ORG 0000H
LJMP MAIN
ORG 0003H
LJMP IN_T0
ORG 0100H
MAIN:SETB IT0
SETB EA
SETB EX0
MOV DPTR,#8000H
MOV A,#00H
MOVX @DPTR,A
JMP $
IN_T0:MOV DPTR,#8000H
MOVX A,@DPTR
MOV P1,A
MOV A,#00H
MOVX @DPTR,A
RETI
END