freemodbus-v1.5.0.zip is from freemodbus.org
Download was moved to sourceforge.net/projects/freemodbus.berlios/

The rest is from the Oasis4 CVS directory, written by Mike Risi

I diffed Mike's code with the freemodbus download.
Mike added the port directory (presumably for talking to
the PIC serial ports).  The rest is only slightly modified.

