Can you show some kind of schematic or sketch of what you are intending to hook up?

There are quite a number of details that you have not specified that will need to be defined so that we can give you some guidance. A schematic of the circuit surrounding the opto-coupler, its input sources, its output loads, and power supply / ground conections would go a long way toward defining those details.

Also are you sure you want to use a 4N35? There are much better opto couplers these days that have much higher current transfer ratio. These better type couplers would make driving by the parallel port bits much more practical.

Michael Karas