Hi,
yep, there sure is, a UC100 will work and a USB-to-parallel converter from a computer store won't.
The UC100 has a FPGA chip inside that takes numerical trajectory data from Mach and converts it into beautifully timed pulse streams for your
drivers. While it plugs into your PC with USB and its output is a parallel plug, DB25, its NOT a USB-to-parallel but an external motion controller.
It is a WAY WAY clever little gadget.
Craig