OSDev.org

Posted: **Thu Mar 03, 2005 9:44 am**

Hey,

The BIOS seems to be able to set VESA mode no matter what card is running in the system.

Therefore, there must be a standard way in which the BIOS addresses the video card and a standard way in which it tells it to switch modes? ...

So all video cards must have a standard VESA interface.

So, why can't we do the same thing? Through the same interface? With the same registers?

CPU mode should be irrelevant because it's talking straight to the card.

Posted: **Thu Mar 03, 2005 9:49 am**

yes, there is a standard interface: the BIOS finds the "magic sequence" at the end of video ROM and calls a rom-bootstrap function that register ROM-provided service as entry point for int 0x10...

That actually means that the code under "int 0x10" is not some mother board code ... it's some code that is shipped within your video card and mapped in memory by the BIOS ... Since that code has been designed to run in realmode, it *does* matters whether you're in protected mode or not.

Posted: **Thu Mar 03, 2005 11:54 am**

oh darn. okay

thanks for the info.

OSDev.org

VESA - If the BIOS can do it, why not us?

VESA - If the BIOS can do it, why not us?

Re:VESA - If the BIOS can do it, why not us?

Re:VESA - If the BIOS can do it, why not us?