I don't understand the purpose of this tool. MAME recently split the DC bios into separate files and Demul doesn't know how to handle it yet a non-merged set or even a merged copy of this file would eliminate that issue though This here will pull the games out of a current MAME set the only real issue is if you have a MAME split set the DC.zip file won't work unless it is merged together with all of the other files that go with it now. That is because they changed a lot of the ROMs at the time to match the changes that MAME had made to the ROMs