Unisys Corporation

Haeng D Park

Carl R Crandall

Craig B Johnson

Thomas N DeVries

Michael J Heideman

Hans Christian Mikkelsen

Michael C Otto

Stephen H Anderson

Timothy T Cain

David W Dorumsgaard

Glenn C Kaiser

Thomas P Cooper

Michael J Rieschl

David A Novak

Joseph E Kessler

A method for efficiently saving data to tape, preferably within the ANSI X3.27 standard format sends signals to the tape drive to allow the tape drive to buffer the required tape marks, which the standard requires. Although the standard presumed these would be required for synchronization and would be written when produced, we do not adhere to that thinking. Instead we synchronize only at the logical end of the application constructed file, or at the end of the tape in one embodiment, saving time in writing through avoiding stop-start activities of the tape drive, thus allowing newer tape drives to take advantage of the features of the ANSI X3.27 standard. We also provide an embodiment, which allows for non-ANSI standard (i.e., unlabeled) tapes to be used.

System for improving performance writing streaming tapes

An apparatus for and method of implementing a cluster lock processing system having a relatively large number of commodity cluster instruction processors which are managed by a highly scalable, off the shelf communication processor. Because the commodity processors have virtually no system viability features such as memory protection, failure recovery, etc., the communication processor assumes the responsibility for providing these functions. The low cost of the commodity cluster instruction processors makes the system almost linearly scalable. Furthermore, having a fully scalable communication processor ensures a completely scalable system. The cluster/locking, caching, and mass storage accessing functions are fully integrated into a single hardware platform.

Standard channel I/O processor (SCIOP)

A system and method for testing I/O components without requiring initiation of the test I/O requests from the operating system via the instruction stream. An I/O system facilitates I/O operations between a processing system and I/O devices during normal I/O processing. An exerciser initiation queue is established, which corresponds to an operating initiation queue used during normal I/O processing. The I/O system is configured to monitor for test I/O requests on the exerciser initiation queue in lieu of monitoring for standard I/O requests on the operating initiation queue. A testing module enters the test I/O requests on the exerciser initiation queue in a format analogous to standard I/O requests entered on the operating initiation queue during normal I/O processing. The test I/O requests on the exerciser initiation queue are processed via the I/O system. Upon I/O completion, status may be returned to the testing module for processing of test results.

System and method for performing input/output diagnostics

A method of and apparatus for efficiently and effectively coupling a newly designed peripheral device to a legacy data processing system. The approach utilizes emulation of a SCSI tape device by a SCSI DVD device. Through device emulation, system-wide modifications are minimized.

Method and design for a DVD SCSI tape controller

A system and method for processing I/O requests in a computing system. I/O packets are created via an operating system associated with the computing system, where the I/O packets include I/O transaction information. The I/O packets are made accessible to an I/O system. A command for a channel type connecting a target I/O component to the I/O system is constructed, where this command construction is based on the I/O transaction information provided in the I/O packet, and based on physical aspects of the target I/O component and channel type provided independently of the I/O packet. The constructed command is issued to the target I/O component in accordance with the channel type.

System and method for facilitating use of commodity I/O components in a legacy hardware system

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Shoreview, MN, United States of America

Haeng D Park