There's a Youtube channel called Ben Eater that does a great job of explaining computing from first principles. He built a computer out of discrete components on breadboards. He also has a great series where he wires up a 6502 microprocessor and basically builds a little 8-bit microcomputer around it, again on breadboards, in a way that you'll get. He sells them as kits, so you can play at home if you want. They're also just nice educational evening calm time viewing.

Yup, it was fully known as IBM PS/2, for "Personal System 2". IBM wasn't happy about how the original PC system got cloned to hell and back, so they designed a more proprietary and patentable system. Suffice to say it was a massive failure, what with it being incompatible with basically all of third party hardware. But the keyboard and mouse ports were widely regarded as a good idea! (and probably not as patentable)