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So, I'm relatively new to HTPC - going in stages and what I have now is a PC in my A/V rack going to a regular SD display through S-Video on my Radeon AIW 8500DV at 800x600. No big picture wins although you can do some fun stuff with TheaterTek and whatnot.


Anyway, everything pretty much worked in Windows 2000, but there were some features I thought I needed so I upgraded to XP Pro two days ago. (7.1 Audio support for my Terratec card and Remote Desktop so I can do maintenance w/o the crappy display, mainly)


Things were fine with XP for a while, but I suddenly have been seeing what looks like a weird color dithering effect. Any complex shade is now a base color with a pattern of diagonal lines from lower-left to upper-right. If you go to displays, it shows the colors as set to "high" but instead shows several patches each with those bands. Changing the display resolution, color depth all have no apparent effect.


I had been using the default drivers with XP (new install) but I pulled the latest down from ATI. No change. I don't actually have a PC monitor to test this on other than the television, but I suppose I could borrow one from someone.


Has anyone seen anything like this before? Apologies if this has been addressed before, I poked around in the FAQ(s) for a while but didn't see anything similar.


Thanks.


-Jon
 

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The lines are a defect in the drivers or design. ATI seems unwilling to even acknowledge the problem. This thread has been going on forever about the issue:


Radeon 8500 has bad TV out at 800x600, need others to confirm
http://www.rage3d.com/board/showthre...eadid=33591219


A post I found with google is interesting:

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From: Mike T ([email protected]$tream.net)

Subject: Re: TV out on Matrox vs. sVideo out on ATI TV wonder

View: Complete Thread (8 articles)

Original Format

Newsgroups: alt.comp.periphs.videocards.ati, alt.comp.periphs.videocards.matrox, comp.sys.ibm.pc.hardware.video

Date: 2002-08-12 21:43:44 PST


"[email protected]" wrote in message

news:[email protected]

> Interesting - can you elaborate a bit more on the measurements as I am

> curious.


I have designed video equipment for almost 40 years. I have Tektronix TV test equipment. I use 2 DVD video test disks, Video Essentials and Avia for measuring the video performance when playing the DVD player to the TV out on the graphics card. The standard multiburst test signal contains video frequencies up to 5 MHz, and you measure the video level at each frequency.


The ATI AIW 8500DV reproduces the 5 MHz test frequency at about 20% of what it should be.


The Matrox G450 reproduces the same 5 MHz test at about 90% of full level, big difference.


Also the ATI card shows additional frequencies that should not be present,

and are due to improper frequency scaling and poor design. I use a HP spectrum analyzer to measure these distortion products. You can see this distortion as a fine vertical grid on the video image when playing DVD videos, and jagged diagonal lines in video images that are non-existant when playing the Matrox G450 with the same DVD player software and DVD disk. I have a 2 year old ATI Rage 128 with TV out and it looks very similar to the AIW 8500DV, no improvement from ATI in over 2 years on the TV out quality. I guess the money is spent on 3D gaming speed, which I have no interest in.

...

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source:
http://groups.google.com/groups?hl=e...ews.com&rnum=2



Like he mentions, my older AIW 128 is affected by the issue too, just not as bad. Note this is not an interference problem caused by poor S-video cables. It manifests itself as a pattern of faint diagonal lines running from the bottom left to the top right like: ///

It's best seen on medium brightness colors. White or dark, it's not visible, though I'm sure it's reducing the sharpness. The pattern does not move or change, even with different resolutions. The 720x576 tweak using Powerstrip that was mentioned in the rage3d.com thread does not change anything (at least for me). I'm not buying ATI again...
 
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