Bios | Ppsspp

The (PlayStation Portable Simulator Suitable for Playing Portably) emulator is unique because it does not require a BIOS file to run games . Unlike other emulators (such as those for the PS1 or PS2) that need original console firmware to function, PPSSPP is a "high-level" emulator that replicates the PSP's operating system environment through its own code.

If you still wish to use your PSP's firmware or experiment with different firmware versions, here's a general guide: ppsspp bios