Sonic CD (Decompilation) Guide

Guide Author: MewLew

Requirements

  • Game data.rsdk file - You must own a copy of Sonic CD to obtain the required data files.

Obtaining the data.rsdk File

  1. Open your Sonic CD game directory.
  2. Locate the ‘data.rsdk` file.

Important: The Sonic Origins data file (SonicCDu.rsdk) is not compatible with this port. You must use the original Sonic CD release’s data.rsdk file.

Internal Setup

  1. Launch Sonic CD to initialize the folders.
    • The app will force close.
  2. Upload the data.rsdk file:
    • Open the Dev Portal.
    • Go to File Explorer > Local App Data > Sonic CD.
    • Navigate to the Local State folder.
      • Click Choose File, locate your data.rsdk file, and Upload.
  3. Launch Sonic CD and you’re ready to play.

Modding

  • This port is built on an older version of the Sonic CD Remake, so the mod folder/script approach to modding will not work.
  • However, you can unpack the data.rsdk file, replace the assets directly, and then repack the rsdk. This means only mods that replace the original assets will be compatible.
  • For convenience, you can use this tool.

Additional Notes

  • You can upload save files (Sdata.bin) to the same directory as the data.rsdk file.
  • If button inputs are not working when the game starts, quit and restart the game.
    • Press the Xbox button, hover over Sonic CD, press Start, and choose Quit.