IDC internal | Signal Name | Description | pin number |
|---|---|---|---|
| 1 | DCD | Data Carrier Detect | 1 |
| 2 | DSR | Data Set Ready | 6 |
| 3 | RXD | Receive Data | 2 |
| 4 | RTS | Request to Send | 7 |
| 5 | TXD | Transmit Data | 3 |
| 6 | CTS | Clear to Send | 8 |
| 7 | DTR | Data Terminal Ready | 4 |
| 8 | RI | Ring Indicator | 9 |
| 9 | GND | System Ground | 5 |
Pin 10 removed in connector. Internal IDC connnector wired to external port with a simple flat ribbon cable.