Usually SCPH-XXXXX.bin , rom1.bin , rom2.bin , and erom.bin .
: Run the emulator; it will prompt you to select the BIOS folder. Refresh List : Click "Refresh list" to see your BIOS versions appear. Select & Finish Pcsx2 1.6.0 Bios And Plugins Download
Ensure your BIOS files are not inside a subfolder within the bios directory. They must be directly in the folder. Usually SCPH-XXXXX