Asus M4A78T-E - Manual (Page 50)

2-30 Chapter 2: Hardware information
Chapter 2
7. IEEE 1394a port connector (10-1 pin IE1394_2)
This connector is for a IEEE 1394a port. Connect the IEEE 1394a module cable to this connector,
then install the module to a slot opening at the back of the system chassis.
Never connect a USB cable to the IEEE 1394a connector. Doing so will damage the
motherboard!
8. Serial port connector (10-1 pin COM1)
This connector is for a serial (COM) port. Connect the serial port module cable to this connector,
then install the module to a slot opening at the back of the system chassis.
The COM module is purchased separately.