Hi,
The Fax port was used in the early V 3 printer drivers since it was a kernel mode printer driver. The later V3 drivers and the V4 drivers do not need the port but that doesnt really affect how your app interacts with the printer driver. In V4 you 'll use the FaxMan printer ActiveX or .Net or DLL component to interface with the printer driver much like V3 did.
What exactly are you needing to do ?