WDC on a card for the PC is indeed Western Digital Corp. I recognize that number, but I can't remember what it is (they make HD controller, FD controller, EGA, VGA, ETHERNET, SCSI, and many other chips.). I looked at a few old MFM controllers and they all had WDC42C... chips. I suspect it's either an EGA or a VGA. What kind of connectors/ports/id markers were on the pcb's?