Recce: How to Change Game ID for Patched DS RPM

The Nintendo DS (NDS) has been one of the most successful handheld consoles of all time, with a vast library of games. Over time, many fans and developers have ventured into patching these games to either enhance features, fix bugs, or create custom content. When dealing with patched DS ROMs (RPMs), it’s often necessary to modify the Game ID. This guide will walk you through the process of changing the Game ID of a patched DS ROM, ensuring your custom game runs smoothly on emulators or real hardware.

Changing the Game ID can be necessary for several reasons. It can be useful when multiple versions of a game are patched, and the emulator or hardware identifies them incorrectly. Additionally, changing the Game ID is sometimes required to bypass region-locking or to ensure that cheat codes work correctly with the patched game.

What is a Game ID?

Before we dive into the process, it’s important to understand what a Game ID is and why it’s crucial for ROM hacking.

A Game ID is a unique identifier embedded in the header of a Nintendo DS ROM file. It helps the system (whether it’s an emulator or a physical DS) recognize and distinguish between different games. The Game ID is typically assigned by the game’s publisher and is used in several areas, such as save file management, cheat device compatibility, and region settings.

In the context of patched DS ROMs, the Game ID may need to be altered to ensure that the ROM functions properly with cheats, custom firmware, or other modifications. Changing the Game ID can also be part of managing multiple custom or patched versions of the same game, ensuring they are identified correctly by the system.

Tools You’ll Need

To change the Game ID of a patched DS RPM, you’ll need a few specific tools:

1. A DS ROM (Patched Version): This is the ROM file of the game that you want to modify.
2. Hex Editor: A tool used to view and edit the raw data of the ROM. Common hex editors include:
   • HxD (Windows)
   • Hex Fiend (Mac)
3. Nintendo DS Emulator (Optional): For testing your modified ROM (e.g., Desmume or No$GBA).
4. Backup Tool: It’s always good practice to keep a backup of the original file before making any changes.
5. ROM Patching Tools: If you need to apply patches or changes to your ROM, tools like NDSTokyoTrim (for trimming ROMs) may come in handy.

Steps to Change the Game ID for a Patched DS RPM

Now that you have your tools ready, let’s walk through the process of changing the Game ID for a patched DS RPM.

Step 1: Backup Your ROM

Before making any modifications, it’s critical to back up your original ROM file. This ensures that if something goes wrong, you can always revert to the original version.

• Create a copy of your patched DS ROM and store it in a safe location.

Step 2: Open the ROM with a Hex Editor

1. Download and install a hex editor (such as HxD or Hex Fiend).
2. Open your patched DS ROM file in the hex editor.

Step 3: Locate the Game ID

The Game ID in a Nintendo DS ROM is typically located at a fixed position within the ROM file header. In most cases, the Game ID is located at the 0x0A0 position in the ROM header, though this can vary slightly depending on the specific game or patch.

To find the Game ID:

1. Go to address 0x0A0 in the hex editor. This is usually where the Game ID starts.
2. The Game ID is often represented as a 4-byte value (8 characters in total) in the ROM’s header. For example, a Game ID could look like “A123” or “B456”.
3. The Game ID is typically in ASCII format, so it should be readable in plain text once you navigate to this section.

Step 4: Modify the Game ID

1. Select the 4-byte Game ID string in the hex editor. This is where you’ll be making your changes.
2. Edit the Game ID to your desired value. The Game ID should be a valid 4-character string. It’s important to choose an ID that is unique and does not conflict with existing IDs, especially if you plan to use cheats or custom firmware with the ROM.
   • For example, you might change “A123” to “XYZ1”.
3. After making the change, save your ROM file.

Step 5: Save and Close the ROM File

Once you’ve made the changes:

1. Save the modified ROM.
2. Close the hex editor.

Step 6: Test the Modified ROM

After modifying the Game ID, it’s time to test the ROM to ensure that it works correctly.

1. Use an emulator (such as Desmume or No$GBA) to load the modified ROM.
2. Test the game to see if it runs correctly, ensuring the patch functions as expected and that the Game ID change doesn’t interfere with any essential gameplay functions.
3. If you are using cheat codes, test them to see if they are recognized by the emulator or if the Game ID change has affected their operation.

If you encounter issues, you may need to double-check that the Game ID is correctly applied or investigate other aspects of the ROM, such as the patch itself or other potential conflicts.

Step 7: Apply Additional Patches (If Necessary)

In some cases, after changing the Game ID, the ROM may require further patching or adjustments, especially if you’re modifying the ROM to be compatible with specific firmware or custom patches. You can use tools like NDSTokyoTrim to apply additional changes or to optimize the ROM for a specific platform.

Step 8: Flash to a Real DS Console (Optional)

If you plan to run the modified ROM on a real Nintendo DS console:

1. Flash the modified ROM to a flashcart (such as R4, DSTT, or Acekard).
2. Insert the flashcart into your Nintendo DS and test the ROM directly on the hardware.
3. Ensure that the ROM loads without issues and that the Game ID change has not caused any compatibility problems with the console’s operating system or firmware.

Conclusion

Changing the Game ID for a patched DS RPM is a straightforward process that can help resolve issues with multiple patched versions of the same game, enhance cheat code compatibility, or improve game identification on emulators and hardware. By following the steps outlined above, you can easily modify your ROM to ensure smooth gameplay and compatibility with various DS tools and patches.

Always remember to back up your files before making modifications, and test your changes thoroughly. With the right tools and approach, changing the Game ID of a patched DS ROM is an easy task that can enhance your gaming experience.