DNA Hardcopy service

[Chris Lindblad <cjl%ai.mit.edu@RELAY.CS.NET>]

    Date: Fri, 22 Sep 89 14:13:11 EDT
    From: MILLER@vax.cam.nist.gov


       Date: Fri, 22 Sep 89 11:50 N
       From: CLAASSEN%HNYKUN53.BITNET@CUNYVM.CUNY.EDU

       Hi there,
       We want to print Symbolics files and screendumps over the DNA network on
       a laser printer attached to a VAX. Is there an easy solution?
       We haven't been able to find documentation on using a VAX spooler. In
       case there is no easy solution is it possible to create a postscript
       file from a bitmap (and send it over the network to the VAX printer)?

       Wim Claassen.
       University of Nijmegen

    I have written a hack that does this. It is inspired by Chris Lindbladt's LPD-USER
    and based on the COMMAND service example that appears in the DNA manual
    (latest and most correct version is in the Tech bulletin 7.2 Issue 1).

    It defines a hardcopy service for DNA (although the VAX doesn't know it has
    one!).  The strategy is to that the server code, instead of sending the text (etc)
    to a `real' printer, writes it into a file on the vax in the user's homedir.  Upon 
    closing the printer stream, it then invokes the appropriate printing command on 
    that file using the COMMAND service.

    Actually, our situation is slightly worse; Our printer lives on a SUN. We dont 
    yet have TCP, but one of our vaxers has written a vax proc which transfers the 
    file to the sun and requests the print.  The net result is transparent however; 
    the lispm just gives the vax command to print; what the vax does with the
    command -- who cares!

I believe if you were actually using the VMS print spooler then the right
thing for the software is to just send the data to the file "LP:" on the vax,
and it will ge automatically spooled.  I'm not sure - I haven't printed
anything on a VMS since 1982.

    This hack does not involve itself with the formatting; it assumes that the stuff
    being input to it is already formatted.  For a postscript printer you would still
    need the LGP3-SW, for other kinds of printers you may have to write it yourself.

    The COMMAND service is pretty neat because you can define all sorts of CP commands
    which actually run stuff on the vax (at least non-interactive stuff; but even LaTeX)
    and print the results back on the lispm. There are some examples of this in the hack too.

    Thats the basic outline, but I hesitate to post the code to the net because 
    1) it is evolving 2) there are a few site-specific sections.  However, if there is
    interest, perhaps I can post a copy with the most obnoxious hacks flagged.