I presume
somebody's mentioned Exidy already? (hey, you didn't specify
that the cartridges had to have the correct guts...)
Did you perhaps mean Exatron as in "stringy floppy"? Or am I showing
my age again?
I thought so too,. at first. And then I rememebrs something I've posted
often enough. The Exidy Sorceror ROM cartridges were actually 8-track
tape housings (the sort of thing you used to stick in your car tape
player) with the tape and spools removded, some bits of the hosing cut
away, and a PCB inside containing the ROMs. The PCB had edge fingers to
connect it to the rest of the machine, accssible through the front side
of the carttridge.
-tony