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From: "Prashant TR" <prashant_news AT yahoo DOT com>
To: "Ulf Wikström" <ulf_julius AT hotmail DOT com>
Cc: <djgpp AT delorie DOT com>
Subject: Re: Absolute addresses
Date: Fri, 19 Nov 1999 11:12:06 +0530
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Reply-To: djgpp AT delorie DOT com

From: Davin McCall <DavMac AT iname DOT com>


>The "method for using 32-bit memory
>addresses without using pm" is called "real big mode" or "unreal >mode"
>(amongst other names) and is a royal pain

It isn't really a pain, but you normally won't need to do this if you're
using DJGPP. This takes just a few lines of assembly code, but it
must be 16-bit. I use this to write memory testing routines. But
for your kind of implementation (VGA mem. access), there are
better ways to do it.

>
>
>On Wed, 17 Nov 1999 10:04:42 +0100, "Ulf Wikström"
><ulf_julius AT hotmail DOT com> wrote:
>
>>I'm using DJGPP with inline assembler.

>>How do I specify an absolute memory adress using assembler???  >>I would
>>like to access vga-memory...

You can create a selector whose base = the vid. mem. base. You can pass the
value of this selector to the asm function and use it there. Cool, isn't it?

See section 18.2 of the FAQ for more details about this.




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