BGB's Tracer

[Dybbles]

I am having difficulties using BGB's Tracer. As in, I have no idea how to use it. It seems to work differently than VBA's Tracer and FCEUXD's tracer. I tried using Visual Boy Advances Tracer, but.... For some reason when I try prssing F11 to go into the debugger, it won't work. I am trying to hack a music modifier for Mega Man Xtreme because it's being picky, and only wants to work at certain times, so I am tying to hack an asm code that finds the permanent music address.

Any help on this would be appreciated. In either understanding how BGB's Tracer works, or getting Game Boy games to work on VBA's Tracer.

[Helder]

BGB Tracer looks just like the no$ series of emulator debuggers so if you have used any of those then you should have no issues. Try using the MESS debugger as well since it has an awesome trace log feature and isn't too hard to use once you get it. If you plan on using BGB Tracer I can give you some detailed info on how to use it but I will have time only in a few days.

[Dybbles]

I've only used No$GBA's debugger briefly for NDS asm hacking.
I have no idea how to even use MESS. I can't get anything to even start. I'd much rather be taught how to use BGB's debugger since I am more used to using that specific emulator for asm hacking.

You can take as much time as you need to prepare. Thank you for responding to reply Helder.

[Helder]

Ok first things first I always have my Emulator open up in the Debugger mode by going to options and turning that on in the Debugger Tab, then I hit F9 for the game to start.

I used your current game you are Megaman Xtreme hacking for my following information.

Searching for Cheats:
On the Debugger window Click the "Window" menu at the top then choose cheat searcher", the rest is self explanatory since you have experience with other emulators this isn't hard to figure out.

Using the "cheat searcher" I found the weapon charge level code at D571.

Using Breakpoints:
Now to hack an ASM code out of the RAM code we go to the "Debug" Menu in the Debugger Window and choose "access breakpoints" , on the new window you can add a range of addresses or just the one we want. So I input D571 and I leave it on write because I want to alter what gets written to it or atleast see how its being written and make a code after some observations. Hit the ADD and also Enable it.

Now having the breakpoint enabled every time I held down the Shoot Button to Charge my weapon it loaded the value 02 then it loaded 04 and finally 06, the only difference is that each value was at a different address so looking that the instruction for the 02 value I see this:

6A90 36 02 ld (hl),02 [hl register holds our RAM address]

using this I can just change the 02 to 06 and have the weapon shoot charge shots instantly, and my code ended up being:

Shoot Charged Shots
06A-919-E62


I notice also when I have the breakpoint set to this address that I cant shoot more than once because there is an instruction constantly being run until the shot is off screen ,so by my observations if we can skip this sub-routine that is not allowing us to shoot more than one Charged Shot it will make the code more useful. But this emulator doesn't have a trace log feature, the Trace (F7) function in this is just to follow the next instruction but there are useful things in the emulator like the jump to return (F8) which will break at the return which shows where in the ASM the jump was to that sub-routine and from there you can do manual tracing to see what does what.

I hope this is of some use to you or anyone wanting to learn to do GB/C hacking.

EDIT:
After using the MESS Debugger with Trace Log Feature I found the code to stop running the sub-routine to stop us shooting multiple power shots.

6a06:ef:00 > 00A-069-5D5

I basically changed the conditional jump so it always goes forward and not jump back to the subroutine there fore I can shoot many charged shots.

[Dybbles]

I already knew like 98% of what you said. But I never knew I could press [F8] to do a jump to return. I'll try using that method. Maybe I should just man up and learn how to use MESS like the big boys, lol. Thank you for helping me, Helder. I really appreciate it.

[Helder]

I figured you might but since there has not been a real Trace feature added like on MESS, FCEUX and SNES9X Debugger I wanted to clarify somethings so that you or anyone else doesn't get the idea that the feature is there which sucks it isn't. So the real alternative is to use MESS. I can upload a Preconfigured MESS so all you need is to load up the ROMs you add and configure the controls and directories. Tell me if you're interested in this.

[Dybbles]

I can upload a Preconfigured MESS so all you need is to load up the ROMs you add and configure the controls and directories. Tell me if you're interested in this.

I am extremely interested in this! That would be awesome of you Helder!

[Helder]

I will have the link up in a bit but be warned it is over 700mb, it has all the Bios files for all the systems it emulates which is why its so massive. One drawback with the new MESS versions is the inability to edit the ROM like the old ones where I could Edit them and test ROM codes on the fly. Now I use it for tacing games and using another emulator to test the ROM codes, this only applies to the Cart based consoles not the CD based ones.

[Dybbles]

Ok. I understand. Thank you for doing this, Helder. I really appreciate this.

[Helder]

Here it is for anyone who wants it,

http://www.filedropper.com/messgh

[Dybbles]

Thanks, Helder!
I'll try it out rightaway.