NASM on 2k

Alright, I've been trying to learn a little ASM on the sly (*snort*)... I felt like trying to do some stuff on my parents 2k box (Too little *NIX specific info, it's there, but there's more for Windows, so I'll just learn it here at first...), so I got the obligatory printing lines (Hello world! )... And this was what the code looked like:

Code:

    org 100h
    mov dx,msg
    mov ah,9
    int 21h
    mov ah,4Ch
    int 21h
    msg db 'Hello, World!',0Dh,0Ah,'$' 

So it compiles and everything works... Then I think God damn 0Dh,0Ah (\r\n) is ugly... Let's do this:

Code:

    org 100h
    mov dx,msg
    mov ah,9
    int 21h
    mov ah,4Ch
    int 21h
    msg db 'Hello, World!',0Dh,0Ah,'$'
    break db 0Dh,0Ah 

So that compiles... Then I try putting break instead of 0Dh,0Ah (I was making sure I didn't do something wrong with declaring the db ) and I get...

Weird... I tried putting break db infront of msg db, nothing... I tried doing:

Code:

   msg db 'Hello, World!',[break],'$' 

Now I get this:

Anyone got any ideas? ASM is woowoo

 

The hell.... This compiles:

Code:

   org 100h
   mov dh,msg
   mov dl,break
   mov ah,9
   int 21h
   mov ah,4Ch
   int 21h
   break db 0Dh,0Ah,'$'
   msg db 'Hello, World!'

But I get this:

Weird...

 

oh my god, you brainwashed your computer and its talking giberish... eak!

 

I'm guessing ax register is just full of other stuff...Another problem I'm having (One thread would be better since I'm getting trouble getting replies already ) is the following:

Code:

    org 100h
   mov ah,01h
   int 21h
   mov ah,al
   mov al,DOLLAR
   xchg dx,ax   ;saves me a byte
   mov  ah,09h
   int 21h
   mov ah,4Ch
   int 21h

   DOLLAR db 'aaaa','$'

Echoes input to output (01h) but for some reason it prints alot of crap and doesn't have aaaa in there anywhere....

Is ah/al/ax just full of crap? Or is there a better way to move al to dx then al to ah, '$' to al, and ax to dx?

 

Alright, after looking at some ASM example code (Which I didn't understand at all ) I tried xchg bx,ax xchg cx,bx etc. until I got cx into dx and it appeared to work, when I try to recreate it doesn't work anymore... It only worked partially on a side note, it echoed input to screen, printed crap, then printed aaaa and ended... I'l try to recreate it...

EDIT: And oh, you can do xchg ah,al and save yourself a byte.

 

FYI I posted on clax86 and I got the problem (char input and string output == no-no) In case you want to see the thread (Google Groups suck but for those of you with no ISP NNTP access, well first sucks for you , second the link is...)

http://groups.google.com/groups?dq=...ps?hl=en&lr=&ie=UTF-8&group=comp.lang.asm.x86