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Mail Archives: djgpp/1999/02/24/18:07:40

Message-ID: <36D47F81.83695BBA@teleline.es>
Date: Wed, 24 Feb 1999 23:38:57 +0100
From: Mariano Alvarez =?iso-8859-1?Q?Fern=E1ndez?= <malfer AT teleline DOT es>
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To: djgpp AT delorie DOT com
Subject: Re: GRX question
X-Infomail-Id: 919897549.4244010A81106E.37549
Reply-To: djgpp AT delorie DOT com

Ludvig Larsson wrote:

> 8-bit colormodes are very easy to access, you just put the
> apropriate 8-bit variable in the right place:)
>
> 4-bit colors are different, you have to share every char(8 bit, the
> smallest variable you can use easily) so, writing
> to one pixel on screen means that you have to look up the char
> and then modify either the 4 lowest bits or the 4 highest bits
> and then put everything back in the videomemory.
> You can offcourse have a buffer in memory repressenting the
> screen to avoud reading the slow videomemory, but even
> with that, it will be slower.

I agree, but... why it's Windows in VGA 4 bit color mode so fast? And,
why BIOS routines are faster than GRX in 4 bit color mode?




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