melonDS Android

Overview

melonDS Android is a free, open-source program that lets an Android phone, tablet or handheld play Nintendo DS games, and also some Nintendo DSi games. It is the Android version of melonDS, a well known DS emulator for computers. An emulator is a program that imitates a game console, so the games made for that console can run on another device.

It is made for people who want a good DS emulator on Android and do not mind a few settings. It handles the two screens of the DS with several layouts, supports the microphone, cheats, achievements and more. It does not need a separate download for each game: you point it to a folder and it lists your games.

You can get it on Google Play or from the project page on GitHub, where the source code is public under the GPL-3.0 license.

Key words explained

• ROM: a game from a DS cartridge, saved as a file on your device. DS ROMs usually end in .nds. The app can also read them from inside ZIP or 7z archives.

• BIOS: a small program built into the console that starts it up. The DS has two, called ARM7 and ARM9 (named after the two processors inside the console).

• Firmware: the software stored in the console that shows its start menu and keeps the owner's settings, such as the nickname. The emulator can imitate these, so it is optional for most games.

• Dump: a copy of a BIOS, firmware or game made from your own console or cartridge.

• NAND: the internal memory of a DSi, where it keeps its system and downloaded games (DSiWare).

• DSi: the later model of the DS. Some games and downloadable titles only work in DSi mode.

• JIT recompiler: a technique that translates the console's code into your device's code while the game runs. It makes emulation much faster.

• Renderer: the part of the emulator that draws the 3D graphics. It can draw them on the processor (Software) or on the graphics chip (OpenGL).

• Internal resolution: how many pixels the 3D graphics are drawn with before being shown on screen. Higher gives sharper 3D but needs a stronger device.

• In-game save: the save the game itself makes when you use its save menu, like on a real console.

• Save state: a snapshot of the whole game at one exact moment, which you can restore later.

• Layout: the way the two DS screens and the on-screen buttons are placed on your device.

• Frame rate: how many images per second are shown. The DS runs at about 60.

System requirements

• A 64-bit Android device. The project says performance is good on 64-bit devices with threaded rendering and the JIT recompiler on, and poor on 32-bit ones, which cannot use the JIT.

• Most 64-bit phones from the last several years should be fine at the default settings. Higher resolutions with the OpenGL renderer need more power.

• To check your device: open Settings > About phone and look at the processor, or search for your phone model's specifications. Almost every phone sold in the past years is 64-bit.

What you need

• The app. Why: it is the emulator itself.

• Your own games, dumped from your own cartridges. Why: the app does not include any game. This site does not explain how to get them, and you must not download games you do not own.

• Optional, BIOS and firmware dumped from your own DS: bios7.bin, bios9.bin and firmware.bin. Why: the app has built-in replacements, but real files improve compatibility and let you open the real DS start menu.

• Only for DSi mode, the same three files plus nand.bin, all dumped from your own DSi. The wiki also says the DS files are needed in that case, because DS games are run with them. Homebrew (games made by fans) cannot run in DSi mode.

• Optional: a Bluetooth or USB game controller. Why: the screen buttons work, but a controller is more comfortable.

The project does not provide a guide to dump these files, and neither do we. They must come from your own console.

Installation

1. Easiest way: open the Google Play page on your device and tap Install.

2. Other way: download the APK (the Android install file) from the releases page. Open the file; Android will ask once to allow installs from your browser or file manager. Accept.

3. The releases page also has nightly builds, which get new features first. The project warns that they may be buggy and may need the app's data cleared after an update. Beginners should use the stable version.

First setup

Names of options can change slightly between versions. The project wiki has a page that explains every setting.

1. Put your games in one folder on your device, for example a folder called DS in your internal storage. The app scans only one folder, but it also looks inside the folders it contains.

2. Open the app, then go to the settings and open the ROMs section. Choose Search directory and pick that folder. Your games then appear in the list.

3. Optional, BIOS and firmware: copy bios7.bin, bios9.bin and firmware.bin into one folder. In the settings, open System > Custom BIOS and firmware and choose that folder as the DS BIOS directory. The file names must be exactly these.

4. Check the indicator next to the setting. A red mark means no file was found, an orange mark means some are missing (tap it to see which), and no mark means all is well.

5. Show boot screen: if on, the DS start menu opens before the game, like on a real console. Leave it off for a direct start, and it must be off for homebrew.

6. Optional, DSi: choose the DSi BIOS directory (with the four files, including nand.bin) and set Default system to DSi. The wiki marks DSi mode as experimental.

7. Check System > Enable JIT: it should be on. It is only available on 64-bit devices.

8. Tap a game in the list. If it shows the game within a few seconds, it worked.

Adding your games

• Copy your game files into the folder chosen as Search directory. Files can be .nds, or inside ZIP or 7z archives.

• Compressed games are extracted before they start. The app keeps the extracted files in a cache to load them faster next time. In Settings > ROMs you can set Max. ROM cache size or clear the cache if it takes too much storage.

• Icon filtering only changes how the game icons look in the list: pixelated or smoothed.

Controls

• Touchscreen: the DS bottom screen is touch-sensitive, and on Android you simply touch it with your finger.

