Intel H61 User Manual page 19

(8) USB 2.0 Port Headers (9-pin): USB2/USB3
(Optional for Model NLH61 & NLH61-6C only)
(9) USB 3.0 Port Headers (19-pin): USB3_1/USB3_2
*USB3.0 headers (USB3_1/USB3_2)
(Optional for Model NLB75 only)
*The above diagram for illustration is from model NLB75.
(10) COM2/4/6/5; COM7/8/10/9 (9-Pin): Serial Port Header
COM4:RS232/422/485 serial port header;
COM2/6/5 & COM7/8/10/9: RS232 serial port header only.
*Note: COM7/8/10/9 port: only optional for Model NLH61 & NLB75.
*USB2 header
Pin 1
20
Pin 1
15
12
10