VT100 User Guide| Chapter 2 | Contents |
| Pin Number | Description | Pin Number | Description |
|---|---|---|---|
| 1 | Protective ground | 14 | (not used) |
| 2 | Transmitted data | 15 | Transmit clock |
| 3 | Received data | 16 | (not used) |
| 4 | Request to send | 17 | Receive clock |
| 5 | Clear to send | 18 | (not used) |
| 6 | Data set ready | 19 | Speed select (secondary request to send) |
| 7 | Signal ground (common return) | ||
| 8 | Carrier detect | 20 | Data terminal ready |
| 9 | (not used) | 21 | (not used) |
| 10 | (not used) | 22 | Ring indicator |
| 11 | Same as pin 19 | 23 | Same as pin 19 |
| 12 | Speed indicator (secondary carrier detect) |
24 | (not used) |
| 25 | (not used) | ||
| 13 | (not used) |