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.

Abstract: An error detecting and correcting system, comprising: a memory for storing data including a first section, the data being stored in the first section in rows and columns; first means for storing first check bits for the rows of data; and error correcting means, including: means for generating check bits for the columns of data so as to produce a check word for a predetermined number of the rows of data; a second section for storing at least one check word; and processor means operatively coupling the generating means with said first and second sections to enable the error correcting means to utilize the first check bits to locate a row of data in which at least one bit is in error and also to enable the error correcting means to utilize said check word to correct any errors which exist in the row of data.

Abstract: A digital circuit is disclosed which may be used to sequence a series of events and which can alter the sequence of events as a function of the inputs to the circuit. A read-only memory is accessed by an address register which can increment the address of the instruction which it is desired to access from memory either incrementally, as by counting, or in a branching mode by altering the address by an amount corresponding to a portion of one or more of the instructions taken from the memory. Branching may be conditional or unconditional.

Abstract: An electrical bus bar is disclosed which is formed of two parallel bars that lie together in juxtaposition in parallel planes except where conformations in one or both bars result in their separation to form a region into which a connector pin can be inserted. A means is provided for holding the two bars of the bus bar together so that they grip the connector pin after the pin is inserted into the connection position. Several means are disclosed for holding the bars together. The preferred means for that purpose is a non-conductive, resilient material which encompasses the two bars that form the bus bar and grips them together sufficiently to pinch the two bars against opposite sides of a connector pin with which they are assembled.