I need code to interface two PC?s via the parallel port. I currently
have code to do this, but it may not be fast enough. I need the code
to transfer information at 9,600 bits per second continuously and
19,200 bits per second peak.

What I really need is code that can interface a Linux and Windows XP
based system, but if you can get code that can interface two windows
XP systems that will be fine too because we can just port the code to
Linux. Remember there are security restrictions on the use of the
parallel port in windows XP so win 95/98 code will not work. The code
may (but does not have to) make use of the interrupts on the PC for
example a interrupt is triggered when information is received then the
operating system calls a routine (made by us) handle the information.