How to use Action Replay Codes on Desmume
Game: Castlevania Dawn of Sorrow
Using codes on the Desmume Emulator is a piece of cake - the bigger problem is finding codes that actually work! CodeBreaker codes do not work on the Desmume emulator and they share the same format as Action Replay codes which often leads to confusion.
To get started with inputting codes, on the Desmume toolbar select "Emulation" as shown in the screen shot above then select "Cheats" and "List". Doing this will bring up the same box that you see in the screen shot below.
At this screen you'll want to choose Action Replay. Unless of course you have a code that you know is for internal instead... but 95% of the time it's Action Replay. For the purposes of this guide, the game that I am testing cheats for is Castlevania: Dawn of Sorrow (USA). If you go to my Castlevania: Dawn of Sorrow (USA) Action Replay Codes page you'll find a code for Max Gold, which is the one I will be using to teach you how to setup codes.
Max Gold: 020F744C 000F423F
When you click on the Action Replay button the box you see in the screen shot below will appear. You're going to want to input the code into this box, as you see in my screen shot and (optional) name the code so you remember which each one does.
If you're at all confused use my screen shot on the left below for guidance.
With this out of the way click "Update" and you'll then see your code appear in the Cheats List, shown in my screen shot above. We're basically done at this point, all you need to do is click "save" and you'll be taken back to the game.
Now check to see if your code works, if it doesn't and you've followed these steps exactly then there's probably something wrong with your code or the code is for a different region than your game. You can't use a code meant for the (Europe) version of Castlevania on the (USA) version.
Additionally there is one more thing that could cause issue - different game versions or hacked games. The Pokemon games in particular have a lot of "Fan hacks" which often change the memory addresses of the game. The majority of codes won't work for games like these.
As you can see, I now have 999,999G. The code worked.