From: David Monro (davidm@fuzzbox.ml.org)
Date: Tue 22 Dec 1998 - 23:47:55 IST
All I can add to this thread is that my 4M ViRGE/VX has this dark screen problem, but otherwise appears to work, at least for 8 bit modes. (The standard bios modes below 640x480 all work fine of course). I've had a bit of a play with the code and have gotten precisely nowhere. I'm slightly puzzled about the whole problem, since according to XFree86 the ramdac is treated as a trio64 ramdac, which I think is how svgalib treats it as well. Must be something subtle I haven't noticed in the XFree code somewhere (I did notice that it calculated some of the clock registers slightly differently, but hacking it to make it the same made no difference whatever to the display, and IIRC for the cases I was trying the values were going to be the same whichever code it used). Of course if it is part of the graphics processor code instead of the ramdac code I wouldn't have noticed it, so that might be the next thing for me to look at (but I don't have enough disk to unpack my xfree tree at the moment, so that will have to wait). Odd side note - specifying 'dac_8_bit' in the XF86Config for XF86_SVGA 3.3.3 produces the following slightly confusing output: (**) SVGA: Option flag "dac_8_bit" is not defined for this driver (**) SVGA: Using 8 bits per color component (**) SVGA: Using 8 bpp, Depth 8, Color weight: 888 where not specifying it produces: (**) SVGA: Using 8 bpp, Depth 8, Color weight: 666 Go figure :-) David > > > From what you describe, if the image itself is ok, 'just' very dark. I > > assume your S3 has an 8bit per R/G/B RAMDAC and either the S3 chipset or > > the svgalib driver does not know about and does not make the necessary > > modifications to transfer 6bit color values to 8bit. As a result, every > > color is too dark by a factor a little bit larger than 4. > > Someone who had a similiar problem, but the problem did not > appear in 1.2.13. > the Card was an S3-Virge 2Mb, and you can try contact the other one > having this problem as > "Hollow Chocolate Bunnies of Death Inc. <skully@skully.clipper.net>" > > Maybe someone can tell what was changed (probably in the s3 driver) > from 1.2.13 to 1.3.0 that causes this bug. > > Matan Ziv-Av. zivav@cs.bgu.ac.il > >
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