I have been challenged in the past on here that I could not possibly have worked in IT in the 1970s - but we women were there at the start.
Absolutely there were plenty of women back then and I’m sorry previous posters have not believed you.
For decades, women were leaders in computer science but then, in 1984, their representation in the field dropped dramatically in a way unseen in any other scientific or technical field.
The first personal computers weren't much more than toys and they were marketed almost exclusively to boys and men. Computer geek culture also began to emerge during this period and TV shows, movies, and video games all reaffirmed that computers were the domain of boys.
By 1984, the first generation of students who could have had a home computer entered college. Research at the time found parents were much more likely to buy computers for boys than girls and many more boys had experience programming prior to entering college. As a result, many young women discovered that they were already significantly behind their male peers from day one and, often facing discouragement from their fellow students and professors alike, women left computer science programmes in droves.
Interestingly, prior to the introduction of the home computer and the gendered marketing of it as a 'boy' device, women were very active in the field and saw a sharp increase in their numbers between 1970 and 1984, just as you describe.
Their representation in the field peaked in 1982 when 37% of computer science degrees were awarded to women; by 2011, according to the Computing Research Association, that number fell to 12%.
For adult readers who would like to learn more about the unsung female heroes who built the Internet, I highly recommend “Broad Band" at www.amightygirl.com/broad-band
To introduce kids to the brilliant women who programmed the world's first all-electronic computer, I recommend the chapter book "Women Who Launched The Computer Age" for ages 6 to 8 www.amightygirl.com/women-launched-computer-age and the picture book “How a Team of Women Coded the Future” for ages 5 to 9 www.amightygirl.com/instructions-not-included
For an inspiring book about pioneering women in technology - which includes a variety of hands-on STEM projects that kids can try at home - I also highly recommend ‘Gutsy Girls Go for Science: Programmers’ for ages 8 to 11 at www.amightygirl.com/gutsy-girls-programmers