Encoder circuits for parallel port hookup?

Hi all,

I know I saw them somewhere before, but I just can't seem to locate the
circuit diagrams on either CNCDRO/Mach2 groups anymore.
What I am looking for is the circuit diagrams that show how to hook up
an optical encoder to the parallel port (I assume it needs some
transistors to drive the input pin... Or at the very least some
resistors somewhere? Any help would be great!)

The other thing I was looking for was the design that allowed you to use
a small stepper as an encoder.. Since I have these in abundance and
they're a lot cheaper than an encoder. Was it called an MPG? I can find
no circuit diagrams for it at all...

Thanks,
~Abby