modem drivers for windows xp

Check the following sites
1)www.modem-drivers.com/modem
2)http://modemsite.com/56k/sm56.htm
3)www.56k.com/inits/a2z
http://win2000tips.home.att.net/drivers
www.rosyscomputers.com/drivers
YOu may want to check for W2K drivers they may work for XP

While Motorola made the chipset, they did not make the modem itself.

Try to identify who made and sold the modem, and go to their web site for drivers.

The links that soulrider gave you should be able to help you identify the modem mfg.

If not, here are 2 more

www.modemhelp.org
www.driverguide.com

from http://e-www.motorola.com/collateral/SM56_DRIVERS.html#DFVwin98 you may download the drivers for all OS. Use Windows 2000 drivers for Windows XP.
However, I have a feeling that Windows XP already has the drivers for Motorola SM56 with Speakerphone.