I/O Control Block Structure for Concurrent Operations on an I/O Device
Original Publication Date: 1987-Aug-01
Included in the Prior Art Database: 2005-Feb-01
This article descibes a technique which provides input/output (I/O) devices with concurrent operations compatible with program views of the device. Conventional notions of an I/O device always being in a slave relationship to the program have resulted in limitations on the concurrency of operations possible with the device. For example, the IBM Series/1 control block structure for an I/O device consisted of one device control block (DCB) in execution at a time, supplemented with an attention-interrupt capability to shoulder tap the program of the presence of data not solicited from the viewpoint of the program.