The MiSTer is compatible with a wide variety of controllers, including most USB adapters for original console game pads. For general use, some common wired controllers that work great with the MiSTer are the Hori Fighting Commander, the Xbox One controller, the 8BitDo SN30 Pro (which is nice because it also has analog sticks), and both the Saturn USB controller and Genesis 6-Button USB controller from RetroBit, which are officially-licensed Sega products. Wireless controllers that come with USB receivers like the wireless Genesis 6-Button controller from RetroBit also work great, although you have to remember to keep the controller charged. Most USB controllers are compatible with the MiSTer, so try using what you have on-hand before buying anything.
Plug your USB controller into the USB hub and press the ESC key to bring up System Settings. Select “Define joystick buttons” and press enter.
You will be asked to press right on the d-pad so that the system can detect what joystick you’re using. It will then ask you to tilt stick 1 right. If you are using a controller that lacks analog sticks, just press the space bar on the keyboard to skip both this entry and the next (“Stick 2 Test”). The system will then walk you through defining all of the possible controller inputs. If your controller features fewer buttons than the system is asking for, just press the space bar on the keyboard to skip some of them. The system will then ask you to define mouse inputs. Use the space bar to carefully skip through these until it asks for the “Menu” button.
This is the input that will replace the ESC key on the keyboard, and will be used in the menu system to call up the System Settings interface, but will also be used to bring up the core menu when you’re in the middle of playing a game. If your controller has more buttons than you’ve already assigned (for example, L2/R2 or the “PS” button on a Hori Fighting Commander) then you can simply use of one of those. If you don’t have any unused buttons on the controller, the system will allow you to use a button combination. Down + Start is a common choice.
Next it will ask you to define “Menu OK” and “Menu Back” buttons, which are your select and cancel buttons within the menu system. These can both be buttons that you’ve already assigned; A and B are common choices, respectively. Lastly it will try to define the analog sticks on the controller. Again, if you don’t have them, use the space bar to skip.
With the controller definition completed you can now unplug the USB keyboard, as you will no longer be needing it unless you’re using a MiSTer core that requires it (such as the computer cores). However, any time you want to use a new controller with your MiSter it needs to first be defined using the above procedure, which will require that the keyboard be used.
Now to copy your games onto the SD card, and get to gaming!