How to convert NTSC-J (JP) to NTSC-U(US) codes?

[Shenmue_Trilogy]

I would like to convert some NTSC-J PS2 codes to NTSC-U but was not able to find any method or tool.
I am refering to GT3 480p codes:

Gran Turismo 3 NTSC-J:

D02E6F8A 0A00FDFE //check for SEL+R2
202F14C4 00000002 //16bit
202F14CC 000001C0 //resolution
202F14FC 00000002 //16bit
202F1504 000001C0 //resolution
204A0A20 00000001 //12000020 to 01
20256DB0 34020001 //disable interlacing shaking
2019206C 00000000 //nohud
201920EC 00000000 //nogt3logo
2024D620 00000000 //no multiplication of vert resolution
20254C14 00000000 //sharper image
 
D02E6F8A 0A00FEFE //check for SEL+L2 things back to default
202F14C4 00000001
202F14CC 000000E0
202F14FC 00000001
202F1504 000000E0
204A0A20 00000003
20256DB0 304200FF
2019206C 10400004
201920EC 0C0654A4
2024D620 00084040
20254C14 50830003

[felixthecat1970]

I would like to convert some NTSC-J PS2 codes to NTSC-U but was not able to find any method or tool.
I am refering to GT3 480p codes:

Gran Turismo 3 NTSC-J:

D02E6F8A 0A00FDFE //check for SEL+R2
202F14C4 00000002 //16bit
202F14CC 000001C0 //resolution
202F14FC 00000002 //16bit
202F1504 000001C0 //resolution
204A0A20 00000001 //12000020 to 01
20256DB0 34020001 //disable interlacing shaking
2019206C 00000000 //nohud
201920EC 00000000 //nogt3logo
2024D620 00000000 //no multiplication of vert resolution
20254C14 00000000 //sharper image
 
D02E6F8A 0A00FEFE //check for SEL+L2 things back to default
202F14C4 00000001
202F14CC 000000E0
202F14FC 00000001
202F1504 000000E0
204A0A20 00000003
20256DB0 304200FF
2019206C 10400004
201920EC 0C0654A4
2024D620 00084040
20254C14 50830003

better aproach is documented changed values in .pnach (hex values after // ) and find values near of changed addreses in memory, (or if you lucky the are same addreses positions) but some games change routines example: tekken tag USA v1,v2 (interleacing codes) > tekken tag Japan v3 not have same routines so will not work, if you want port codes try ask coder to seend documented values changed after // tag.

[xMichael]

One method is using tools such as cheat engine to find the exact memory location of the codes in the JP version, getting some hex bytes around it and searching for the "array of bytes" on the USA version of the game. This is somewhat advanced though. And it's not guaranteed to work, especially if you're a newbie because there's some things that must be understood before attempting it.