Il existe un programme pour interchanger les boutons O et X des PSP 1.50 JAP
Pad Region Swapper (Jap1.5 only) : It swaps O and X buttons for the JAP PSP 1.5 (only JAP&1.5!) So your JAP psp become like US.(only for buttons)
How?: Just follow instructions on your screen and don't forget to plug you AC adapter.
How to reverse?: Easy you just have to go to system setting
Restore default Setting.
http://files.pspupdates.com/cgi-bin/...0,0,0,0,21,896
De Yoshihiro une fois de plus, comme quoi, il ne fout pas rien