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Amiga computer related discussion => Amiga Software Issues and Discussion => Topic started by: motorollin on July 04, 2007, 09:25:56 AM

Title: Interlaced CGX screenmodes
Post by: motorollin on July 04, 2007, 09:25:56 AM

Any CGX screenmode above 1024x768 on my A4000 is interlaced. Though 1024x768, which is not interlaced, is rock solid, the interlaced higher-res screens are a bit flickery. Is there any way I can configure this out, or is it a limitation of my monitor?

--
moto

Title: Re: Interlaced CGX screenmodes
Post by: AmigaMance on July 04, 2007, 12:30:23 PM

 I think this is a limitation of your graphics card. I have a BVision and it also flickers at very high resolutions. It has to do with the video bandwith of the card, iirc.
 You can try to raise the pixel clock frequency. It will reduce the flicker but it will likely increase the pixel distortion. (or whatever it is called)

Title: Re: Interlaced CGX screenmodes
Post by: Jeckel on July 04, 2007, 12:58:21 PM

Just check your monitor frequency settings in CGXMode.

I guess it's in no way a limitation on your CGX card. I have an old CV64 (not CV64/3D) and i can display 1024x768x24b and 1280x1024x16b without flickering and without "distorsion".

Title: Re: Interlaced CGX screenmodes
Post by: jj on July 04, 2007, 01:32:38 PM

I too have run resolutions the same and higher than this on a cv64/3d andd bvision without these problems.  Has to be settings and/or monitor

Title: Re: Interlaced CGX screenmodes
Post by: motorollin on July 04, 2007, 03:17:09 PM

I'll try my Thinkpad at the same resolution on the same monitor and see if I get the same flicker. If I do, at least I'll know there's nothing I can do about it. If I don't, then I'll have a play in CGXMode and see if I can reduce or remove the flickering.

Thanks

--
moto

Title: Re: Interlaced CGX screenmodes
Post by: pVC on July 04, 2007, 04:07:30 PM

It's pretty easy to look at CGXMode if the scan mode setting is set to normal or interlaced ;)

Title: Re: Interlaced CGX screenmodes
Post by: cv643d on July 04, 2007, 04:25:11 PM

I have run my CV643D at 1600x1198 in 256 colors no interlace.

Same with my BvisionPPC but then in 16-bit.

Title: Re: Interlaced CGX screenmodes
Post by: motorollin on July 04, 2007, 05:58:04 PM

I have already tried setting it to normal instead of interlaced but when I test the screenmode it's stretched double height. I suppose I can compensate for this by changing the frequencies?

--
moto

Title: Re: Interlaced CGX screenmodes
Post by: motorollin on July 05, 2007, 06:57:59 PM

Ok I set the screenmode to Normal instead of Interlaced and found a frequency that worked, and my display is rock solid now :-D

Thanks guys

--
moto

Title: Re: Interlaced CGX screenmodes
Post by: AmigaMance on July 05, 2007, 07:09:01 PM

 Hey. i tried to select "interlaced" for scan mode and it doesn't let me to do that! It goes back to normal automatically. It accepts normal or doublescan only, never interlaced. What's the deal with this? I'm using the latest V4 update. :-?

 Also, what the MorphOS logo doing in the test screen. I can't remember if it was there from the beginning.

Title: Re: Interlaced CGX screenmodes
Post by: pVC on July 05, 2007, 08:21:18 PM

AmigaMance: Why an earth you would like to use interlaced mode for anything?-)

Title: Re: Interlaced CGX screenmodes
Post by: AmigaMance on July 05, 2007, 08:33:04 PM

 You are right. I'm just curious to see if there is something wrong with my setup.