From:	rylan AT intekom DOT co DOT za (StefanViljoen,6599)
To:	<djgpp AT delorie DOT com>
Cc:	<malfer AT teleline DOT es>
Subject:	Re: GRX question
Date:	Fri, 19 Feb 1999 23:13:26 -0800
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Message-ID:	<19990219213654.AAG23095@jackal.intekom.com.intekom.co.za@default>
Reply-To:	djgpp AT delorie DOT com

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> From: Mariano Alvarez Fernández <malfer AT teleline DOT es>
> Newsgroups: comp.os.msdos.djgpp
> Subject: GRX question
> Date: Thursday, February 18, 1999 2:40 PM
> 

>   1- My video car is a S3 Trio 64, and using de S3 or the VESA driver I
> can't start the 800*600 16 colors mode (even with modetest program). No
> problem in other modes like 800*600 256 colors.

I have EXACTLY the same card - but I do not use GRX. Rather I use Allegro,
which supports this card natively up to its 16bit resolution. My S3 has 1
meg of ram and works well with Allegro. Why not try allegro instead of GRX?
http://www.talula.demon.co.uk/allegro/
 
>   2- I have noticed the 16 colors modes are very slow, however the 256
> colors modes are really fast. Are there any reason?

There is a very good reason - 16bit color uses more memory. In the 256
color mode, you have one byte corresponding to one pixel - thus to show 100
pixels you use exactly 100 bytes. In 16bit color modes you have two or more
bytes corresponding to one pixel. Thus, to show 100 pixels you need 200
bytes. Get the idea? To use 16bit modes you have to write twice the number
of bytes into video RAM - this is why it takes longer.

This message courtesy of
RylanNet rylan AT intekom DOT co DOT za
http://home.intekom.com/rylan/
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StarWars for ever!.

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