I bought a Psp 3004 with firmware ver 6.20 to an officemate for a price of Php 4.5K. It comes with UMD games like KillZone Liberation,Gangs of London and Namco Museum Battle Collection. I haven’t tested a PSP 1000,2000 so I can’t comment on the difference between 3004. I tried to google around forums for a possible hack inorder for us to play using an ISO or CSO. Unfortunately, there are no Firmware upgrades or downgrade available for such version. In order to be sure, We also went to Gameline in SM Taytay to check out if they have some possible solution to play ISO on the PSP 3004 version 6.20 but they alkso don’t have any hacks available for the 6.20 version.
They just told us that it could be available next year. I think I will return this back to my officemate and prefer to buy a PSP 2000 with firmware version 5.02 and lower.