Moving HP Laserjets to Ethernet

[Daniel Devasirvatham 21321]

We have several HP laserjet printers (+ II & III) which are now running 
off serial links to System V computers.
I am trying to work out a simple way to move them to ethernet.  
They will then be driven by an existing Vax (Ultrix 4) installation
on the ethernet backbone, which already has postscript.  
So, rather than trying to install new hp downloadable fonts etc,
we would like to make these hp laserjets look like postscript printers.

What hardware is available to interface GPIB/HPIB or RS232 to ethernet
(thick lan) ?  This could be either a standalone box or a card that
replaces the current interface card in the laserjets.  Hp makes
a box (expensive) which seems to be tailored to Novell Nets.
Also, would such an interface require special driver software on the
host ultrix computer ?

Hp also makes a postscript cartridge for the laserjet.  
We have the 2 MB memories need to use it.  Will plugging
this in make the hp laserjets look like postscript printers to the outside 
world, or would they still need to be sent special escape sequences etc ?
In short, would we need hp laserjet drivers for ultrix ?

Are there any other alternatives ?

Replies could be sent either to the net (preferable) or the email address below.

Thanks in advance.

Daniel Devasirvatham

dmjd at nyquist.bellcore.com