Assembly: code examples

Example 1： Print Hello World

;  Remind developers of the meaning of each paragraph 
assume cs:code, ds:data
 
  
; -----  Data segment  begin ----- 
data segment            
    age db 20h ;db: Represents a byte 
    no dw 30h  ;dw： For two bytes 
    db 10 dup(6) ;  Generate 10 A continuous 6 
    hello db 'Hello World!$'  
data ends  
; -----  Data segment  end ----- 


; -----  Code segment  begin ----- 
code segment  
start:     
    ;  Manual settings ds Value 
    mov ax, data
    mov ds, ax
    
    mov ax, no
    mov bl, age

    ;  Print 
    mov dx, offset hello 
    ; offset hello： representative hello The offset address of    
    mov ah, 9h
    int 21h 
    
    ;  sign out 
    mov ax, 4c00h
    int 21h    
code ends
; -----  Code segment  end -----    
   
   
;  End of compilation ,start It's the program entrance 
; start The segment is the code segment 
;  therefore cs The value is code Segment address of the segment 
;  amount to cs The value of has been automatically set 
end start

Example 2：ax,bx Data exchange

assume cs:code, ds:data, ss:stack

; ---------  Stack segment  --------- 
stack segment   
    db 10 dup(8)
stack ends 

; ---------  Data segment  --------- 
data segment   
    db 20 dup(9)
data ends 

; ---------  Code segment  --------- 
code segment
start: 
    ;  Manual settings ss and ds
    mov ax, stack
    mov ss, ax   
    mov ax, data
    mov ds, ax

    mov ax, 1122h
    mov bx, 3344h  
    
    ;  Use stack 
    mov sp, 10 
    push ax
    push bx
    pop ax
    pop bx
    
    
    ;  sign out 
    mov ax, 4c00h
    int 21h   
code ends

end start