Seconded, with part 2. I didn’t major in compsci, so I had never learned how computers work in any deep sense, and this was really eye opening. It takes you through how to build a cpu and then how a succession of binary instructions produces interesting behavior, and then how you can layer abstractions on top, like assembly language and stack operations, and then how to compile code down to those binary instructions and what has to happen at the OS level for this code to run.

It’s also opened my eyes to how much more I still have to learn!

You can do parts 1 and 2 at the same time, btw.