AppleTalk in OSX does not support PostScript 1; nor does it support the oldest AppleTalk protocols. For example, an HP LaserJet 4M going through an Asante AT-to-eNet bridge will not work for many OSX printing tasks yet works fine for OS9. This is due to the changes in AFP done for OSX (yielding what is not called AFS). AFS does not support the older AT stacks. The solution for many of the older printers (like HP's) is to use an MIO card for ethernet connectivity and enable IP printing. This does not require GhostPrint or any of that garbage. Just assign a legal IP address (10.10.10.0, for example) and set that IP as the one you want when you create an IP printer in the OSX Print Center. Be careful not to use an IP address that might be assigned to a Mac for Internet use by a router (192.168.1.3, for example) as two devices with the same IP is "no bueno".
All that being said, it sometimes is better to replace that old laserprinter with a new one. I've found the Brother 5070N to be excellent in quality, speed, and compatibility for OS9, OSX, and Windows. I just saw it for a tad over $400 at pagecomputers.com.