Yeah, Im pretty sure those dont fit in the DS anyway...

The DS has two processors: one to play DS games and one to play GBA games. The GBA has two processors: one to play GBA games and one to play classic GB games. Without the latter processor, the DS is incapable of running classic GB games, so they decided to put a piece of plastic in the GBA slot that blocks off the notch indicating it's a classic GB game; even if this notch was removed, the game still wouldn't run.


As for attempting to connect a pair of games via Game Link Cable using two Game Boy Advance systems (or one Game Boy Advance and one Game Boy Color), it doesn't matter whether you use the GBC or the GBA cable. It is clearly stated in the instruction manuals of all modern Pokémon games that the classic ones cannot be connected.

The reason behind this is because the classic games have a different method of calculating IVs, EVs, stats, shininess, Pokérus, friendship, and a number of other factors. In fact, it's somewhat amazing that Game Freak even allowed the second generation to connect with the first because of the changes that still managed to get through and survive through a pair of transfers (like from Gold to Red, then Red to Silver). However, when the programming code was changed between the second and third generation, connection was deemed impossible.

Between the third and fourth generation, importing only added new information to existing Pokémon. Most of the code involving stats was still the same, but the original third generation data didn't support things like capture date. Some other data, such as capture region, was previously hidden, but was made visible in the fourth generation. Due to this data addition, reverse transfer (from fourth to third generation) was also not possible.

(However, looking back, I don't see why they couldn't have run an "import" scheme between the second and third generation like what they did with the Pal Park. The games could have re-calculated statistics or approximated the new IVs, and converted shininess to the newer, independent variable. Capture ball might have had to be botched with a "?".