If you have a jailbroken PS3 (CFW or HEN), you have multiple ways to play PS1 games: loading ISO files via WebMan MOD or multiMAN , or installing PKG files. Here is why the PKG route is superior for portability:
: Frequently used to create the base EBOOT.PBP file that the PS3's emulator recognizes. ps1 pkg games for ps3 download portable