Open your emulator's settings. Most will have a directory labeled "BIOS" or "System."
Ensure the filename matches exactly what the emulator expects (e.g., scph5501.bin vs SCPH5501.BIN ). Some emulators are case-sensitive. ps1-rom.bin bios
While modern emulators like , ePSXe , and RetroArch (Beetle PSX) have become highly advanced, they still rely on the BIOS for several key reasons: Open your emulator's settings