Had to build a CPU from "scratch" at CMU. Of course, we were allowed to use 290x bit-slice parts. And PALs or FPGAs (we didn't use FPGAs; if you were sufficiently clever you could get the whole thing in one FPGA.) Designed our own ISA though. Had to be able to do a 16 bit multiply. Looked like a multicolor explosion of wire-wrap.
One of the other groups built a fully asynchronous machine. Ours was a single board, but theirs had a backplane (using an 80 SCSI cable.) Each unit had a value line and a ready line, so the system advanced to the next state as the parts were ready.
One of the other groups built a fully asynchronous machine. Ours was a single board, but theirs had a backplane (using an 80 SCSI cable.) Each unit had a value line and a ready line, so the system advanced to the next state as the parts were ready.
Happy days.