[comp.unix.questions] lp spool system query

tron@mrecvax.UUCP (Carlos Mendioroz) (08/11/87)

I 'm running ULTRIX 1.2 on a uVax and have a pair of printers connected
to the same port (a tty line) via an inteligent switch.
The problem is how to tell lpd that both printers share the same tty line
and so, he shouldn't try to write both at the same time.
I 've tried using the same spool directory but that didn't work.

Any suggestion ?
Thanks in advance.

Carlos G Mendioroz - Ministerio de Relaciones Exteriores y Culto
		     Buenos Aires  ARGENTINA
UUCP : {seismo|uunet|pyramid!utai|decvax!utcsri}!atina!mrecvax!tron 

"I've had nothing yet",Alice replied in an 
offended tone, "so I can't take more."
"You mean you can't take less," said the Hatter:
"it's very easy to take more than nothing."

bruce@chas2.UUCP (Bruce McLaughlin) (08/13/87)

In article <374@mrecvax.UUCP> tron@mrecvax.UUCP (Carlos Mendioroz) writes:
>I 'm running ULTRIX 1.2 on a uVax and have a pair of printers connected
>to the same port (a tty line) via an inteligent switch.
>The problem is how to tell lpd that both printers share the same tty line
>and so, he shouldn't try to write both at the same time.
>I 've tried using the same spool directory but that didn't work.

I'm having the same trouble with a set of Sun 3/50's nfs'd together and 
sharing 4 printers (2 Epsons, 2 HP LJ+) off of two of the Sun serial ports.
We are trying to go through a set of "smart" boxes (The Logical Connection).

I found some filters in mod.sources Volume 3 for the laser printers, and am
now getting things other than garbage to print, but trying to get...

    Sun-A to spool things on Sun-B to printer-C while
    Sun-C spools to printer-D  while
    Sun-D spools to Sun-C for printer-A ..... etc.

Needless to say, the contention is not working out well.
Help, please????

     ... cit-vax!elroy!jplgodo!chas2!bruce 

  --Bruce McLaughlin          Jet Propulsion Laboratory
                              4800 Oak Grove Drive, M/S 301/250D
                              Pasadena, California, 91109

     "Wisdom suffers only when Triumph meets Conviction"

brad@bradley.UUCP (08/18/87)

Well I have something like your problems....I have a printronix
MVP printer....I wanted to be able to print 10 chars/inch and if
someone else sent something at 17 pitch not to come out at the same
time (which is easy....just have them use the same lock file).  But
as I recall this had a draw back of either the 17 pitch coming out
at 10 pitch ( I think the spooling directories were the same), or
the 17 pitch file not coming out until someone sends another 17 pitch
file while the printer is not printing another pitch.

My fix was to patch lpd to wait for the /dev/tty entry to be unlocked
via flock and to have the lock files in different directories.

The solution might not be helpful for binary sites.


Bradley Smith			UUCP: {cepu,ihnp4,noao,uiucdcs}!bradley!brad
Text Processing			ARPA: cepu!bradley!brad@CS.UCLA
Bradley University		PH: (309) 677-2337
Peoria, IL 61625