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Fun fact! The Nintendo DS audio chip has a distinctive buzz that's visible in all audio tips uploaded to YouTube, and you can even hear it on this page! It come

Fun fact! The Nintendo DS audio chip has a distinctive buzz that's visible in all audio tips uploaded to YouTube, and you can even hear it on this page! It comes from.... a bug in the popular DeSMuMe emulator. Yes, it turns out that the people that designed the "2sf" format used for unofficial music rips simply used stripped down ROMs and code extracted from a version of DeSMuMe. Community tooling later allowed you to batch convert them to MP3, and the rest is history. Line rips recorded from the audio jack of the device don't have this distinctive buzz. Extra fun when some official soundtrack releases contain the buzz :) There's some other fun facts about the DS (its 3D hardware is scan line based, not frame buffer based! Which means you can't do post processing on it without some hacky tricks... can you tell it was from the team that made the PPU, rather than a modern GPU or even an SGI-derived one?), but that one is my favorite. Edit: minor correction, the N64 supported AA, which is another reason jagged polygons are less common.

archseer 6y ago
Interesting! Do you have any examples or further reading links about the buzz? I skimmed through the audio samples on the page but I couldn't quite hear it.
- Jasper_ 6y ago
  It's probably most notable in Mario Kart DS's bassline. I'll see about getting a comparison with what it should sound like later today.
TazeTSchnitzel 6y ago
> Edit: minor correction, the N64 supported AA So did the DS: http://melonds.kuribo64.net/comments.php?id=32 http://melonds.kuribo64.net/comments.php?id=32
- Jasper_ 6y ago
  > To begin with, antialiasing is applied to polygon edges based on their slopes, in order to make the edges look smoother. There is no antialiasing applied inside polygons or at intersections between two polygons Oh my. You really can tell this GPU was done by a 2D PPU team.
  - pcwalton 6y ago
    And look at the way it tries to figure out a "foreground" and "background" color by doing some sort of bizarre approximation of depth peeling. What a glorious, and terrifying, hack.
mrguyorama 6y ago
You say in the article that the 3D engine can only display to one screen at a time, but some games definitely play 3D content on both screens (like Legend of Zelda Phantom Hourglass). How do you think these games are accomplishing this?
- Jasper_ 6y ago
  I didn't write the article, and I'm not much of an expert on DS graphics (it's too surreal for me). But you can copy 3D content to 2D images and then display it using the 2D engine, I believe, and then use 3D on the other screen through the direct method. Pretty much everything on the DS is a bizarre special case, and Nintendo's in-house staff is very good at exploiting every last trick in the book.
  - WorldMaker 6y ago
    The article mentions that the Main 2D Engine had a mode that could write to a framebuffer that was the combined area of both screens, and could pull from the 3D engine into that full framebuffer layer. Also, you'll notice in the New Super Mario Bros example that many of the sprites were pre-rendered 3D and the 2D engine was just pulling bitmaps at that point. So a bunch of options with all sorts of interesting trade-offs and it would be interesting to see breakdowns of specific games and how they used the trade-offs.
- Asooka 6y ago
  From what I remember playing with the homebrew devkit, there is a hardware flag saying which screen the 3d engine writes to. So you will flip that flag every frame and have 30fps per screen.

archseer 6y ago

Interesting! Do you have any examples or further reading links about the buzz? I skimmed through the audio samples on the page but I couldn't quite hear it.

Jasper_ 6y ago
It's probably most notable in Mario Kart DS's bassline. I'll see about getting a comparison with what it should sound like later today.

TazeTSchnitzel 6y ago

> Edit: minor correction, the N64 supported AA So did the DS: http://melonds.kuribo64.net/comments.php?id=32 http://melonds.kuribo64.net/comments.php?id=32

Jasper_ 6y ago
> To begin with, antialiasing is applied to polygon edges based on their slopes, in order to make the edges look smoother. There is no antialiasing applied inside polygons or at intersections between two polygons Oh my. You really can tell this GPU was done by a 2D PPU team.
- pcwalton 6y ago
  And look at the way it tries to figure out a "foreground" and "background" color by doing some sort of bizarre approximation of depth peeling. What a glorious, and terrifying, hack.

mrguyorama 6y ago

You say in the article that the 3D engine can only display to one screen at a time, but some games definitely play 3D content on both screens (like Legend of Zelda Phantom Hourglass). How do you think these games are accomplishing this?

Jasper_ 6y ago
I didn't write the article, and I'm not much of an expert on DS graphics (it's too surreal for me). But you can copy 3D content to 2D images and then display it using the 2D engine, I believe, and then use 3D on the other screen through the direct method. Pretty much everything on the DS is a bizarre special case, and Nintendo's in-house staff is very good at exploiting every last trick in the book.
- WorldMaker 6y ago
  The article mentions that the Main 2D Engine had a mode that could write to a framebuffer that was the combined area of both screens, and could pull from the 3D engine into that full framebuffer layer. Also, you'll notice in the New Super Mario Bros example that many of the sprites were pre-rendered 3D and the 2D engine was just pulling bitmaps at that point. So a bunch of options with all sorts of interesting trade-offs and it would be interesting to see breakdowns of specific games and how they used the trade-offs.
Asooka 6y ago
From what I remember playing with the homebrew devkit, there is a hardware flag saying which screen the 3d engine writes to. So you will flip that flag every frame and have 30fps per screen.