MSI ATX BX13 User Manual page 41

The mainboard provides a UHCI(Universal Host Controller Interface)
Universal Serial Bus root for attaching USB devices like: keyboard, mouse
and other USB devices. You can plug the USB device directly to this
connector.
USB Port 2
1 2 3 4
USB Port 1
PIN
1
2
3
4
2-36
SIGNAL
VCC
-Data0
GND
+Data0