Dreamcast Image Builder/Modding Games

This guide explains how to use Dreamcast Image Builder to apply mods and create modified GDI or CDI images of Dreamcast games.

Building a Modified Game Image

1. Download and run the latest version of DreamcastImageBuilder.exe.
2. Switch to the Games tab and select the game you would like to mod in the games list.
3. In Select the input path to the original GDI, locate the folder containing the original GDI file. Only TOSEC GDI and Redump CUE dumps are supported at the moment.
4. If the GDI is the correct version, you will see a confirmation below saying this is the correct version.

1. In Select the output path for the patched image, locate the folder where you would like the patched game to be built. It can be any folder that can be written to without admin rights (not in C:\Program Files) on a drive that has enough space for the GDI and temporary files (about 3.2GB for Sonic Adventure).
2. (Optional) Switch to the Options tab and in Location under Emulator Settings select the path to demul.exe, redream.exe or flycast.exe.
   Depending on the game and mod, some mods may only work on specific emulators, and/or not work on hardware.
3. Switch to the Mods tab and check the mods you would like to apply.
   Dreamcast Image Builder comes with some built-in mods. See Adding Mods on how to add mods made by other people. If a ... button appears on the right when a mod is selected, it means this mod has configurable options (submods). Click the ... button to toggle submods.
4. Switch to the Codes tab (if applicable) and select the codes you would like to apply.
   Codes are only available for the flycast emulator. If the Codes tab does not appear, it means the game doesn't have a codes file at the moment.
5. Switch to the Build Image tab. Check the CDI checkbox at the bottom (if applicable) if you want a CDI file, or leave it unchecked if you want a GDI file. If the CDI checkbox is greyed out, CDI support is not implemented for this game at the moment.
6. Click Save Settings at the bottom. Then click Build or Build & Run. Wait for the process to finish.

1. • You can click the Stop button to abort the build process.
2. If you clicked Build & Run, the emulator will run automatically. If you have located the emulator in the Options tab, you can also use the Run and Stop buttons to run and terminate the emulator at any time.