this is a complete arithmetic-logic unit (ALU) using discrete relays — and not high-density types either — these are the big honking clear-cased kind. The design is neatly, intentionally ...

The NedoNAND has been a recent example, a modular PCB-based design. TTL and CMOS logic chips made their debut over 50 years ago so you might expect there to be nothing new from that direction ...