The Sega Master System, an iconic 8-bit console that rivaled the NES, brought fans a variety of exceptional games, including unique versions of classics like Golden Axe, Double Dragon, and Streets of Rage. It even pushed its limits with titles like Mortal Kombat and Asterix & Obelix, which rivaled the performance of 16-bit Megadrive/Genesis games of the time.
For retro gaming enthusiasts, playing Sega Master System games on modern systems can be challenging, but the Steam Deck, combined with the powerful EmuDeck software, makes it possible. Here's a comprehensive guide on how to set up and enjoy Sega Master System games on your Steam Deck.
Updated January 15, 2024, by Michael Llewellyn: While the Steam Deck is more than capable of running Sega Master System games, achieving the optimal performance of an 8-bit console can be tricky. This is where Decky Loader and the Power Tools plugin come into play. The EmuDeck developers recommend installing both to enhance your retro gaming experience. This guide has been updated to include detailed installation steps and a fix for restoring functionality after a Steam Deck update.
Before Installing EmuDeck

Before you begin installing EmuDeck on your Steam Deck for Sega Master System games, ensure you have the necessary tools and settings in place for a smooth installation:
- Make sure your Steam Deck is either plugged into a power source or fully charged.
- You'll need a high-speed micro SD card to insert into the bottom of the Steam Deck and format it directly on the device.
- Alternatively, you can use an external HDD, though this will compromise the Steam Deck's portability.
- Using a keyboard and mouse can simplify the process of transferring files and running installation programs. If you don't have these, you can access the built-in keyboard by pressing the Steam and X buttons simultaneously and use the trackpads as a mouse.
Activate Developer Mode
To ensure your emulators run smoothly, you must activate Developer Mode on your Steam Deck:
- Press the Steam button to open the left access panel.
- Navigate to the System menu and select System Settings.
- Toggle Enable Developer Mode on.

- Find the Developer menu at the bottom of the access panel.
- Open the Developer menu and under Miscellaneous, enable CEF Remote Debugging.
- Press the Steam Button, select Power, and restart the Steam Deck.
Note that CEF Remote Debugging can be disabled after a system update, which may affect plugins, programs, and emulators. Always check the Developer Menu post-update to ensure it remains enabled.
Installing EmuDeck In Desktop Mode

To install EmuDeck, switch to Desktop Mode:
- Press the Steam button, select Power, and choose Desktop Mode.
- Use a browser like Chrome or Firefox to download EmuDeck.
- Select the appropriate SteamOS version and start the download. Once downloaded, double-click the installer and opt for the recommended install to begin the process.
- Choose Custom Install.
- After installation, open the menu and select the SD card image labeled Primary. This will rename your SD card to Primary, making it easier to locate under Removable Devices in the Dolphin file manager.
- You can install all emulators or focus solely on the Sega Master System by selecting Retroarch.
RetroArch is a versatile application that can run various emulators for classic gaming systems. These are accessible under the 'Emulators' tab in the Steam library.
- Ensure the Steam Rom Manager is selected alongside Retroarch to display the games in the main Steam library.
- Navigate through the options and activate the 'Configure CRT Shader for Classic 3D Games' feature if you want that classic TV look for your games.
- Select Finish to complete the installation.
Transferring Master System ROMs
With Retroarch and EmuDeck installed, it's time to transfer your Sega Master System ROMs:
- Open the Dolphin File Manager.

- In the left panel, scroll to Removable Devices and open the SD card labeled Primary.
- Navigate to the Emulation folder and click on ROMS.
- Find the 'mastersystem' folder in the list.
- Transfer or copy your Sega Master System files. These ROM files typically have the '.sms' extension, such as 'Pro Wrestling.sms.' Ignore the file named 'media.'
Adding Master System Games To The Steam Library

To play Sega Master System games in Gaming Mode, add them to your Steam Library:
- Open EmuDeck in Desktop Mode.
- Click on the Steam Rom Manager.
- Click Next on the Welcome to SRM! page.
- Toggle Parsers off.
- Highlight Sega Master System on the Parsers screen.
- Select Add Games and then Parse.
- Ensure the games and their cover arts are displayed and select Save to Steam.
Fix Or Upload Missing Artwork

