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DesMuMe Faq

If the FAQ is unable to answer your question(s), then please make sure that you also consult the manual.


General Questions

What does desmume emulate and on what systems?

Desmume attempts to emulate, as faithfully as possible, the Nintendo DS and Nintendo DS Lite handheld game consoles (nds). It currently runs on Windows, Linux, and mac OSX. DSi is not supported.

What does DeSmuME mean?

DeSmuME is a Nintendo DS emulator and the name is a play of words - DS Emu + ME (like FlashMe - firmware hack and PassMe mod-chip for DS) The name DeSmuME derives from the popular use of ME in Nintendo DS products by homebrew developers. So DeSmuME would equal DSemuMe. Other popular uses of ME include:

  • LoadMe - a generic patcher for commercial DS roms that works with any GBA Flash Card
  • PassMe - "mod-chip" using which takes authentication from an original DS card an allows execution of unauthenticated DS rom code - from the GBA cartridge slot / GBA flash card.
  • FlashMe - a hacked firmware for DS that allows you to start code in DS mode from a flash card in the GBA slot.
  • WifiMe - are a set of a custom drivers and software by FireFly for RALink based wireless network cards enabling to boot homebrew code on DS via Nintendo Wireless Multiboot method.

Its name is derived from emu which is short for emulator, DS and me. It's possibly supposed to mean "DS emulator for me".

Under what license is desmume distributed ?

Desmume is distributed under the Gnu General Public License, or GPL: http://www.gnu.org/licenses/old-licenses/gpl-2.0.html

Can I freely copy desmume ?

Yes you can, as long as you adhere to the license as specified in the GNU GPL.

Why doesn't my desmume play this game?

Go to desmume.org and make sure you are using the latest version. Hint: desmume 0.8 and 0.3.4 are very old. Older versions will not be supported, under any circumstances.

Why does this game fail to save?

Desmume's autodetection for save types is not very good. For now, you need to manually specify the correct save type for your game. Consult the manual for details on how to do this for your platform. We want to fix this, but there are no specific plans so far. You may also consult http://www.advanscene.com/ to easily identify the save type for your game.

Can I use my save state's across versions ?

Probably not. Due to the constant internal changes in desmume, it is unlikely that a save state created with one version will work with another version of desmume. Please note that the use of SAVESTATES is discouraged, as these are likely to break between emulator versions. Instead use SAVE FILES. These are likely to survive between emulator versions. This means that you will have to use save points within the game. SAVE FILES are stored in .sav files. Also, see this article for further details : Savefile or savestate

Can I convert a no$gba nocash .sav savefile to desmume ?

Yes, go here http://shunyweb.info/convert.php

Why can't I find a mac binary?

We have an 0.9.2 mac binary which might not be linked to from the downloads page yet. Go to https://sourceforge.net/project/showfiles.php?group_id=164579&package_id=186413

Why does my mac binary say something about being unsupported?

You have probably downloaded the i386 version of desmume for MAC, and are running on the PPC platform (or the other way around). Please verify if you're running on Intel (i386) hardware, or on PPC (G4, G5) hardware, and download the appropriate binary.

Where can I report bugs?

In the official bug tracker. Feel free to post to the bug tracker as long as you are willing to take ownership of testing that bug and letting the developers know when it is resolved to your satisfaction. Just don't submit a bug report and run. You may also request features around the same location, too, but in the other trackers.

Can I attach files to bug reports I did not create myself ?

SourceForge likes for folks to only respond on items they submit. If you see a ticket that represents something you are encountering, SourceForge doesn't necessarily want you commenting on that. The reasoning for this given by SourceForge is that they feel it is best to open your own ticket, which helps appreciate the extent of issues in many cases. The authors of desmume may or may not agree with this point of view from SourceForge.

How do I get the latest svn code and build desmume myself?

Please check out the instructions related to your platform, over at Installing DeSmuME from source

Whats 'svn' ?

svn is a developers tool. It's used to let multiple developers work on the same codebase without conflicts. If youre an end-user, don't worry about it. And if you're a developer, see the question on how to get the latest svn code and build desmume yourself. See wikipedia for more info

What compilers are supported for building desmume from source ?

  • At the moment, for Windows Microsoft Visual C++ 2005 and 2008 are the only supported compilers. Dev-c++ is not supported. Why won't you just download visual c++ express?
  • For Linux, any recent version of GCC and toolchain should work.

