Write Retail & Debug ROMs to 3DS and DSi Cartridges

June 20, 2025

After years of development, I’m excited to finally release my 3DS Cartridge Writer project—a tool that allows you to write both Retail and Debug ROMs to 3DS and TWL (DSi) flash cartridges.

This project is built on a custom version of GodMode9 (v2.1.1), developed with significant help from xluma. By reverse engineering the cartridges, we were able to create custom firmware to enable this unique functionality.

Download

GodMode9 Cart Writer V0.11 Alpha

What You’ll Need

A modded 3DS capable of booting custom payloads. If you’re using Luma3DS, simply add the custom GodMode9 payload to your luma/payloads folder on your SD card.
ROM files: Place your .3ds or .nds files in the gm9/in folder.
boot9.bin: Make sure a copy of boot9.bin is in the gm9/support folder—this is required for writing to work.

Supported Cartridges

3DS Cartridges
- Write both Retail and Debug ROMs.
- The ROM must be a valid, fully-signed dump—similar to Sky3DS dumps.
- For CARD2 games, you’ll need a “V2” cartridge (the grey factory cards I sell, or the small black NDS-shell cartridges with blue labels).
TWL/DSi Cartridges
- Ensure your ROM includes the correct blowfish tables before writing—otherwise, it will not boot correctly.
- These cartridges also accept standard NDS ROMs.

Disclaimer

This software is experimental and provided as-is. No warranty is provided, and I cannot be held liable for any potential damage to your hardware.

Important Notes

Save Chip Compatibility
You must use the correct save chip for your game. If the cartridge does not match the game’s required save type, you’ll receive an error at boot.
Need a save sub-board for your dev cart? I sell them at eevitronics.jp.