Paul Flint

You are welcome. I spent a couple of hours yesterday searching for how to get it working as I wanted to use RetroArch with the mame core instead of the separate MAME and MESS that I was currently using. I could not find the answer anywhere so decided to work it out. The less emulators and cores I have to use, the simpler the config is (once you get it working) and as you say, the mame core gets updated.

If you want to use the MESS core, put them in a folder RetroArch\system\mess2014\roms

If you edit the RetroArch.ini file in RocketLauncher\Modules\RetroArch you can specify the location for the MAME BIOS files. Add these two lines: [mame] BIOS_Roms_Folder=..\Emulators\RetroArch\system\mame\roms (or the path to your MAME/MESS BIOS files) Use the mame core in RetroArch This way you can keep all of the BIOS files in one location. You should be able to use RetroArch and the MAME core for all of the old systems like Bally Astrocade, Arcadia 2001, Entex, Channel F etc.