I got VESA working and am able to write colour data to the screen, but, having specified the linear addressing flag, the screen data is "chopped" into megabyte (2^20 byte) sections allowing me to only write to the top and bottom thrids of my screen at 1024x768x32bpp.

Does this imply a memory limit or does VESA split the memory up?

Any ideas what's going wrong?

Thanks,

COD3B453

Are you using real mode or protected mode? From my experience I can say that lfb needs to be accessed from protected mode. Full lfb access doesn't work from real mode nor unreal mode.

regards,
Mac2004

I think you need to implement A20, as i had the same problem years ago, but it was the bottom half that was black, but this was at a smaller size.
If you have enable A20, make sure it works, as some do not work on some PC.

Well it's supposed to be in protected mode... But I don't know how I would test that for sure, other than the fact that it hasn't faulted and hung or rebooted.

Thanks for the tip, Mac2004, I'll check I haven't done something stupid.

I missed your reply when I was writing my last reply...
I'd forgotten to include my a20.inc, but also didn't realise A20 would affect something like that
Thanks, Dex4u!

Your welcome , Oh yes with out A20 enabled, you can only access every other MB.