: Some emulators, particularly on Linux-based systems like Knulli or OnionOS, are case-sensitive. You may need to ensure the filename is exactly psxonpsp660.bin (lowercase) or PSXONPSP660.bin (uppercase) depending on the core's requirements.
No legitimate emulator developer includes this file with their software. You must dump it yourself from a PSP you own. psxonpsp660.bin
Unlike traditional BIOS files extracted from original PS1 consoles (like scph1001.bin for US or scph5502.bin for EU), this file is . Using it eliminates the need to maintain multiple files for different game regions. : Some emulators, particularly on Linux-based systems like