Two-Wire Modem (9-25)
From HwB
This cable should be used for DTE to DCE (for instance computer to modem) connections without hardware handshaking.
Pinout
9 PIN D-SUB FEMALE to the Computer
25 PIN D-SUB MALE to the Modem
| Female | Male | Dir | |
|---|---|---|---|
| Shield Ground | 1 | ||
| Transmit Data | 3 | 2 | 
|
| Receive Data | 2 | 3 | 
|
| System Ground | 5 | 7 | |
| Jumper these: | |||
| Request to Send | 7 |
| |
| Clear to Send | 8 |
| |
| Data Set Ready | 6 |
| |
| Carrier Detect | 1 |
| |
| Data Terminal Ready | 4 |
| |
| Request to Send | 4 |
| |
| Clear to Send | 5 |
| |
| Data Set Ready | 6 |
| |
| Carrier Detect | 8 |
| |
| Data Terminal Ready | 20 |
|