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SVGA
Posted: Tue Aug 09, 2005 11:00 pm
by AltCtrlDel
i have been searching for a long time for some resource describing concepts of 32-SVGA programming using VBE2.0.
things like window, bank, bank switch, ... etc
the VESA specifications are useful for those who understand the concepts already!
i would be very thankful if somebody can describe it or can relevant resources
Re: SVGA
Posted: Tue Aug 09, 2005 11:00 pm
by Osbios
ok, try this:
1. use vga
2. use vesa1..2..3
3. try to hack nvidia/ati drivers *G*
With vga you can learn the basics. Then try vesa. Most int10h vesa functions are in 16bit rm, but there is also a rm call who gives a pm call address for vesa.
--> read the vbe docs!!!
And dont use banks, plz!!! use LFB!!!
Re: SVGA
Posted: Tue Aug 09, 2005 11:00 pm
by carbonBased
Some cards don't even support an LFB, so you'll have to support banked modes to support some cards.
It's ugly, yes, but if you do it right, it's not that bad.
--Jeff
Re: SVGA
Posted: Tue Aug 09, 2005 11:00 pm
by AltCtrlDel
well, i have already worked with VGA 13h mode since i started developing my OS and i am migrating to SVGA now .
all i used to do then is to intialize the 13h mode palette before switching to PM .. puting a pixel somewhere on the screen was no more than just puting a color byte in its appropriate place
now i dont know what to with all the VBE functions in the VESA docs (windowing, banks, scanlines..)
all i need to learn is the concepts .. some absract definitions for all these things
something else i want to ask about..
i have used the DEBUG utility in windows to read the mode information .. all the modes have the attributes 001Ah .. doesn't that mean it is not supported by hardware?
Re: SVGA
Posted: Wed Aug 10, 2005 11:00 pm
by AltCtrlDel
OK .. i think i have worked it out (!!) .. and i have developed some code that works well on hardware,but doesn't work on VirtualPC and VMware emulators.
thnx for ur cooperation
Re: SVGA
Posted: Thu Aug 11, 2005 11:00 pm
by Osbios
AltCtrlDel wrote:OK .. i think i have worked it out (!!) .. and i have developed some code that works well on hardware,but doesn't work on VirtualPC and VMware emulators.
Thats ok! My floppy and dma driver only work on real hardware, too.
Re: SVGA
Posted: Thu Aug 11, 2005 11:00 pm
by carbonBased
Dunno if this'll help or not, but I wrote a chapter on VESA (banked, pmode banked, and lfb) programming (also includes mode 0x13, but you have apparently done this already anyway).
You can find it at:
http://www.neuraldk.org/document.php?djgppGraphics
It's meant for DJGPP, but I'm sure the concepts can port easily enough to an OS.
--Jeff