What was it like to program ENIAC? There’s a simulator to let you try it for yourself.

The Video

I recently watched a great video on how ENIAC was actually programmed. This was part of a 75th anniversary of the first general-purpose electronic computer. Lots of great details like the lack of any bulk storage; only the 20 accumulators could hold changing values. Everything else was either Control or ROM (in modern terms).

You can see why it took a lot of brain power to create programs for it. Trying to solve sets of differential equations, using numerical methods, with only 20 “variables” is an exercise in puzzle-solving. (I wonder how ChatGPT would do at writing a correct, working ENIAC program?)

Watch it on YouTube

But, Wait! There’s More!

The speaker, Brian L. Stuart, has much more to offer on his web site, including the simulator he demonstrates in the video. In the near term, I’ll be reading his papers on “Programming ENIAC”, “Debugging ENIAC”, and “Simulating ENIAC”. I’d put links here, but it requires an account with the IEEE to access. Fortunately, my work provides that, as do most University libraries.