Abstract: A tape library system for handling multi-volume tapes includes an automated tape system with at least one tape unit and a robotic tape handling system. The tape library system receives requests from at least one host for access to a specified tape volume in a specified tape unit. The tape library system includes a tape/library control unit that receives the request from the host computer and maps the specified tape volume to a tape cartridge. The TLCU determines if the tape cartridge is currently loaded in a tape unit and, if the tape cartridge is not loaded, commands the robotic tape handling system to load the cartridge into an available unit. The TLCU forms a virtual path between the host computer and the loaded tape unit. Data is then transferred between the loaded tape unit and the host computer. Thus, the host computer is presented with a virtual view of connection to the specified tape volume loaded in the specified tape unit.

Abstract: A forward chaining expert system is disclosed for use in analyzing categorization problems such as in diagnosing device malfunctions. The expert system is particularly useful in diagnosing malfunctions in a knowledge domain having a hierarchical functional decomposition. In such a knowledge domain, the hierarchical decomposition is used in constructing a collection hierarchically related rule sets which constitute the rule base for the expert system. The novel inferencing engine of the expert system iteratively examines rules within a selected rule set and: (a) determines the veracity of rule premises when compared with data within a fact base and (b) examines any statuses returned from the performance of rule consequents. Thus, upon encountering a rule consequent returning success, the inferencing engine selects a new rule set at a lower level in the rule set hierarchy and applies the new rule set to the data retained in the fact base.

Abstract: A bi-directional translator is disclosed which translates between low level substantially binary records of a data repository (such as a data log) and substantially equivalent high level English-like terms. Thus, the translator is used to translate English-like queries for the data repository into equivalent binary records which can, in turn, be used in retrieving appropriately matching records from the data repository where the data repository records are redundant and have both time related dependencies between the records and have a plurality of different binary formats. Subsequently, the translator is used to translate the retrieved records into substantially equivalent non-redundant English-like terms having no time related dependencies between terms and such that the data format for the terms is substantially uniform.