3Com U.S. Robotics 56K Voice User Manual page 29

The jumper shunts will be hanging from single jumper pins as shown in
the following illustration.
4. To change the COM port and IRQ settings, you need to reposition the
jumper shunts on the COM port and IRQ pins. To do this, lift the
jumper shunts off the pins.
Grasp the jumper shunts with a tweezers or needle-nosed pliers. DO
NOT grasp too firmly, as you may crush the shunts. If a jumper shunt
seems stuck, gently rock it back and forth as you lift. Do not touch
any other part of the modem or your computer with the
tweezers/pliers. A shunt needs to be sitting on both jumper pins in
order to effectively set the modem to the desired setting.
5. Move the jumper shunt to the new setting.
The COM port setting can involve one to three shunts. The four
possible COM port settings are as follows:
Unlike most COM port settings, the IRQ setting involves only one
jumper shunt. Simply move the jumper shunt to the pins labelled
with the IRQ you need.
Internal Modem Installation with Windows 3.x
56K Voice Faxmodem Internal - User's Guide 23