Hi! I'm trying to connect three 8051 (AT89C52) ucontrollers through RS485 (DS485 by Maxim-IC). One uC will act as master while the other two will act as slaves. The object is to perform serial communication (using the 9-bit mode). I've connected the A & B's of three 485's together. Other connections are:- 485 --------- uC RO (Receiver Output) --------- RXD RE (Receiver Output Enable)--------- P1^5 DE (Driver Output Enable) --------- P1^6 DI (Driver Input) --------- TXD Kindly tell me how the addressing will be done and how can I accomplish this. If anyone has a code for it in C, kindly mail it to me at umer_blue@yahoo.com Regards!