| computer serial port Pin Name | computer serial port Pin Number | Direction | mouse Pin Number | mouse Pin Name | Description |
| CD | 1 | <-- | 5 | CD | Carrier Detect |
| RXD | 2 | <-- | 4 | RXD | Receive Data |
| TXD | 3 | --> | 7 | TXD | Transmit Data |
| DTR | 4 | --> | 6 | DTR | Data Terminal Ready |
| GND | 5 | --- | 2 | GND | Ground |
| DSR | 6 | --> | 1 | DSR | Data Set Ready |
| RTS | 7 | <-- | 3 | RTS | Request to send |
| CTS | 8 | <-- | 8 | CTS | Clear to Send |
Pin 9 on the 9pin d-sub is not connected.
