The MelonDS emulator’s release candidate has been officially promoted to a stable release, marking a major milestone for the Nintendo DS emulator after over two years of continuous development.

This release, very similar to the release candidate released last year, includes several bug fixes that emerged in the final testing phase.

Among the most notable improvements is the ability to use multiple windows with OpenGL on Windows , although, depending on the quality of the drivers, this may cause a performance penalty due to data sharing between multiple OpenGL contexts.

The developers are still working on a solution to this issue and are open to suggestions. To make managing multiple windows clearer, a tag system has been added to the titles, such as [p1:w2], which indicates the second window of the first multiplayer instance.

Among the new features, the integration of support for add-ons such as Motion Pak and Guitar Grip stands out , thanks to the contribution of a PR from asie, along with improvements that reduce audio latency.

Issues related to the DSi camera have also been resolved, allowing titles that use it to function properly, although performance may be impacted by the simultaneous use of the DSP. Implementing the HLE DSP is a future goal the team intends to work on.

A key change is the refactoring of the emulator core, which now allows multiple instances to run within a single process. This improvement not only optimizes local multiplayer but also lays the groundwork for future support for netplay.

In this regard, local network multiplayer has been reintroduced and improved, making it possible to play with friends on the same network, provided you have a high-quality Ethernet connection.

Another notable innovation is the new compute shader-based OpenGL renderer , which combines the precision of the software renderer with upscaling support, overcoming the limitations of previous versions.

At the same time, the Nintendo DS’s software renderer and GPU temporal model were refined through in-depth research into the original console’s technical specifications.

The update also introduces multi-window support, a much-requested feature that allows you to spread your emulator screens across multiple windows, offering greater flexibility and customization.

Additionally, support for flash cards like the R4 Revolution and M3 Simply has been added , allowing you to use the original menus for these cards. To round out the package, numerous bug fixes and general optimizations further improve the overall experience.

Characteristics

Nearly full core (CPU, video, audio, etc.).
JIT recompiler for fast emulation.
OpenGL renderer, 3D upscaling.
RTC, microphone, lid closing/opening.
Joystick support.
Savestate.
Various display position, sizing and rotation modes.
(In development) Wifi: Local multiplayer, online connectivity.
(In development) DSi emulation.
DLDI support.
(In development) Add-ons for the GBA slot.
…and much more on the agenda!

How to use

Booting via firmware (not directly) requires a BIOS/firmware dump from an original DS or DS Lite. DS firmware extracted from a DSi or 3DS is not bootable, as it contains only configuration data and is only suitable for directly booting games.

Possible firmware sizes

128 KB : DSi/3DS DS Mode firmware (reduced size due to missing bootcode).
256 KB : Standard DS firmware.
512 KB : iQue DS firmware.

DS BIOS dumps from a DSi or 3DS can be used without compatibility issues. DSi BIOS dumps (in DSi mode) are not compatible (or maybe they are, I don’t know).

Changelog

Fixes to the build system and continuous integration (Nadia).
DSi Title Manager: Fixed title string handling (Rayyan).
Fixed an issue where gdbstub would not activate until the console was rebooted (ZNixian).
Improved audio when the emulator is not running at 60FPS (Jakly).
Fixed numerous compilation warnings (Nadia).
Fixed bugs related to the frame limiter (Jakly).
Added support for solar sensor even without Boktai ROM (Jesse).
Set SDL_HINT_APP_NAMEto better identify the application (redbluegreenhat).
Fixed undefined behavior in (Jesse) indexing ARCode::Code.
DLDI: Added support for unaligned I/O in the melonDLDI driver (Arisotura).
Audio: Fixed applying microphone settings when closing the dialog (Arisotura, Nadia).
Multiplayer: Load correct firmware for each specific instance (Arisotura).
3D: Small fix in translucency flag assignment (Jakly).
AES: Tad key (edo9300) loaded.
Slot-2: Added support for Motion Pak and Guitar Grip (asie).
DSP: PDATA reads fixed (Arisotura).
Slot-2: Now does not return 0 when trying to read from GBA GPIO address (edo9300).
Camera: DMA activation ensured at the end of each frame (Arisotura).
NDMA: Fixed IRQ generation in infinite repeat mode (Arisotura).
Camera: Fixed resolution selection logic (Arisotura).
UI: Fixed OpenGL issues with multiple windows open (Arisotura).
UI: Added a way to distinguish between multiple windows (Arisotura).
Camera: Improved timing accuracy and FIFO management (Arisotura).
DSi: Added support for VRAM timings on 32-bit bus (bit13 of SCFG_EXT9) (Arisotura).
Audio: Using a single buffer, improves audio latency (Sparronator9999).
Fixed “full bios boot” flag not being set correctly when initially creating the DSi class (Jakly).