Do these network printers have ethernet ports on them? Do you connect to them on other systems using LPT? I'm not sure which OS started having LPT support, but you can probably look it up on Apples tech info library. From what I recall, the earliest support was in the Destop Printing addon. You installed the latest Destop printing and created a Destop Printer. The options for the Destop Printer allowed you to print to an LPT port. I think in later OSes like 9, it was more integrated with the Chooser, but I am not sure. I have used LPT with OS8.1, so I know support goes back at least that far.