Question about Cheat feature and source code.

[cp25stack]

Question about Cheat feature and source code in Snes9xTYL 0.4.2

Hello i am newby here and just begin to use snes9xtyl042.
I had try to use cheat feature (use RAW code mode and my psp is 2.71SE-C)
And found that the cheat feature doesn't work well.
Cheat works when i call Enable Cheat from menu after that Cheat's status was off only.
It does not look like it lock the value of specific address every frames.
So i understand that may be the program forgot to call cheat function every end of some loop.

I had fast scan the source code, and see something i don't understand.
- As i understand the core function of using cheat is "S9xApplyCheats()"
- I see the program call this function when user call Enable Cheat via the Menu
and when start load ROM only.
- But should it has somewhere that always call S9xApplyCheats() every loop of running doesn't it?
If not the value will not lock as we want.
[In my case i add Mario's HP to 2, it work only when i call Enable Cheat via menu after disable it first.
But after i hitted by enemy my HP go back to 1, the value doesnot locked.
This behaviour can explain by the code S9xEnableCheat(uint32 which1) line 98 in cheats2.cpp.
That code will work only when is was diable before call EnableCheat doesn't it.]
- Does it because of calling S9xApplyCheats() in line 746 in gfx.cpp that was commented?
Is that the place to put that function to work? Or is there any problem to call that function there?

Sorry if i misunderstand something.
Thanks for reading.

[exenteth]

I too have had a problem with cheats, and your explanation for it certainly sounds plausible.. I haven't looked at the source code myself (fearing there would just plain be too much look at, heh) but that sounds about right...

unfortunately I don't think any of the developpers will be visiting this forum anytime soon to give you an answer

Oh well.. let me know if you find a way to insert the required code and recompile the project

[Tinnus]

cp25stack said:

I had fast scan the source code, and see something i don't understand.
- As i understand the core function of using cheat is "S9xApplyCheats()"
- I see the program call this function when user call Enable Cheat via the Menu
and when start load ROM only.
- But should it has somewhere that always call S9xApplyCheats() every loop of running doesn't it?
If not the value will not lock as we want.

Game Genie style cheats change the game ROM data, not the RAM, so it should only be needed to be patched once.

[cp25stack]

Hi,


"Game Genie style cheats change the game ROM data, not the RAM, so it should only be needed to be patched once."
<----

It seem you are right, but for some case or some code only.
Even in Game Genie it has many type of code, some code is assume to patch ROM that means
it should work once when initial game ROM. But there are still have another type of code that should
write into RAM every cycle of running.

And in my case i use RAW code, that should always understand that it will lock the value in specific address to be
my value every cycle of running. For example in the case of character's HP code, you need to lock it to be some value
every frame, if not when you hitted by enemy the game mechanic (game binary code) will assign new value to it.
Then at the end of frame the Cheat function work and restore it to be max health value...
May be you can patch ROM at once and change the mechanic of game that make it will not decrease
character health when hitting with enemy. It is possible to do that but very hard to find that code in practical.
So i think that many people prefer find code address from RAM and lock its value every cycle of running.

=====================================================================

And i will inform some advance in this matter if i know something useful to user here.
But i wont sure the thing will be like I disagreeumption or not.
Because, respectly to the code author, i think the cool guy like them may not make easily mistake such as
forgot to open their code. May be that line of code will make problem or something in the game, i dont know.

but i will try to compile, build and findout.
(it is rather hard for me to do that because the...bad internet connection that i had, i cant get the required library)

finally thank for tell me that this board was omitted by the developer , i think i will try to mail them instead.

[cp25stack]

OK, Progress of this story. There are both good and bad news.

Bad news...
I use the source from "http://yoyofr92.free.fr/psp/files/snes9xTYL-0.4.2-src.rar"
which should be a lastest version. Build it with no alter any line of code.., and it gave me Snes9xTYL 0.4.2Me.
Then try to use it with my favorite game Super Mario World. It make game freeze many times.
mostly random freeze when load new stage and always freeze when load stage after save state.
I still dont have any clue for this matter.
Possibility
- My Cygwin or Toolchain or Compiler setting...
- My way to alter the original Makefile, since the original won't work with my environment.
- The way i make kxploit to make it run on 1.5FW from 1.0 EBOOT.PBP

Good news...
Above suusmption seem to be correct.
After i open the comment in line 746 of gfx.cpp, the cheat feature is work normally. (I try RAW code)
(I can see the result becase the emulator doesn't freeze too much until cannot play, it still can play.)
One more evident to support I disagreeumption...
I compare the snes9xtyl source code with original snes9x (on PC) code, and see that
in the PC version it has that code in line 746-gfx.cpp open.

Summary..
- May be i will try to continue to findout what happen, what make my compiled version freeze.
- But easy than that, i will send mail to the author and request them to open comment in that line and
rebuild and release it Or another people that can biuld it with no problem.
- About my version, i had upload it at...
www.geocities.com/cp25stack/Snes9x.zip
If anyone want to try, try it by your own risk.. (I must say this "save myself" statement)
For honestly, i just open comment on that line and rebuild project, just that. so should be no any harmful.

[cp25stack]

Long time had pass, i had forgot about this emu already.
But since the fw3.x homebrew fever occured several month ago,
many homebrew needs to re-port to support 3.x version.
So there are new version of this emu and their source around the internet.
I had try the above assumption again.

1 For the source that download from this site.
After build it, i found some problem about, may be, sound ?
While playing RockmanX, when face vava in opening stage and the music change
the game will freeze. But if i press LR and select not emulate sound, the game can continue
but with very low speed every time when music change (ie. when select stage, facing boss).
May be this is the same problem of my previous evperiment last year.

2 Use Ruka source from this link
www.dcemu.co.uk/vbulletin/showthread.php?t=83146&highlight=ruka
-- thanks to Tinnus that give the link.--
(I heard that ruka version didn't have problem about sound any more)
It works fine, (except that this version cant real sleep the PSP )
No sound problem, and when i open the comment of function "S9xEnableCheat"
of line 6xx (sorry cant remember exactly) in gfx.cpp, the RAW code cheat can now lock
the value correctly. I had play test RockmanX all the game and no problem.
And test Super mario world, only the first world, it work fines too.
(i am still pitty that ruka version cant sleep the PSP )

In conclusion, i still dont sure that why the developer of this emu had close the
function "S9xEnableCheat" in file gfx.cpp. Will it cause bad effect or not?
And may be there are some version of this emu that can use RAW code already
(but i cant found any of it).
But i hope my experiment may be some useful to someone
who will improve this emu in the future.
****Because i am a great fan of cheating ****

PS. if anyone want to try my ruka's edited version, you can download from here.
rapidshare.com/files/91659680/rukaEdit1lineVersion.rar.html
(Only one thing that i change is open comment in line 6xx of file gfx.cpp)
The way to use is the same way of using ruka's version.