BIOS VIDEO MODES Question *

[dan nelles]

Hello folks !


I would like to ask if the LIST of VIDEO MODES supported by any VGA/SVGA BIOS is an **arbitrary choice** . . . or if the list of modes can be changed/added at will and if so, how.


Also, given today's high powered vga hardware, suppose I desired something called VESA MODE 104h to be available in the vga bios. Would that stress the internal hardware unnecessarily, do you think ??

thanks,
Dan

 

[streetfighter 2]

Great question. I've actually asked a similar one myself. I wanted to output a 480x272@60Hz for my PSP but my graphics card doesn't list that mode. I asked on TPU whether it would damage my GPU and qubit indicated it was a potential issue. In the end I tried it but Display Changer threw an indecipherable error message so I gave up.

I've also wondered what was special about Ultimarc's ArcadeVGA cards which allows them to output to old sk00l arcade monitors. The card looks stock, as far as I can tell, but it has a custom driver (and BIOS?).

I think the trouble with 104h is that it isn't an odd resolution with an odd color depth and refresh rate; 104h is a completely different thing with it's own memory addressing system, registers and BIOS requirements. It's a world of difference from just changing the resolution/depth/refresh.

I could be completely wrong about everything I've just said, but I think you'd need to have hardware support for 104h, it's not something that can simply be enabled by changing a few minor things in the card's BIOS.