Print string terminated by zero (0x00) using int 0x10 bios TTY:

// print string terminated by zero
    lea dx,welcome //<-pointer to string
loop:
    mov bx,dx
    mov al,byte ptr[bx]
    cmp al,0
    jz exit_loop
    inc dx
    mov ah,0x0e
    mov bx,0x04
    int 0x10
    jmp loop
exit_loop: