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From: hyc@math.lsa.umich.edu (Howard Chu)
Newsgroups: comp.sys.atari.st
Subject: Re: Pictures on the ST (Amiga's RULES)
Message-ID: <1990Jul3.061429.6414@math.lsa.umich.edu>
Date: 3 Jul 90 06:14:29 GMT
References: <672.26899914@desire.wright.edu> <1990Jul2.071658.16558@math.lsa.umich.edu> <725.268f2179@desire.wright.edu>
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Organization: University of Michigan Math Dept., Ann Arbor
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In article <725.268f2179@desire.wright.edu> arc@desire.wright.edu writes:
>Hey, bud, our screens (640x200, 320x200, etc.) update at 60 frames per second. 
>ONLY our interlace mode updates at 30 frames per sec.  DON'T even start!!!

> ALso, we have a blitter and many co-proc's and the ONLY "co-processor" YOU
>have is a DMA controller, BIG DEAL!  Later

>------------------------------------------------------------------------
>=    ///           | Bryan K. Fite             | Arc@Desire.Wright.edu =
>=   /// Amiga!     | ^Service Engineer^        |         -or-          =
>= \XX/ The One     | Arc Electronics, Inc.     |    Arc@WSU.BITNET     =
>= ____& Only...    | Wright State University   |"Ouch! Quit-it." - Bart=
>=                  | Dayton, Ohio              |  Depeche' Mode, Now!  =
>========================================================================

Nice job of cutting down on the quotes there, "bud." Note that I said on a
so-called megapixel display. I have it on good authority that the 2024 monitor,
which displayes 1024x800 pixels, is only redrawn at 15 hertz. Granted, it's
a fair amount of work getting 800K pixels onto a screen, but this display
will only spit out 4 gray levels for all that time & effort spent in
interleaving frames. My "garbage" Atari with "no coprocessors" puts out
an 800x500 monochrome display at 70 hertz. For 4 graylevels I drop down to
35 hertz or so. For me to stoop to the slow redraw speed the Amiga spits out
I can gain another frame time, for 16 gray levels. And this is on a stock
Atari monochrome monitor, not some jazzed up $700 "megapixel" tube.

I didn't bring this up to dump on your machine, I was merely quoting a figure
for the sake of comparison. No need for an antagonistic attitude...

[But since you brought it up ... *One* DMA controller is more than adequate,
given a powerful enough selection of devices attached to it. In my case, I
happen to have a NeXT box attached to my ST, and I've found it pretty adequate
for most of my multiprocessing needs.]
--
  -- Howard Chu @ University of Michigan
  one million data bits stored on a chip, one million bits per chip
	if one of those data bits happens to flip,
		one million data bits stored on the chip...