This is the config for the stepper-driven Sherline lathe which is
generously on loan from NIST.  It has spindle speed control by analog
input, which is driven by software-generated PWM on a parallel port
pin.  The motors are driven with step/dir and the spindle encoder
(for synchronized motion/threading) is counted by software on the
parallel port too.  This all makes for a fully functional lathe
using simple hardware.  The power is all in HAL; the hardware is 
just a single parallel port interface and simple stepper drivers.

