To play the ISOs found on this site you will need:

• A PSP (obviously)
  
• Big memory card (2GB would be enough)
  

You will need to downgrade your psp (to v1.50) in order to play these PSP ISOs. Downgrading your PSP WILL void your warranty. Any e-mails or comments about how to downgrade will be ignored. I have found this guide which explains how this downgrade is done. Click here. Everything you need can be found on that forums.

Tools needed to downgrade:

• An unpatched GTA Liberty Stories or Lumines Game (Original, not a downloaded ISO).
• PSP with a version of 3.50 or older. Versions newer than 3.50 cannot be downgraded at this moment.
• Patience. Don’t rush this downgrading procedure or else you will end up with a bricked PSP.
• Big enough memory card. The downgrade files are mostly bigger than 32mb, so you will need a bigger memory card than just a 32mb.

Once you succesfully downgraded to v1.50 you will need to upgrade it back to the custom firmware 3.40-OE. And additionally you can install devhook.


From http://www.pspisos.info/how-to-play-the-isos/.