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From: henry@utzoo.UUCP (Henry Spencer)
Newsgroups: net.text
Subject: Re: Laser Printer Woes
Message-ID: <6860@utzoo.UUCP>
Date: Tue, 24-Jun-86 19:18:24 EDT
Article-I.D.: utzoo.6860
Posted: Tue Jun 24 19:18:24 1986
Date-Received: Tue, 24-Jun-86 19:18:24 EDT
References: <861@rti-sel.UUCP>
Organization: U of Toronto Zoology
Lines: 22

> The problem surfaced when I was drawing some horizontal lines with
> LaTeX.  The lines that resulted were longer than specified.  The 
> problem gets worse as the line length increases...
> Vertical lines are much more accurate.  When I translated the same
> DVI file for our 240 dpi Imagen, the line lengths were accurate.

There is a known "problem" with the little Canon engine.  The vertical
resolution is determined by how far the paper moves between scan lines,
which I think is a matter of gear ratios in the engine.  So that's
pretty much fixed.  The horizontal resolution is determined by the dot
rate at which the controller sends video to the engine.  The "problem"
with the engine is that the right video rate for horizontal=vertical
resolution is almost BUT NOT QUITE equal to one of the standard crystal
frequencies.  So most of the controller manufacturers are lazy and use
the standard crystal, even though the result is slightly wrong.

I measure the resolution as 298.5/inch horizontal by 302.5/inch vertical
on my LaserJet Plus.  As they say, "your mileage may vary".
-- 
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