mov ax, 0		; move segment into AX (0000h)

	mov es, ax		; update ES with segment in AX

	mov al, 0x40		; move desired interrupt number into AL
	mov bl, 4		; bl = 4

	mul bl			; multiply AX (0000h) with 4

	mov bx, ax		; move result in AX into BX

	mov si, handler_address	; move adress of interrupt-handler into SI

	mov [es:bx], si		; move first word in SI into ES:BX

	add bx, 2		; add 2 to BX

	mov ax, cs		; move segment into AX 

	mov [es:bx], ax		; move segment in AX into second word in ES:BX

	; calls to 0x40 will now be redirected to handler_address