Post count: 203

neogeo – (should contain MANY files), this goes into the /home/pi/RetroPie/roms/fba – yes, into the roms folder with the roms themselves

GBA – gba_bios.bin – it goes into: /opt/retropie/emulators/gpsp/raspberrypi – with the emulator itself

its strange that neither of them need to go into the /BIOS folder huh? lol
you don’t need anything for MAME I believe, I have been playing around with MAME only for a little while but it seems that you don’t need any BIOS files for it

just in case:
for sega CD you need to place those into the: /BIOS folder in /home/pi/RetroPie/BIOS and name it us_scd1_9210.bin (this is for the USA bios, different names for Japanese and European ones, check the wiki)