For posting formatted code, please refer to this: http://www.8052.com/users/jonled/noob.pdf


The way I see it you need to:

in main
configure interrupt for edge detection

in interrupt
look at flag and do either condition 1 or 2

condition 1): set interrupt for timer overflow, set port on, start timer, set or clear flag and return

condition 2): turn port off, reconfigure interrupt for edge detect, set or clear flag and return


Jon