Damn! That chip has a datecode of 1982, so it almost certainly has the FuF protection. We could dump 7/8ths of it electronically (and there probably is some as-yet-undiscovered way to get that 8th bit out too), but it really needs a decap to get everything.
There exists a possibility of doing a 'live decap' leaving the bond wires and legs intact of a chip when decapping it (hence leaving the chip alive/functional; this was successfully done by digshadow on the upd1771 scv sound mcu before we knew how to electronically dump those), but it is much more involved than a normal decap is.
"When life gives you zombies... *CHA-CHIK!* ...you make zombie-ade!"