3Com U.S. Robotics 56K Voice User Manual page 35

20. Set the Baud Rate to the highest option and Flow Control to Hardware.
Then click Advanced.
21. In the Interrupt Request Line (IRQ) box, select the IRQ.
22. Click OK.
23. You will see a screen prompting you to restart Windows. Click
Restart Now.
Turn to "Software Installation" on page 29 for information about installing
communications software.
Internal Modem Installation with Windows 3.x
56K Voice Faxmodem Internal - User's Guide 29