Partially true, partially not. Yes, the GBA expects lightning-fast response times, and the only thing a slot-1 user would have that would be fast enough would be the DS's on-board RAM. However, there is only 4 MB of this, which would have to store both the rom and the emulator itself. Perhaps a paging system could be created that would call up chunks of ROM into RAM as needed in order to get 4 MB games to run, but this would probably be pretty slow.Yeah, then... anyway, I just thought the following:
The Gba has just a lil better specs then the SNES, so what's going on anyway... I don't quite understand.... I could only think of it this way:
The DS is too slow to read the fast GBA Cards, cause compared to the SNES Cards they have (really) fast read speeds, or ?
However, the GBA's specs far surpass the SNES's, hence why it's possible to emulate the SNES on the GBA in the first place. http://wiki.pocketheaven.com/SNES_Advance has a chart that compares the specs of the two systems. The SNES also expects fast response times as far as I know, which is why the paging system is needed in SNEmulDS in order to run games larger than 2-3 MB.
Bottom line however, emulating the GBA on the DS would take quite a bit of work, and very few developers would even give it that much effort because the DS already has 100% compatible hardware emulation via slot-2, while a software emulator would never be able to reach that level of speed and compatibility.