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Comment by Kronopath | Hacker News Reader

It might be DS emulation for 3DS. I'm pretty sure that DS games run under software emulation on that platform, given that you can do things like hit the "home" button to return to the 3DS's menu.

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Nope. I think its hardware emulation. The DS games run on one of the processors. I think its the processor that runs the system OS, which is why you can't just back out of a DS game into the main menu, you have to quit the game. Also the reason why you don't get street passes when you play DS games.

IIRC, it can't run the System OS at the same time because the system switches in to 'DS Mode'. The DS actually had two processors inside, and AFAIK the 3DS under-clocks both processors to match what the DS had and runs the games that way (And thus, while it's in 'DS Mode' the only way back to 3DS mode is via the Home button).

Its also interesting to note that this is how Nintendo has handled backwards compatability for every gameboy generator. In the DS the GBA's arm was used for sound processing. And the GBA has a GBC's z80. The GBC itself was just a GB z80 with a higher clock and special memory space for color palettes.

I believe that's also how the PS2 worked. I think it used the PS1 processor as the sound chip as well so they didn't need to emulate the processor.

Likewise the Sega Master System used a Z80 as its CPU; later, Sega used it for the Genesis / Mega Drive's sound management processor (plus a Yamaha synthesizer). If you plugged in the Power Base Converter, the Z80 would become the CPU and let you play Master System games.

More interestingly, I read something not to long ago that the GBA games released for the 'Ambassador' program on the 3DS are also run right on the hardware (For better or worse). I feel like that means the GBA's processor is also inside of the 3DS, probably because for 'DS Mode' to work it'd have to have a compatible sound processor in there somewhere.

> Its also interesting to note that this is how Nintendo has handled backwards compatability for every gameboy generator.

Same pattern as how they handled Game Cube compatibility on the Wii, I believe. I wouldn't be surprised if Wii mode on the Wii U were similar, but I'm not familiar with that.

True, in the case of both the Wii and WiiU they are mostly higher clocked Gamecubes. This is why Dolphin started as a Gamecube emulator and added Wii support. About a year ago I talked with one of the Dolphin developers and he anticipate extending to the WiiU once we have the CPU headroom.

I don't know who you talked to, but Dolphin will never have support for Wii U. Wii U emulation requires a completely different emulator type compared to Wii emulation.

Source: I'm a Dolphin developer.

Sorry then I must be wrong. All I remember it from was an IRC conversation on the PPSSPP channel.

IIRC Wii's CPU is a faster GameCube CPU, but the Wii U one is totally new, so the Wii U includes a Wii CPU.

That's cool, I didn't know that. Thanks!

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