Intel H110 Technical Manual page 26

(5) GPIO1(10-pin): GPIO Header
(6) COM5/COM6 (9-pin): RS232 Serial Port Header
COM5
COM6
8
6
4
2
(2.0 pitch)
9
7
5
3
Pin 1
2
Pin 1
(2.54 pitch)
Pin NO. RS232 Pin NO.
DCD
Pin 1 Pin 2
Pin 3 SIN Pin 4
Pin 5 SOUT Pin 6
Pin 7 DTR Pin 8
Pin 9 GND
21
10
9
RS232
DSR
RTS
CTS
RI