Chapter 1 Motherboard Description
1-14
Connectivity
The many ways that a serial port can be used make it necessary to be familiar with
the pinout diagram. The following chart gives you the function of each pin on the
9-pin connector. This information can be used when configuring certain software
programs to work with the serial port.
Signal Name DB9 PIN DB25 PIN
DCD Data Carrier Detect 1 8
RX Receive Data 2 3
TX Transmit Data 3 2
DTR Data Terminal Ready 4 20
GND Signal Ground 5 7
DSR Data Set Ready 6 6
RTS Request to Send 7 4
CTS Clear to Send 8 5
RI Ring Indicator 9 22
To Next Page
