4-3.asm

来自「1、熟悉运算类指令对标志位的状态影响以及标志位状态的表示方法； 2、掌握条件转」· 汇编 代码 · 共 29 行

DATA_SEG SEGMENT
     STRING DB 'I am a student!'
     LENGTH EQU 15
DATA_SEG ENDS


CODE SEGMENT
     ASSUME CS:CODE,DS:DATA_SEG
START:
     MOV AX,DATA_SEG
     MOV DS,AX

     MOV BX,OFFSET STRING
     MOV CL,LENGTH
GOTO:MOV AL,[BX]
     CMP AL,'a'
     JB SKIP
     CMP AL,'z'
     JA SKIP
     SUB AL,20H
SKIP:MOV [BX],AL
     INC BX
     DEC CL
     JNZ GOTO

     MOV AH,4CH
     INT 21H
CODE ENDS
END START