I uploaded this driver before, but using the second model number, which is one assigned by Hawking Technologies.
The unit identifies itself to Windows 9x Plug n Play as Rockwell RC56D2 Serial PnP, V.90, K56Flex, Voice, Speakerphone.
I just caught on PnP must stand for Plug and Play!
There must be other manufacturers who used this chip.
Hint to AOL users your software has probably detected you unit as Rockwell (generic) K56. It may perform slightly better if you change that (using Expert Add) to Rockwell (generic) V.90.