The ports were all on the same bus! You can send signals meant for any of the three of them into any of the three of them and it’ll work.
Well, the memory card slots and Serial Ports 1 and 2 anyway. The Game Boy Player connects via the parallel port.
Three ports, actually. One for network, one for the GBA player, and one that wasn’t used as far as I can recall.
Not totally useless!
The ports were all on the same bus! You can send signals meant for any of the three of them into any of the three of them and it’ll work.
Well, the memory card slots and Serial Ports 1 and 2 anyway. The Game Boy Player connects via the parallel port.
https://www.copetti.org/writings/consoles/gamecube/