What's the most accurate GG-to-Hex translator out there (for NES)?

[marzsyndrome]

I've tried stuff like online converters, gg2conv, and FCEUX's built-in translator and yet the results never match what the actual offset states inside the ROM.

I know I received help in knowing the real offsets-to-edit for Rodland before, so there must be another general solution out there!


Thanks.

[marzsyndrome]

I take it no-one really knows then? :-(

[Hybrid]

what game are you trying

[marzsyndrome]

Gradius (the first one) for the NES atm.

[Pugsy]

Ensure you have the correct ROM that the cheat was made for...be VERY aware that there are many versions of games and often the GG code will work for just one version! I cannot overstate how important this is...the GG code will likely only work with the version it was made for!


Programs You will Need installed and ready to use:
Java GGEncoder (GG Code converter - one of many, don't think it matters which you use) http://games.technoplaza.net/ggencoder/java/applet/
MESS (Emulator) http://www.mess.org/
HxD (Excellent and Free Hex Editor) http://mh-nexus.de/en/


Example using Whipon's Bomberman (J) Infinite Lives SXOGAGVG cheat

1. Enter the code SXOGAGVG into the GG Decoding program, this will give you an address if 4490 and a compare value of C6 (+ a value of A5 which we will use in Step 11).

2. Add 0x8000 to the address, so we now have an address of C490. If you don't understand this use the windows calculator change it to scientific mode and press the hex button and use "4490+8000="

3. Start MESS in the debug mode and run the NES emulation with the Bomberman (J).nes ROM, I prefer to do this from the commandline:-

mess -debug nes -cart "Bomberman (J).nes"

4. MESS will open in the debugger, you will need to breakpoint out when the address c490 contains the compare value c6. You can do this by entering these 3 lines is in the debugger (take special note there are 2 equals signs!):-
8 Letter GG Codes:

bp c490,maincpu.pb@c490==c6
bp c490-1,maincpu.pb@c490==c6
bp c490-2,maincpu.pb@c490==c6

NOTE: 8 letter NES GG codes can be safely converted but 6 letter codes have no compare value so you will have to modify the following method by just using a simple BPs and hoping for the best (as long as you have the correct version of the ROM it should work - but having the correct ROM is the major risk factor in using 6 letter codes)
6 Letter GG Codes:

bp c490
bp c490-1
bp c490-2

5. Press F12 to play the game and lose a life, as long as you have the right version of the ROM that the GG code was made for the debugger will activate again (if the debugger doesn't activate try another version of the ROM and repeat from step 3).

6. The Debugger will now be onscreen again, press CTRL+M and type c490 into the address box and hit return

7. Make a note of the values at address C490, so we have:-

C490 C6 68 30 03 4C 08 C4

8. Open the "Bomberman (J).nes" ROM in HxD

9. Hit CTRL+F to open a search box, ensure datatype is Hex-Values and type "C6 68 30 03 4C 08 C4" into the box and click ok.

10. You will find that you have "C6 68 30 03 4C 08 C4" highlighted, pressing F3 should result in a can't find dialog box opening if it doesn't and it jump to another address range you need to record more values after "C6 68 30 03 4C 08 C4" from Step 7.

11. You now have a unique match at offset 4A0. Change the C6 to A5(see step 1) save the modified "Bomberman (J).nes" ROM (Ctrl+S or File>Save).

12. Play the ROM you should now have Infinite Lives...job done.