I'm trying to use the NeoGeo rom in RetroArch and I can't figure out which core to use. FBneo said it was from an unknown romset and all the other cores I tried didn't work.
With arcade games, even if an emulator supports a system, it needs to be explicitly told to be able to load a certain rom by the author. MAME has a sort of rom database, and emulators like FBNeo use that database as a basis (emphasis on as a basis, it supports plenty of things MAME doesn't).
If you download the one labelled as MAME and extract it, it isn't just the rom, but a modified copy of MAME with the arcade rom extracted to /roms/doubledragon. There's a file in the base MAME folder extracted titled 'run.bat.' Running this will force MAME to run the rom.
Just use that.
I managed to get Xeno Crisis to work in FB Neo but i suspect it's because it has already been recomplied and not because the .xml file was updated with the correct attributes? XenoCrisis came with a sample xml file. I thought maybe I could just create an XML file for Double Dragon One to make it work?