Mednafen often checks the MD5 or SHA-256 hash of the BIOS file to ensure it is a "clean" dump. If the hash does not match its internal database, the emulator may refuse to load the game. 3. BIOS Management and Troubleshooting
Mednafen’s design philosophy——makes BIOS files non-negotiable for several cores. The emulator is literally a CPU/GPU/SPU emulator waiting for external firmware to tell it what to do. Without the BIOS, the emulated console never wakes up. mednafen bios
For users, this means: