Tandem Computers Incorporated

Thumbscan, Inc.

James M Lyon

Matthew C McCline

William J Carley

Michael John Skarpelos

Robbert Van Der Linden

Malcolm Mosher, Jr

William P Cargile

Franco Putzolu

Richard D Freeman

Steven R Pearson

A fault tolerant computer system distributes audit trail files containing audit records, across an arbitrary number of disk volumes. After one audit trail file becomes full, audit records are directed toward a next audit trail file stored on a different disk volume. Storage of newly generated audit rotates through the disk volumes in round-robin fashion. Full audit trail files are eventually archived and their space becomes available again for renaming and storage of newly generated audit records. The number of audit records available for on-line recovery after a failure is not limited to the storage capacity of any single disk volume. Furthermore, there is no contention for disk access between archiving of full audit trail files and storage of newly generated audit records.

Multi-volume audit trails for fault tolerant computers

System-critical files are protected from being inadvertently modified or deleted by placing them in a Reserve name space of storage that requires any process seeking modifying access to the Reserve name space to have a 'Right' to do so. The right to modifying access is garnered by a process first making a call to a system library procedure that causes a memory-stored data structure associated with the calling process to be modified, identifying the process as one with a Right to make modifying access to the Reserve name space. Any attempt to modify, delete, or create any file residing in the Reserve name space without the Right will be refused.

Method and apparatus for preventing inadvertent changes to

An improved recovery method utilizes sequence numbers to order log records and reduce the excess compensating actions due to a failure during recovery. Next undo records are written to the log after a preset number of compensating actions which include the sequence number of the record currently being scanned. After a failure, all records between the next undo record and the record having the sequence number included in the next undo record are ignored during when the log is scanned backwards.

Method for providing recovery from a failure in a system utilizing

A multiple processor system includes at least one process pair each including a plurality of modules. The modules perform functions related to multiple independent threads, and are arranged in a predetermined order such that higher modules are dependent upon lower modules, and lower modules are independent from higher modules. Each process pair is initially unaware of the number and order of the modules. The order of the modules is related to dependency and interdependency between the modules so that there is a portion of higher modules and a portion of lower modules. Multiple independent threads process the modules to cause activities in the portions of higher modules to take place before activities in the portions of lower modules.

Transaction monitor process with pre-arranged modules for a

A semiconductor device that functions as a key to control access to a computer or a software program resident in a computer or provides for secure communications is disclosed. The device executes an algorithm that combines a root and a seed to produce a password. The password is input to the computer. The computer uses an equivalent algorithm to produce a password within the computer. Comparison or other methods are employed to allow access to the computer or computer program or to allow for secure communications. The computer can be coded to produce on a video display thereof a time-space stimulus pattern which can be received by sensors of the key. Alternatively, a keypad can be employed to input the stimulus output from the computer into the access key. Further the present system allows for secure communication using algorithms between different computers and between distant locations.

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San Jose, CA, United States of America

James M Lyon