Hi Sparks
If it’s additional I/O you’re after you may like to take a look at PoKeys USB key board emulator. WWW.poscope.com It provides digital I/O, 5 analog inputs (10-bit) and 1 analog output (10-bit). All the I/O are controlled by the provided software which allows either to use the graphical user interface or advanced console type interface. The settings can be stored on the device, so no special software is needed on target system.
There is also a Mach3 plug-in. The UK distributor is www.paltronix.com
Ivan.