We use the TI 75179.  It's a separate transmitter and receiver in
one chip.  TI also has a transceiver that transmits and receives on the
same pair (allowing the transmitter to be tristated).

Harold

On Mon, 5 Jan 1998 14:34:17 -0500 Jeff Cesnik <jcesnik@CLARAVISTA.COM>
writes:
>Does anyone have an example schematic (or know where to find one)
>using
>two PIC16F84's communicating over an RS-422/485 link?  I've done
>RS-232,
>but have absolutely no experience with balanced line communications.
>Can someone recommend a good line driver/receiver suitable for
>interfacing with the PIC?
>
>-Thanks
>