ENIAC Programmers– The Unsung Women in Tech

Kathy Kleiman, Jean Bartik, Marlyn Meltzer, Kay Antonelli, Betty Holberton  Image Courtesy: eniacprogrammers.org

Kathy Kleiman, Jean Bartik, Marlyn Meltzer, Kay Antonelli, Betty Holberton

Image Courtesy: eniacprogrammers.org

What is ENIAC:

The ENIAC (Electronic Numerical Integrator and Computer) was basically the heavier predecessor to the computers and laptops used in today’s world.

This clunky computer was revealed after World War II. Mr. John Mauchly unveiled it in sci-fi fashion which caught the public’s attention.  

The ENIAC was used in World War II for calculating artillery trajectories. The ENIAC was quite a heavy computer. About 18,000 vacuum tubes were used in this machine. It was 1000 times faster than other developed machines during WWII and 2,400 times faster than a human brain for calculating the trajectory. The programming was done by setting 1,200 10-way switches on each portable function table.

Reason For Forming The ENIAC Programmers Team

After World War II, there was a shortage of male engineers in the United States. Consequently, the US Army posted the job positions for women who would be able to manually calculate the artillery trajectories. Mauchly assembled a team of six brilliant women; Jean Jennings, Marlyn Wescoff, Ruth Lichterman, Betty Snyder, Frances Bilas, and Kay McNulty who were given a title of ‘The ENIAC Programmers’.

Jennings recalls the time when she joined the team:

I had no idea what the job was or what the ENIAC was? All I knew was that I might be getting in on the ground floor of something new, and I believed I could learn and do anything as well as anyone else
Image Courtesy: U.S. Army

Image Courtesy: U.S. Army

These women got a detailed training for six weeks at the Army base. After the completion of training, they were provided with the blueprints to the ENIAC and the wiring diagrams for all the panels. The group was told to work out how this machine works and find out how it could be programmed.

The Success of ENIAC Programmers

It was not a simple task to program the ENIAC. It required the analyzation of differential equations. The sextets needed to figure out how to patch the cables so the cables could be connected to the right electronic circuits. It also required the setting up of thousands of 10-way switches. These brilliant women hand-wired the machine for routing the data and program pulses by using cables, switches, and digital trays. This was a strenuous task which was perfectly completed by this group of women. They programmed the ENIAC without using any programming tool or languages. Once they completed programming the ENIAC, it was able to run a ballistics trajectory within seconds.  

Through their hard work, team collaboration and continuous effort, the sextets gained the trust of the ENIAC engineers and the mentorship of John Mauchly.  

Their major task was to develop different concepts such as subroutines and nesting which they accomplished successfully.

The Team of Six Women Worked in Pairs

First four (ENIAC board is on the left)  Image Courtesy: U.S. Army

First four (ENIAC board is on the left)

Image Courtesy: U.S. Army

After the end of World War II, the ENIAC programmer team kept on working. They became such experts in their work that they were not replaced when the male soldiers returned from the War. However, the sextets were forgotten and not appreciated for their work until the mid-1980s.  

They were rediscovered by Kathy Kleiman,s a young computer programmer. She saw an old picture of the ENIAC and she asked about the women in the picture.  A representative at the Computer History Museum told her that they were models for making the product look better. She did her own research and found out the history of the ENIAC programmers. She then started a project “ENIAC Programmers Project” in which she found out the truth of the forgotten ENIAC programmers.


One of the team members, Jennings, recalls her experience:

Since we knew both the application and the machine, we learned to diagnose troubles as well as, if not better than, the engineers. I tell you, those engineers loved it. They could leave the debugging to us.

Despite these six women hailing from different backgrounds, they became close friends and worked together well.  Snyder was a Quaker, Wescoff and Lichtermann were Jews, McNulty was a Catholic, whereas Jennings was a Protestant.

While giving an interview, Jennings talks about the diversity in their team:

We had a wonderful time with each other, mainly because none of us had ever been in close contact with anyone from one of the others’ religions. We had some great arguments about religious truths and beliefs. Despite our differences, or perhaps because of them, we really liked one another.
ENIAC Team  Image Courtesy: eniacprogrammers.org


Image Courtesy: eniacprogrammers.org

Tayyaba Qamar