Setting up internal serial ports

  1. If you are installing a new interface card to add serial ports, you will have to power down the computer and open it up. Identify an unused slot of the type required by the card and remove the corresponding cover from the back of the case. Depending on the number of ports supported by the card, you may also have to connect a serial port header to the card and install it in another unused opening in the back of the case.
  2. Identify the serial ports you've installed:
    1. Right-click the My Computer icon on the desktop, and then click Properties.
    2. Click the Hardware tab, then click the Device Manager button.
    3. Expand the Ports (COM & LPT) entry. The serial ports should each be listed as Communications Port (COMn) or mumble Serial Port (COMn), where n is the port number and mumble is some descriptive text.
  3. Connect two ports with a null modem cable, to provide a connection between them.