LPS (Digital PrintServer) questions

From: Michael Sokolov <msokolov_at_ivan.Harhan.ORG>
Date: Wed Jun 9 17:46:22 2004

Hi everyone,

In my search for what would be the best laser printer for me, I'm
currently thinking about DEC LPS17, aka Digital PrintServer 17.
A DEC dealer close to me is willing to sell me one for a reasonable
price, and it seems like a really cool printer: just like the
LPS40/20/32 monsters, but fits on a tabletop.

Like all Digital PrintServers, it has a built-in VAX CPU running the
PostScript interpreter. However, the firmware image for this VAX,
containing the PS interpreter and everything else, does not reside in
ROM but is instead down-line loaded on powerup over Ethernet, I presume
via MOP. So it needs a MOP server on the network serving its firmware
image. I can set up a MOP server, but I don't have the LPS firmware
image.

So here comes my first question to the list: does anyone have an LPS
firmware image or is one publicly available on some archive site?
DEC docs seem to imply that the firmware is the same for all LPS'es, is
this true or not? I need an image that can run on LPS17 as that's the
only LPS I can get.

Second question. It is my understanding that once an LPS has booted its
firmware, it becomes an independent node on the network accepting print
jobs from anywhere on the network. Is this true or not? The protocols
it speaks are DECnet and TCP/IP, right? If so, how does it obtain its
DECnet and IP addresses? And if I want only one of the two, how do I
configure it? Does it down-line load a configuration file from the MOP
server along with the firmware image specifying DECnet and IP addresses?
What is the format of this file?

Third question. It is my understanding that the protocol spoken over TCP/IP
is extremely simple: no LPR/LPD or anything like that, just a simple TCP
port, you connect to it and everything sent to that TCP port goes to the
PostScript interpreter's %stdin, and this port is 170. Is my understanding
correct? If so, that's perfect, that's exactly what I want, I don't want
it to do any spooling or other lpd-level intelligence, I want my 4.3BSD
server to do all that, with a raw PostScript over Ethernet connection to
the LPS.

Fourth question. Is this PostScript-over-Ethernet connection on TCP port
170 binary clean, or is 0x04 (^D) interpreted as end of one PS job and
beginning of the next? In other words, does my lpd on the 4.3BSD host
driving it need to send a 0x04 between print jobs or should it close the
TCP connection and reopen it instead?

Fifth question. Is there any access control mechanism by which LPS firmware
can be configured to accept connections only from certain sources, or will
it always accept connections (and print jobs) from the entire Universe?

TIA for any help,

MS
Received on Wed Jun 09 2004 - 17:46:22 BST