Modifying a PSX.EXE File

Post by **DRRDRR** » May 12th, 2020, 9:51 pm

Hi, everyone.

I'm trying to modify a couple of values in a PS1 game's PSX.EXE demo (taken from OPM Summer 99) basically trying to change which two selectable characters there are, since I re-did the entire game's audio and wanted to make it work for an altered demo version of the game.

I've attached the EXE if you guys wanna take a look. I've spent hours trying to disassemble the thing, and I found basically everything I need except for this one specific thing. It's 4 AM and I figure it's time I take a break and ask the people who know waaay more about this stuff than me =P

Any help you can provide would be greatly appreciated. Thank you!

Post by **Administrator** » May 12th, 2020, 10:38 pm

Best method to do this would be by using NO$PSX, Ghidra and IDA. Then, you can use PSFlab to inject or patch the instructions.

Post by **DRRDRR** » May 13th, 2020, 1:16 pm

Shadow wrote: ↑May 12th, 2020, 10:38 pm Best method to do this would be by using NO$PSX, Ghidra and IDA. Then, you can use PSFlab to inject or patch the instructions.

The sound is entirely done and playable in the game, I'm just trying to change the value in the .EXE that changes the two playable characters to two different ones. I've tried to pinpoint exactly where that might be, but no luck still... thank you for the reply, though!