Redundant disc computer having targeted data broadcast

摘要

A redundant disk computer system providing targeted data broadcast on the data bus to a plurality of devices on the data bus, such as computer central memory and a plurality of storage media disks (parity and data) under control of a real time operating system. Each of the plural disk storage media is each connected to the data bus with a corresponding enhanced disk adapted including a demand page memory of size sufficient to include a selected block of data and arranged to provide access to a selected portion of that data. The redundant array computer operating system provides the control and selected designation of the disk adapters as targeted receivers to read data "broadcast" over the data bus, providing simultaneous transfer of data over the data bus. Each enhanced disk adapter further includes exclusive-OR logic thereon to provide direct calculation of parity from the newly received data and a subsequently received old data on a single subsequent data bus cycle. Thus, according to the present invention, the number of data bus data transfers is reduced and significant improvements in system performance is provided.