I found these comments about the SM56:
Q: "When I run the diagnostics under the win98 modem properties it tells me that it cannot open the comm port. What is the best way to get Windows to assign a valid comm port to this modem? I have tried the Windows modem setup routine and that doesn't work. The modem gets set up but when I run the diag. it cannot find the modem on the comm port I select. Any help will be appreciated."
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A: First, DON'T use the drivers from the CD that came with the modem. Go on the Motorola site and get the newest version and also get their 'cleaner' program. Decompress your drivers to an empty folder. Then remove the modem from the system by clicking the 'modem' icon from the control panel. Run the cleaner program to remove all your drivers. Shut down your computer.
Second, Turn on your computer and enter your BIOS (usually you press the 'Delete' key on startup) and disable all your COM ports there (it's in the Integrated Peripherals if you have an Award BIOS), if you have a serial mouse, leave the COM1 there.
When you boot Windows let it try to find the modem (if you didn't run the cleaner, it will be reinstalled as before) and redirect it to the folder where you decompressed the new drivers.
That should do it I think. I remember that the SM-56 installed itself on COM5 (it assigns a new COM port apparently, but that prevented me from using DOS programs from the prompt, because they didn't recognize a COM5). Also I remember that it didn't behave as a normal modem when you ran the diagnostic from the modem properties (I don't remember if it gave me a can't 'open port' error) but I think this is ok if the modem dials allright.
I hope this helps you, but I can also give you another advice; toss it in the garbage when you can afford another modem, trust me it's worth it..
Also you can create additional com ports. In add hardware you need at least up to comm4 as the sm56 likes to be on comm4 or 5. After you create these additional comm ports then install your software"
Drivers.
Removal instructions.
ISA & PCI uninstall utilities & repeat drivers.