The 8-Bit Computer That's Been Built By Hand
nk497 writes "Forget snapping a few components into a motherboard — programming enthusiast Jack Eisenmann has made his own PC from scratch. His Duo Adept, as he's named it, features 64KB of main memory, 256 bytes of RAM and, in total, 263 lines of code for his homemade OS. Sure, it can't run Crysis, but it does run a game he's written himself."
I wasn't around for this sort of stuff but wasn't this the sort of thing Radio Shacks customers were doing 25+ years ago?
Here's one that running Minix: http://www.homebrewcpu.com/
Reminds me of the one my brother built here except my brother's computer runs Minux.