I only just got my ds lite and my last gameboy was the original B&W brick, so I'm new to all this. I was just wondering, using GBA backups on a supercard can i play wifi 2 player?
It is not possible, if you read your DS manual it even states that GBA games cannot be used in multiplayer, also has a small list of peripherals that do not work with the DS, including the GBA link cables, gba wireless adapters and even going as far to say the Gameboy camera and printer won't work with it.