Here is some pictures from verbose output. I connected the mouse/keyboard to the USB 2.0 ports on the top as seen in the pictures attached, which are next to the PS/2 ports.
at the back there is 4x USB2.0 ports, and 2x USB3.x , 1 x FlashUSB .
at the front i got 1 x USB2.0 and 1x USB 3.x
that's 4 + 2*2 + 1 + 2 +? = 11 ? not sure the red one how much is it . so there ports are not more than 15.
Recorded this video as well : (edit: video link removed, in-case its breaking the rules, if it does not break the rules i will repost it,most of the info is the same as in the pics anyway)
I noticed, if i start unplugging then re-pluging the USB mouse or keyboard, i get a few lines of verbose output, as if its scanning and waiting for something. it's not a total crash, but perhaps it's trying to search for the mouse / keyboard.