Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!magnus.ircc.ohio-state.edu!tut.cis.ohio-state.edu!sei.cmu.edu!fs7.ece.cmu.edu!o.gp.cs.cmu.edu!andrew.cmu.edu!jj1h+ From: jj1h+@andrew.cmu.edu (Joseph Jackson) Newsgroups: comp.lang.postscript Subject: Re: How can I tell if a file is "postscript" Message-ID: Date: 7 Mar 91 00:17:08 GMT References: <7647@uceng.UC.EDU> <1991Mar4.075212.12828@lth.se> <1894@chinacat.Unicom.COM>, <1448@vidiot.UUCP> Organization: Academic Computing, Carnegie Mellon, Pittsburgh, PA Lines: 36 In-Reply-To: <1448@vidiot.UUCP> Excerpts from netnews.comp.lang.postscript: 6-Mar-91 Re: How can I tell if a fil.. Vidiot@vidiot.UUCP (2017) > Not quite. The %! on the first line is required by the LaserWriter > printers and compatibles. It is NOT part of the definition for EPSF or > EPSI. If that special comment line is missing, the LaserWriter series > printers will change to Diablo emulation mode and the PostScript program > will print out as a source listing, i.e., the PostScript code will print > as normal text and the program will not run. No, really. It's just a comment to the LaserWriter. Trust me! I use kermit to have close and personal conversations with my LaserWriters all the time and never bother typing in the PostScript magic characters. What you are most likely seeing is the effect of some nice spooling software. Many spoolers will wrap non-PostScript files with a simple PostScript program which causes the file to be shown line-by-line on the page (as though you were using a very slow and expensive line printer. ;-) What kind of system are you using? How are your printers attached? If you do have some way of getting your PostScript engine to perform automatic mode changing, I'd be interested in learning more about it. How is the printer changed from Diablo emulation mode back to the normal PostScript interpreter? How does it know that the Diablo document is finished printing? Perhaps the mode switching is a feature of some custom PostScript interpreter which must be downloaded to the printer every time it is powered up? Joe Jackson Distributed Workstation Services Carnegie Mellon University Internet: jj1h+@andrew.cmu.edu Bitnet: jj1h+@ANDREW AT&Tnet: (412) 268-8799