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From: crs@cpsc6a.att.com (Chris "Nothin' Fancy" Seaman)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: (Non) Square Pixels?
Message-ID: <2405@cpsc6a.att.com>
Date: 13 Feb 90 21:32:13 GMT
References: <4687@lmrc.uucp> <3119@cello.UUCP> <4736@lmrc.uucp> <3053@d75.UUCP>
Organization: AT&T (CPSC), Oakland, CA
Lines: 23

robin@sabre.uucp (Robin D. Wilson/1000000) writes:

[ Pixel shape vs. aspect ratio discussion deleted... ]

< This is aspect ratio.  Specifically you are looking for a 1 to 1 aspect ratio.
< I am not sure, but I believe a 640 by 400 hi-res interlaced screen is a 1 to 1
< aspect ratio.  If the 640 by 400 screen does turn out to be 1 to 1, then any 
< equal sub-division will be also.  For example, 320 by 200 should also be 1 to 
< 1, and any multiple of 8 to 5 will end up being 1 to 1.  If 640 by 400 is not
< 1 to 1, then forget what I said.

None of the current screen modes on the Amiga have a true square pixel
aspect ratio.  In order to achive this, the ratio of horizontal to vertical
pixels would need to be 1.33 to 1 (or 4 to 3).  A little simple math tells
us that, in 320x200 and 640x400 modes, the pixels are 20% taller than they
are wide.  The ECS will provide a 'square pixel' mode in the 640x480, non-
interlaced productivity mode, but there are no others that I am aware of.

-- 
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