# Mesen
Mesen is a multi-system emulator (NES, SNES, Game Boy, PC Engine, Master System/Game Gear) for Windows, Linux and macOS built in C++ and C#.
## Development Builds
[](https://github.com/SourMesen/Mesen2/actions/workflows/build.yml)
Latest development builds:
* [Windows](https://nightly.link/SourMesen/Mesen2/workflows/build/master/Mesen%20%28Windows%29.zip)
* [macOS - Intel](https://nightly.link/SourMesen/Mesen2/workflows/build/master/Mesen%20%28macOS%20-%20macos-12%29.zip)
* [macOS - Apple Silicon](https://nightly.link/SourMesen/Mesen2/workflows/build/master/Mesen%20%28macOS%20-%20macos-14%29.zip)
* [Linux](https://nightly.link/SourMesen/Mesen2/workflows/build/master/Mesen%20%28Linux%20-%20ubuntu-20.04%20-%20clang%29.zip)
* [Linux - AppImage](https://nightly.link/SourMesen/Mesen2/workflows/build/master/Mesen%20(Linux%20x64%20-%20AppImage).zip)
**macOS**: The macOS build still has a number of limitations (e.g no gamepad support).
**SteamOS**: Running Mesen through the Steam Deck's _Game Mode_ is possible with some caveats regarding rendering the UI.
SteamOS instructions and caveats
Due to Gamescope (SteamOS' compositor) not handling Avalonia UI's popups very well (a [solution](https://github.com/AvaloniaUI/Avalonia/pull/14366) is available but [has been reverted due to other issues](https://github.com/AvaloniaUI/Avalonia/pull/14573)), Mesen's menus for settings are not working through Gamescope unless running Mesen [through running KDE Plasma's Desktop through a script](https://www.reddit.com/r/SteamDeck/comments/zqgx9g/desktop_mode_within_gaming_mode_updated_for_new/).
Installation instructions:
* Download the **[Linux - AppImage](https://nightly.link/SourMesen/Mesen2/workflows/build/master/Mesen%20(Linux%20x64%20-%20AppImage).zip)** nightly build.
* **Mark the AppImage as executable.** (right click > Properties > Permissions > Is executable)
* Add the application as a non-Steam shortcut to be able to run it through Steam on both _Desktop Mode_ and _Game Mode_. (right click > Add to Steam)
* Customise the non-Steam shortcut through Steam to your desire. (in Steam: search the AppImage's filename, right click > Properties; from there you can change the icon, shortcut name and launch options)
* Create a folder called `Mesen.AppImage.Config` in the same directory where the AppImage is stored.
* Run it the first time. When asking where to store the settings, choose the `Store the data in my user profile` option. 
* Set up the controls as asked by Mesen.
**Due to Gamescope not rendering the UI menus, it is recommended to bind some keyboard shortcuts to L4/R4/L5/R5 (the Back Grip Buttons).** You can rebind controls in _Game Mode_ by clicking the Controller icon. You can save the layout by clicking the Cog icon (next to `Edit Layout`) > Export Layout > select `New Template` as the Export Type to use it across multiple shortcuts.
It is recommended to:
* Bind `Control Key + O Key` to open the file picker for opening a game file.
* Bind `Escape Key` to pause emulation.
* Bind `F11` to enter in or out of fullscreen.
**If sound does not work**, check if an audio device is chosen by Mesen. (in Mesen: Settings > Audio > General (Device))
**To make game-specific shortcuts**: Repeat the non-Steam shortcut step on the Mesen AppImage. Customise the new shortcut with a Launch Option (in Steam: right click > Properties; Launch Options). To find possible Launch Options, check the Command-line options menu (in Mesen: Help > Command-line options). When you want to supply a game with the shortcut, put the entire file location of the game in double quotes ("game-filepath") as the first part of the launch options. Add additional options (`--fullscreen` for example) _after_ the file location.
## Requirements
To run Mesen, the following prerequisites must be installed:
**Windows**: [.NET 6 Runtime](https://dotnet.microsoft.com/en-us/download/dotnet/6.0)
**Linux**: [.NET 6 Runtime](https://dotnet.microsoft.com/en-us/download/dotnet/6.0), SDL2
**macOS**: [.NET 6 Runtime](https://dotnet.microsoft.com/en-us/download/dotnet/6.0), SDL2
## Compiling
See [COMPILING.md](COMPILING.md)
## License
Mesen is available under the GPL V3 license. Full text here:
Copyright (C) 2023 Sour
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see .