Pin 4 is the common pin and pins 1, 8, 6 and 9 can each be associated with a different command using the same pull down style menu in the serial port setup (see wiring example 1 below). A serial port has 9 pins and by connecting arcade buttons to different pins you can trigger different commands. Using a serial port you can have up to 4 buttons each with different commands. You can use the pull down menu to set a command for right, left and middle mouse buttons. This will allow up to 3 buttons and is configured under the “Controls” tab in Booth. You can use an inexpensive mouse that can be found for less than $10 at most electronics stores. This will require some minor soldering but is not complex. One is to use a USB mouse and take it apart and replace the original mouse buttons with arcade buttons. There are 2 ways to use arcade buttons with Darkroom Booth.