DEC TO BIN IN ASM

.MODEL TINY

.CODE

MAIN PROC

    CALL INDEC
    PUSH AX
    CALL NEWLINE
    CALL NEWLINE
    POP AX
    CALL OUTDEC


EXIT:
    MOV AH,4CH
    INT 21H

MAIN ENDP

CALL INDEC
CALL OUTDEC


NEWLINE PROC
    MOV AH,2
    MOV DL,10
    INT 21H
    MOV DL,13
    INT 21H
    RET
NEWLINE ENDP

OUTDEC PROC

       PUSH AX              ;save registers
       PUSH BX
       PUSH CX
       PUSH DX



@END_IF1:
;get decimal digits
       XOR CX,CX            ;CX counts digits
       MOV BX,2D           ;BX has divisor
@REPEAT1:
       XOR DX,DX            ;prepare high word of dividend
       DIV BX               ;AX = quotient, DX = remainder
       PUSH DX              ;save ramainder on stack
       INC CX               ;count = count + 1
;until
       OR AX,AX             ;quotient = 0?
       JNE @REPEAT1         ;no keep going
;converts digits to characters and print
       MOV AH,2             ;print char function
;for count times do
@PRINT_LOOP:
       POP DX               ;digit in DL
       OR DL,30H            ;convert to character
       INT 21H              ;print digit
       LOOP @PRINT_LOOP     ;loop until done
;end_for
       POP DX               ;restore registers
       POP CX
       POP BX
       POP AX
       RET
OUTDEC ENDP



INDEC PROC

      PUSH BX                 ;save registers used
      PUSH CX
      PUSH DX
;print prompt
@BEGIN:
      MOV AH,2
      MOV DL,'?'
      INT 21H                 ;print '?'
;total=0
      XOR BX,BX               ;BX holds total
;negative = false
      XOR CX,CX               ;CX holds sign
;read a character
      MOV AH,1
      INT 21H                 ;character in AL
;end_case
@REPEAT2:
;if character is between '0' and '9'
      CMP AL,'0'              ;character >= '0'?
      JNGE @NOT_DIGIT         ;illegal character
      CMP AL,'9'              ;character <= '9'?
      JNLE @NOT_DIGIT         ;no, illegal character
;then convert character to a digit
      AND AX,000FH            ;convert to digit
      PUSH AX                 ;save on stack
;total = total * 10 + digit
      MOV AX,10               ;get 10
      MUL BX                  ;AX = total * 10
      POP BX                  ;retrieve digit
      ADD BX,AX               ;total = total * 10 + digit
;read a character
      MOV AH,1
      INT 21H
      CMP AL,0DH              ;carriage return?
      JNE @REPEAT2            ;no, keep going
;until CR
      MOV AX,BX               ;store number in AX
;if negative
      OR CX,CX                ;negative number
      JE @EXIT                ;no, exit
;then
      NEG AX                  ;yes, negate
;end_if
@EXIT:
      POP DX                  ;restore registers
      POP CX
      POP BX
      RET                     ;and return
;here if illegal character entered
@NOT_DIGIT:
      MOV AH,2                ;move cursor to a new line
      MOV DL,0DH
      INT 21H
      MOV DL,0AH
      INT 21H
      JMP @BEGIN              ;go to beginning
INDEC ENDP

END MAIN