System which matches a received sequence of channel commands to sequence defining rules for predictively optimizing peripheral subsystem operations

摘要

A state of operation is established in accordance with rules for a peripheral subsystem which enables reduced channel time for executing ensuing related channel commands of the same channel program. In a peripheral data-storage subsystem, a set of rules of operation are established. Each rule sets forth a predetermined set of sequences of channel commands during any chain of channel commands (channel program) which predict ensuing channel operations in channel program currently being executed. Once any rule is satisfied, a state of operation is established in the subsystem for responding to ensuing channel commands in the same channel program and which relate to the channel commands set forth in the rules. So long as such related ensuing channel commands continue or until the end of the channel program the state of operation is maintained in the subsystem. During the state of operation, responding to the ensuing commands is speeded by performing preparatory subsystem operations before executing the ensuing channel commands. In a search for a desired record function, the state of operation causes data to be next searched to be staged to an electronic buffer such that the ensuing channel commands are executed at electronic speeds rather than related to the latency time of disk recorders.