Abstract: A method and system for communicating digital data particularly adapted for transferring large amounts of bulk data from a first station to a second station over a long propagation delay path, as for example, between first and second earth stations via a satellite repeater. The system implements a procedure or protocol which is characterized by causing the source station to continuously transmit data frames at fixed intervals, each such data frame including an identification number and an information field, generally containing a portion of a user data record. Error checking means at the destination station determines whether the data frames received thereat are error free. The destination station also continuously transmits data frames at fixed intervals substantially synchronized with the source station data frame intervals.

Abstract: An information exchange processor suitable for coupling a plurality of host computers to a plurality of communication channels each of which may utilize a uniquely defined communication discipline. More specifically, the information exchange processor comprises a master bus, one or more host memory input/output units each serving a different host computer, one or more microprocessors, one or more memory devices, and a plurality of device input/output units each of which serves one or more communication channels. Each communication channel can serve a peripheral device having a different communication discipline. In addition, the information exchange processor disclosed also provides a capability for interconnecting two communication channels having either the same or different communication disciplines for effecting direct information transfers therebetween without requiring monitoring by a host computer.