Greetings!  I've just built an XY plotter to practice CAD/CAM skills on before starting real machining.
How do I tell Mach3 that I just want to draw lines, and have no Z axis, just a pen controlled by a solenoid, i.e., a single bit?
Thx. 

Connect your pen solenoid to the Z axis direction pen.  Then a negative Z move ( Z-.001) will lower the pen and a positive move (Z0) will raise it.  We do the same with laser control.
John Champlain

Thanks.  Perfectly obvious once you know it.  That's what being a newby is all about.

We all were once.  ;>)
John Champlain