Re: Dual Head on Dell 640 ATI Radeon Mobility 7500

[Barry Warsaw <barry python org>]

On Friday, May 23, 2003, at 12:30 PM, Hugh Caley wrote:
> The attached XF86Config will give me the two displays (second display 
> is a Dell 1024x768 LCD attached to the laptop's VGA port).  The 
> primary display has some artifacting but basically works.  The 
> secondary display is terribly artifacted, with streaky repetitions of 
> some of the primary display's elemenets, the cursor is a square, etc.  
> Nevertheless, I can open a terminal on the primary display, drag it to 
> the secondary display, and use it, even if is very difficult to read.

This is probably not related, and I hate to bum out an otherwise 
successful XFree86 day, but I have long seen artifacts on my Linux 
system.  For me the artifacts are probably not screen capturable short 
of taking a picture of my screens.

The artifacts manifest themselves as ghosted vertical lines, snow-like 
noise, and other fuzzy anomolies, almost as if the video card is not 
driving the screens at the right rates.  It's much worse for the VGA 
port than the DVI port -- and both ports are running Dell E171FP flat 
panels at their native 1280x1024 resolution.  They are both pushing 
75Hz instead of the "optimal" 60HZ, but I don't really think that's the 
problem (at one point in the RH7.3 days I had them driving at 60Hz and 
it didn't help).

It could well be the card, but I'm sure it's not anything else in the 
chain as I drive the same flat panels from my Radeon 8500 Mac card on 
OSX and it looks great.

I'd love to hear if anybody has any clues.

-Barry