isport:			       	   	;tests if we run on PC or PF
	push 	di
	push 	es
	mov 	di,0fff0
	mov 	es,di			;es=0fff0
	mov 	di,0ee	
	cmp 	es:w ptr [es:di],04350	;test 0FFF0:00EE if there is 'PC'
                			;if it is 'PC' -> we are on PF
	pop es
	pop di

	jne 	exit	         	;jmp if it is not Portfolio