4800 HD (250-3539) Connecting a Serial Device Faxback Doc. # 1391 You can connect a serial mouse, fax, external modem, or other serial device to your computer's built-in serial port. 1. Prepare the serial device according to its user's guide. 2. Turn off the computer. 3. Pull down the cover on the back of the computer. 4. Connect your serial cable's DB-9 connector to the serial port. The serial port is identified by the serial port symbol (IOIOI) in the inside of the pull-down cover. 5. Turn on the computer. 6. If you are installing a mouse, load the mouse driver software, following the information supplied with the mouse. Your serial port is identified as COM1. Some applications ask you for this information before you can use a device connected to the serial port.