[argyllcms] Re: Help: We don't have access to the RAMDAC

  • From: Stefan Döhla <color@xxxxxxxxx>
  • To: Graeme Gill <argyllcms@xxxxxxxxxxxxx>
  • Date: Sat, 20 Jan 2007 20:02:56 +0100

> Perhaps you haven't set your
> display to a 24 bit depth visual ? There's really no point in trying
> to calibrate a display unless it is at least running 24 bit, and I've
> no idea how a less than 8 bit per component frame buffer is wired to
> a 256 entry RAMDAC.

My old Toshiba Portege notebook was in former times running with a
64 entry RAMDAC. The range was from 0x0000 to 0xffff - and it worked!

This was with XFree86 some time ago until I updated to X.org (some current
version - not exactly sure which one) - and there setting RAMDAC
values only works with a 24 bit depth visual.

The reason seems to be the driver which implements RAMDAC settings
only for 24 bit depth - not for other depths (for my old laptop it's
the Savage driver).



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