Geert Uytterhoeven wrote:Nope. The PC BIOS looks for "expansion ROMs", and calls initialization routines in the ones it finds. It then expects to be able to call INT 10 to position the cursor and print text (and read the cursor position, what's on screen, etc.). You could have a BIOS on a network card that provides the necessary interrupt routines, but actually talks to a remote X server for display functions. (yes - it might need to advertise itself as a video device for this to work)
<>On Wed, 20 Oct 2004, Jon Smirl wrote:
If you want to be able to see the BIOS, you'll need some legacy emulation,If you implement VGA you will be able to boot and work in any x86Ugh... I prefer _not_ to have VGA compatibility.
system without writing any code other than the BIOS.
but it should be enough to implement MDA output.
Since some VGA cards used to depend on the MDA/CGA BIOS routines, mostRight - all video cards provide these BIOS routines (including one the one being considered here). They aren't in the system BIOS. (Not that there are no broken BIOSes around, but strictly speaking, there is no need at all for the system BIOS to know anything about the display card being used)
(all?) BIOS variants will implement all nescensary IO functions. You'll
need some MDA registers for the cursor position (that don't even clash with
EGA/VGA/CGA), 4K mapped memory at B000:0000 and a loop translating the text.