Multiple PICs on usart network

[timmers]

Attached is a pdf schematic similar to Jose P's posting, but halving the number of transistors per channel.
Also need to add a TX BUSY bus to prevent collision. (Hold to ground when transmitting, tristate when idle).
A similar circuit ran fine at 115200 baud.

Almost any signal diode in series to the TX pins (cathode to the TX pin) with a bus pull up resistor on the anode could also work fine.

Tim.