIAC, 2008, Computer History Museum.
Marlyn Meltzer and another programmer wiring the ENIAC, Columbia University.
Three programmers setting switches on the ENIAC, Fortune Magazine.
Even though the ENIAC was completed too late to be used during World War II, it supported many scientific projects for the United States government. One of its first tasks was to perform calculations for the design of the hydrogen bomb. The ENIAC was also used for weather prediction and wind tunnel design. The ENIAC was retired in 1955.