This is my first attempt and building a snes multicart of any type. Since most snes hardware is playable on a powerpak I decided to go hardcore and wire up a superfx 2 cart. The 34 pin ide connector at the back wires up both the eprom for the cart as well as the crystal oscillator that determines the gsu 2 speed. So I just plug a little black box into the back and inside the box is the eprom of a game and the crystal oscillator that makes the gsu 2 run at the fastest speed that the game can run at.
The black box on the front is temporary I ran out of space inside of the cart and had to cut a hole in the front for wires. Later I plan on removing the big black cover and installing a much smaller cover.