Has anyone else actually used mode 3 for anything ? I have just implemented a master slave network with it and it seems more trouble than its worth ! You could do the same job by using just plain old vanilla 9bit serial, without the address recog. Even with recog, any serial traffic with bit nine false triggers an interrupt, and you have to make sure you were the unit last addressed anyway.

I now have a nice Delphi test application that drives an RS485 network of 80C320 uc from a PC serial port. Anyone want a copy of the source ?

Steve