EXTension Port

The EXTension Port of the Nintendo 64 game console, is found on it bottom side. It reads "EXT." and stands for extension. It is a cartridge drive but with a slightly different interface than the one above on the main deck.It has the same number of pins as the main cartridge slot and the same data transfer speed.

When not in use, it is covered by a plastic cap, which one has to remove before installing the 64DD under it.

EXT named ports can be found on many Nintendo consoles, such as the Game Boy, the Super Nintendo/famicom and even the Game Cube.