First - this printer port works perfectly ok with a printer.
If I load mach3. I disable all the motor outputs.
I go to config - ports and pins - outputs.
I set up either all of the enables or all of the outputs
using the pins I used for the motors 2,3,4,5,6,7
then if I "apply" then I can toggle these outputs and
the led's on the outputs of my breakout card toggle!
John F