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Re:Disk I/O in Pmode / VBE
Posted: Fri Mar 12, 2004 6:09 am
by bubach
So what do VESA do? It?s code for checking for a svga card, loading the driver from the card rom and "translate" calls to VESA to the specific card driver, is that right?
Then you would be able to make a "32 bit VESA (special hobby os edition)" that does the same thing, and just give it a int number.
Becasue it sounds on you like you have to write drivers to all diffrent svga cards?
/ Christoffer
Re:Disk I/O in Pmode / VBE
Posted: Fri Mar 12, 2004 6:32 am
by BI lazy
Hej!
bubach, listen: VESA is a standardized (hm, well, mostly) interface to the BIOS of the video card. It hides the Internals by providing standard calls (int 0x10, usw ... you know what i mean?) These are executing functions of the video cards bios which are doing the actual grunt work according to what you tell them to do with the int 0x10 call. If a video card doesn't provide this interface (certain ATI chip sets f. ex.) there is no way except writing to registers to set required video modes - what otherwise the bios of the card is doing for you.
And no, it doesn't do any translation, it executes the command you tell it.
By using standard Vesa calls, you can avoid writing to registers of the video adapter yourself.
Hope this helps
hej da!
Re:Disk I/O in Pmode / VBE
Posted: Fri Mar 12, 2004 6:48 am
by Candy
bubach wrote:
Then you would be able to make a "32 bit VESA (special hobby os edition)" that does the same thing, and just give it a int number.
If you can "convince" commercial companies to include your vesa-something in their products, yes.
Becasue it sounds on you like you have to write drivers to all diffrent svga cards?
Uhhuh. You have to write a driver for each card / cardtype.
Re:Disk I/O in Pmode / VBE
Posted: Fri Mar 12, 2004 6:59 am
by bubach
Ok, ok. i give up...