Video of YACC 2020 monitor program and BASIC interpreter.
Yacc1 will be a multi-board system requiring a motherboard, really more of a basic bus-board, for cards to plug into. For my previous 1802 projects single row breakaway headers with a simple bus-board made of either Veroboard or a simple PCB had all the pins, a grand total of 3X, required.
This custom cpu project will require far more interconnects so I ended up selecting DIN 41612 3 x 32 connectors. They physically strong and will withstand the repeated insertions and removals while at the same time quite cost effective
Functional opcodes (not fully tested)