So, this isn’t exactly retrocomputing and it looks like it’s from four years ago, but I just found it and thought that many here may find it interesting.
This guy built a simple 8-bit CPU out of essentially discrete logic circuits (from what I’ve see so far, nothing more complex than a 4-bit adder chip) and explained the entire process.
@screwtape @amszmidt @me @retrocomputing I do vaguely recall it was an interesting question, though not the details. I will admit at least partial interest in the Because I Can factor of historical recreation. ;-)