I have been thinking about that for a while. It looked really complicated at first but i think i get the general idea. The description near the bottom was a bit confusing but the diagram makes sense. Since first looking at RS485 i was going to have the PIC chips switch between sender and receiver. I need data to be sent pretty quick but i dont need quick replies from any of the devices so that would have worked pretty well.

Im doing a little redesigning of the main driver circuit at the moment to add some extra features. The way im doing it might mean i have no choice but to use the 555 way. They are extra components but i suppose they are pretty cheap.

Thanks for clearing that up anyway. Saved me from releasing the mysterious blue smoke again