逆序输出字符串

DATA  SEGMENT
       INF01  DB        0DH,0AH,'INPUT STRING1:$'
       INF02  DB        0DH,0AH,'OUTPUT STRING2:$'
        BUFA  DB        81
              DB        81 DUP(0)
        BUFB  DB        81
        DATA  ENDS
        CODE  SEGMENT
              ASSUME    DS:DATA,CS:CODE
      START:  MOV       AX,DATA
              MOV       DS,AX
              LEA       DX,INF01
              MOV       AH,9
              INT       21H
              LEA       DX,BUFA
              MOV       AH,10
              INT       21H
              LEA       SI,BUFA+1
              MOV       CH,0
              MOV       CL,[SI]
              ADD       SI,CX
              LEA       DI,BUFB
       NEXT:  MOV       AL,[SI]
              MOV       [DI],AL
              DEC       SI
              INC       DI
              LOOP      NEXT
              MOV       BYTE PTR [DI],'$'
              LEA       DX,INF02
              MOV       AH,9
              INT       21H
              LEA       DX,BUFB
              MOV       AH,9
              INT       21H
              MOV       AH,4CH
              INT       21H
        CODE  ENDS
              END       START