The ancestor of the RCX was the "programmable brick" project out of the MIT Media Lab in the mid-1990s

http://archive.pbrick.info/The%20MIT%20Programmable%20Brick%...

https://web.archive.org/web/20011212030110/http://fredm.www....

Growing up in New England at the time, I was very lucky that they ran a pilot project at my elementary school. We programmed our "sketches" (though we didn't use this term) in LogoWriter on Mac LC IIs and flashed them using a weird dongle that connected to the brick via RJ11 cable.

I owe a lot to my teachers and Fred Martin's group. I don't think I'd be a developer today without that experience.