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From: cet1@cl.cam.ac.uk (C.E. Thompson)
Newsgroups: comp.lang.postscript
Subject: Re: Detecting color printer
Message-ID: <1991Jun20.204930.29990@cl.cam.ac.uk>
Date: 20 Jun 91 20:49:30 GMT
References: <1991Jun20.053653.20412@sci.ccny.cuny.edu> <3551@laura.UUCP>
Reply-To: cet1@cl.cam.ac.uk (C.E. Thompson)
Organization: U of Cambridge Comp Lab, UK
Lines: 32

In article <3551@laura.UUCP> klute@tommy.informatik.uni-dortmund.de (Rainer Klute) writes:
>In article <1991Jun20.053653.20412@sci.ccny.cuny.edu>,
>kly@sci.ccny.cuny.edu (Gregory Kozlovsky) writes:
>|> I would like to create a Postscript file which would be printed
>|> differently on color and black&white printers. For example, lines
>|> which have different colors on a color printer should be drawn with
>|> different dash patterns on black&white one. What is the correct way
>|> to ask the printer?  I would prefer not to use level 2 features.
>
>I do it by testing whether the PostScript interpreter knows about the
>setcolorscreen operator:
>
> ...

Unfortunately, although this may have been a good risk in the past, it
will not continue to work. All Display PostScript implementations, and
all level 2 implementations, will have 'setcolorscreen' regardless of 
whether any associated device supports multiple colours.

In fact, regardless of not wanting to use level 2 facilities, I can't
see any way of determining this information using only the operators    
defined to be in the level 2 set. For Display PostScript you could look
at the 'Colors' value in the directory returned by 'deviceinfo'.      

PPD files contain an entry *ColorDevice indicating whether the device
supports colour. If you are using a document manager that replaces   
%%BeginFeature/%%EndFeature sections from PPD files, you could make  
use of this.

Chris Thompson
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