%define cr      0x0a
%define lf      0x0d
%define endl    0x0

; Reads a character
; out:
;   al = asci character
;   ah = scan code
read_char:
    mov ah, 0
    int 0x16
    ret

; Prints a character
; in:
;   al = asci character to print
print_char:
    mov ah, 0x0e
    int 0x10
    ret

; Prints a null terminated string
; in:
;   si = null terminated string pointer
print_line:
    .loop:
        cmp byte [si], 0
        je .done
        mov al, [si]
        call print_char
        inc si
        jmp .loop
    .done:
    ret