Re: Help implementing spindle & coolent on/off

> I like to put a 74HC541 with EIGHT 4K7 pull-up resistors to each

INput line from the LPT-1 before "anything else" I want to control
with the LPT-1. This "buffers" the LPT-1 and kinda "isolates" it
(no, NOT the same way an "opto-isolator" does!)

Is an "opto-isolator" better in any way than a 74HC541 or similar
chip (or indeed a ULN2003 or even 74HC4538) at protecting the
computer's ports from the outside world ? ie. Is there any reason to
use an opto instead of a buffer ?

Rab