Apple PowerBook (200 Series) - Manual (Page 41)

7 Choose Control Panels from the Apple ( K ) menu and open the Express Modem
control panel.
8 Choose Express Modem Settings from the pop-up menu.
9 Click Use External Modem to activate the external modem.
Leave Use External Modem selected even when you use your internal
modem.
10 Close the control panel.
The external modem is ready to use.
If you don’t have the Express Modem control panel: The Express Modem
control panel is part of version 1.5 of the Express Modem software. If you
have an earlier version of Express Modem software, or if you have another
kind of internal modem, you can activate an external modem by opening the
PowerBook Setup control panel and clicking the Normal button.
33 Connecting Additional Equipment