.MODEL SMALL
.STACK
.DATA
    msg1  db '1+2+...+$'
    odoa  db 0dh,0ah,'$'
    t1    db 20 dup (?)
    tt    db 20 dup (?)
    oper  db 120
    tmp   db ?
    ans   dw ?
    tmp1  dw ?
    tab   db '0123456789'
.CODE
beg: MOV   AX,@DATA
    MOV   DS,AX
;
    call  clrscr
    lea   dx,msg1
    mov   ah,09
    int   21h
;
    xor   si,si
    xor   ax,ax
    lea   bx,tab
    mov   dl,10
    mov   al,oper
    mov   tmp,al     ; store 120 into tmp
;
cont:
    idiv  dl
    mov   tmp,al      ;  ah is the remainder, al is the quotient
    mov   al,ah
    xlat
    mov   tt[si],al
    inc   si
    xor   ax,ax
    mov   al,tmp
    cmp   al,0
    je    final
    jmp   cont
;
final:
    mov   cx,si
    dec   si
pri:
    mov   dl,tt[si]
    mov   ah,02h
    int   21h
    dec   si
    loop  pri
;
    mov   dl,'='
    mov   ah,02     ; print '='
    int   21h
;
;  begin to sum up total
;
    xor   ax,ax
    mov   al,oper
    mov   cx,ax
    xor   ax,ax
sum:
    add   ax,cx
    loop  sum
;
;   print result
;
    mov   ans,ax        ; store the sum result
;
    xor   si,si
    xor   dx,dx
    lea   bx,tab
    mov   cx,10
    mov   ax,ans
;
cont1:
    idiv  cx
    mov   tmp1,ax      ;  dx is the remainder, ax is the quotient
    mov   al,dl
    xlat
    mov   tt[si],al
    inc   si
    xor   dx,dx
    mov   ax,tmp1
    cmp   ax,0
    je    final1
    jmp   cont1
;
final1:
    mov   cx,si
    dec   si
pri1:
    mov   dl,tt[si]
    mov   ah,02h
    int   21h
    dec   si
    loop  pri1
;
    lea   dx,odoa
    mov   ah,09
    int   21h
;
    mov   ah,4ch
    int   21h
;
clrscr proc
       push  ax
       push  es
       push  di
       push  cx
       mov   ax,0b800h
       mov   es,ax
       xor   di,di
       mov   cx,2000
       mov   ax,0720h
       rep   stosw
;
       mov  dx,0
       mov  ah,02
       int  10h
       pop  cx
       pop  di
       pop  es
       pop  ax
       ret
clrscr endp
END beg