Craig,

Check out the Winbond web site. I'm sure that they make the old line of Dallas Semi's Turbo chips. I think they are the foundry for Dallas.
I think they have changed the Dallas parts from Eprom to flash but everything else is the same.(two pointers, two serial ports, and 1K of Xram on the chip.
Needhams EMP-20 supports Winbond.

Buck Stein