Question

汇编语言 字符串逆序输出

DATAS SEGMENT
XX DB 0AH,0DH,"please input string:$"
BVF DB 30
DB ?
DB 30 DUP(?)
DATAS ENDS

SSEG SEGMENT STACK
STK DB 100 DUP(?)
SSEG ENDS
CODE SEGMENT
ASSUME CS:CODE,DS:DATAS,SS:SSEG
START:
MOV AX,DATAS
MOV DS,AX
LEA DX,XX
MOV AH,9
INT 21H
LEA DX,BVF
MOV AH,0AH
INT 21H
MOV CL,BVF+1
AND CX,0FH
BIAOJI:MOV AH,2
MOV DL,BVF[CX];这里
INT 21H
LOOP BIAOJI
MOV AH,4CH
INT 21H
CODE ENDS
END START
能给我讲讲错在哪里吗

Answer 1

DATAS SEGMENT
    XX DB 0AH,0DH,"please input string:$"
    BVF DB 30
    DB ?
    DB 30 DUP(?) 
DATAS ENDS
          
SSEG SEGMENT STACK
    STK DB 100 DUP(?)
SSEG ENDS
CODE SEGMENT
    ASSUME CS:CODE,DS:DATAS,SS:SSEG
START:
    MOV AX,DATAS
    MOV DS,AX
    LEA DX,XX
    MOV AH,9
    INT 21H
          
    LEA DX,BVF
    MOV AH,0AH
    INT 21H
          
    MOV CL,BVF+1
    AND CX,0FH
    MOV BX,CX
    ADD BX,1        ;确定BX的值，找到最后一个元素的偏移位置
          
BIAOJI:MOV AH,2
       MOV DL,BVF[BX]   ;这里括号内必须是BX,SI,DI寄存器其中之一
       INT 21H
       DEC BX       ;指针往前移
       LOOP BIAOJI
       MOV AH,1
       INT 21H      ;暂停一下，查看输出的字符。若无，则一闪而过
    MOV AH,4CH
    INT 21H
CODE ENDS
    END START

Answer 2

;字符串逆序输出
DATAS SEGMENT
XX DB 0AH, 0DH, "please input string: "
YY DB 10, 13, '$'
BVF DB 30
DB ?
INB DB 30 DUP(?)
DATAS ENDS
CODE SEGMENT
ASSUME CS:CODE,DS:DATAS
START:
MOV AX, DATAS
MOV DS, AX
LEA DX, XX
MOV AH, 9
INT 21H
LEA DX, BVF
MOV AH, 10
INT 21H
MOV CL, BVF + 1
CMP CL, 0
JE EXIT
MOV CH, 0
LEA BX, INB
ADD BX, CX
LEA DX, YY
MOV AH, 9
INT 21H
MOV AH, 2
BIAOJI:
DEC BX
MOV DL, [BX]
INT 21H
LOOP BIAOJI
EXIT:
MOV AH, 4CH
INT 21H
CODE ENDS
END START