Capcom 1985 · Motorola 6809
My favourite arcade of them all, so I got myself a working PCB. Or mostly working. An intermittent memory issue meant diving into 6809 assembler to write custom test routines and corner the fault. After a lot of bench work it has been solved, and Sir Arthur runs flawlessly on original hardware.
The full debugging saga, the test routines, the traces and the eureka moment, will be told properly here soon.
The PCB board
Up and running
The setup
So then I mapped the whole thing
All 283 chips and every wire between them, rebuilt from the original 1985 Capcom drawings into an interactive schematic. Browse both boards, click any net to trace it across the machine, follow a band-cable pin from one board to the other, compare against the manual scans, and find exactly where each chip in this story lives.