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From: orcutt@deimos.esd.sgi.com (Allen Orcutt)
Newsgroups: comp.sys.ibm.pc.misc
Subject: Re: Super VGA in an IBM XT.
Message-ID: <1991May15.172613.21980@odin.corp.sgi.com>
Date: 15 May 91 17:26:13 GMT
References: <1991May6.115535.5317@marlin.jcu.edu.au> <1991May13.205551.1369@mck-csc.mckinsey.com> <1991May14.225823.19549@rodan.acs.syr.edu>
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Reply-To: orcutt@deimos.esd.sgi.com (Allen Orcutt)
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In article <1991May14.225823.19549@rodan.acs.syr.edu>, amichiel@rodan.acs.syr.edu (Allen J Michielsen) writes:
|>    Most all Super VGA cards have enough memory onboard. Being in a XT only
|> slows it down by about 1/2 due to a 8 bit slot.  The big factor is clock 
|> rate of the system, and more importantly, the speed of the bios.  If the
|> XT system were using a inboard 386 pc, the video would be quite fast.
|> 
|> al
|> 
|> -- 
|> Al. Michielsen, Mechanical & Aerospace Engineering, Syracuse University
|>  InterNet: amichiel@rodan.acs.syr.edu  amichiel@sunrise.acs.syr.edu
|>  Bitnet: AMICHIEL@SUNRISE 

-- 
Is it actually true that the 8-bit bus slows VGA by about 1/2?  That would
imply that all pixel values written over the bus to the VGA card were
packed into 16-bit values.  I'll bet (although not much) that most pixel
writes are 8-bit writes which waste half of the possible bus bandwidth.

***************************************************************************
Allen A. Orcutt