Historical essay
Women in Tech from ENIAC to MOM

Women in Tech from ENIAC to MOM

On September 24, as I enjoyed my second coffee of the morning and caught up on news, a photo caught my eye. In the image, women in colorful saris congratulated each other amidst massive computer monitors. The exuberance of the photo arrested me — as did the obvious techy setting, nerd that I am — but, sadly, what really drew my attention was the fact that these women seemed … out of place. And I wasn’t the only one drawn in by this image. The photo, snapped by AFP photographer Manjunath Kiran, quickly made the rounds on news outlets and social media.

The photo (reproduced in larger form below, attached to one of thousands of tweets) captured the moment on the 24th when the Indian Space Research Organization (ISRO) successfully put a satellite in orbit around Mars. The Mars Orbiter Mission (MOM) spacecraft, called Mangalyaan in Hindi, represents a handful of firsts: it’s India’s first Mars trip, it’s the first time any country made it there on the first try, and it makes India the first Asian country to successfully enter Mars’ orbit.

The photo represents something at once cheering and disappointing: cheering because it exemplifies women’s key roles in STEM fields, but disappointing as a reminder that there’s still so far to go. Too many news headlines still read “Women Do Science!” rather than “Scientists Send Satellite to Mars!” I’m being a touch hyperbolic here, I know. But it’s to make the point that, while I like seeing stories about women’s achievements in science, I look forward to a day when those stories can highlight the achievement rather than the gender (or clothing) of the scientist.

As fellow Nursing Clio author Carolyn Herbst Lewis discussed in Girls, STEM, and My List of “Ingenious Inventors,” women’s STEM contributions are consistently neglected, and this makes it difficult for girls and women “to envision themselves as scientists.” As she described, there are many great programs geared towards getting women and girls into STEM fields. Groups from local and national DIY maker labs to Google and the US Department of Education all run programs offering resources, activities, and role models. And as the wonderful comments on that post show, there are so many examples of women who’ve made enormous contributions to STEM fields! But these women’s stories still rarely make it into the curriculum, and despite all of the efforts women are still underrepresented in STEM across the board. According to statistics aggregated by the National Girls Collaborative Project, for example, women earned only 18% of all computer science degrees in 2013, and made up only 13% of the engineering workforce in 2014.

We still have a long way to go. In the meantime, we need to remember that women are not newcomers to STEM. In fact, the first programmers of the digital computer age most often were women.

Ada Lovelace portrait by Alfred Edward Chalon. (Source: Science & Society Picture Library, Licensed under Public domain via Wikimedia Commons.
Ada Lovelace portrait by Alfred Edward Chalon. (Source: Science & Society Picture Library, Licensed under Public domain via Wikimedia Commons.

The 30-ton Calculating Machine and the Women Who Made It Work

Any history of women in STEM should probably start with Ada Lovelace. Born in 1815, Ada King, Countess of Lovelace, befriended Charles Babbage in 1833 and brought her interest in machines and her training in mathematics (uncommon for women of her time) to bear on Babbage’s Analytical Engine. Her work with Babbage on the Engine — which he never built, but which had all the elements of a modern computer — included some of the first algorithms intended to run on a machine. For this, she’s been called both the “prophet of the computer age” and the world’s first programmer.

In the twentieth century, women also played a key role in the development of a machine called the Electronic Numerical Integrator And Computer (ENIAC), the first general purpose electronic computer.

ENIAC, built during World War II, started as a secret collaborative project between the US Army and the University of Pennsylvania Moore School of Electrical Engineering. Developed by J. Presper Eckert and John W. Mauchly, ENIAC would never have existed without a large support team that included six women selected to program the gargantuan machine.

When made public in 1946, however, the women responsible for making the hulking computer and its more than 17,000 temperamental vacuum tubes work largely disappeared from the story. And that didn’t change for quite some time. As Jennifer Light, a historian of science who uncovered this little-known history, noted, history has long valued hardware over programming, and the “achievements” of men over the “support” of women.[1] This sidelining of women’s roles in the project started in 1946 with images like this:

The classic shot of the ENIAC while still at the Moore School. The total processing power of the ENIAC can now fit on a chip about the size of a dime. (Source: US Army photo, Public domain, courtesy Harold Breaux. Historic Computers Images.)
The classic shot of the ENIAC while still at the Moore School. The total processing power of the ENIAC can now fit on a chip about the size of a dime. (Source: US Army photo, Public domain, courtesy Harold Breaux. Historic Computers Images.)

