Hacking Sequential codes PSX

[jin299]

Helder what is the purpose for using the instruction la (Load Address) in asm when trying to find a code with the debugger and what is the difference between loading a value and storing one in mips, because it can be quite difficult to understand the difference between the two?

Also when hacking a code with the debugger, why is it that most of the time all the information you want is usually located near where the first breakpoint occured, but sometimes you have to trace up or down in the the debugger to find where abouts exactly the address for the code you are looking for is?

[Helder]

Like I said before it's either 16bit or 32bit and it can be decreasing or increasing when jumping so you have to try both. I start a search right as I leave the ground then again once I move up slightly, I don't do any searches while coming down from a jump as that's usually different. Once you find the ASM for it you will notice that it affects all characters including enemies, you need to trace back to find the Player's data by looking at the registers but that's up to you to do.

[jin299]

Helder how exacly do you hack a moon jump ram code for Megaman 8 for the psx?

I prevously tried hacking the code by using changed value searches using 32 bit searches as instructed by you but to no avail I couldn't seem to find anything relating to the moon jump ram address in the game?

[jin299]

Hey Helder and hey to all the game hacking community how are you all doing these days, I took a bit of a break from hacking ram and ASM codes for the Playstation console in general, for a while but I'm am back now hacking again and and trying to find new hacks for the Street Fighter Series fighting games for the Psx gaming console.

So I was just wondering Helder could provide me with some help and some advice on how to about hacking and finding the following ram codes for the game Street Fighter EX2 Plus, for the Psx.

The first code i'm trying to hack is a fireball color modifier for the game and the second is a fireball speed modifier for the game, because I already tried previously hacking these two codes for the game myself through normal ram hacking but found nothing myself in regards of finding any of the two codes for the game?

[Helder]

Try 32bit searches, many jump codes use 32 bit values and might help narrow things down and sometimes when you jump the value goes down instead of up so look for that too.

[jin299]

Okay, but this game man is very hard to hack ram codes for some reason, because at the moment I'm trying to hack a moon jump code for the game, but so far have found nothing using different to searches and increased/ decreased searches it's one of the many codes I'm struggling to find in the game?

[Helder]

Only way around that is to use MESS as it has an ignore command that is awesome.

[jin299]

It seems to me that read breakpoints are far much easier to use In order to find where the correct instruction to the ram address is located in the debugger, with write breakpoints there is a lot more backtracing involved in order to find what your looking for.

Now regarding write breakpoints any idea on how to deal with breakpoints that constantly break one after the other, because with these other random ram addresses nearby each other in the registers, It can be quite challenging sometimes to find the correct ram address to load the value into, when using the debugger.

[Helder]

Read shows where it gets the value for the ram address but usually is a few routines up from the write breakpoint, it's good to see what is happening from the beginning till there is a write at the end to give you a better understanding of all the ASM in between.

[jin299]

It certainly would man, the debugger is great, for tackling such problems isn't it Now regarding Breakpoints I have found that using read breakpoint to be hugely helpful in finding the values for a ram address in a game, but what exactly is purpose of combining a read break with a write, when hacking in asm example [!?]?

[Helder]

Using the debugger is of course really helpful unless that ram code by itself works without problems.

[jin299]

I get what you mean man, so basically because the game uses dma it wouldn't be wise to change to the characters and levels in the game, because in each level the adresses are different right, but for games that are not dma protected this method of switching characters and levels and in the game then searching unchanged value search would be alright to use.

So basically hacking the same code using the debugger through asm would ultimately allow me to defeat the dma protection in the game allowing me to use the same ram code on every level and mode of the game.

Now regarding the control the computer ram code I found you mean that I should use the memory viewer and look at the registers in the debugger to get an idea of what is happening in the code, using breakpoints to help.

[Helder]

Since this game uses some kind of DMA and you have been hacking it you should know if things change level to level or only in different modes. Generally what your doing is correct in order to eliminate false possibilities and if that code is correct or not is a step in the right direction. I would look at the memory viewer in realtime and see what is happening around that address.

[jin299]

I took your advice man and I used the same character in the same level in demo mode and in arcade mode when hacking the code and found this interesting ram hack, 30098851 00A2, the code gives me cpu properties, as a human controlled player, do you think this could be the code I'm looking for, and what could I do with the code in asm hacking.

Also normally to help eliminate junk addresses in art money I switch characters and levels and then use the unchanged value when hacking a ram code, to narrow down the searches is it okay to do this, or overall this a bad hacking method idea to use when hacking ram codes in the game.

I know it depends the code your trying to hack in the game, example for character modifier ram codes this simply wouldn't be logical at all to implement giving the nature of how the code is hacked but I'm sure it is okay to use in other ram hacks right?

[Helder]

Seems it's the wrong code but you could leave it on so it doesn't show up again when searching. I would make sure the Demo level is also the same level you play with the same character too then do some searches.