two simple question of newbie

[t48605]

yeah the first is about memory address , for example : 0x11223344 , what does it mean ??? ( 0x what is it ? )
and the second is two instruction ( uhm I hope I remember them exactly )
they are 

Code Select Expand

mov ah,4C0h   
                and
             

Code Select Expand

mov ax,09h
so what is the roles of them ???
thanks !!!
                     

[zcoder]

t48605,
0x just before numbers means hex a hex value

mov ah,4C0h loads ah a 8bit reg with a value, but 4c0h is to big a value for ah

mov ax,09h is the same but it's a 16 bit reg AX is both ah and al reg's together.
ah being the high order reg while al is the low order reg, ah+al = AX.

I hope that explains it for you??

Zcoder....

[PBrennick]

t48605,,
To amplify on what zcoder said, if you were to use

mov ax,4C00h

it would be a 16bit instruction that is used to exit from your program, usually to DOS.

mov ax,09h
is used to set up for the 16bit instruction called Print String.  The string would be pointed to by DX

Both of those instructions are executed by

int 21h

hth,
Paul

[zcoder]

PBrennick,
You think thats what he meant? silly me LOL

Zcoder....

[t48605]

thanks ! Both of you  :P

[PBrennick]

t48605,
It is our pleasure, we enjoy helping, really!

Paul