How to patch PS1 ISO's with ASM codes?

[denben0487]

Ok, no problem. Thank you.

Пожалуйста!

[orcanaoftime]

I'm from Belarus, I use a translator ... Sorry, in your language will not ...

Ok, no problem. Thank you.

[denben0487]

Could you please give some english instructions. Thanks!

I'm from Belarus, I use a translator ... Sorry, in your language will not ...

[orcanaoftime]

How to patch PS1 ISO's with ASM codes small instruction...

Could you please give some english instructions. Thanks!

[denben0487]

How to patch PS1 ISO's with ASM codes small instruction...

[MasterGrand]

Yeah sorry.

Example:
In your image I see the address -> 80072AD4
Opcode: add r3, r4

And you want to change it from add to sub, or something else:
right click on that address, click on "Change instruction", write the code "sub r3, r4", then click OK.

This is just an example.
anyway what game are you hacking? just for curiosity

Hi dude, I like Suikoden 2

[luc-ita]

Yeah sorry.

Example:
In your image I see the address -> 80072AD4
Opcode: add r3, r4

And you want to change it from add to sub, or something else:
right click on that address, click on "Change instruction", write the code "sub r3, r4", then click OK.

This is just an example.
anyway what game are you hacking? just for curiosity

[MasterGrand]

That is the space where you can write and change the selected opcode at selected address

Please can you put example to be more clear.

Thank you advance

[luc-ita]

That is the space where you can write and change the selected opcode at selected address

[MasterGrand]

Click on "Debug" in the tool bar, then click on "Define Break/Condition," then when it asks you to type in your breakpoint, type it like this.

Examples:
[800970AA]! <-------- This is a "write" breakpoint.
[800970AA]? <-------- This is a "read" breakpoint.

The exclamation point represents a "write" break point and the question mark represents a "read" breakpoint.
You can go here for more info: http://problemkaputt.de/gbahlp.htm#breakpoints
As far as I know, setting up the breakpoints in No$psx is the same as setting them up in No$gba.

Thanks dude

But what add here ?

[Dybbles]

I wonder how add breakpoint on no$psx ?

Click on "Debug" in the tool bar, then click on "Define Break/Condition," then when it asks you to type in your breakpoint, type it like this.

Examples:
[800970AA]! <-------- This is a "write" breakpoint.
[800970AA]? <-------- This is a "read" breakpoint.

The exclamation point represents a "write" break point and the question mark represents a "read" breakpoint.
You can go here for more info: http://problemkaputt.de/gbahlp.htm#breakpoints
As far as I know, setting up the breakpoints in No$psx is the same as setting them up in No$gba.

[MasterGrand]

I wonder how add breakpoint on no$psx ?

Thank you

[orcanaoftime]

OK, thanks for the answer.

I guess I was thinking along the lines of something like Magic Engine codes for the Turbo Grafx-16, then using an emulator to find where the values are stored in the rom. I will try your method out.

[Pyriel]

Your question doesn't make much sense. If you have GameShark codes, those contain the memory addresses for values to be overwritten. If you're looking to relate that to executable file, you can just load that in a disassembler and find the relevant address. The easiest way I've found to get the actual offset into the file is similar to what I mentioned earlier. Take a string of 16 bytes from the disassembler, load the EXE in a hex editor, and search.

If you want to be more direct, the PSX EXE is a structured file with different segments described by headers. Find the file offset and load offset values for the executable segment in the headers, and then do the math (Code Address - Segment Load Offset + Segment File Offset = File Location). Sometimes disassemblers will cough up those values in a summary somewhere. I don't remember the exact structure offhand, but it's well-documented.

Using an emulator anywhere in this wouldn't be very efficient. Unless NO$PSX outputs debug information in the console window or a log, or the game uses modules and it's easier to start your work with memory dumps than trying to search individual files for certain data.

[orcanaoftime]

Does anyone have a method to search where the values in the SLUS etc are stored, using Gameshark codes in no$psx?