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Mail Archives: djgpp/1998/10/17/01:43:13

Message-ID: <00d001bdf990$af591660$b36f19c4@default>
From: rylan AT intekom DOT co DOT za (StefanViljoen,6599)
To: <djgpp AT delorie DOT com>
Subject: Re: Assembly woes...
Date: Sat, 17 Oct 1998 07:36:30 +0200
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-----Original Message-----
From: Ron Barbosa <rbarbosa AT mediaone DOT net>
Newsgroups: comp.os.msdos.djgpp
Date: Friday, October 16, 1998 7:49 AM
Subject: Assembly woes...


>syntax.  My assembly is infantile-to-nonexistant.  I've seen a few
>online mini-books and howtos but they are for Intel syntax.


There is a freeware intel syntax compiler for DJGPP called NASM:

http://www.cryogen.com/nasm/

It takes intel syntax and can output DJGPP compatible .COFF object files. I
use it for all my projects.

>If anyone out there would be
>kind enough to explain it to me, and give me some insight to converting


>les di,video_buffer

Loads the address of video_buffer into the ES:DI register

>mov al,BYTE PTR color


Sets the AL register (subregister of AX) to the address of the variable
color

>mov ah,al

Extends the value in AL into AH, i. e. just copies it over

>move cx,320*200/2

Sets CX to 32000

>rep stosw

Stores the value in the AX register to ES:DI 32000 times. What this does in
effect is to copy the video_buffer to the screen - many games  / graphics
progs use this or something very similar to do animation and effects.

Check out the attached file for a DJGPP + NASM implementation of exactly the
above.

- Raw text -


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