Saphiresurf said:
oh ok. but the ds/dsi are still faster than the gba why cant they emulate gba? (im almost sure thats another noob question)
There's not really a set number or anything, but the host device usually does have to be several times stronger than the device it's emulating. The DS has a 66MHz main processor (ARM9) and a 33 MHz sub-processor (ARM7) while the GBA runs at 16 MHz (ARM7), so it would be a stretch. Compare this to the iPod Touch which has (at least) 400 MHz of processing power and 128 or 256 MB of RAM. Furthermore, it would be difficult to find a place fast enough to accommodate the GBA game, since it expects the "cartridge" to respond lightning-fast. The only thing the DS has that would be fast enough is its 4 MB of RAM, which wouldn't even be enough to hold the smallest GBA games (when you consider that the emulator itself must also live in this 4 MB). The emulator could be coded to prevent the game from freezing when data isn't supplied fast enough, but obviously you'd get lag.
The DSi would in theory make GBA emulation
slightly more possible, but we still don't have access to DSi mode, so we're stuck with the exact same limitations we had on the DS. That's why the additional horsepower of the iPlayer is necessary for GBA emulation to become possible.
Really, there's nothing stopping someone from porting VBA directly to the DS and hacking it into working, but it wouldn't run fast enough to be at all playable. The DS simply doesn't have the power to do it without some sort of help, like with the iPlayer.
On a side note, you may be interested to know that the GBA emulators for the iPlayer and the iPod Touch are actually based off the same thing. Exophase originally made gpSP for the PSP, using a dynamic recompiler to achieve the efficiency needed to get full speed. This is the emulator that was ported to the iPlayer by darkchen, and to the iPod Touch / iPhone by ZodTTD. In both cases, the only reason it was possible to port gpSP was because the dynamic recompiler was already made to compile to the MIPS architecture of the PSP's processor, which just so happens to be the same architecture used by both the iPlayer and iPod/iPhone.
