[NTLUG:Discuss] XFree86 Config

[Darin W. Smith]

On Fri, 9 May 2003 09:06:33 +0000, Tom McDonald <tom at compuclaim.com> wrote:

> On Fri, 09 May 2003 01:51:26 -0500
> Chris Cox <cjcox at acm.org> wrote:
>

>> If by "shadow" you mean a faint ghosting, this is usually caused
>> by an impedence mismatch on an analog cable (assuming this is an
>> analog VGA cable).
>> ...

It can also originate at the video card.  I had a GeForce2 card that looked 
OK on CRTs, but when I hooked up an analog flat panel, I had ghosting-- 
mainly in bright white areas--that I could not get rid of.  I tried a 
different cable and that didn't change it.  I then started googling and 
found out that many GeForce2 cards based on the Nvidia reference design 
(mine was an AOpen and was based on the ref. design) had ringing due to 
poorly chosen values on the filters on the analog out lines.  They 
suggested replacing a couple of surface-mount caps and resistors on the 
board, and showed the correct values.  My surface-mount soldering skills 
are not that great, so I opted instead to go for a Xtacy GeForce 4 MX 440, 
which cleared up almost all of the ghosting.  I still sometimes get a very 
faint ghost on bright white areas, but it is so faint that my brain has 
adapted my vision not to see it.  Note that I didn't say "not notice it" 
but "not see it."  I have to think and look very hard and change my focus 
to see it now.  Funny how the brain can do that...

So, try a cable first; after that, you might want to try a different card.

This is why my next flat-panel will be a digital interface, not analog...I 
really won't have to worry about it then.

-- 
D!
Darin W. Smith
AIM: JediGrover