Nhập xuất số thập phân trong Assembly

.model small
.stack 100
.data
    CLRF db 13, 10, '$'
.code
    main proc
        mov ax, @data
        mov ds, ax
        call inputDec

        push ax         ; luu Ax lai
        mov ah, 9       ; xuong dong
        lea dx, CLRF
        int 21h
                        ; lay Ax ra
        pop ax
        call outputDec

        mov ah, 4ch
        int 21h

    main endp

    inputDec proc
        ; Vao: nhap vao so
        ; Ra: So luu trong Ax
        push bx
        push cx
        push dx

        batDau:
            mov ah, 2
            xor bx, bx
            xor cx, cx
            mov ah, 1
            int 21h
            cmp al, '-'
            je dauTru
            cmp al, '+'
            je dauCong
            jmp tiepTuc

            dauTru:
                mov cx, 1

            dauCong:
                int 21h

            tiepTuc:
                cmp al, '0'
                jnge khongPhaiSo    ; khong lop hon hoac bang
                cmp al, '9'
                jnle khongPhaiSo    ; Khong nho hon hoac bang
                and ax, 000fh       ; doi thanh chu so
                push ax             ; cat vao ngan xep
                mov ax, 10

                mul bx              ; ax = tong*10
                mov bx, ax
                pop ax
                add bx, ax          ; tong = tong*10 + so
                mov ah, 1
                int 21h
                cmp al, 13          ; da enter chua?
                jne tiepTuc         ; nhap tiep

                mov ax, bx          ; chuyen KQ ra ax
                or cx, cx           ; co phai so am khong
                je ra
                neg ax              ; neu la so am thi doi ax ra so am

            ra:
                pop dx
                pop cx
                pop bx

                ret

            khongPhaiSo:
                mov ah, 2
                mov dl, 0dh
                int 21h
                mov dl, 0ah
                int 21
                jmp batDau


    inputDec endp

    outputDec proc
        push bx
        push cx
        push dx

        cmp ax, 0   ;   neu ax > 0 tuc la khong phai so am ta doi ra day
        jge doiRaDay
        push ax
        mov dl, '-'
        mov ah, 2
        int 21h
        pop ax
        neg ax  ; ax = -ax

        doiRaDay:
            xor cx, cx  ; gan cx = 0
            mov bx, 10  ; so chia la 10
            chia:
                xor dx, dx  ; gan dx = 0
                div bx      ; ax = ax / bx; dx = ax % bx
                push dx
                inc cx
                cmp ax, 0   ; kiem tra xem thuong bang khong chua?
                jne chia    ; neu khong bang thi lai chia
                mov ah, 2
            hien:
                pop dx
                or dl, 30h
                int 21h
                loop hien

                pop dx
                pop cx
                pop bx
                ;pop ax
        ret

    outputDec endp

end main