The PS2 Keyboard/Mouse PMOD Connector has incorrect silk screen. The labels for VE and Gnd are backwards. VE is really GND, and GND is really VE. This is the +5V external input to power mice that run off of 5V (which almost all PS/2 mice actually do run off of 5V). Swapping VE and Gnd caused me to burn my mouse. It drew about a half-amp of current and immediately smelled that lovely smell of burning electrical components. I had to purchase a second PS/2 mouse once I found out the problem. If I connect the external power opposite of the silkscreen I am able to communicate with the mouse.