Given the age of the Sega Master System, you might encounter missing or incorrect artwork. Here's how to fix or replace it:
- Click Fix on the cover frame.
- The Steam ROM Manager usually displays cover art automatically. If it's missing, enter the game's title into the Search for game field.
- Browse the list of game covers, select the best one, and choose Save and close.
Upload Missing Artwork
If the Steam Rom Manager can't find the correct artwork, follow these steps to upload it:
- Use a browser to find the correct artwork and save it to the Steam Deck's Pictures folder.
- Click Upload on the cover frame.
- Select the new artwork from the Pictures folder, then save and close.
- If the image isn't displaying, use the left and right arrows to find it.
- Click on Save to Steam.
- Once the batch files have finished processing, switch back to the Steam Deck's Gaming Mode.
Playing Master System Games On The Steam Deck

After the Steam Rom Manager has uploaded the covers and game artwork to the Steam library, you can access the emulated games just like the official ones:
- In Gaming Mode, press the Steam button below the left trackpad.
- Select Library from the side menu.
- Press the R1 button to highlight the new Collections tabs.
- Click on the Sega Master System window.
- Select the Sega game you want to play and start enjoying it.
Improve Performance
To address potential stuttering and frame rate issues with classic games on the Steam Deck, follow these steps:
- Open your Sega Master System game and press the QAM button below the right trackpad.
- Open the Performance menu.
- Toggle 'Use game profile' on.
- Increase the Frame Limit to 60 FPS.
- Enable Half Rate Shading.
Install Decky Loader For The Steam Deck

The EmuDeck developers recommend installing Decky Loader and the Power Tools plugin for enhanced control over the Steam Deck's performance with emulated games. Here's how to install them:
- Connect a keyboard and mouse for easier navigation. (Alternatively, use the trackpads and the on-screen keyboard by pressing Steam and X.)
- If in Gaming Mode, press the Steam button, select Power, and switch to Desktop Mode.
- Open a web browser (downloadable from the Discovery Store if needed).
- Navigate to the GitHub Decky Loader page.
- Click the large Download icon to start the download.
- Once downloaded, double-click the launcher and select the Recommended Install option.
- After installation, restart the Steam Deck in Gaming Mode.
Install Power Tools

With Decky installed, add the Power Tools plugin:
- In Gaming Mode, press the Quick Access Menu (QAM) button beneath the right trackpad.
- In the QAM, select the new plugin icon at the bottom.
- Choose the store icon at the top of the Decky Loader menu.
- In the Decky Store, find the Power Tools plugin and install it.
Power Tools Settings For Emulated Games
- Press the Steam button and open your Library to launch a Master System game from your Collections menu.
- Press the QAM button, select Decky Loader, and then the Power Tools menu.
- Turn off SMTs.
- Adjust the number of Threads to 4.
- Press the QAM button again, then open the Performance menu by selecting the small battery icon.
- Enable Advanced View.
- Turn on Manual GPU Clock Control.
- Increase GPU Clock Frequency to 1200.
- Select the Per Game Profile option to save these settings for each game.
Fixing Decky Loader After A Steam Deck Update

Major Steam Deck updates can alter menus and settings, potentially removing third-party apps from your Quick Access menu. Here's how to restore Decky Loader and your plugins:
- If in Gaming Mode, press the Steam button, open the Power menu, and switch to Desktop Mode.
- Once in Desktop Mode, open a browser.
- Go to the Decky Loader GitHub page and click the Download icon.
- This time, select Execute instead of Recommended Install.
- Enter your pseudo password when prompted. If you haven't set one up, follow the on-screen instructions to create a memorable password and keep a record of it.
- After installation, turn off the Steam Deck and restart it in Gaming Mode.
- Press the QAM button, and the Decky Loader app, along with your settings and plugins, should return to their previous state.

