From:	"Guido Bursch" <bursch AT uni-muenster DOT de>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Why add 36008 to offset to reach buffer?
Date:	11 Apr 1997 00:37:22 GMT
Organization:	Westfaelische Wilhelms-Universitaet Muenster, Germany
Sender:	"Guido Bursch" <bursch AT uni-muenster DOT de>
Message-ID:	<5ik142$jro@majestix.uni-muenster.de>
NNTP-Posting-Host:	pppe023.uni-muenster.de
Mime-Version:	1.0
Lines:	29
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

Hi all!

I have a question for my little virtual screen program.
I made up a virtual scree in mode 13h with:

unsigned char virtscreen[64000];

Then I try to access it via inline-asm:

__asm__("
  pushl %%eax\n
  movl $36008, %%eax\n  ?????
  movb $15, %0(,%%eax,1)\n
  popl %%eax"
  :
  : "m"(&virtscreen)
);

and then copy it with dosmemput or movedata to video memory.
It changes the first pixel to white (what I want).
But why I have to add 36008 to the 'offset' (eax) to
reach the first pixel?
It would be great, if anyone would tell me what I'm
doing wrong.

               Thanks alot!!

BTW: Please dont't email me personally (it may cause problems).

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