On the back were a number of ports, including connectors for power, the controllers, and an expansion port.

On the side of the 7800 was an expansion port, reportedly for a planned connection with a laserdisc player.

Shell has indentation of where expansion port was to be.

Same as above but with only a small blemish on the shell where the expansion port was.

The expansion port was removed in the second and third revisions of the 7800.

Features such as auxiliary weapons and "systems" (put into the expansion ports) allowed for a variety of different possibilities.

Ten pins were added that connected a cartridge directly to the expansion port on the bottom of the unit.

A large array of expansion ports were provided, including:

The unit plugs into the expansion port of the computer.

This solved the problem of the Multiface using up the computer's only expansion port.