From:	jim AT curved-logic DOT com (James Shaw)
Newsgroups:	rec.games.programmer,comp.os.msdos.djgpp
Subject:	Re: VBE Mode List
Date:	Thu, 26 Mar 1998 11:07:41 GMT
Organization:	http://extra.newsguy.com
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To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

"Adrian Francis" <adrian DOT francis AT cableinet DOT co DOT uk> wrote:

>Hi,
>
>I have created a VBE interface in DJGPP but I am having problems
>with the VideoModePtr, which is a pointer to a list of available video modes.
>
>I have read the VBE2.0 specification and it does not seem to state
>what sort of pointer this is.  I have presumed that it is a real-mode
> far pointer but no matter what I try I cannot get access to the list.
>
>Can anyone help?  A code snippet would be useful!

#define FLAT_PTR(x) (char *)(((x>>12)&0x000ffff0)+(x&0xffff))

char *flat_address = FLAT_PTR(card_info->vidmodeptr);

The format is a ulong, word:word, the first word is the segment, the
second is the offset.

You'll need to use DPMI function 0x800 (physical->linear mapping)
before you can write to that address though.

Jim

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