Abstract: A system and method for maintaining a communications within a computer system after a data transport failure across a first link. Fail-over capability is attained by re-establishing communications across a secondary link using different transport mechanisms. Between two Input/Output Processors (IOPs) within a computer system, such as a server, a series of data transactions therebetween are queued until transaction completion. Upon detection of a failure condition between the IOPs across the first link, the IOPs engage fail-over mechanisms to preserve uncompleted data transactions until communications are re-established across the secondary link.

Abstract: Techniques used in communicating messages between processes are described using a shared message buffer pool and incoming message lists associated with each process. Associated with each process is message management information. Using the message management information, incoming messages to a process are retrieved, outgoing messages to another process are sent, and message buffers are allocated as needed from a free message buffer list. The free message buffer list is a shared resource from which processes obtain a free message buffer to send a message to another process. Access to the shared free message buffer list and process message lists is synchronized through discipline imposed upon updating and accessing various fields of the data structure without requiring a global locking mechanism for synchronization of shared resources.

Abstract: In a computer system, data records stored in nonvolatile memory are read into a volatile memory and operated on in a sorting operation. A tournament-type sort is applied, with the tree size dynamically reconfigured within the volatile memory as a function of the number of data records to be sorted. The memory space occupied is reduced by the reconfigured tree and sort speed is augmented.

Abstract: A system and method to reduce power consumption in a portable computer system while allowing the CDROM drive to continue playing audio CDs. When the system enters a suspend mode, the status of the CDROM drive is checked, and if it is playing an audio CD, it remains powered, otherwise power to the CDROM drive is also suspended. The system recognizes when the audio CD is finished playing and then places the CDROM drive into the suspend mode.

Abstract: A screwless technique for mounting a circuit board in a computer chassis is provided in which circular portions of keyhole-shaped mounting openings in the circuit board body are first moved downwardly over notched chassis mounting bosses. The circuit board is then forwardly moved transversely to the bosses to move opening edge portions of the circuit board body into the boss notches in a manner releasably preventing the circuit board from being lifted off the bosses. A retaining bracket is placed adjacent a body edge of the installed circuit board to block the board against rearward releasing movement relative to the chassis bosses.

Abstract: A computer system, such as a server disposed in an enterprise, accessible from a remote terminal for remote management applications. The computer system includes a remote console functionality assist logic structure for effectuating the sending and receiving-of signals from the remote terminal. The remote console functionality assist logic structure is controlled by a dedicated processor that receives interrupts therefrom in response to a remote management application. The processor can also control one or more peripheral devices provided in the computer system, wherein the controlled peripheral device or devices are disposed up-stream or down-stream from the processor.

Abstract: Multiple instances of operating systems execute cooperatively in a single multiprocessor computer wherein all processors and resources are electrically connected together. The single physical machine with multiple physical processors and resources is subdivided by software into multiple partitions, each with the ability to run a distinct copy, or instance, of an operating system. At different times, different operating system instances may be loaded on a given partition. Resources, such as CPUs and memory, can be dynamically assigned to different partitions and used by instances of operating systems running within the machine by modifying the configuration. The partitions themselves can also be changed without rebooting the system by modifying the configuration tree. A grouping of partitions, a community, shares memory. Memory may be private to a particular partition or may be shared by partitions within a community.

Abstract: A printed circuit board retainer. The printed circuit board retainer directs the movement of a printed circuit board during installation into an enclosure. In a relaxed position, the retainer forms a barrier to the withdrawal of the printed circuit board from the enclosure. The printed circuit board retainer may be displaced from its relaxed position and locked in an open position to facilitate during installation and withdrawal of the printed circuit board.

