What is it that the PS2 looks for before booting the game? Like why can't a US PS2 boot a PAL or JAP PS2 game or vice versa? I understand that the PS1 use sub-code channeling to detect the what country the disc is from.But with that homebrew mem card tool would it be possible to edit it to boot original import disc? And with the GameShark/ActionReplay they work. What is it that they are using to make the PS2 boot that PS2 coders/hackers aren't or dont have access to? I know that those companies aren't licensed. I am new to the PS2 Dev scene so I hope you guys will be easy on me.