Apple Macintosh PowerBook 1400 - Manual (Page 45)

4 Choose the type of PC Card modem you have in the pop-up menu on the upper left.
5 Choose the slot your modem is in from the pop-up menu on the upper right.
6 Change any other settings you want in the dialog box and click OK.
Then prepare and send your fax.
Configuring other software for use with a PC Card modem
Always be sure to specify the location of a PC Card modem when you
prepare to use software with it. Many programs are preconfigured for a
modem connected to the printer/external modem port, and you must change
that setting before you can make a successful connection.
45 Using Expansion Bay Modules and PC Cards