It does not have a cartridge slot and thus is a dedicated console.
The two cartridge slots are designed to share data between the games.
The second and last one revision reverted to a single cartridge slot.
The cartridge slot is at the back of the bottom panel, where one would expect to find it.
Those consoles don't have the cartridge slots, and games are recorded directly on internal memory.
Four fret buttons are located on the side of the unit near the cartridge slot.
In some cases, a game system clone will have built-in games, and a cartridge slot for expansion.
One of these notches was placed as to avoid pressing a switch inside the cartridge slot.
Later models had only a single cartridge slot.
Using these cartridge slots, a wide variety of peripherals could be connected.