Re: svgalib screen sync once more...

[Heather <star@starshine.org>]

> Hi folks,
> 
> Some of you perhaps read the thread about my svgalib screen sync problems 
> with the DSTN 640x480 screen of my laptop and ct65535 chipset.
> One of the problems I could solve:
> My console isn't scrumbled any more when I switch back from graphics to
> textmode, I achieved this by using TextClockFreq 20.0 (strange to me, as
> this is lower than in standard VESA modes - If someone could enlighten
> me?), but it works.

Projector-type LCDs (esp the older ones) often have a range something like
15 or 18 to about 35 dotclock.  So 20 is solidly in its range.  The other
one it had been using might have been borderline.

> The other problem grew even weirder:
> When I switch to graphics mode with dvisvga or zgv, the LCD-screen is
> scrumbled and shows very strange patterns. I can restore this with
> LCD/CRT/LCD switch (also was like that in X).

SVGAlib is controlled at a dif't location than X is, but you can use X's
data (if you've got it solved) to your advantage.  The directory you want 
to look at is /etc/vga/

> When I switch to graphics mode with gs or gnuplot, I DON'T have this
> problem.
> So is this a problem with svgalib configuration or a bug in dvisvga/zgv?
> (The latter would perhaps mean, that X has the same bug) (or even a bug in
> the hardware?)
> If I use the UseModeline option and change the modelines, I get absolutely
> no effect, the screen looks exactly the same, no matter what kind of
> modeline I specify (of course modesize always stays the same (640x480)).

If you're absolutely positive that your chipset is VESA compliant, you can
tell that to SVGAlib... though it doesn't help X much.  I've always liked
chips&tech but I think ct65535 is a bit old, so I dunno how it will turn
out.  

> TIA,
> Regards,
> Daniel

Best of luck 

* Heather Stern * star@ many places...