This photo, the most widely published image of the computer, accompanied a February 1946 New York Times article that hardly mentioned the women in the background. It described how ENIAC could complete in just 15 seconds an equation that would have taken a person several weeks. But it didn’t say how much time and effort it took the women programmers to physically set up the equation on the machine.[2] The women programmers, without whom the 40, 9-foot tall cabinets full of capacitors, switches, vacuum tubes, and wires would have been useless, went largely unrecognized for many years.

Women learning differential equations for calculating ballistic trajectories. The instructors included three men and nine women. (Source: Top Secret Rosies: The Female Computers of WWII.)
Women learning differential equations for calculating ballistic trajectories. The instructors included three men and nine women. (Source: Top Secret Rosies: The Female Computers of WWII.)

Light, in her fittingly titled 1999 article, “When Computers Were Women,” tells the story of the women without whom ENIAC may never have been. Her title references the fact that the electronic computers we’re so familiar with today took their name from a human job title. As Paul Ceruzzi said, before computers were machines, “computers were human.”[3] The computational work we depend on electronic computers for today used to be done by hand, by people called computers.

Before World War I, most computers were men, but by World War II the job had been feminized and most computers were women. During WWII, the US Army’s Ballistics Research Laboratory hired about 200 women to work as computers calculating ballistics trajectories for artillery. This was not easy work. It required solving complex differential equations to determine the arc a fired shell might take depending on various conditions. Each trajectory could take between 20 minutes and several days to complete. The resulting firing tables meant the difference between artillery hitting enemy soldiers, or your own.

The US Army agreed to fund the ENIAC project because it needed these firing tables faster than human computers could produce them. But ENIAC couldn’t run calculations by itself. A team of people needed to physically program equations into the machine. For that, the Moore School hired six of its human computers: Kathleen McNulty, Frances Bilas, Betty Jean Jennings, Ruth Lichterman, Elizabeth Snyder, and Marlyn Wescoff. These six women went from being computers themselves, to being “operators” of a mechanical computer — the first modern programmers.

“The eniac was a son of a bitch to program”[*]

Though engineers thought of it as “merely clerical” work, programming the ENIAC quickly turned out to be much more complicated. Jennifer Light quotes two of the original ENIAC programmers’ recollections of just how challenging the work was. Kathleen McNulty recalled that:

[gblockquote]”Somebody gave us a whole stack of blueprints, and these were the wiring diagrams for all the panels, and they said ‘Here, figure out how the machine works and then figure out how to program it.’ This was a little bit hard to do. So Dr. Burks … explain[ed] to us how the various parts of the computer worked, how an accumulator worked. Well once you knew how an accumulator worked, you could pretty well be able to trace the other circuits for yourself and figure this thing out.”[/gblockquote]

Betty Jean Jennings explained how she and the other programmers eventually

[gblockquote]”could diagnose troubles almost down to the individual vacuum tube. [Out of more than 17,000!] Since we knew both the application and the machine, we learned to diagnose troubles as well as, if not better than, the engineer.[4][/gblockquote]

The Rest of the Story

Here’s how the ENIAC story should have looked in 1946. These were the first programmers — called “operators” at the time — of the modern digital age. (Click any image for a slideshow.)

The Erasure

Part of Jennifer Light’s argument is that, as in other wartime industries, the ENIAC media campaign celebrated women’s participation, but defined programming as clerical, and therefore feminine, work. The media described women’s work on the ENIAC project as difficult, but at the same time classified them as subprofessional. This type of “feminization” in both computing and the sciences not only contributed to women’s invisibility, but also justified lower pay and lack of career advancement. As Light explains, leaders of the ENIAC project referred to the women operator/programmers most often as “ENIAC girls,” a collective erasing and diminution of their expertise.

This advertisement for Optical Scanning Corporation equipment disparaged women computer operators as inefficient and encouraged replacing them with new technology. (Source: "Researcher Reveals How "Computer Geeks" Replaced "Computer Girls," Gender News, 2011.)
This advertisement for Optical Scanning Corporation equipment disparaged women computer operators as inefficient and encouraged replacing them with new technology. (Source: “Researcher Reveals How “Computer Geeks” Replaced “Computer Girls,” Gender News, 2011.)

Others have looked at this history more extensively since the 1990s, and their accounts point to similar factors. With the end of the war, women were encouraged — and forced — to leave their war-time jobs, including projects like ENIAC. But, as Kathy Kleiman has noted, these first programmers were irreplaceable in the short term, and so a few stayed on as programmers and teachers, but without the professional prestige of later male programmers and software engineers. By the 1960s, according to Nathan Ensmenger, the “masculinization” of programming was in full swing. This process included disparaging women as computer operators, forming exclusive professional organizations, discouraging hiring women, and erecting educational and cultural barriers.

