This is great! I remember as a teenager back in the 80s I built a 4-bit CPU (actually, not much more than an ALU really) using 74-series chips I'd salvaged in p

This is great! I remember as a teenager back in the 80s I built a 4-bit CPU (actually, not much more than an ALU really) using 74-series chips I'd salvaged in part from old mainframe boards I found at my local scrapyard. I loved inventing the instruction set, which made me realise why opcodes are encoded the way they are. Probably one of the best learning experiences I ever had.