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32bit Video
Posted: Tue Aug 17, 2004 11:42 pm
by jinksys
I need to manipulate the video card in 32bit mode. Anyone
have any info/links about the VGA CRTC etc? I really dont
feel like writing a vm86 monitor and would rather stay in
32 bit land.
Re:32bit Video
Posted: Wed Aug 18, 2004 12:14 am
by Candy
jinksys wrote:
I need to manipulate the video card in 32bit mode. Anyone
have any info/links about the VGA CRTC etc? I really dont
feel like writing a vm86 monitor and would rather stay in
32 bit land.
search for tauron VGA utilities, source for manipulating VGA.
PS: vga doesn't go above 640*480. Try VBE2/3 for that.
Re:32bit Video
Posted: Wed Aug 18, 2004 2:12 am
by srg
If you can find a copy, get Programmers Guide to the EGA and VGA Cards or even better Programmers Guide to the EGA, VGA and SuperVGA Cards both by Richard F. Ferraro. They are excellent.
The snag is that these books are rarer than rocking horse c**p.
BTW vga is 640x480 16 colour, 320x200 256 colour.
I was looking at the VBE 3 spec and the Pmode part, to me at least, books rubbush, I think v86mode is the only way for that BIOS.
srg
Re:32bit Video
Posted: Wed Aug 18, 2004 4:04 am
by Pype.Clicker
afaik, you can get info about VGA registers through the HardWareVga page of the FAQ and Christopher Giese's OS has code to set up 320x200x256 using ports only... need to check the info. brb with links.
Re:32bit Video
Posted: Wed Aug 18, 2004 5:37 am
by jinksys
thanks for the replies,
although I think my question was asked wrong.
Im not that interested in graphics, Im mainly
interested in text mode right now.
Re:32bit Video
Posted: Thu Aug 19, 2004 8:48 am
by Ozguxxx
So you want to create your own fonts?
Re:32bit Video
Posted: Thu Aug 19, 2004 9:20 pm
by jinksys
nope.
At the moment I know how to add text by directly writing to the
video card's framebuffer, but I want to scroll text, change text
modes, etc without using the BIOS. Hopefully this clarifies my
question
Re:32bit Video
Posted: Fri Aug 20, 2004 2:08 am
by Pype.Clicker
well, you have an option for hardware-assisted scrolling that consist of using the CRT start offset register from the VGA: Just tell it that your screen starts 160 bytes further than 0xB8000 and you've scrolled one line down. When the whole first screen has disappeared, quickly copy what you have on the "bottom" half back on the 'top half' and you're ready for 25 more scrolls.
Note that it only works if you can afford 8K for one console (which means you can have only 2 physical consoles instead of 4 otherwise in the 16K of text VRAM)