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From: dj@ctron.com (DJ Delorie)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: Chips & Tech 82C451 VGA chip - will it support 640x480x256 mode ?
Message-ID: <1589@balrog.ctron.com>
Date: 30 May 91 12:52:26 GMT
References: <10654@castle.ed.ac.uk>
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In article <10654@castle.ed.ac.uk>, whb@castle.ed.ac.uk (H Bruce) writes:

> The VGA chip is a Chips & Tech 82C451 with 256K of RAM. 
> It only seems to support a 800x600x16 SVGA video mode and ignores attempts to
> switch it into the 640x480x256 mode.  
> However there is space on the card for another 256K of RAM - if this is
> installed with the 640x480x256 mode work ?

> The suppliers say they won't do the upgrade and if we do it'll void
> the warranty !!  Futhermore the "Programmer's Guide to VGA Cards" does
> not explicity say that the card will or will not support the 256
> colour SVGA mode.

I used to work with C&T and this chip at a previous job, and the info
I got back then is that the '451 can do 800x600x16 (and maybe
640x400x256 - I don't recall), but the '452 is required to do more
than that.

DJ
dj@ctron.com