Hello,
I have the Gigabyte MA78GM-S2H motherboard with an integrated 780G chipset
and Radeon HD3200 graphic card. The card work perfectly under Linux with both fglrx and open ati drivers. However, I would also like to connect a TV through a
VGA<->SCART cable (http://www.mythtv.org/wiki/index.php/RGB_Scart). The following Modeline works well with an old graphics card (ATI Mach64) in the same computer:
ModeLine "720x576@25i" 13.5 720 732 795 864 576 581 586 625 interlace -hsync -vsync
so that I know that the modeline and cables are OK. However, for the Radeon HD3200, I am having problems setting the dotclock to a sufficiently low value. The fglrx driver refuses to do it (saying that the dot clock is too low), the open ati driver
pretends to honour the "ForceMinDotClock" but probably does not set the frequencies correctly because the TV cannot sync, I only get moving bands.
Do you know if that is a real hardware limitation that the Radeon HD3200 cannot generate such low dot clock frequencies? Or is it just software? Would you know of some other way to circumvent it?
I eventually want to buy a HD TV with a HDMI input but at the moment I would like to use our old TV, so I need the low-resolution / low-frequency TV modes. And the old Mach64 seems to be too slow for full-screen video.
Thank you very much for your help,
Jan
I have the Gigabyte MA78GM-S2H motherboard with an integrated 780G chipset
and Radeon HD3200 graphic card. The card work perfectly under Linux with both fglrx and open ati drivers. However, I would also like to connect a TV through a
VGA<->SCART cable (http://www.mythtv.org/wiki/index.php/RGB_Scart). The following Modeline works well with an old graphics card (ATI Mach64) in the same computer:
ModeLine "720x576@25i" 13.5 720 732 795 864 576 581 586 625 interlace -hsync -vsync
so that I know that the modeline and cables are OK. However, for the Radeon HD3200, I am having problems setting the dotclock to a sufficiently low value. The fglrx driver refuses to do it (saying that the dot clock is too low), the open ati driver
pretends to honour the "ForceMinDotClock" but probably does not set the frequencies correctly because the TV cannot sync, I only get moving bands.
Do you know if that is a real hardware limitation that the Radeon HD3200 cannot generate such low dot clock frequencies? Or is it just software? Would you know of some other way to circumvent it?
I eventually want to buy a HD TV with a HDMI input but at the moment I would like to use our old TV, so I need the low-resolution / low-frequency TV modes. And the old Mach64 seems to be too slow for full-screen video.
Thank you very much for your help,
Jan
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