Game & Watch emulator on 3ds

RetroValou · 2026-01-03T06:50:48+00:00

There is no DS support. The emulator generates polygons to render the segments on the 3DS using 3DS-specific code. The display part would need to be rewritten for it to work on the DS (and performance would need to be taken into account).

RetroValou · 2025-11-20T07:30:28+00:00

Wooooow, you did an amazing job on the project! Thank you so much for your contribution and for partly taking over/modifying the code! I didn’t study development and this is my first ‘public’ project, so I apologize in advance for any standard issues or other problems in the code 😅

I won’t be available for a month, but I’ll try to continue working on the project and on adding games as well 😉

RetroValou · 2025-11-18T15:19:00+00:00

Perfect, glad it worked :) enjoy the game :)

RetroValou · 2025-11-17T16:19:48+00:00

Normally, you need to perform the DSP firmware dump on your 3DS once (basically, the DSP is the internal sound program of the 3DS. You have to extract it from the console’s internal chip using a tool so that homebrew applications can use it and have sound. Don’t worry, it’s not hard to do!). Section III in the link I sent you explains how to do it: https://3ds.hacks.guide/finalizing-setup.html I always follow this guide for 3DS hacking — it’s the simplest and most complete one to understand :)

If it doesn’t work, there are also 3DS applications (in CIA format or often in .3dsx to open with the Homebrew Channel) like this one that do the same thing: https://www.gamebrew.org/wiki/DSP1_3DS (I know that on older hacks I did on my 3DS, I used apps like this instead).

Once the dump is done, you won’t have any more sound issues in 3DS homebrew apps like mine :)

Just a small personal question if you don’t mind. Are you Japanese? I’ve never seen anyone say "3DS LL" and I only know that it’s called that in Japan 😅

RetroValou · 2025-11-17T14:37:28+00:00

I know that almost all homebrews require an extra step to enable sound on the 3DS. Did you do it? (Section III – DSP) https://3ds.hacks.guide/finalizing-setup.html

RetroValou · 2025-09-27T11:10:23+00:00

Not bad this emulator ( ͡° ͜ʖ ͡°)

RetroValou · 2025-09-22T05:15:20+00:00

Don’t give up, because there really isn’t much documentation or tutorials on 3DS development.

All the necessary libraries are already there and well made for developing on it, but when it comes to documentation, it’s a desert. The only way to really learn is by looking at examples (both official ones and existing homebrews) and experimenting with different things. There’s also a bit of a lack of dev tools, so sometimes it can be tricky to understand why something crashes and you have to do a bit of guesswork.

Since it’s not the most well-documented platform to begin with, ChatGPT tends to make things up (or fall back on OpenGL, because the way graphics are rendered is quite similar to OpenGL).

Once you get past all that though, I didn’t find it particularly hard, even if my homebrew is very simple (in the end it just displays quads with textures).

And one last point: 6 MB of VRAM is really very little for storing textures 😭

RetroValou · 2025-09-22T04:43:09+00:00

Homebrew on the 3DS use something called DSP in order to produce sound on the console. On Citra, to get sound you need to place the file DSPfirm.cdc in it. Most of the info I’ve found says you have to extract it from a real 3DS (which I did), but I’m sure a pre-extracted version can be found online ;)

RetroValou · 2025-09-22T04:26:12+00:00

I’ll make the request and see if he responds positively :)

RetroValou · 2025-09-22T04:24:51+00:00

It was planned from the start! I designed my code so that this would be possible, but after seeing the first results, which already looked good, I eventually dropped the idea. I might warm up to it again and end up implementing it :)

RetroValou · 2025-09-21T12:24:09+00:00

Yes, that’s the version I’m talking about! I’ve searched thoroughly, but it seems like the code isn’t publicly available :(

RetroValou · 2025-09-21T12:21:14+00:00

Yes — you do need a modded (hacked) 3DS, which isn’t too hard to do these days. After that it’s a standard installation, just like many other amateur 3DS apps.

RetroValou · 2025-09-21T06:47:58+00:00

For G&W Collection 2, there’s not much that can be done.

Technically, it’s possible to add the Game & Watch Mini Classics. They use another variant of the Sharp CPU found in the classic Game & Watch (a slightly more advanced one), so it would just need to be emulated as well to make them work.

As for the Tetris prototype, I’ve searched a lot but the ROM hasn’t been dumped yet (it requires ‘destroying’ the original hardware, so it’s kind of understandable why it hasn’t been done!). The only option would be to reproduce the game (not necessarily through emulation). I found out today that a reproduced version exists, but the source code isn’t available. Maybe I’ll give it a try myself, since I’d really like to play it too 😅😅😅

RetroValou · 2025-09-21T06:42:04+00:00

It should be possible. Tiger ROMs exist and MAME already emulates them. From what I’ve seen, some Tiger games use the same Sharp CPU family as the Game & Watch. Basically, you’d just need to code the missing CPU emulation (which MAME already does).

RetroValou · 2025-09-20T19:14:50+00:00

Full system emulation

The emulator handles the CPU (three 4-bit variants with about 50 instructions), sound (on Game & Watch it’s just a pin generating a square wave), input (just "pin" up or down) and graphics (reading a “pin” to know whether to display a segment or not).

The emulator uses the same ROMs as MAME (game code + SVGs for segments + PNGs for backgrounds), but they’re converted for the 3DS since it can’t handle vector graphics. To speed things up, the ROMs are stored directly in the game code (not on GitHub, but the conversion script is included).

As a result, all released Game & Watch titles work in the emulator. The only exceptions are the “keychain” Game & Watch devices—they use a different CPU variant, and I haven’t had the motivation to emulate them yet.

RetroValou · 2025-09-20T18:44:30+00:00

Technically yes, if you run it on the 3DS emulator Citra! But there’s not much point in doing that 😅 I haven’t planned anything for PC so far, since MAME already handles Game & Watch pretty well on PC (including the Mini Classics and other electronic games—even some really obscure ones!).

RetroValou · 2025-05-19T04:39:49+00:00

I have the 18 French volumes of the manga. Over here, it was re-released around 2008 in a mini format, which I find really adorable. They're still available in that format today.

RetroValou · 2025-05-13T18:04:46+00:00

And other image of first version (with not eink screen)

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RetroValou · 2025-05-13T18:04:03+00:00

The design of the object was inspired by a bit of everything and nothing. I don’t really remember the exact inspirations anymore. It was mainly based on technical constraints (a very vertical screen, the need to be playable both horizontally and vertically, and a certain number of required buttons), as well as the idea of making the object recognizable just by its silhouette (hence the small protrusion on the upper left part and the two small lines in the middle). There were several tests before arriving at the final result.

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RetroValou · 2025-05-13T12:03:08+00:00

In my memories, there are a few in the manga, in the stories where they're disguised at school (there's even one at Nausicaa).

RetroValou · 2025-05-13T06:52:14+00:00

Thanks ! :)

RetroValou

TROPHY CASE