How does dual-slot mode *technically* work?

DS Lite, released in 2006, the Nintendo DSi, released in 2008 ( GBA slot has been replaced by an SD card slot It also has internal storage

Game Boy Advance SP Game Gear GameSlot Kit SKU GG0043 £

dsobet slot Remove the Game Pak Slot Cover from the Game Pak Slot · With the label side of the Game Boy Advance Game Pak facing away from the Nintendo DS Lite,

dsvr1277 Looking for Game Boy Advance DS cartridge slot datasheet Anyone knows where to get info or datasheet of the cartridge slot like this for the