On Son, 2002-11-03 at 17:03, Aymeric Vincent wrote: > > Michel D�nzer <[EMAIL PROTECTED]> writes: > > > It's also my impression that dualhead support shouldn't be hard to add > > looking at the radeon driver. In fact, it might be doable without docs, > > someone even posted a quick'n'dirty but untested patch here. If you > > absolutely need to consult documentation for something, I'll gladly look > > it up. And once you've achieved something, ATI might be less hesitant to > > provide the docs to you. > > Actually, I would like to understand how the r128 chip reads the video > memory and sends it to the CRTC, because when I use 15/16 or 24 bit > modes, the display on the CRT monitor (through CRTC2) is split > horizontally in two/two or four respectively, and the same half or > quarter left-hand side of the screen is repeated on the right. The > Flat Panel driven by the first CRTC is OK. Does such a behaviour ring > a bell?
The columns are okay? > [ My interpretation is that the CRTCs have a small buffer that can > contain a certain amount of pixels (obviously depending on the number > of bytes per pixel), and if for whatever reason the video memory can't > keep up, they will redisplay what is available in their buffer until > the next line. ] That's not my understanding, for what that's worth. (Why would the video RAM not be able to keep up, anyway? Keep up with what?) The colors are okay, i.e. it's not displaying 8 bit data in another depth? > If I understand correctly, you have access to the ATI documentation, > and although I may be wrong, it looks from experimental values I get, > that in xc/programs/Xserver/hw/xfree86/drivers/ati/r128_reg.h, the > offsets of R128_FP_CRTC_H_TOTAL_DISP and R128_FP_CRTC_V_TOTAL_DISP are > shifted by 4 bytes, from 0x0254/0x0258 to 0x0250/0x0254. I suspect the > same shift occurs for the radeon. Could you please confirm this? Depends how you think they're shifted. ;) For the Radeon, the docs I have say 0x250/0x254; the Rage128 docs I have don't cover these registers, but I guess they may well be the same. -- Earthling Michel D�nzer (MrCooper)/ Debian GNU/Linux (powerpc) developer XFree86 and DRI project member / CS student, Free Software enthusiast _______________________________________________ Xpert mailing list [EMAIL PROTECTED] http://XFree86.Org/mailman/listinfo/xpert
