Nullmodem 25 to 25 Pin Cable Pinout
From AllPinouts
Cable pinout for: Nullmodem 25 to 25 Pin
Use this cable between two DTE devices (for instance two computers).

25 PIN D-SUB FEMALE to Computer 1

25 PIN D-SUB FEMALE to Computer 2
| D-Sub 1 | D-Sub 2 | ||
|---|---|---|---|
| Receive Data | 3 | 2 | Transmit Data |
| Transmit Data | 2 | 3 | Receive Data |
| Data Terminal Ready | 20 | 6+8 | Data Set Ready + Carrier Detect |
| System Ground | 7 | 7 | System Ground |
| Data Set Ready + Carrier Detect | 6+8 | 20 | Data Terminal Ready |
| Request to Send | 4 | 5 | Clear to Send |
| Clear to Send | 5 | 4 | Request to Send |
Notes
- DSR & CD are jumpered to fool the programs to think that they are online.
