A plurality of external storage devices for storing therein data processing history information. The history information obtained from the processing executed in a data processing system is cyclically written in principle in these external storage devices each time the history information occurs, thereby distributing the load required for the processing to store the history information.
A multiple processor system composed of a plurality of instruction processors allows a plurality of its subsystems for performing data processing in each unit to be operable simultaneously with and parallel to each other in each of the instruction processors. The multiple processor system has a processor designation table and a control processing subsystem. As the processor designation table specifies correspondence relation between a subsystem accessing to each input-output resource and the instruction processor executing the subsystem, the processing control subsystem transfers control of the processing to the instruction processor to be designated by the processor designation table in accordance with the subsystem to be used with reference to the processor designation table during execution of the data processing.
A network system includes a plurality of printers and a digital copying machine interconnected through a data transmission line, detects a free space in an image memory of each printer, adds a user identification code to image data of a document read in an image reading section of the digital copying machine, and then sends the image data to a printer with the image memory having a sufficient free space so as to store the image data. With this structure, even if the digital copying machine does not have an image memory, it is possible to store the image data subjected to an image formation within the network and omit an image reading process when performing an image formation according to the same image data later. Moreover, with this structure, various processing can be executed on the image data by effectively using the functions of the respective apparatuses.
A data processing method using a plurality of data processing apparatuses is provided. In the method, a current data processing apparatus adaptively processes data using data processing history information of a previous data processing apparatus. The method includes receiving data from one of the data processing apparatuses, receiving data processing history information regarding processing of the data by the data processing apparatus, and processing the data based on the data processing history information.
A data management apparatus for high-speed, seamless recording and reproduction of data, equipped with a recovery function and a defective region detection function, a data management function, and a recording medium. The data management apparatus records blocks of a fixed size on a first recording medium after dividing a stream data in blocks of a fixed size and manages the stream data recorded on the first recording medium based on the file management information to specify the stream data. After generating retrieval information on the blocks of a fixed size, the retrieval information is recorded in the blocks of a fixed size. File management information based on the retrieval information when the recovery of the file management information is requested. The retrieval information is recorded on a remaining region of the last sector where the data block is recorded.
A disk array controller providing a variable configuration data path between the host system and the individual disk drives within a disk array and parity and error correcting code generation and checking. The controller includes host interface logic for converting data received from the host system via a 16 or 32-bit SCSI bus to 16, 32 or 64-bit data words multiplexed across one, two or four 16-bit buffer busses, and for converting data received from the buffer busses to the proper form for transmission to the host system. A bus switch, including an exclusive-OR circuit for generating parity information, is connected between the buffer busses and six disk drive busses for directing the transfer of data and parity information between selected buffer and drive busses. The controller further includes a storage buffer connected to the buffer busses to provide temporary storage of data and parity information. The host interface logic, bus switch and storage buffer, under the direction of an included processor and DMA control logic, performs array read and write operations requested by the host system in accordance with RAID level 1, 3, 4 or 5 protocols.
