Abstract: A bidirectional repeater apparatus includes a plurality of line drivers for driving data signals in the opposite direction over communication lines, logic circuit means operated in response to the driving of the data signals over the communication line for generating trigger signals, a dual one-shot circuit connected to said logic circuit means for enabling the operation of the line drivers when triggered and a feedback circuit operated in response to the driving of a data signal over the communication line in one direction conditioning said logic circuit means to generate a trigger signal operating one of the one-shot circuits to output a signal enabling one of the line drivers to drive a data signal in the opposite direction over the communication line.