> a friend of mine has one. > i doubt he'll be gung-ho about > dumping the roms, though.
I tend to doubt the ROMs are actually different. It sounds like Sega just bolted on some kind of stock reverb unit like from a guitar amp (it's certainly not a subtle effect). So either the schematics/wiring diagram shown in the video or some very good pictures of the reverb unit's PCB would be handy.