You will be
Buying one License for the Parallel Port Legacy Plugin for Mach4. This
plugin allows the use of the parallel port as a motion control device on
supported computer systems with Mach4.
IMPORTANT NOTE: The LICENSE will only work for
the Computer for which you supply the PC ID at checkout. Each PC has a
unique ID code and the license works in coordination with this code. The
PC ID for this plugin will be the same as the PC ID for Mach4