Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uwm.edu!bionet!apple!kchen
From: kchen@Apple.COM (Kok Chen)
Newsgroups: comp.lang.postscript
Subject: Re: PostScript -- Stop Bashing Adobe
Message-ID: <39069@apple.Apple.COM>
Date: 28 Feb 90 18:12:05 GMT
References: <9460@imagen.UUCP> <18053@rpp386.cactus.org>
Organization: Apple Computer Inc., Cupertino, CA
Lines: 45

woody@rpp386.cactus.org (Woodrow Baker) writes:

[ in response of Ivan Bach's bringing up DDL (you *are* kidding, Ivan, 
  right?) when talking about PostScript, ]

>hmmmm...  They ARE similar, but I think that the statement above is not
>quite true.  I don't think that DDL is anyways close to the power of a
>general purpose language, such as postscript has.  I seem to remember that
>DDL is not really a programming language, more of a printer controller.
>I have not used DDL extensivly.  HP was trying to keep it to proprietary
>when they were considering it, and no matter how I tried, I could not
>get any documentation on the language.  So I may be all wet behind the
>ears in regard to ddl. 


Yes (re: last sentence above).

DDL[rip] was indeed programmable.  A scan of its manual will show which
two PDLs that preceeded it heavily influenced it (hint: both PDLs had
John W.'s imprint on them :-).  Perhaps the person who was responsible 
for the DDL manual can comment.  I know she reads this newslist from the 
same machine that I do (hi, Debra! :-).  

IMHO, DDL had *even* more features that can potentially slow down a 
printer than PostScript. :-)  And, IMHO, it also had the wrong "kitchen-
sinks" thrown in.  Minimal cover (in the Algebraic sense) was never a 
design consideration (just take a look at all the redundant raster-ops 
that were thrown in in the original version - an overkilling reaction to 
PostScript's distinct lack of such facilities - note that I am not saying 
whether more raster-ops are needed or not :-).

It was introduced *after* PostScript has already been globally accepted
by the printing community.  A case of too little, too late.  And, modulo
job control facilities, it did *not* give the market anything tangibly 
different from PostScript other than the fact that it *was* different 
from PostScript.  Many elements of DDL, e.g. fount scaling, were held 
with even greater secrecy than you see in PostScript.  (There are probably 
all of a half-dozen people on earth who knows the details of DDL's fount 
mechanism. :-)   Again, IMHO.


Kok Chen/AA6TY			kchen@apple.com
Apple Computer, Inc.

Disclaimer, disclaimer, DISCLAIMER up the whazoo for this posting!