Message-ID:	<32FA140C.4BC8@pobox.oleane.com>
Date:	Thu, 06 Feb 1997 18:25:32 +0100
From:	Francois Charton <deef AT pobox DOT oleane DOT com>
Organization:	CCMSA
MIME-Version:	1.0
To:	Jeff Standish <jestandi AT cs DOT indiana DOT edu>
CC:	djgpp AT delorie DOT com
Subject:	Re: vertical retrace and LCD screens
References:	<5daceq$sci AT cymbal DOT cs DOT indiana DOT edu>

Jeff Standish wrote:
> 
> the "vertical retrace".  But I'm working on a notebook, which means an
> LCD screen instead of a CRT.  Is there something analogous to a vertical
> retrace with LCDs?  I'm familiar with CRTs, but LCD displays are still
> new to me.
> 

It works on my notebook, at least. 

The vertical retrace is something the video card does, so as to be able 
to work with CRT monitor: every so many pixels, the graphic card stops 
reading pixels for a while, so that the monitor can do retraces (vertical 
or horizontal). 

On a LCD screen, nothing actually happens during the retrace, but there 
is a retrace every screen (except maybe for some special modes which 
would only work on LCD screens, but I don't see the point in developping 
for them).

Francois

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