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From: nsus_cif@troi.cc.rochester.edu (Nick Susch)
Newsgroups: comp.windows.ms
Subject: Re: Flicker. . .in 1024x768x256 w/Nec 3D
Message-ID: <12162@ur-cc.UUCP>
Date: 12 Feb 91 18:00:11 GMT
References: <91042.221913MXP122@psuvm.psu.edu> <15085@uudell.dell.com>
Sender: news@uhura.cc.rochester.edu
Organization: University of Rochester - Rochester, New York
Lines: 34

In <15085@uudell.dell.com> jporter@twaddle.dell.com (Jeff Porter) writes:

>In article <91042.221913MXP122@psuvm.psu.edu>, MXP122@psuvm.psu.edu (Malzor) writes:
>|> OK, I remember some talk a while back about flicker in this mode with a Nec
[Stuff about problem with filcker in 1024x768x256 mode when running in
	enhanced mode]
>|> Thanks.

>The flicker is a function of the refresh rate of the display which is in
>turn controlled by your graphics card.  To get 1024x768 resolution, your
>graphic cards (as do most VGA/ super VGA) use interlaced mode.  In interlaced
>mode, the graphics card updates the even scan lines and odd scan lines during
>alternating frames.  The net effect is that the even scan lines are updated
>30 times a second and the odd lines are updated 30 times a second.  At this
>low speed, some flicker is noticable, especially with high contrast images.

I assume that the first person is using a Tseng ET4000 board. I also have
this board and have this annoying flicker problem. I know that 1024x768
is interlaced, but the flicker is horible under windows. If I exit
windows and run a program in 1024 mode, I *can* tell it is interlaced,
but it is *very* slight, and the screen in very easy to read. But as soon
as I start up windows in 386 mode, something happens to the card. The
flicker becomes unbarable. I have discoverd, using the option of my NEC
3D which saves the screen setting to each particular sync, that the 1024
mode under windows is a different sync then the "regular" 1024 mode. Does
anyone know why this happens? It's like their is two modes on the ET4000,
regular interlaced, and really slow interlaced, and windows picks the
wrong one. Any help would be appreciated.

---
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