melonDS

melonDS is one of the most accurate DS emulators, and it supports DSi mode. In exchange, it requires genuine system files extracted from a console.

1. The files you need

For DS mode:

• bios7.bin
• bios9.bin
• firmware.bin

For DSi mode, you also need a NAND image.

Watch out for a classic pitfall: a DS firmware extracted from a DSi or a 3DS will not allow booting from firmware. You need a dump from an original DS or DS Lite.

2. Extracting your files

1. You need a DS or DSi you own, and a way to run homebrew on it (a flashcart with dump support, or a compatible console).
2. Dumping tools retrieve the BIOS and firmware in a few minutes.
3. Transfer them to your PC or phone.

3. Configuring melonDS

1. Open Config → Emu Settings.
2. Enter the paths to bios7.bin, bios9.bin, and firmware.bin.
3. For DSi, also provide the path to the NAND.

Without these files, melonDS simply refuses to start — that's not a bug.

4. Recommended settings

• OpenGL renderer with an increased resolution for a sharper image.
• Dual-screen layout: set it up according to your monitor (side-by-side is often more comfortable than stacked).
• JIT enabled — this is what makes emulation run smoothly.

5. Not working?

• melonDS refuses to launch → one of the three files is missing or its path is wrong.
• Booting from firmware fails → your firmware comes from a DSi or a 3DS; you need one from a DS or DS Lite.