Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!ccavax!tinkelman
From: tinkelman@ccavax.camb.com
Newsgroups: comp.windows.x
Subject: Re: X-extensions on X terminals?
Message-ID: <14712.25a1cf11@ccavax.camb.com>
Date: 3 Jan 90 15:08:17 GMT
References: <4819@emory.mathcs.emory.edu>
Organization: Cambridge Computer Associates, Inc.
Lines: 46

In article <4819@emory.mathcs.emory.edu>, km@mathcs.emory.edu 
(Ken Mandelberg) writes:
> DEC seems to be featuring Display Postscript as an extension.
> Will DEC applications that need this require the capability
> in the server, or will it fall back to a host based process
> to translate the extension for basic X servers (say for an
> X terminal).

First, as I understand it the Display PostScript extension is currently
available only on DEC's Ultrix X-Server product.  I was told at the 
Fall '89 (Anaheim) DECUS Symposium that there were business negotiations 
under way between Digital and Adobe regarding putting Display PostScript 
on the VMS X-Server.  (But ``don't expect anything in less that 6-9
months.)  There was no mention of Display PostScript on the other DEC
X-Servers products, eg DECwindows/PC or the DECwindows Terminal (the
latter to be called a VT1000?).

DEC did not seem to be setting any policy on how they thought the
extension should be used.  They said ``It's up to the application
developer.''  The choices seemed to be: 

	(1) Application requires the extension, 
	(2) Application runs with reduced functionality on X-servers
	    without the extension, or
	(3) Applications run with reduced performance on X-servers
	    without the extension.

For example, if your application labels lines running at a arbitrary
angles, with Display PostScript you would probably simply rotate the
text.  Without Display PostScript you could omit the text, output it
non-rotated, or convert the text to an X bitmap in your application.

DEC seemed very unsure of just how this extension would be used.  On the 
distrbution tape they included four implementations of a ``sample
calculator'' program, using various amounts of Display PostScript.  It's
interesting to picture your application as running on a dual processor
configuration -- one of which is running Display PostScript.

I doubt very much that DEC will be shipping standard applications that
require Display PostScript on the server in order to run at all. 

A side thought: I wonder what the plans are for the second meg of ROM
(socketted but not populated) on the DECwindows Terminal?
-- 
Bob Tinkelman, Cambridge Computer Associates, Inc., 212-425-5830              
bob@ccavax.camb.com  or ...!uunet!ccavax!bob