Serial (RS232) null modem cable (DB9-DB25). Pinout and signals for building a serial (RS232) nullmodem cable

Use this cable between two DTE devices (for instance two computers).

	DB9 pin D-SUB female to PC1
	DB25 pin D-SUB female to PC2

	DB9	DB25
Receive Data	2	2	Transmit Data
Transmit Data	3	3	Receive Data
Data Terminal Ready	4	6+8	Data Set Ready + Carrier Detect
System Ground	5	7	System Ground
Data Set Ready + Carrier Detect	6+1	20	Data Terminal Ready
Request to Send	7	5	Clear to Send
Clear to Send	8	4	Request to Send