From: Shawn Hargreaves <Shawn AT talula DOT demon DOT co DOT uk>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: VBE 2.0 Pmode Bank Switching...
Date: Fri, 14 Feb 1997 20:09:17 +0000
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Schuster writes:
>What's the difference between the vesa modes? Is it the speed?
>just to be answered in short terms, no asembler code

Yup. With VESA 1.x, every time you switch banks (this has to be done
several times during most drawing functions), you have to call a 16 bit
real mode interrupt function, which involves the cpu switching from
protected mode into real mode and back. This is slow...

With VBE 2.0, you get protected mode functions for doing the bank
switching, which avoids the mode switch and is therefore a lot faster.
And on most recent cards, VBE 2.0 lets you use a linear framebuffer,
which removes the need for bank switching altogether, making graphics
coders very happy :-)

/*
 *  Shawn Hargreaves - shawn AT talula DOT demon DOT co DOT uk - http://www.talula.demon.co.uk/
 *  Ghoti: 'gh' as in 'enough', 'o' as in 'women', and 'ti' as in 'nation'.
 */