I'm printing on an old HPLJ6 as network printer connected to a SMC Barricade Printserver. I use CUPS and GimpPrint for running it on my iMac. The manual of the SMC7004ABR simply says:
For configuration, proceed as with every other Unix derivate.All in all it's true while using CUPS in OS X. What it doesn't say, however, and this is essential, is: You must name the queue "LPT1" or else it won't work! This missing piece of information gave me a hard time, and I just recently found out by chance.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20030808055457243