How to import a non-full romset of mame games with the retroarch core

[ragna314]

1. I import rom files from a folder
2. I create a platform called "Mame0"
3. I choose retroarch as emulator
4 Then the games don't open
5. So, I go to manage emulators i select retroarch and associated platforms, 
then add "Mame0" with the mame_libretro core.
6. The games do not open.

[Lordmonkus]

Make sure the check box for "extract files" is not enabled, that will prevent mame games from working.

[ragna314]

unchecking extract doesn't fix it