Im Compiling using MSVC Express On Windows, and I get the error : "ml.exe" not found.

ml.exe was not included in earlier downloads of MSVC++ 2008 Express Edition. Uninstall, redownload and install again. See http://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=326875 for details. ml.exe shoud be located in the "Microsoft Visual Studio 9.0\VC\bin" directory.

Im a developer, and would like to contribute to the codebase. What can I do ?

To start you off in the right direction, the best thing you can do is join the developer team on IRC and discuss your intentions with the developers.

Im not a developer, but would like to help out anyway. What can I do ?

The most helpful thing you can do is use it, learn its ins and outs, and learn how to compile svn builds. Then monitor it for regressions and report bugs. You can patrol the bug tracker for bugs which could use elucidation or which, based on your awareness of how the emulator is changing, might be fixed without us having specifically addressed the bug. Basically, be a super user. And hang out on irc. Also, adding to or perfecting the documentation in the wiki is useful. You could also watch for and answer questions placed on the desmume forum.

What is this Lua stuff I see?

It is sort of a macro language for interacting with the running game software. Here is an example of it working with an NES game in another emulator, and youtubing for "fceux lua" should suffice to explain it if you don't get the picture from this url: http://www.youtube.com/watch?v=1XNTjVScm_8

What is 'TAS' ?

TAS lets you record the gameplay in TAS format, see http://tasvideos.org for details on TAS (tool-assisted speedruns).

It is hard to zoom in on a widescreen display due to the weird aspect ratio of the DS.

In fact it is hard to zoom in on a 4:3 screen, too. Proposals involve tearing apart windows and floating them side by side or separately or something. This may happen one day, in the form of side by side windows.

Why doesn't my openGL 3d work in linux?

Blame nvidia and ati for putting out shoddy drivers. Then switch to software rasterizer.

Why doesn't my openGL 3d work in windows?

You are probably using an ATI video card. ATI driver support of OpenGL is known to be poor. Get an nvidia. Do not argue with that, we are professional programmers and know what we're talking about. Or, switch to software rasterizer

Why doesn't a menu option or tool exist in my linux or mac build?

Because making portable tools and platform harnesses are not our cup of tea and so a developer puts a feature into whichever ports he cares about. This policy is never going to change, although some features might migrate to other platforms over time. Better check the manual.

Why does music and FMV sound bad sometimes?

Most DS music is sequenced music, loaded from the cart entirely when the level loads. This works fine. Your music that doesn't work is probably streaming music, which loads from the cart on the fly and goes straight to the speakers, and possibly decoded along the way. This includes FMVs. This is much harder to emulate as it requires correct timing, which is not one of desmume's strengths right now. This may not be fixed for a while.

Why doesn't my game boot or progress into the main game engine?

Desmume is not perfect yet. Some games may fail due to wifi emulation. Apparently if you search the web correctly you can find ways to patch games to work better on emulators. Your mileage may vary. If it really doesn't boot up, you can submit a bug report for the game on the sourceforge bugtracker.

What hardware features are emulated?

  • All known 2d graphics features are correct. Mosaics work but are imperfect. There may be small issues with colors as the correct color bit depths are not used at all points in the pipeline.
  • All 3d features are emulated, except for: tests, wireframes, edge marking, fog, and antialising. The opengl engine is near its limit and renders some things incorrectly. Eventually the software rasterizer (will support more features and be far more precise in the basic features. Both engines have trouble with some shadows, but software rasterizer is better. Software rasterizer has some noticeable texturing issues right now, especially in 2d games. Software rasterizer supports more correct lighting interpolation than opengl ever will (e.g. glitches at the edge of the screen while scrolling.) In software rasterizer, there are issues similar to 2d with incorrect bit depth being used in the pipeline. There are inaccurate edge conditions in each renderer; in opengl, textures tend to get overdrawn; in software rasterizer, edges of textures tend to be jittery.

One last thing -- if buttons and labels and menus rendering on the 3d screen are obscured (for example, a button but no label is on it) then you may need to use the software rasterizer.

