A couple of flashcards have extra hardware inside them. For example, a flashcard like the acekard 2i is just an ordinary flashcard. But the Supercard DSTWO actually contains its own processor and memory built into the cart itself that can be used for extra juice in more advanced emulators. It has its own special emulators that will only function on the DSTWO. There's a couple of others like this, the iplayer and i believe the ismart mm. I forget if that's all of them. Most of the rest don't have that extra hardware however, so they're only able to use the specs inside the DS itself.