Jean Bartik

Jean Bartik was a foundational figure in the history of computer science.

As one of the original six programmers for the ENIAC, she helped define how humans communicate with machines. The ENIAC, or Electronic Numeric Integrator and Computer, was one of the first large-scale electronic computers ever built. Bartik was a member of the "Sensational Six," a group of women who pioneered the discipline of digital programming. Their work transformed computing from a manual process into a sophisticated science. By developing early methods of instruction, they paved the way for the modern digital age.

Programming the ENIAC was a physical and highly technical process. Because it was the first computer of its kind, no manuals or textbooks existed to guide the users. The programmers had to teach themselves by studying complex schematic diagrams of the machine's hardware. They also interviewed the engineers who had built the device to understand its inner workings. To input instructions, the women had to physically modify the machine. They moved switches and rerouted heavy cables to set up specific mathematical problems. This hands-on approach required a deep understanding of how electricity moved through the system.

During this era, the team developed several fundamental programming techniques that are still used today. They created subroutines, which are small, reusable segments of code. They also utilized nesting, a method where one instruction is placed inside another. Bartik and her colleague Betty Holberton were particularly skilled at these tasks. They even expanded the machine's capabilities to handle Los Alamos nuclear calculations. Their success was proven during a public demonstration on February 15, 1946. This event showed that the ENIAC could complete in 20 seconds what would take a human computer 40 hours to finish.

One of Bartik's most significant technical achievements was converting the ENIAC into a stored program computer. Before this change, the machine had to be physically rewired for every new task. By March 1948, Bartik led a team that allowed the computer to hold its instructions in its own memory. This conversion made the machine much more efficient and accurate. It allowed the ENIAC to assist with complex wind tunnel programs for researchers. This transition from manual wiring to stored instructions was a massive leap forward for technology.

Bartik's career continued through the development of several other landmark machines. She worked with the original ENIAC designers, John Eckert and John Mauchly, on the BINAC and the UNIVAC. The BINAC was notable for being the first computer to use magnetic tape instead of punch cards for data storage. It also utilized a unique twin unit concept. Later, Bartik played a vital role in designing the logic circuits for the UNIVAC. The UNIVAC was a crucial machine because it helped launch the commercial computer industry. She even co-programmed the first generative programming system, known as SORT/MERGE.

Jean Bartik's early life in Missouri shaped her mathematical talent. Born Betty Jean Jennings in 1924, she was the sixth of seven children. She graduated from Northwest Missouri State Teachers College in 1945. She was the only student in her class to earn a mathematics degree. During World War II, the U.S. Army recruited mathematicians to calculate ballistics trajectories. While she initially did these calculations by hand, she eventually transitioned to using the ENIAC. This move from manual calculation to electronic computing marked the beginning of her historic career.

For many years, the contributions of the ENIAC programmers remained largely unrecognized. Much of the credit for the machine's success was given to its male engineers. However, researchers like Kathy Kleiman began uncovering the truth in the 1980s. Kleiman identified the women and recorded their oral histories to preserve their stories. This work helped the world realize that these women had essentially invented digital programming. Today, Bartik is celebrated as a pioneer. Her legacy lives on in the technology we use and in the honors named after her, such as the Bartik theme in Drupal software.