How to bind M62-M65 codes to parallel port?

Eric_SJ wrote:

That makes complete sense now, but I don't recall seeing anywhere in the documentation that a "wire" is needed to connect the signal to the pin.

In HAL nomenclature "foo" is the signal, and motion.digital-in-00 and parport.0.pin-NN-in are pins.
parport.0.pin-NN-in is a HAL Output pin (it's an IN into the computer, but an OUT in HAL) and motion.digital-in-00 is an input pin.

A signal (like foo) can be connected on one or many lines to one output pin and as many input pins as you like. Where an output pin "writes" a value to the signal, and the input pins "read" the value from a signal into a component.

So

net foo input-pin
net foo output-pin

is exactly the same as
net foo input-pin output-pin
or
net foo output-pin input-pin.

You could also have
net foo input-pin
net foo input-pin-2 output-pin input-pin-3
net foo input-pin-4 input-pin5 input-pin-6
if you felt that way inclined. Or you could put them all on the same line.