Compaq 6730b - Notebook PC

Serial port
Pin Signal
1 Data carrier detect
2 Received data
3 Transmitted data
4 Data terminal ready
5 Signal ground
6 Data set ready
7 Request to send
8 Clear to send
9 Ring indicator
Universal Serial Bus
Pin Signal
1 +5 VDC
2 Data -
3 Data +
4 Ground
152 Chapter 9 Connector pin assignments