For emulators like PCSX2 (PC) or AetherSX2/NetherSX2 (Android), the BIOS file is mandatory. Emulators do not ship with BIOS files due to copyright laws. Therefore, users must provide their own.
Why scph10000.bin is popular among users: Scph10000.bin Ps2 Bios
The internet is flooded with corrupted BIOS files. If your SCPH10000.bin does not work: Verdict: Use the SCPH-10000 for Japanese games released
While nostalgic, the SCPH-10000 is not the best performing BIOS for modern emulation. untamed aesthetic of the launch unit
Verdict: Use the SCPH-10000 for Japanese games released between 2000 and 2004, as well as homebrew. Switch to a later BIOS (like SCPH-70012 for the US) for late-gen titles like Persona 4 or God of War II.
For North American and European gamers, the PS2 was a mysterious machine from Japan. The SCPH-10000 BIOS retains the original Japanese boot sequence, interface sounds, and system menu (OSDSYS). Using this BIOS in an emulator like PCSX2 evokes the raw, untamed aesthetic of the launch unit, complete with the futuristic "spaceship" startup sound that was slightly altered in later firmware updates.