  • All sound features are emulated. The microphone support is new and the manual should be consulted, where you will find out, among other things, that it is only supported in windows right now.
  • Wifi is not supported. It is currently under slow and incomplete development. Therefore, you may find this option missing, or simply 'greyed-out' for now. Also, since WIFI support does not work yet, don't ask any questions about it's functioning because it still is unfinished and does not work yet.
  • We are unaware of any outstanding issues in the core system hardware (cpu, dma, mmu) but there are certainly still some. The instruction and memory timings are quite incorrect; however, this seems not to hurt most softwares.
  • DLDI does anybody know if this still works?

Dynamically Linked Driver Interface, commonly known as DLDI, is a driver framework that allows NDS and GBA homebrew to easily read and write to any number of different devices, just by substituting a driver file.

  • RTC (real-time clock) works; If it didnt, then the time in your games stays at 00:00:00, and your random number values always come up the same.

Does the GDB stub still work?

This has not been built into the public releases, nor has the feature been tested in a while. If you want to be a test user, please hop on IRC and coordinate with the developers. The most recent time it was tested was on 06-11-2009, with the Insight GDB variant on windows with a recent devkit pro, and that got positive results.

How do I enable the GDB stub on the Windows port ?

Add #define GDB_STUB to src/windows/defaultconfig/userconfig.h.

Where/what is IRC?

IRC is an on-line communication system.

data you need:

  • server: irc.freenode.net
  • port: 6667
  • channel: #desmume

what to use:

  • mIRC - windows
  • ChatZilla - FireFox add-on
  • xchat - X
  • plenty other, see wikipedia

Where is the manual?

A manual for desmume is over at http://wiki.desmume.org/index.php?title=Manual. It may not have the information that other entries in this FAQ promised that it would.

Where is release 0.9.3 ?

Desmume 0.9.3 does not exist. It was sneaked out of our staging area. It has bugs, which is why we hadn't released it yet. So we decided not to release it at all. Any release claiming to be 0.9.3 wont be supported.

How do I enter 'cheat codes' in desmume ?

It is impossible yet to use "commercial" codes, such as Action Replay and Codebreaker, so what you'll have to do is manually search for, and alter the memory positions to your advantage. They are called 'raw' or 'internal' cheats. There's an excellent article in the wiki on Using Cheats in DeSmuMe . As of 0.9.4, there will be support for Action Replay cheat codes.

Why is the emulator slow?

Because nobody pays us to work on it full time and it runs fast enough for us to be happy. Well, almost.

  • The cheapest way to get 60fps is to buy the cart.
  • If you are in Windows, make sure you have tried the SSE build which helps a little bit.
  • If you are using someone else's unofficial "svn" build it probably is not fully optimized since we make our Windows releases using some profiler-guided optimization which helps by several FPS. For all I know they are also carriers of viruses, and lately they tend to crash on vista.
  • If you can handle it, turn off the sound.
  • Use frame skip. Even frameskipping 1 will help and many games will stay playable.
  • (0.9.4+) In the sound options, set interpolation to none which should help a little bit.
  • (0.9.4+) Turn on the sound option "ADPCM Caching"; this is new and experimental, and will break some things, but it should offer a substantial speedup in some cases.
  • Try the software rasterizer. In many cases, especially games which make only light use of the 3d hardware, this will actually run faster, by as many as 10 FPS. But it might also run slower, by as many as 10 FPS.
  • Buying a newer, faster computer is somewhat more expensive, but it has other side benefits.
  • A faster CPU is more helpful than a bleeding edge graphics card. Desmume is more CPU intensive than it is GPU intensive. It just needs a graphics card that is glitch-free, and currently the nvidia cards have a better track record. A newer graphics card has a slim possibility of increasing speed.

Why does the emulator take a million years to start up and/or devastate my system or unarchiver when I run it?

This is a problem with the desmume 0.9.2 that some people impolitely distribute themselves. Redownload 0.9.2 from sourceforge.net or get a newer version. It isn't a virus or anything, it is a bug in the application that can just bring a system to its knees. It tries to allocate 1GB of virtual memory. This also crashes or freezes some virus scanners (I've seen it on AVG).

What does the number/percentage in the desmume title bar mean ?

  • For the windows port, the percentage is the emulated arm9 CPU load average. The CPU in an actual Nintendo DS is an ARM9 CPU. The percentage shows us how busy the emulated CPU is. This number isnt really for you.
  • For the Linux GTK and Glade ports, it's frames per second (fps).

What's the difference between the the Windows 'desmume' and 'desmume_sse2' versions ?

desmume_sse2 uses some SSE2 optimizations for 3D matrix calculations. If your CPU supports SSE2, better use this version. Otherwise use the other version. Any modern Intel CPU (AMD or intel) will support SSE2.

