Jeff, Illustrator 88 usually displays the PostScript error in the printing dialog BEFORE giving the final message "A PostScript error has been generated…." Watch carefully. The most likely PostScript errors are: (1) VM error–you have run out of memory. Often occurs if you are using more than one PostScript header…
I have TOPS on my little network (Mac Plus, Mac SE, LaserWriter Plus) but it was not being used while I made the tests. (I do understand it's not entirely passive, but in any event, I was using the scanner connected to the SE and printing on the LW without…