ORG 00H


START:setb P2.7
call delay
mov a,p2
mov p1,a
clr P2.7
call delay
MOV A,P2
MOV P1,A
JMP START
delay:mov r3,#1
d2:   mov r5,#20
d1:   mov r4,#248
      djnz r4,$
      djnz r5,d1
      djnz r3,d1
      ret
END