Does desmume make use of multiple CPU's or multiple cores ?

Currently, there are no multi core optimizations. Everything runs in a single thread. You benefit MUCH more from a single greater Ghz cpu than from multiple cores or from multiple CPU's.

What are the minimum hardware requirements for desmume ?

From a purely technical viewpoint, there are no minimum requirements. However, for 'real-world' playable speeds, you would need at least the following :

  • Windows OS: Windows XP or Vista
  • Linux OS: Any recent Linux distribution with a 2.6 kernel.
  • 2 GHz Processor
  • 512 MB Available System Memory
  • Available Hard Drive Space: A few MB for desmume, and several GB for the nds files.
  • 128 MB 3D Video Card (Nvidia GeForce 6800 or better), ATI cards are not recommended.
  • Optional: Sound Card, if you want sound support
  • Optional: Microphone, if you wish to make use the Windows Microphone feature

What are the recommended hardware requirements for desmume ?

From a purely technical viewpoint, there are no recommended requirements. However, for 'real-world' playable speeds, the following gives you good performance:

  • Windows OS: Windows XP or Vista
  • Linux OS: Any recent Linux distribution with a 2.6 kernel.
  • 3 GHz Processor
  • 1 GB Available System Memory
  • Available Hard Drive Space: A few MB for desmume, and lots of GB's for the nds files.
  • 512 MB 3D Video Card (Nvidia GeForce), ATI cards are not recommended.
  • Sound Card.
  • Microphone.

In general, the more Ghz, the better. The faster memory, the better. Desmume currently won't benefit from multiple cores. Desmume currently is, unfortunately, slower than no$gba.

Does desmume support wifi ?

Wifi is not supported. It is currently under slow and incomplete development. Therefore, you may find this option missing, or simply 'greyed-out' for now. Also, since WIFI support does not work yet, don't ask any questions about it's functioning because it still is unfinished and does not work yet. Furthermore, current development activities focus mainly on the Windows build.

Why do I get an assert in wifi.cpp which keeps me from playing a game?

This was a glitch in 0.9.2 release. The download package has been replaced. Download it again and check the changelog to see if you have the fixed version.

OK, then why does it make my firewall alert since 0.9.2 ?

Your firewall is stupid, or winsock is stupid, (I am not sure which yet) for alerting just when winsock gets initialized. The emulator hasnt actually tried to connect to the internet yet. How could it? There isn't any wifi. All we are doing is some network initialization code. For those of you who are still not satisfied, then I will admit that there is actually some wifi code--but it doesnt actually do anything yet! Except alert your firewall. Sorry. Also, maybe that is actually a good, unobtrusive time for firewalls to alert. But I am not sorry for calling them stupid. They are hyperactive crybabies.

OK, so then why did my build come with winpcap.dll? Or why do I get crashes when I run desmume on vista which mumble something about winpcap?

Because you are running an unofficial build, from dubious origins, made by unknown people. The desmume team cannot support builds it did not create itself. Therefore, you are advised to stop using unofficial builds, as you can expect no support from the desmume team or on the desmume forums. Only use builds you downloaded from the desmume website.

What is WFC / WIFI Connection

See the article Nintendo wifi config utility

Does desmume support the microphone ?

Yes, but only on the Windows port. You do have to have an actual microphone attached to your PC, though. And perhaps somewhat confusing, the Linux ports do report 'Microphone successfully initialized' on startup of the emulator - but currently this is just a piece of stub (dummy) code used only to correctly start the emulator. In 0.9.2 the microphone in windows really only works for noise.

Where can I find technical details on the Nintendo DS and GBA ?


Does the 'GBA slot' option let me play GBA games ?

No. A 'real' Nintendo DS can use the gba slot to play gba games, but desmume does not emulate this. But a 'real' Nintnedo DS can also use the gba slot to access gba roms and sram so that ds games can import savefiles, and that part is emulated by desmume. If you are looking for a Game Boy Advance (GBA) emulator, perhaps you can try mednafen or visualboy advance.

How do I "Close the DS" ?

