You don’t need to download shady “ROM packs.” Instead, convert your own PS1 discs legally:

These files are what you use to play commercial PSP titles like Grand Theft Auto: Liberty City Stories or Monster Hunter Freedom Unite .

This process allows you to play classic PS1 titles—such as Crash Bandicoot , Spyro the Dragon , or Metal Gear Solid —natively on the PSP without needing an external emulator app. The PSP's firmware contains a built-in PS1 emulator (pops), and Eboots are designed to run on it seamlessly.

: To run "homebrew" or unofficial EBOOTs (games not bought from the PS Store), your PSP must have Custom Firmware installed (such as PRO-C or ME).

: These are "converted" files. To play original PS1 games on a PSP, the disc image (typically .BIN or .ISO ) must be converted into an EBOOT format. How to Create/Convert EBOOTs