8086 ASSEMBLY LEVEL PROGRAM TO CONCATENATE TWO STRINGS IN DIFFERENT SEGMENT

EXTRA SEGMENT
INST1 DB 20 DUP(0)
EXTRA ENDS
DATA SEGMENT
INST2 DB 20 DUP(0)
RESULT DB 40 DUP(0)
MSG1 DB 10,13,'ENTER THE FIRST STRING: $'
MSG2 DB 10,13,'ENTER THE SECOND STRING: $'
MSG3 DB 10,13,'CONCATENATED STRING IS: $'
NEW DB 10,13,'$'
DATA ENDS
CODE SEGMENT
ASSUME CS:CODE,DS:DATA,ES:EXTRA
START:
MOV AX,DATA
MOV DS,AX
MOV AX,EXTRA
MOV ES,AX
LEA DX,MSG1
MOV AH,09H
INT 21H
MOV BX,000
UP1:
MOV AH,01H
INT 21H
CMP AL,0DH
JE DOWN1
MOV [INST1+BX],AL
INC BX
JMP UP1
DOWN1:
LEA DX,NEW
MOV AH,09H
INT 21H
LEA DX,MSG2
MOV AH,09H
INT 21H
MOV CX,BX
MOV BX,00
UP2:
MOV AH,01H
INT 21H
CMP AL,0DH
JE DOWN2
MOV [INST2+BX],AL
INC BX
JMP UP2
DOWN2:
PUSH BX
MOV DI,0
MOV SI,0
UP3:
MOV AL,[INST1+DI]
MOV [RESULT+SI],AL
INC SI
INC DI
LOOP UP3
POP CX
MOV DI,0
UP4:
MOV AL,[INST2+DI]
MOV [RESULT+SI],AL
INC SI
INC DI
LOOP UP4
LEA DX,NEW
MOV AH,09H
INT 21H
LEA DX,MSG3
MOV AH,09H
INT 21H
MOV [RESULT+SI],'$'
LEA DX,RESULT
MOV AH,09H
INT 21H
INT 3
CODE ENDS
END START
END