• On-screen buttons: a virtual copy of the DS buttons. In Settings > Input you can turn Show soft input off if you use a controller, change its opacity, and set vibration on touch.

• Layouts: Settings > Input > Layouts lets you choose, create or edit the placement of the screens and buttons. Since version 2.0.1, parts of a custom layout can sit inside the camera cut-out area. The app supports dual-screen and foldable devices, and can use one display for each DS screen.

• Controller mapping means telling the app which controller button does what. Go to Settings > Input > Key mapping, choose a DS button, then press the controller button you want for it.

• Microphone: some games ask you to blow or speak. In Settings > Audio, Microphone source can be None, Blow (a constant blowing sound) or Device microphone. The last one needs the audio recording permission from Android.

• Fast-forward: speeds the game up. Settings > General > Fast-forward max speed sets how fast it can go.

Graphics and performance settings

• Enable JIT (System): translates the game code quickly. Recommended: on. It may very rarely crash a game; if you suspect that, turn it off and test again.

• Threaded rendering (Video): draws 3D on a separate thread. Recommended: on. It usually helps 3D games but may cause small visual glitches. Turn it off if you see them.

• Renderer and resolution: the app offers a Software renderer, which is the most accurate, and an OpenGL one that can raise the 3D resolution on strong devices. Start with the default and raise it only if the game stays smooth. Version 2.0.1 improved OpenGL speed. These options are not described in the wiki, so look at their descriptions in the app.

• Filter (Video): smooths the image or adds an effect. Pure taste; none of them change how the game plays.

• FPS counter position (Video): shows the frame rate on screen, so you can see if the game runs at full speed.

• Sustained performance mode (General, on some devices): stops the device from slowing itself down when hot, and saves battery, at the price of some performance. Try it if speed drops after a long session.

• Audio latency and Interpolation (Audio): lower latency means less delay in sound but may cost performance; interpolation can improve sound quality at a cost too. Leave them at default unless the sound crackles.

Saves

There are two kinds of saves. An in-game save is made by the game itself, in its own save menu, like on a real DS. A save state is a snapshot of the whole emulator at one moment, made from the app. Use both: in-game saves are safer, save states are handy before a hard moment.

• In-game saves are stored as a SAV file. By default they sit next to the game. Settings > Save Files lets you turn off Save next to ROM file and pick a Save file directory instead. Changing the folder does not move old saves: copy them yourself.

• Save states go where Save state location says: the save folder, the game folder, or the app's internal folder. The internal folder keeps things tidy but is harder to reach for a backup.

• A game opened without being scanned has its saves in Android/data/me.magnum.melonds/files/saves, according to the project.

• Rewind (Settings > General) takes you back a few seconds, useful after a mistake.

• Backup: copy your save folder somewhere safe from time to time. Uninstalling the app or clearing its data can delete saves stored in the app's own folder.

Extras

• Achievements: sign in to RetroAchievements to earn achievements in supported DS games.

• Cheats: turn on Enable cheats in Settings > Cheats, then import a cheat database in XML format. Cheats can then be switched on and off one by one for each game.

• Wi-Fi: Nintendo's online service has been closed since 2014, but the wiki explains how to use a community replacement service, on the Wi-Fi Connectivity page.

• Local multiplayer: it exists, but the wiki warns that connections between devices will most likely fail. See the Local multiplayer page.

Updating

• Google Play installs updates by itself, or when you tap Update on the app page.

• With an APK, download the new one from the releases page and install it over the old one. Your data is kept.

• Before a nightly build update, back up your saves, because the project says clearing the app's data may be required afterwards.

Common problems

• The game is very slow. Cause: JIT or threaded rendering is off, or the resolution is too high, or the device is 32-bit. Fix: turn on Enable JIT and Threaded rendering, use native resolution or the Software renderer, and check the FPS counter.

• The game does not start or freezes. Cause: a missing or wrong BIOS or firmware. Fix: check the indicator in System > Custom BIOS and firmware, and make sure the file names are exact. Or clear the BIOS setting to use the built-in replacements.

• DSi mode does not work. Cause: a missing file. Fix: the DSi directory needs bios7.bin, bios9.bin, firmware.bin and nand.bin, and the DS directory must be set too.

• A homebrew program does not run. Cause: Show boot screen is on, or DSi mode is selected. Fix: turn the boot screen off and use DS mode.

• My saves are not where I expected. Cause: the Save Files settings or a game opened outside the scanned folder. Fix: check Settings > Save Files, and put the game in the Search directory.

• The game list is empty. Cause: no folder chosen, or the files are not .nds, ZIP or 7z. Fix: pick the folder again in Settings > ROMs.

• The microphone does nothing. Cause: the Android permission was not granted, which sends the app back to the Blow option. Fix: allow audio recording for the app, then choose Device microphone.

• Crashes after updating. Cause: a nightly build. Fix: back up your saves, clear the app's data, or go back to the stable version.

For a bug, you can look at or open an issue on the project issue tracker.

Going further

• Project wiki, with every setting explained.

• BIOS and firmware page of the wiki.

• Releases for stable and nightly versions.

• melonDS, the computer emulator this app is based on.

• Lemuroid, simpler, for many consoles in one app.

• melonDS on a computer.