A computer program product for use with a computer system having a main storage device in processing communication with a plurality of channels, said channels coupled to at least one control unit capable of coupling to a plurality of input/output devices, comprising:
- a data storage element included in said main storage device having a computer usable medium with computer readable code means for receiving and retrieving data;
- computer readable code means for concurrently receiving multiple packets of data from said channels;
- computer readable code means for concurrently storing multiple packets of data in said data storage element;
- computer readable code means for concurrently storing and retrieving multiple packets of data between said channels and said data storage element;
- computer readable code means for transferring execution of certain channel functions to said control unit and having means for combining certain commands and multiple data packets in one sequence;
- computer readable code means for sending only one start data command and only one end command notification before and after a plurality of data packets is transferred respectively.