Years ago I worked my way through some of the electrical schematics in the book “Code: the hidden language of computers” using a modded version of redbrick that added some basic support for cable bundles, junctions, a timing crystal, etc. started with basic logic gates and then eventually I was able to get as far as building an 8 bit ALU and 1kb of memory in game. I don’t think I’d understand even close to as well how these things work if not for this amazing creation!