

I will always recommend Ben Eater’s breadboard computer 6502 project for anyone who wants to know how it works. The 8-bit breadboard computer project as the next step too, to really dive into all the pieces. But the 6502 project is a nice entry point into hardware itself as well as the basic components of processor and memory. How and what the 1s and 0s are doing and how to make them do what you want them to do. Getting up to a working character display and serial input for a keyboard to type is such a satisfying process that takes only a few hours if you kinda know what you’re doing and a few days if you know nothing.
What about a hard drive made of network pings?
https://m.youtube.com/watch?v=JcJSW7Rprio