emu8086 Assembly Input output with three characters

Question

good day everyone, i'm new to this language and here is a code i modified that should accept input ABC and return ABC but it returns ABB. i tried it with AH,BH and Ax,Bx it gets worse. How do I modify this ( for now our teacher wants us to stick to MOV,INT,LEA and what is on the code here). thanks for tips and answers

.MODEL SMALL
    .STACK 100H
    .CODE
     MOV AH, 01H ; Character input with echo
     INT 21H ; Character in AL
     MOV BL, AL ; Save in BL    

     MOV AH, 01H ; Character input with echo
     INT 21H ; Character in AL
     MOV CL, AL ; Save in CL

     MOV AH, 01H ; Character input with echo
     INT 21H ; Character in AL
     MOV DL, AL ; Save in DL

     MOV AH, 02H ; Display character function    

     MOV DL, 0DH ; carriage return
     INT 21H

     MOV DL, 0AH ; line feed
     INT 21H  

     MOV DL, BL ; Get character stored in BL and display
     INT 21H   
     MOV DL, CL ; Get character stored in CL and display
     INT 21H  
     MOV DL, DL ; Get character stored in DL and display
     INT 21H  

     MOV AH, 4CH
     INT 21H
     END

Answer 1

At line 14, you save the third character in DL, but, later, you lose this value by assigning ODH and OAH to DL. The solution is simple : store the third character in another register instead of DL, for example, CH, at the bottom you display CH instead of DL (arrows <============== point to the changes) :

.MODEL SMALL
    .STACK 100H
    .CODE
     MOV AH, 01H ; Character input with echo
     INT 21H ; Character in AL
     MOV BL, AL ; Save in BL    

     MOV AH, 01H ; Character input with echo
     INT 21H ; Character in AL
     MOV CL, AL ; Save in CL

     MOV AH, 01H ; Character input with echo
     INT 21H ; Character in AL
;    MOV DL, AL ; Save in DL
     MOV CH, AL ; <============================

     MOV AH, 02H ; Display character function    

     MOV DL, 0DH ; carriage return
     INT 21H

     MOV DL, 0AH ; line feed
     INT 21H  

     MOV DL, BL ; Get character stored in BL and display
     INT 21H   
     MOV DL, CL ; Get character stored in BL and display
     INT 21H  
;    MOV DL, DL ; Get character stored in BL and display
     MOV DL, CH ; <============================
     INT 21H  

     MOV AH, 4CH
     INT 21H
     END

I chose CH because it's a register that is not been used in the code.

Answer 2

There is a more Efficient way

MAIN PROC

MOV BH,0
MOV BL,10D


   INPUT:
   MOV AH,1
   INT 21H
   CMP AL,13D
   JNE NUMBER 

   JMP EXIT


   NUMBER:
   SUB AL,30H
   MOV CL,AL
   MOV AL,BH
   MUL BL
   ADD AL,CL
   MOV BH,AL

   JMP INPUT

EXIT:

   AND AX,0
   MOV AL,BH
   MOV CL,10D

   MOV BX,0000H    

   STORE:
   DIV CL
   MOV [0000H+BX],AH
   ADD BX,2H
   MOV AH,0
   CMP AL,0
   JNE STORE

   MOV AH,2
   MOV  DL,0DH
   INT 21H
   MOV DL,0AH
   INT 21H

   PRINT: 
   SUB BX,2H
   MOV DL,[0000H+BX]
   ADD DL,30H
   INT 21H
   CMP BX,0
   JNE PRINT



MAIN ENDP

END MAIN