Faster Printing

Lee Fedor fedor at dsg.csc.ti.com
Fri Jun 30 04:34:33 AEST 1989


This is to recap what I did to fix my problem, I wish to thank all the
other sun-spots readers who gave me their suggestions and put me on the
right track.

What I actually did was to change the setting on our Omni-laser 2115
Postscript printer to 34.8k baud.  If you have the same type of printer,
you go through the software setup on the front panel to change this. If
you have some other type of printer you will need to check the users
manual on how to change your baud rate.   

Then I went into our /etc/printcap file and changed the entry on the 4th
line of the postscript section from br#9600: to br38400: as it shows below
*.

lp|lw|ps|postscript|PostScript:\
	:lp=/dev/lw:sd=/usr/spool/lw:\
	:lf=/usr/spool/lw/lw-log:af=/usr/adm/lw.acct:\
*------>:br#38400:rw:fc#0000374:fs#0000003:xc#0:xs#0040040:mx#0:sf:sb:\
	:if=/usr/tran/sparc/lib/psif:\
	:of=/usr/tran/sparc/lib/psof:gf=/usr/tran/sparc/lib/psgf:\
	:nf=/usr/tran/sparc/lib/psnf:tf=/usr/tran/sparc/lib/pstf:\
	:rf=/usr/tran/sparc/lib/psrf:vf=/usr/tran/sparc/lib/psvf:\
	:cf=/usr/tran/sparc/lib/pscf:df=/usr/tran/sparc/lib/psdf:

There was no need to change anything else to get this to work.

Anyway, here are the responses I received from the various other
helpful sun-spots readers:

----------------
>From:    daniel at unmvax.cs.unm.edu (Tommie Daniel)

We are sending data to our postscript printer via an ethernet gateway
that connects our ethernet (tcp/ip) to the apple share network. This
way the Suns take advantage of the 38.4Kbaud apple nettwork connection
on our Laserwriter IINX. Gateways are kind of expensive but it sure beats
9600 baud.

Tommie 
----------------
>From: sylvman!root at uunet.UU.NET (Root Operator)


Have you considered using the parallel port on an ALM-2 and standard 
trancript.  When you do the transcript installation you have to modify
the 'confi_lw' file variable `TTY` to mcpp0.  If you are using a 
printer with a parallel port, this should work.

I personally have NOT run a postscript printer this way , by I have run a 
shinko CHC-65 Color printer with not problems.

Let me know what the results are.

		Ed Haggerty
___________________

>From: berg at lindy.Stanford.EDU (Eric M. Berg)

> My sales rep from Sun says that they don't sell anything like that,
> and even if I bought a parallel board from a third party vendor the
> software wouldn't support postscript.

This sounds like nonsense, but there may be an element of truth in it.
It's nonsense because PostScript is merely printable ASCII text, so
how could it not be supported?

The element of truth is that most PostScript printers (I assume you're
using something other than an Apple LaserWriter, since it doesn't have
a parallel port) can "talk back" (i.e. send status messages) to the host.
(Of course, it's up to the host software to listen for them and pass them
to the user; I'm not sure if Transcript does so or not.)  The relevant
point is that parallel port drivers probably aren't made to listen for
messages coming back from the printer, which serial line drivers are.

Sorry this message isn't more specific, but maybe this will shed some
light on your question.


-- 
Eric M. Berg	415/322-0606	     Internet: A.Eric at GSB-How.Stanford.EDU
Price Waterhouse Technology Centre   UUCP:...decwrl!gsb-how.stanford.edu!a.eric
68 Willow Road, Menlo Park, CA 94025 
Disclaimer: Don't confuse my opinions with those of my employers.


---------------------
>From: ekrell at ulysses.att.com

There are Postscript printers which can run their serial interface
at 38400 baud (which is how fast ttya and ttyb will run).
If you have a printer which can't run that fast, you can buy
a serial to parallel converter (make sure it runs at 38400) and
use it to drive your printer on the parallel interface.
I got one of these from "Black Box Corp." for $150 or so.
-- 

Eduardo Krell                   AT&T Bell Laboratories, Murray Hill, NJ

UUCP: {att,decvax,ucbvax}!ulysses!ekrell  Internet: ekrell at ulysses.att.com

--------------------------
>From: Ken Yap <ken at cs.rochester.edu>

I don't see why the software cannot support a parallel interface.
All Transcript (for example) wants to see is a device to open.
The XON/XOFF handshake would be replaced by the ack/busy of
the parallel interface. I don't know what one would do about
the reverse channel needed for status messages though. Maybe
these parallel printer interfaces are bidirectional?

------------------------
>From: sysrick at cfht.cfht.hawaii.edu (Rick McGonegal)

The alm-2 board from Sun has a parallel interface on it that is centronics
compatible. Try "man alm".

We have not got it to work yet on our Sun 4/280 but that is mainly due
to lack of engineering time to install and test.

I would be interested in a summary if you get around to it.
 ----------------------------------------------------------------------------
 Rick McGonegal			INTERNET	sysrick at cfht.hawaii.edu 
 C.F.H.T. Corp. 		BITNET		sysrick at UHCFHT

------------------------
>From: Alexander Dupuy <dupuy at cs.columbia.edu>

Have you tried increasing the speed of the laserwriter serial line?  It is
possible to run laserwriters at speeds of up to 38400 (if the Sun can keep up).
The laserwriteer manual tells you how to increase the speed of the laserwriter
in postscript, then you merely have to change the speed entry in the printcap
file.

@alex
--------------------------

Hope this is all helpful.  If you have any questions feel free to give
me a call and I may or may not be able to answer them for you.
Have a nice day!!!

Regards,
Lee Fedor
fedor at dsg.csc.ti.com
Texas Instruments Incorporated
12501 Research Blvd
Mail Station 2201
Austin, Texas 78714-9149
(512) 250-7573



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