Protected mode 13h

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-KEN-

Protected mode 13h

Post by -KEN- »

I was wondering if there's an easy way to set different modes (mainly switching from 13h
back into text mode) in protected mode. I think using DJGPP's _farpokeb() could work, but
I'd have no clue how to use it anyway...little help? :)
J.Weeks

RE:Protected mode 13h

Post by J.Weeks »

>On 2001-12-02 21:53:01, -KEN- wrote:
>I was wondering if there's an easy way to set different modes (mainly switching from 13h
>back into text mode) in protected mode. I think using DJGPP's _farpokeb() could work, but
>I'd have no clue how to use it anyway...little help? :)

UHm... is this for OSDev? In other words, is using the BIOS out of the question? There is a way, without using the BIOS, to set standard vga modes using the vga's ports... there's source out there on the net somewhere (some help here guys... I think someone on this list actually wrote the code... where is it? :)

However, with using the BIOS, I think you have to go through int 0x10, and use all those pmode calls :)

Jeff
Guest

RE:Protected mode 13h

Post by Guest »

Yeah, it's for OSDev, so unless I jump out into real mode, use int 10h,
then jump back to protected mode, I can't figure out another way to set it, and I really don't want to have to do it that way...
so if anyone knows that'd be a big help :)

Thanks anyway though, j.weeks
Guest

RE:Protected mode 13h

Post by Guest »

Just write a real vga driver. You can find most of the basic knowledge necessary to understand video timing from the xfree86 video timings howto (http://www.linuxdoc.org/HOWTO/XFree86-V ... ngs-HOWTO/). Once you understand this and have the documentation for the VGA register set, the rest is easy and very obvious. (The register specs can be found at http://sf.znet.com/~vhold/FreeVGA/vga/portidx.htm)
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