CODE SEGMENT
          ASSUME CS:CODE,DS:CODE,ES:CODE,SS:CODE
         
V_TAB EQU 21H*4
SEG_D EQU 0000H
     

           ORG 1000H
           MOV AX,SEG_D
           MOV DS,AX
           MOV BX,V_TAB
           MOV AX,OFFSET INT_SER
           MOV WORD PTR[BX],AX
           INC BX
           INC BX
           MOV DX,0
           MOV WORD PTR[BX],DX
           MOV AX,1234H
           MOV BX,1234H

           INT 21H
           NOP
           NOP
           INT 3
INT_SER: ADD AX,BX
 IRET
CODE ENDS
     END 
      
           