Emulator melonDS

Systems: Nintendo DS (nds) · Runs as: homebrew NRO · Get it: hb-app.store listing · GBAtemp continuation thread

melonDS is the DS emulator of choice on Switch. The port started with Hydr8gon, got its big performance work (JIT recompiler) from RSDuck, and is carried on today by community builds — grab whichever the GBAtemp thread or the Homebrew App Store currently points at.

This is the one emulator on this wiki with a hard BIOS requirement — it won't start games without DS system files.

Install

1. Download the release and extract it to your SD card so you end up with sd:/switch/melonds/ containing melonds.nro and its support files.

2. Add your DS system dumps to that same folder, with these exact names:

   File	Size	What it is
   bios7.bin	16 KB	ARM7 BIOS
   bios9.bin	4 KB	ARM9 BIOS
   firmware.bin	128/256/512 KB	DS firmware

3. Launch from the homebrew menu.

Firmware caveat: a firmware dump from a DSi or 3DS only carries configuration data — games boot fine with it, but the "boot the DS menu" path needs firmware dumped from an original DS or DS Lite.

Point it at your HaulNX library

melonDS opens ROMs through a file browser and doesn't care where they live:

1. Download DS games with HaulNX — they land in sd:/roms/nds/.
2. In melonDS, browse to /roms/nds and pick a game.

Unzip first. melonDS wants bare .nds files — if HaulNX brought a game down as a .zip, extract it in place before it will show up as loadable.

Saves and tips

• Game saves (.sav) are written next to the ROM in sd:/roms/nds/ — same warning as mGBA: deleting a game's files from the library folder deletes its save. Back up .sav files before cleaning house.
• Performance is very good for most 2D titles with the JIT enabled (it is by default in modern builds); heavy 3D games benefit from docked mode and an overclock.
• The touchscreen maps to the Switch touchscreen in handheld mode — many DS games are simply nicer undocked.