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Path: utzoo!watmath!clyde!rutgers!im4u!milano!peterson
From: peterson@milano.UUCP
Newsgroups: comp.text
Subject: Re: Why troff?
Message-ID: <3605@milano.UUCP>
Date: Fri, 30-Jan-87 16:54:47 EST
Article-I.D.: milano.3605
Posted: Fri Jan 30 16:54:47 1987
Date-Received: Sat, 31-Jan-87 08:24:53 EST
References: <362@linus.UUCP> <106@tg.UUCP> <1556@trwrb.UUCP> <827@cartan.Berkeley.EDU>
Sender: peterson@milano.UUCP
Distribution: comp.text
Organization: MCC, Austin, TX
Lines: 29
Keywords: TeX, troff
Summary: font portability

In article <827@cartan.Berkeley.EDU>, rusty@weyl.Berkeley.EDU (Rusty Wright) writes:
> One of the TeX advantages that you forgot is font compatibility.  If
> you use TeX and stick with TeX's Computer Modern font then you can be

On the contrary, TeX can have more problems than troff with font
compatibility at different sites, although you may mean it at a
different level than I.  The TeX dvi printer form cannot be printed
without access to the same font tables that were used to format the
document.  Troff dvi, on the other hand, has all positioning information
built into the dvi data stream.  Thus, it is possible to take a
troff dvi file and transmit it across the country to another site
(or across campus) to another site with different fonts and get it to
print reasonably well.  A TeX dvi file cannot do this unless you have
the same fonts available at both sites.

The problem is with the dvi format.  In troff you say, for each
character: 

	<move x units> <output a character> <move x units> <output...

while with TeX you say 

	<output a character and move as over its width><output...

which is not possible unless you know how wide the character was when
the output was formatted. 
-- 
James Peterson
peterson@mcc.com  or  ...sally!im4u!milano!peterson