hi guys
i've been trying to hex edit some of my ps2 .xps game saves, i've found the offsets for a good part of the stats i'm trying to edit (hp exp items ect) but every time i edit anything it ends up corrupt when i try to load the save

i know this is because of the checksum, but all i really know about it is that it somehow adds up everything in the file and comes up with a number

anyone know how these things work and/or how i can re-check? the file when i'm done to fix it?

and i know there's a checksum fixer on a different site (dunno if you can plug sites here....a place for save tools for ps2 ) but it makes little sence to me

can anyone help me out?