Abstract: A method of sending self-clocking data characters and control characters in a sequence from a first communications node to a second node includes the steps of: encoding each data character as respective code pairs of the form 0XX . . . X1 and 1XX . . . X0 where the X's are the zero and one bits of the data character; encoding each control character as respective code pairs of the form 0XX . . . X0 and 1XX . . . X1 where again the X's are the zero and one bits of the control character; and transmitting, for each character in said sequence, the particular code in that character's code pair whose first code bit is the opposite of the last code bit of the immediately preceding character in the sequence.

Abstract: A method of transmitting isochronous and nonisochronous data through a computer network in which a plurality of stations have respective input and output ports that are serially coupled together to form a loop includes the steps of: transmitting data characters of a nonisochronous frame from a first station in the loop; passing the data characters from the first station through a second station in the loop but with a pair of control characters inserted between any two data characters indicating the beginning and end of an isochronous frame within the nonisochronous frame; passing the data characters and control characters from the second station through a third station on the loop but with another internally generated isochronous data character inserted between the control characters; temporarily stopping the transmitting step in the first station in response to the receipt of at least one of the control characters to pass the isochronous frame through the first station; and proceeding in the first station wi