Today’s Steam Machine news is a fun one for emulation fans. u/HenricusKunraht has released Dual Screen Mode, a small tool that turns a Steam Deck into a wireless Wii U GamePad-style second screen for a Linux gaming PC like the Steam Machine. They shared it on r/steammachine in a post called “I turned my Steam Deck into a wireless Wii U GamePad for my Steam Machine“.
The idea is simple: the game runs on the main PC, while the Deck shows a second screen and handles controls and touch input. I haven’t set it up myself, so everything below comes from the project’s README and the Reddit post.
What Dual Screen Mode does
Dual Screen Mode is a KDE Plasma utility. It creates a virtual display on the host PC, gets Sunshine ready to stream that display, and adds desktop shortcuts to turn the whole thing on and off. On the handheld, you connect with Moonlight and the Deck becomes the second screen.
According to the README, you can use it for:
- A Wii U GamePad-style setup
- A DS or 3DS-style second screen
- A regular wireless second monitor for desktop or gaming use
u/HenricusKunraht said the setup was already possible before, but it meant combining KDE virtual displays, Sunshine, Moonlight, audio settings and terminal commands from several guides. Dual Screen Mode puts the host side in one place. They used it with Cemu and Azahar, and said Cemu worked especially well as a Wii U GamePad.
Steam Machine news: what you need
The README lists the setup the developer has validated for the host:
- SteamOS or another Arch-based Linux install
- KDE Plasma on Wayland
- Sunshine installed through Flatpak (the wizard can install it if it’s missing)
- KDE’s
krfb-virtualmonitorcomponent - The host and handheld on the same local network
The client doesn’t have to be a Steam Deck. The README says it can be another PC handheld, a tablet or a phone that supports Moonlight. Physical controls only work on devices that have them, but tablets and phones can still be used as wireless displays.
One important point: Moonlight still has to be installed and paired by hand. Dual Screen Mode doesn’t install Moonlight or pair your devices. Pairing is done through Moonlight and Sunshine’s normal PIN prompt, and only needs doing once. u/HenricusKunraht said they left this out on purpose rather than trying to automate it.
How setup works
- Download the latest release from GitHub and extract the .tar.gz file, for example with Ark.
- Open the folder and double-click Install Dual Screen Mode.desktop. If KDE asks, choose Launch, not Open with Kate.
- Click Begin setup and follow the wizard. If the KDE virtual-display package is missing, it opens Konsole so you can install it with your normal password, then you click Check again.
- When it’s done, you get two shortcuts: Dual Screen Mode, which turns the virtual display on or off, and Dual Screen Mode Settings.
After that, normal use is: double-click Dual Screen Mode on the host, open Moonlight on the handheld, connect to the paired host and start the stream. Turn on Moonlight’s gamepad mode when you want the handheld’s controls sent to the host. If Moonlight disconnects, the virtual display stays active so you can reconnect.
The README stresses that your password is typed into Konsole, not into Dual Screen Mode, and that the app doesn’t collect or store it.
Audio and touch
You can choose where audio plays. Host keeps it on the PC, and Handheld streams it to the Deck while muting the host’s default output for the session. A third option, Both, is still a work in progress and currently behaves like Handheld. Your previous Sunshine audio setting and volume are restored when you turn the mode off.
Touch was one of the trickier parts. u/HenricusKunraht said Azahar exposed a problem where touches went to the host desktop instead of the virtual display. Version 0.1.4 beta now maps Sunshine’s virtual touchscreen to the virtual display through KWin. How touch behaves inside each emulator still depends on that emulator’s own settings.
Limitations to know about
- It’s an early beta, made by one person and tested mainly with a Steam Machine and a Steam Deck.
- The host has to stay in KDE Desktop Mode while the virtual display is active.
- Gyro and microphone forwarding aren’t included.
- Ubuntu, Fedora, GNOME, X11 and other non-Arch or non-KDE setups aren’t currently supported by the installer.
The project is open source under the MIT licence, and it’s written in plain shell and Python. u/HenricusKunraht was also open that they used AI to help with some of the code. If you change your mind, the Settings app has an Uninstall option that removes Dual Screen Mode’s own changes without removing Sunshine, Moonlight or krfb.
What people are saying
The reaction in the thread was positive. u/TabloidA said this was one of the first things they thought of when setting up Wii U emulation on their Steam Machine, and that getting it working seamlessly in Game Mode, maybe with a Decky plugin, would be the dream. u/KimTe63 had a fair point too: the Wii U GamePad idea always sounded cool, until you actually play and realise how much you look back and forth between the screens.
My thoughts
I love seeing projects like this. Having to stay in Desktop Mode is a limitation, but making the Deck a wireless GamePad with a few clicks is a great use for a handheld you already own. If you’re into emulation, my look at the RetroDECK 0.11.0 preview is worth a read. For more Steam Machine tricks, try my HDMI-CEC tip or the Couch PiP picture-in-picture guide.
