LPD with multiple queues to one device

[dave at sam.cs.olemiss.edu]

We have installed a Postscript card in one of our LaserJet II's and
wish to set up LPD to handle Postscript and HP style files.  The key
is the printer defaults to Postscript and postscript output is easy,
but HP output must switch the mode before printer (and maybe
afterwards). Having two queues pointing to the same device will not
work (I dont think) because output may be mixed since each daemon does
not know of the other one.

Has anyone attempted such a setup?  I assume so since this setup seems
to be evermore popular.  If so, how is it done?

This is the opposite problem from the one PLP solves: That is,
multiple printers on one queue.

Thanks for any information.

dave