Two relays' outputs in parallel (A.K.A. "top half of CMOS NAND cell"): https://commons.wikimedia.org/wiki/File:Relay_nand.svg https://commons.wikimedia.org/wik

Two relays' outputs in parallel (A.K.A. "top half of CMOS NAND cell"): https://commons.wikimedia.org/wiki/File:Relay_nand.svg https://commons.wikimedia.org/wiki/File:Relay_nand.svg (In real life, I might put a diode OR + single relay-based inverter, but that's too far into analog logic for the essentially digital game)