DATA SEGMENT
    Buffer DB 7, '?', 6 dup('?'), '$'
    Error DB 'Error$'
    Message1 DB 'Enter number: $'
    Message2 DB 'Press to show number..', 0Dh, 0Ah, '$'
DATA ENDS

CODE SEGMENT
    ASSUME CS:CODE, DS:DATA
    Start:
    mov ax,DATA
    mov ds,ax

    mov dx,offset Message1
    mov ah, 9
    int 21h

    call Get_integer
    cmp di,2
    jz er

    push ax
    mov dx,offset Message2
    mov ah, 9
    int 21h
    mov ah, 10h
    int 16h
    pop ax

    call Print_integer
    mov ah, 4Ch
    int 21h

    er:
    mov dx, offset Error
    mov ah,09
    int 21h
    mov ah, 4Ch
    int 21h

Get_integer proc

    mov ah,0ah
    xor di,di
    mov dx,offset Buffer
    int 21h
    mov dl,0ah
    mov ah,02
    int 21h

    mov si,offset Buffer+2
    cmp byte ptr [si],"+"
    jz p1
    cmp byte ptr [si],"-"
    jnz p2
    mov di,1
    p1:
    inc si
    p2:
    xor ax,ax
    mov bx,10
    p3:
    mov cl,[si]
    cmp cl,0dh
    jz endin


    cmp cl,'0'
    jb erg
    cmp cl,'9'
    ja erg

    sub cl,'0'
    mul bx
    add ax,cx
    jc erg
    cmp ax, 8000h
    ja erg
    inc si
    jmp p3

    erg:
    mov di,2
    ret

    endin:
    cmp di,1
    jnz p4
    neg ax
    p4:
    ret
Get_integer endp

Print_integer proc

    mov bx, ax
    or bx, bx
    jns ml
    mov al, '-'
    int 29h
    neg bx
    ml:
    mov ax,bx
    xor cx,cx
    mov bx,10
    m2:
    xor dx,dx
    div bx
    add dl,'0'
    push dx
    inc cx
    test ax,ax
    jnz m2
    m3:
    pop ax
    int 29h
    loop m3
    ret

Print_integer endp

CODE ENDS
END Start