Hi! years ago I was clearly interested with playing handheld emulators for the Wii (GB, GBA, etc) with a GBA SP connected through a Gba to GC cable, just for the sake of an original experience; of course, the only way to achieve this was only with a Gamecube and a Gameboy Player using it's original software. Since Game Boy Interface was developed by Extrems (gc-forever forum) I reassumed the interest again into having this feature for the Wii, at first, the app itself lacked the option, but in latest releases, they simply exceed it by far (FIX94 and Extrems code) by coding a payload for the GBA, acting almost totally as a Gamecube controller (heck, even by connecting a gba rumble compatible cartridge it acts as rumble support). Only input available are the d-pad, start, select (Z button) B, A, L and R triggers. It works perfect, no input lag at all. Things needed: -Nintendo Wii backwards compatible (Gamecube controller ports) hacked. -Gameboy advance (original, SP, micro) -Gba to Gamecube link cable (For me only works by using the official one, my third party cable -pelikan- fails to receive the payload transfer, it may vary depending on different manufacturers) -cMIOS (for launching GC homebrew on the Wii) -WiiExplorer (I use this only to load the GBI.dol file in GC mode, it's needed just a single time) -Game Boy Interface app (GBI) downloaded from here: http://files.extremscorner.org/gamecube/apps/gbi/latest Having all of this, it's just a matter of loading the GBI.dol file by SD, USB, SD gecko, etc.. plug the gba to gc cable into port number one previously connected to the gba and waiting in multiboot mode, next step: wait till the payload it is transfered to the gba and bang, the console itself now it's been recognized as a gamecube controller, it will stay in a solid white screen but completely functional, it even works with nintendont (not useful but kind of funny). Now you can reset the Wii and load the emulator of preference (I use gambattte and mgba with retroarch), it works with every app supporting gamecube controllers. I tried to capture the screen (attached file) loaded after launching GBI, just to note how it is detected by loading it on the Wii. I hope this mini tutorial is well explained, if not, feel free to ask.