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>
Content-Type: text/plain; charset=us-ascii
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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