3Com U.S. Robotics 56K Voice User Manual page 31

2. Turn off your computer and unplug it from the electrical outlet.
2.3.Unplug any peripheral devices (printer, monitor, keyboard, mouse,
etc.) from the computer.
CAUTION: To avoid risk of electric shock, make sure your computer
and all peripheral devices are turned off and unplugged from electrical
outlets.
4. Remove the screws from your computer's cover and then remove the
cover, as shown in the following diagrams. Your computer may differ in
appearance from these diagrams, but the basic principle for removing
the cover should be the same. Refer to your computer manufacturer's
manual if you need further instructions.
Internal Modem Installation with Windows 3.x
56K Voice Faxmodem Internal - User's Guide 25