Two-Wire Modem (25-25) Cable

This cable should be used for DTE to DCE (for instance computer to modem) connections without hardware handshaking.

25 PIN D-SUB FEMALE (To Computer).
25 PIN D-SUB MALE (To Modem).

25 PIN D-SUB FEMALE to the Computer
25 PIN D-SUB MALE to the Modem

Female Male Dir
Shield Ground 1 1
Transmit Data 2 2 -->
Receive Data 3 3 <--
System Ground 7 7
Jumper these:
Request to Send 4 -->
Clear to Send 5 <--
Data Set Ready 6 <--
Carrier Detect 8 <--
Data Terminal Ready 20 -->
Request to Send 4 -->
Clear to Send 5 <--
Data Set Ready 6 <--
Carrier Detect 8 <--
Data Terminal Ready 20 -->