After more than half a century of this, the process is now so entrenched that the stereotype of computer science in particular, and STEM fields in general, as male domains is self-perpetuating.

Back To the Present

To return to the photograph that inspired this post, it’s unfortunate that, in all of the MOM news coverage, only a few reports highlighted women’s roles in the project. The work of women like deputy operations director Nandini Harinath and systems engineer Minal Sampath, whose team built three of the spacecraft’s high-tech instruments and who, according to the BBC, plans to be “the first woman director of a space centre,” went largely unreported.

Women still make up only about 10% of ISRO engineers, and 20% of NASA engineers. STEM fields, while no longer formally or informally closed to women, retain male-dominated work cultures and gender-biased (and race-biased) hiring and promotion practices. We need broad-based action to help make STEM fields welcoming to women. This includes funding for educational programs and resources, but it also requires changing a culture that makes girls feel like they don’t belong in these settings. The absence of histories about women’s influential roles in STEM fields, along with the continued under coverage of their achievements in the news today, powerfully shapes these trends.

So, on this Ada Lovelace Day, share this picture a few thousand more times (and maybe this post along with it) and help challenge the stereotype that women find science, technology, engineering, and math boring or too difficult. This isn’t the finish line, but it’s a great step in the right direction.


These issues showed up more in the news over the past few weeks, as Microsoft CEO Satya Nadella and speakers on the “Male Allies Plenary Panel” at the 2014 Grace Hopper Celebration of Women in Computing revealed more about the gender biased nature of the tech world than they probably meant to. As ReadWrite reported, Nadella advised women that “It’s not really about asking for a raise, but knowing and having faith that the system will give you the right raise.” He later retracted the statement, but not before exposing just how profoundly the tech sector misunderstands gender bias. And the “Male Allies” panel didn’t do much better. Selena Larson reported that “In essence, their advice to women was: Work harder, build great things, speak up for yourself, lean in.” In short: it’s up to women to work many times harder than their male colleagues, for less pay, in order to build up “karma” so their (male) bosses will notice them. And if this doesn’t happen, it’s their fault for not speaking up; even though, as we saw recently at the New York Times, being assertive doesn’t necessarily work. These are not solutions. Allies need to first and foremost acknowledge that male gender privilege exists whether they’ve “seen” it or not, and whether men intend it or not. It’s there. Beyond that, here are 10 suggestions from the NCWIT for how to be an advocate.

Further Reading

Rose Eveleth, “Computer Programming Used to Be Women’s Work,” Smithsonian, October 7, 2013.

Laura Sydell, “The Forgotten Female Programmers Who Created Modern Tech,” NPR, All Tech Considered, October 6, 2014.

Grace Hopper Celebration of Women in Computing.

Nathan L. Ensmenger, The Computer Boys Take Over: Computers, Programmers, and the Politics of Technical Expertise (Cambridge, MA: The MIT Press, 2010).

Computer History Museum, Birth of the Computer: ENIAC.

Walter Isaacson, The Innovators: How a Group of Hackers, Geniuses, and Geeks Created the Digital Revolution (Simon & Schuster, 2014).

Two documentaries:

  • Top Secret Rosies: The Female Computers of WWII, produced and directed by LeAnn Erickson and written by Cynthia Baughman (PBS Distribution, 2010).
  • The Computers, co-produced by Jon Palfreman (Co-writer), Kathy Kleiman (Co-writer), and Kate McMahon (Director) (First Byte Productions, 2014).


[*] Betty Jean Jennings, quoted in Alyson Sheppard, “Meet the ‘Refrigerator Ladies’ Who Programmed the ENIAC,” Mental Floss, October 13, 2013. Return to text.

  1. Jennifer S. Light, “When Computers Were Women,” Technology and Culture 40 (July 1, 1999): 455–83. Return to text.
  2. Light, “When Computers Were Women,” 474. Return to text.
  3. Paul E. Ceruzzi, “When Computers Were Human,” IEEE Annals of the History of Computing 13 (July-September 1991): 237-244. Return to text.
  4. Jennifer Light, “When Computers Were Women,” quoting Kathleen McNulty, p. 470, and Betty Jean Jennings, p. 471. Return to text.

Featured image caption: “Left: Patsy Simmers, holding ENIAC board Next: Mrs. Gail Taylor, holding EDVAC board Next: Mrs. Milly Beck, holding ORDVAC board Right: Mrs. Norma Stec, holding BRLESC-I board.” (Source: US Army Photo, number 163-12-62, Public domain, via Historic Computers Images of the ARL Technical Library.)

Adam Turner has a Master's degree in history from the University of Oregon and works as a web developer with a love of clean, standards-based markup and accessible, user-centered design.