neo 4 question

[wildthing]

Only PS1 disks run that are the same region as your PS2 is originally.ie only PAL games run on a Pal machine & only USA game srun on a USA machine.This is one of the downfalls of the NEO chips.
You can either patch these games to the region you require using the 'PATCH-IT' tool from Psxcopyworld Utils section, or use an Action Replay, Exploder or some other PS1 cheat disk to boot them with no problems. I've found that even some Exploder or AR demo disks from my old PS1 magazines work OK.

Hope this helps