This guide details how to play Sega CD games on your Steam Deck using EmuDeck. We'll cover setup, ROM transfer, and troubleshooting.

Pre-Installation: Developer Mode and Essentials

Enable Developer Mode and CEF Remote Debugging on your Steam Deck for compatibility with EmuDeck updates.

1. Power on your Steam Deck.
2. Access the Steam Menu (Steam button).
3. Navigate to System > Developer Mode and enable it.
4. Go to the Developer menu and enable CEF Remote Debugging.
5. Press the Steam button, select Power, and switch to Desktop Mode.

Essential Items:

• High-speed A2 microSD card (for EmuDeck and games).
• Formatted microSD card (format it on the Steam Deck).
• Legally obtained Sega CD ROMs and BIOS files.
• Optional: Keyboard and mouse for easier file transfer.

Formatting your SD Card: Insert the card, open the Steam menu, go to Storage, and select "Format SD Card."

Downloading and Installing EmuDeck

1. Press the Steam button, select Power, and switch to Desktop Mode.
2. Download a browser (from the Discovery Store), and download EmuDeck. Choose the SteamOS version.
3. Run the installer, select "Custom," choose your SD card, then select your Steam Deck.
4. Select RetroArch, MelonDS, Steam ROM Manager, and Emulation Station (or all emulators).
5. Complete the installation.

Transferring Sega CD Files

BIOS Files:

1. Open the Dolphin File Browser (Desktop Mode).
2. Navigate to your SD card (Primary).
3. Go to Emulation > BIOS and transfer your BIOS files.

Sega CD ROMs:

1. Navigate to your SD card (Primary).
2. Go to Emulation > ROMS > segaCD (or megaCD).
3. Transfer your ROMs.

Adding ROMs with Steam ROM Manager

1. Open EmuDeck, then Steam ROM Manager.
2. Click "Next," then click both Nintendo DS windows (this step may seem odd, but is necessary).
3. Click "Add Games," then "Parse." Steam ROM Manager will prepare your games and covers.

Fixing Missing Covers

If covers are missing:

1. Select "Fix."
2. Search for the game title.
3. Choose a cover, highlight it, and click "Save and Close."

Manually Adding Covers: Use a Google Image search to find the cover. In Steam ROM Manager, click "Upload," select the image, and click "Save and Close."

Playing Your Sega CD Games

1. Press the Steam button.
2. Go to Library > Collections.
3. Open the Sega CD folder and launch your games.

Using Emulation Station: (Should be installed if you followed the previous steps)

1. Press the Steam button.
2. Go to Library > Non-Steam.
3. Launch Emulation Station. Use the menu to scrape metadata for better organization (Scrape From: TheGamesDB, Systems: Sega CD).

Installing Decky Loader and Power Tools

Decky Loader is recommended for Power Tools.

1. Switch to Desktop Mode.
2. Download Decky Loader from its GitHub page.
3. Run the installer and choose "Recommended Install."
4. Restart in Gaming Mode.
5. Open the Decky Loader plugin (QAM button).
6. Go to the Decky Store and install Power Tools.
7. In Power Tools, optimize settings (disable SMTs, set Threads to 4, adjust GPU clock in Performance settings).

Fixing Decky Loader After a Steam Deck Update

If Decky Loader is missing after an update:

1. Switch to Desktop Mode.
2. Download Decky Loader again from GitHub.
3. Run the installer (select "Execute," not "Open").
4. Enter your sudo password (create one if needed).
5. Restart in Gaming Mode.

This comprehensive guide should allow you to successfully set up and enjoy your Sega CD games on your Steam Deck.