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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