Time-Shared Dual Channel With Single Channel System Support
Original Publication Date: 1985-May-01
Included in the Prior Art Database: 2005-Feb-18
A second I/O channel was added to a computer system without a change in the channel support of the system and without the addition of a further port for the second channel. This can be done where there is sufficient internal processing and communication bandwidth from the system to the port to add a further channel in a time-shared mode with the existing channel at the port. Two channel controllers alternately interrogate two respective channels to determine if an I/O device to be accessed is coupled to the channel interrogated. The added channel is transparent to the system because selection of the appropriate channel coupled to the single port is controlled independently by the channel controllers. In Fig.