Multiple Concurrent Use of a Streaming Tape Data Path
Original Publication Date: 1989-Apr-01
Included in the Prior Art Database: 2005-Jan-27
A method of data buffering and physical interface management permits the concurrent use of an I/O processor data path for both low-speed (e.g., streaming tape) and high-speed (e.g., DASD) data transfer operations. In its most general form, an I/O processor (IOP) data path consists of a storage port, a device port, and one or more interposed data buffers. The storage port connects the IOP buffer to the host processor's main storage bus, and the device port connects the IOP buffer to some device interface. Idle time for the data ports are especially frequent and lengthy when the data rate of a given port is significantly higher than the average data rate of a connected I/O device.