Structuring IBM System/370 Channels
Original Publication Date: 1978-Jan-01
Included in the Prior Art Database: 2005-Feb-20
A single entity is described which fulfills the requirements for structuring channels. These requirements previously dictated the need for five separate and distinct units. A subchannel is a group of hardware facilities with the capability to control one input/output (I/O) device. A selector channel has a single subchannel and can run only one device at a time. A multiplexer channel has multiple subchannels and can run multiple devices in overlap. The block diagram of a typical selector channel is shown in Fig. 1. The block diagram of a typical multiplexer channel is shown in Fig. 2.