Apple PowerBook (Duo 270C) - Manual (Page 240)

Network
If you installed the appropriate NuBus card in your Duo Dock,
then whenever your PowerBook Duo is docked you have access
to another network type—such as Ethernet or Token Ring—in
addition to your computer’s built-in LocalTalk. The first time you
use the other network, you must open the Network control panel
and select that network type.
Once you have made a selection, the computer remembers it
whenever the PowerBook Duo is docked. Whenever the
computer is not docked, LocalTalk is the network type.
Modem
If you want to use an external modem with your Powerbook Duo
System, connect the modem cable to the Duo Dock port marked
with this icon: W
If your computer has an internal modem, select either Internal or
External Modem in the PowerBook control panel before opening
your telecommunications program.
If you have system problems
If your docked computer crashes (the screen goes blank or fills
with gibberish) or freezes (the pointer doesn’t move and input
devices don’t work), press the power button on the back of the
dock once. Pressing once turns the computer off. Use the Power
On key on your external keyboard to turn the computer on again.
Pressing the power button erases any information you did not
save, but it allows you to restart the system and continue working.
See the troubleshooting section of your PowerBook Duo User’s
Guide for more information about handling system problems.
224 Chapter 13: Building a PowerBook Duo System