After listening to the most recent Planet Money podcast I learned the very moment that women stopped being interested in computers. It happened in 1984.
The commentators went back as far as the 1950s to find some women who were men’s equals in the computer world. This was a time when computers were programmed with the bare bones binary system of 0s and 1s. Some women put together a business and programmed mechanical language for major corporations like Raytheon.
As computers got more sophisticated and the language was able to get more advanced in the programming language of C, a wider range of programs emerged. Many of the program’s involved games to be play for fun like Pong or PacMan. More boys became interested and encouraged to play with computers at this point.
The focus of marketing got to the point that they targeted boys as the majority for purchases. They loved playing the games and hanging out at Radio Shack to see the latest tech. Girls were not involved with computers as much as the boys through 1980s. Even though there were a lot of girls who were just as good in math as boys.
So, as a result, boys tended to have more hands on experience before college than girls did. The computer education did not demand any experience with computers, but boys tended to have the experience which gave them an edge over the girls.
Eventually girls started to drop out in greater numbers from the computer education. It has taken them a long time to catch up to the level of males over the ensuing years.