You can do so with the key BACKSPACE (you can change the mapping on the control configuration)

What is DLDI ?

let me give you an overview on DLDI. You should know that there are many various flash cartridges for DS. They use different file allocation systems, different storage's, etc. They are used for launching homebrew. So to make one program run on all cards. You’d have to write support for each and every card so that it worked for everyone. But none needs support for other cards than their own. And then a genial solution was found. There was an universal IO unit made that’s just interface to IO operations. And compiled program does not know how to handle file system etc. And then user can append IO routines for his own card. “DLDI patch”. So, now when I have an M3 cart, I download rom, patch it with m3 DLDI patch, and it works on my cart. Say you had Supercard instead. You’d have to download very same rom and apply Supercart DLDI patch to it. DLDI patch is the same for all roms. So it’s easy for both developer and end user.

I get the error: "Data could not be accessed. Turn off the power and reinsert the DS card."

This is probably caused by the fact that the automatic savetype detection failed to detect the correct savetype, and you have to set it manually to the correct type. If you are lucky, information about your game (and the corresponding savetype) can be found on a website such as http://www.advanscene.com/. And if you're not as lucky, you'll just have to try them all out until you find the correct type.

Another cause (but much less likely one) could be that your savefile .sav or .dsv has somehow gotten corrupted. try renaming both of them, exit and restart the emulator and reload the game to see if that resolves it.

Also, automatic savetype detection should be working in 99.8% of the cases now, and the only known game for which you still have to set it manually is 'Spiderman 3'. If you find any other game for which automatic savetype detection does not work, please let the developers know by posting on the forum or submitting a bug.

I get the error: "Unable to write data. Please turn off the power and reinsert the game card."

Same problem and resolution as the previous question.

How can I post a savefile or avi capture on the desmume forum ?

After you created it, you can upload it to a free external service provider like MediaFire (http://www.mediafire.com/), and then put the provided links to the page in the message you post on the forum.

How can I post a large log or other text file on the desmume IRC chat room ?

Make use of the external service provider 'pastebin' (http://pastebin.com/), and post the url to it on the IRC channel.

My display is incorrect or corrupted

Try switching the 3D Renderer from opengl or SoftRasterizer, or vice versa, to see if that resolves the bug. In windows, the default hotkey to do this quickly is numpad minus.

My display has flickering graphics in a certain game

In the Windows port, you can choose 'Alternate Flush Mode' in the 'Config | 3D Settings' menu. This fixes some games with flickering graphics.

How do I easily capture the ASM code for troubleshooting purposes ?

Savestate during the problem or just before your problem occurs, and #define WANTASMLISTING in armcpu.cpp. Recompile. Then redirect stdout to a file.

How do I make pokemon save?

Here are step by step instructions for you, before you give up and post on the forum:

  • delete pokemon.sav
  • launch pokemon
  • set save type to 4mbit
  • start a new save file (there isnt even a choice to load right now)
  • save in the game
  • congratulations, you will now have a loadable save file in pokemon

I got a gameplay related question

Please check a site like http://www.gamefaqs.com, and dont post gameplay related questions on the forum or IRC *unless* you believe there is a bug in the emulation of desmume.

What are the origins of DeSmuME ?

DeSmuME is a freeware emulator for the Nintendo DS originally created by YopYop156. The original website was http://yopyop156.ifrance.com

Due to change in French laws regarding emulation YopYop decided to stop development of DeSmuME. However, he released the source under the GPL, and other programmers have picked it up and kept it under active development.

Yopyop said:

It’s release under GPL. I have just removed the new 3D engine because it’s too much bugged. Hopefully it will be helpful for some of you.

The latest statement heard from yopyop was :

DeSmuMe project is over.
You may don’t know but there are a new law in France that could put me in big trouble.
With DeSmuMe, I have closed the doors of game company but I can not offer to pay for it.
The worst thing is that I have found the bad coded instructions.
For those how have download the sources you have to look in sbc, rsbc instructions the Carry flag updating is wrong.
Sorry for the home brew programmers.
For the illegality the demonstration seemed to me convincing thus without proof clarify I prefer to stick to this decision.
It is also the fact that few people seem interested by the project. Put besides some people who sent demonstrations to me which did not go, I received only malls to wonder to make function such or such plays or to ask me why moved is in French .
Thus I will not do something of useless and illegal.
For the site it would not obstruct me if there were not the bond on the left which does nothing but add to confusion on the goal of the project.
And for the sources it is the same problem as for the project.
good week end
edit the law relates to the royalties and the rights close, not?
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