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From: mackay@JUNE.CS.WASHINGTON.EDU (Pierre MacKay)
Newsgroups: comp.laser-printers
Subject: ditroff dvi -> TeX dvi??
Message-ID: <8807192155.AA04632@brillig.umd.edu>
Date: 30 Jun 88 05:32:30 GMT
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ditroff output is basically a human-readable version of the machine input
to the C/A/T typesetter, and therefore limits itself to the resolution
achievable by that film-font machine.  

dvi output addresses an impossibly accurate typesetter with a resolution
to a distance slightly less than the wavelength of visible light.  

You can round dvi down to the relatively crude resolution of ditroff,
but you cannot reliably go the other way.  There are other incompatibilities
as well, but they could be got around.  Even the resolution could be
faked up by a simple multiplication, but who would want to.  The effect
would be to produce a specious appearance of precise resolution in the
translated file, which would then be rounded down again to correspond
with the resolution of a real world typesetter.  It is a good
bet that the inaccuracies introduced would noticeably degrade the
appearance of the page.  dvi-to-ditroff would be more satisfactory,
but again, it would be an odd thing to do, since it would introduce
two stages of round-off (ditroff is hardly ever sent to a C/A/T these
days) where one is trouble enough.


Email:  mackay@june.cs.washington.edu		Pierre A. MacKay
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