Date: Sun, 2 Apr 2000 10:44:20 +0200 (IST)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
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To: djgpp AT delorie DOT com
Subject: Re: VBE question
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On Wed, 29 Mar 2000, batchex wrote:

> LFBPtr = the mapped address returned by int 31h func. 800h
>          ((ebx << 16) + (ecx & 0xFFFF))
> for(i=0;i<width;i++)
>   LFBPtr[i] = some value
> 
> This approach crash my program.

As expected: mapping the memory with function 0800h doesn't allocate
a descriptor for accessing that memory.

> I've read somewhere that I have to allocate a descriptor for use
> with the mapped address. But at what base address? limit?

I think section 18.7 of the DJGPP FAQ answers this and other related
questions, and includes a code example that shows how to do this.