AJMP	START
MOV	C,PSW.5
JC		ERROR			
SETB	PSW.5			
LJMP	MAIN			
ERROR:
CLR		EA
MOV	DPTR,#ERR1
PUSH	DPL
PUSH	DPH
RETI
ERROR1
MOV	66H,#0AAH
MOV	67H,#55H
CLR		A
PUSH	ACC
PUSH	ACC
RETI