main.asm

从键盘输入一个字符串,先把它原样显示一遍 然后将其中的小写字母转换为大写显示,再将其中的大写字母转换为小写显示,最后将其中的大小写字母互换显示.显示字符串的功能调用采用宏,大写转换,小写转换和大小写互

;;;;;主程序，用于调用子程序
       PRINT  MACRO
              LEA       DX,MSG2
              MOV       AH,09H
              INT       21H

              LEA       DX, STRS
              MOV       AH, 09H
              INT       21H
	
              LEA       DX,CLR
              MOV       AH,09H
              INT       21H
	
              LEA       DX,MSG3
              MOV       AH,09H
              INT       21H

              LEA       DX, STRU
              MOV       AH, 09H
              INT       21H
	
              LEA       DX,CLR
              MOV       AH,09H
              INT       21H
     
              LEA       DX,MSG4
              MOV       AH,09H
              INT       21H

              LEA       DX, STRL
              MOV       AH, 09H
              INT       21H

              LEA       DX,CLR
              MOV       AH,09H
              INT       21H
    
              LEA       DX,MSG5
              MOV       AH,09H
              INT       21H

              LEA       DX, STRE
              MOV       AH, 09H
              INT       21H
	
              ENDM
     DATASEG  SEGMENT
        MSG1  DB        'Please Insert:  ','$'
        MSG2  DB        'Your Insert:    ','$'
        MSG3  DB        'LowToUp:        ','$'
        MSG4  DB        'UpToLow:        ','$'
        MSG5  DB        'ChangeTwo:      ','$'
     STRSLEN  DB        20
      ACTLEN  DB        ?
        STRS  DB        20 DUP(?), '$'          ;保存输入的字符串
        STRU  DB        20 DUP(0), '$'          ;保存调用LowToUp后的字符创
        STRL  DB        20 DUP(0), '$'          ;保存调用UpToLow后的字符串
        STRE  DB        20 DUP(0), '$'          ;保存调用ChangeTwo后的字符串
         CLR  DB        0DH,0AH,'$' ;换行
     DATASEG  ENDS
;********************************************************************
     CODESEG  SEGMENT
        MAIN  PROC      FAR
      START:
              ASSUME    CS:CODESEG, DS:DATASEG, ES:DATASEG
              MOV       AX, DATASEG
              MOV       DS, AX
              MOV       ES, AX

              LEA       DX,MSG1
              MOV       AH,09H
              INT       21H
	
              LEA       DX,STRSLEN
              MOV       AH,0AH
              INT       21H
    
              LEA       DX,CLR
              MOV       AH,09H
              INT       21H
    
              LEA       SI, STRS
              LEA       DI, STRU
              CALL      TOUPPER
	
              LEA       SI, STRS
              LEA       DI, STRL
              CALL      TOLOWER
	
              LEA       SI, STRS
              LEA       DI, STRE
              CALL      ULCHG
	
              PRINT
	
              MOV       AH, 4CH
              INT       21H
        MAIN  ENDP
	
     INCLUDE  LOWTOUP.ASM
     INCLUDE  UPTOLOW.ASM
     INCLUDE  CHANGETWO.ASM
	
     CODESEG  ENDS
              END       START