PSP Eboots
The easiest place to download already-converted eboots:
Official PSN eboots
Converted eboots
http://www.devils-shadow.com/forums/psx-downloads/7884-psx-psp-master-list.html
Usually official eboots have superior compatibility, but their number is really low. If you are having some trouble with converted eboots, be sure to download popsloader here:
http://zload.net/v2/archives/file/?id=2417473
... and check the list here:
http://www.devils-shadow.com/forums/psx-downloads/327566-psx-psp-pops-compatibility-game-list.html
... for full compatibility.
Most of the games will work without it nowadays, but for those who won't, you'll need this.
For the guy who is having trouble with FF8, try do download the official eboot.
(feel free to correct me if there's something wrong with the explanation)
... and the place where I usually download mine:
... it's probably the better choice in the long run, give it a shot.
