Introduction ¶

I semi recently bought an original Nintendo Entertainment System from a local retro game store in Santa Cruz called “Level Up Games”. I got the system, power adapter, RF unit, and 1 controller for around 65 dollars. In my off time I sometimes take the bus into the city to check out what games are available at the store. I currently have gotten Excitebike and Super Mario Bros 3. Both of these games offer multiplayer, however multiplayer games obviously require a second controller.

Design ¶

So I made a second controller. The NES controller is actually pretty simple, the only integrated circuit on the controller PCB is a CD4021 shift register, which, using clock and data pins from the NES itself, is able to expand the amount of digital inputs received from the controller. NES controllers have 8 buttons, up, down, left, right, a, b, select, and start, all of which are connected to ground, and pull down the pins of the shift register when pressed. Each pin of the shift register that is connected to a button is pulled up with a 1k resistor, with the other pins connected to wires on the controller port.

Compared to modern controllers, the original NES had an extremely simple control circuit. The design process for the case was also similarly very simple, just a box with holes for buttons.

For designing the top half of the case I had to include walls to keep the buttons from slipping out and falling. Generally speaking, when including posts to screw into when making a 3D printed design I recommend beveling edges so that the base is structurally strong. As of writing this, I have not ordered circuit boards for the NES controller, I will order them with the full mechanical keyboard circuit boards, there will be an update when I have assembled them.