Convert PS1 ISO's To PSP EBOOT! (Play PS1 Games On PSP) - YouTube
Convert PSX Games To PSP Format with PSX2PSP - pspunk
PSP 2001 won't play any PS1 classic games from the PSN store with the CFW 6.61 LME-2.3. Changed the ISO to M33 to no avail. Am I missing something here? : r/PSP