EX1.ASM

DATA SEGMENT
BUFFERIN  DB 80,?,80 DUP('$')
BUFFEROUT DB 80,?,80 DUP('$')
HANDLE    DW ?
FILESIZE  DW ?
FILENAME  DB 'C:\INPUT1.txt',0
FILEOUT   DB 'C:\OUTPUT1.TXT',0
SUCCESS1  DB 'SUCCESS TO CREATE FILE',0DH,0AH,'$'
SUCCESS2  DB 'SUCCESS TO WRITE FILE',0DH,0AH,'$'
SUCCESS3  DB 'SUCCESS TO READ FILE',0DH,0AH,'$'
FAIL1     DB 'FAIL TO CREATE FILE',0DH,0AH,'$'
FAIL2     DB 'FAIL TO WRITE FILE',0DH,0AH,'$'
FAIL3     DB 'FAIL TO READ FILE',0DH,0AH,'$'
DATA ENDS
STACK SEGMENT STACK
         DB 100 DUP(?)
STACK ENDS
CODE SEGMENT
         ASSUME CS:CODE,SS:STACK,DS:DATA
START:   
         MOV AX,DATA
         MOV DS,AX
         MOV CX,0
         LEA DX,FILENAME
         MOV AH,3CH
         INT 21H
         JNC SUCCESSCREATE
         LEA DX,FAIL1
         JMP DISPLAYFILE
SUCCESSCREATE: 
         LEA DX,SUCCESS1
        ;SAVE FILE NUMBER
DISPLAYFILE:    
         MOV AH,09H
         INT 21H
INPUTTEXT:
         LEA DX,BUFFERIN   ;INPUT FROM KEYBOARDS
         MOV AH,0AH
         INT 21H
         
         LEA DX,FILENAME  ;OPEN THE FILE
         MOV AL,01H
         MOV AH,3DH
         INT 21H
         MOV HANDLE,AX
  

         MOV BX,HANDLE
         MOV CL,BUFFERIN+1 ;SIZE OF BYTES OF BUFFERIN
         MOV CH,00H
         LEA DX,BUFFERIN+2 ;ADDRESS OF BUFFER DATA
         MOV AH,40H        ;WRITE FILE
         INT 21H
         CMP AX,CX         ;COMPARE SIZE OF WRITEIN TO BUFFERIN
         MOV FILESIZE,AX
         JZ  SUCCESSWRITE  ;ZF=1,EQUAL
         LEA DX,FAIL2
         JMP DISPLAYWRITE
SUCCESSWRITE:
         LEA DX,SUCCESS2
DISPLAYWRITE:
         MOV AH,09H
         INT 21H
         MOV BX,HANDLE    ;CLOSE THE FILE
         MOV AH,3EH
         INT 21H
         
READFILE:
         LEA DX,FILENAME  ;OPEN THE FILE
         MOV AL,00H
         MOV AH,3DH
         INT 21H
         MOV HANDLE,AX

         MOV BX,HANDLE
         MOV CL,BUFFERIN+1
         MOV CH,00H
         LEA DX,BUFFEROUT+2
         MOV AH,3FH
         INT 21H
         MOV DL,BUFFEROUT+2
         ;ADD DL,30H
         MOV AH,02H
         INT 21H
         ;CMP AX,CX
         JMP SUCCESSREAD
         LEA DX,FAIL3
         JMP DISPLAYREAD

SUCCESSREAD:
         LEA DX,SUCCESS3

DISPLAYREAD:
         MOV AH,09H
         INT 21H 

         MOV BX,HANDLE    ;CLOSE THE FILE
         MOV AH,3EH
         INT 21H

         MOV CL,BUFFERIN+1
         MOV CH,00H

         XOR SI,SI         ;SI=0
         
DISPLAYTEXT:    
          MOV DL,BUFFEROUT+2[SI]
         
          CMP DL,61H         ;JUDGE LOWERLETTER 
          JB  PRINT       ;DL>5AH TURN LOWERLETTER TO UPPERLETTER 
          XOR DL,20H
          MOV BUFFEROUT+2[SI],DL      
          
          
PRINT:    MOV AH,02H
          INT 21H 
          INC SI     
          LOOP DISPLAYTEXT  ;LOOP CX=CX-1

CREATEOUTPUTFILE:
         MOV CX,0
         LEA DX,FILEOUT
         MOV AH,3CH
         INT 21H
         
INPUTOUTPUTFILE:
         LEA DX,FILEOUT   ;OPEN THE FILE
         MOV AL,01H
         MOV AH,3DH
         INT 21H 
         MOV HANDLE,AX 

         MOV BX,HANDLE
         MOV CL,BUFFERIN+1  ;SIZE OF BYTES OF BUFFEROUT
         MOV CH,00H
         LEA DX,BUFFEROUT+2 ;ADDRESS OF BUFFER DATA
         MOV AH,40H       ;WRITE FILE
         INT 21H

         MOV BX,HANDLE    ;CLOSE THE FILE
         MOV AH,3EH
         INT 21H

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