Extrems has just added support for Nintendo DS Rumble packs (GBA cartridges) when using a Game Boy Advance as a controller via link cable. It supports both the DS Rumble Pak support and the DS Slide Controller (mouse?) which includes rumble support:
https://www.gc-forever.com/forums/viewtopic.php?p=41699&sid=9e2ee28b4573ad4fd896a4b9dfb0d322#p41699
#gameboyinterface, #gbi, #gba, #extrems
