Power Macintosh: Modem Port Disabled w/Internal Modem Present

I have noticed that the modem serial port is covered up with a piece of plastic on Macintosh Performa computers with PowerPC, and on many newer "consumer model" Power Macintosh systems. Why is this? Is it possible to uncover it and use it?
Certain Macintosh Performa systems with PowerPC, and Power Macintosh computers may have an internal modem installed in the communications slot. The presence of the internal modem disables the external modem port. Because this port is inactive, it is covered with a piece of plastic.

The following computers were bundled with an internal modem installed in the communications slot:
The following computers may have an internal modem installed in the communications slot, depending upon the bundle configuration. Check to see if the card in the comm slot is an ethernet card instead of a modem card. (Look for a green LED near the ethernet port.)
If you need to use the external modem port, the internal modem must be removed. Instructions for installing a card into the communications slot are included in the User's Guide. You can follow these instructions for removing the internal modem as well. Although such cards are typically user-installable, you may want to contact an Apple-authorized service provider for assistance with this procedure.

Warning: Any damage caused by the addition or removal of the modem is not covered under the warranty.

Note: Any Macintosh desktop computer which has a communications slot will also have the external modem port disabled if an internal modem is installed. However, the external modem port is available if a network card is installed in the communications slot. The following computers have a communications slot:
This article was published in the Information Alley on 26 April 1996.
Published Date: Feb 19, 2012