Abstract: A network controller system including a plurality of network ports and a driver system that operates the network ports as a team. The team is operated to simulate a single logical device in one of several team modes, such as fault tolerance or load balancing modes, to enhance performance of communication of the computer in a network. The driver system periodically determines and updates the status of each of the network ports, where the status of each is based at least on whether at least one directed packet has been received and transferred to the driver system by a respective network port. If any one of the network ports has not received a directed packet within a predetermined time period, the driver system commands another network port to transmit a directed heartbeat packet to the network port that has not received a directed packet. The team may include a primary and one or more secondary ports.

Abstract: A receiver for receiving an analog signal that is digitally modulated using differential binary phase shift keying (DBPSK) and demodulated by a quadrature demodulator into two signals. The receiver converts the two signals into two digital signals using 2-bit analog-to-digital converters. Samples of these digital signals are then encoded according to a maximum likelihood criteria algorithm and decisions are made based on the signal constellation, which identifies the original data transmitted.

Abstract: Multicast addresses on a computer network are dynamically assigned to a temporary node task. In particular, a server dynamically assigns a multicast address to a data stream in response to a request for the data stream from a client. The server assigns the multicast address in cooperation with other servers from a pool of network-allocated but unassigned multicast addresses. Once the data stream is terminated, the assigned multicast address is deassigned and returned to the pool of unassigned multicast addresses for possible reuse by the nodes.

Abstract: The disclosed program checker checks whether a program internally tests for error codes that may be returned by procedures used by the program. The program being tested is executed. Each time that a subroutine in the program is about to perform a subroutine or procedure return operation, a program interpreter is invoked. The program interpreter simulates continued execution of the program once for a good return value and once for each error condition return value that is listed in an error condition table entry for the subroutine in which the return operation is being performed. For each simulation of the program, the program interpreter determines the execution path of the program and then compares the execution path for each error condition return value with the execution path for the good return value.

Abstract: A cryptographic system and method for encrypting and decrypting data using public key cryptography. The encryption and decryption may be divided into tasks that may operate in parallel. A secure method of initializing the cryptographic system to allow for secure operations and protect against tampering with application software. The application program is retrieved from an encrypted file in external memory and authenticated before being executed.

Abstract: A system and method to reduce power consumption in a portable computer system while allowing the CDROM drive to continue playing audio CDs. When the system enters a suspend mode, the status of the CDROM drive is checked, and if it is playing an audio CD, it remains powered, otherwise power to the CDROM drive is also suspended. The system recognizes when the audio CD is finished playing and then places the CDROM drive into the suspend mode.

Abstract: A computer system in accordance with the present invention provides a method of communicating asynchronous events from a mini-port driver of a computer system to a software component without polling the mini-port driver. The computer system provides a monolithic driver as a dispatch between a mini-port driver and a software component. Until an asynchronous event is detected, an event thread in the monolithic driver to a software component is blocked. When an asynchronous event is detected by the mini-port driver, the mini-port driver calls the monolithic driver with a monolithic driver entry point which queues the event and unblocks the event thread. The monolithic driver provides the asynchronous event to the software component through the unblocked event thread. The event thread is then re-blocked and remains blocked until another asynchronous event is detected. Asynchronous events are thereby communicated from a mini-port driver to a software component without polling the mini-port driver.

Abstract: A portable audio player stores a large amount of compressed audio data on an internal disk drive, and loads a portion of this into an internal random access memory (RAM) which requires less power and less time to access. The audio player plays the data stored in RAM and monitors the amount of unplayed data. When the amount of unplayed data falls below a threshold, additional data is copied from the disk drive into RAM. When the portable audio player is turned off, a predetermined amount of audio data is stored in a fast-access non-volatile flash memory unit. When the audio player is turned back on, and play is resumed, a suitable portion of this data can be played while data is being loaded from the disk drive into RAM, thus reducing the amount of time a user must wait before receiving data in response to a play request.

Abstract: A notebook computer base housing has operatively disposed therein a CD ROM drive, a hard disk drive and a floppy disk drive, an AC/DC electrical power converter, a modem, a PCMCIA card bay structure and a battery. This internal provision of three drive units in addition to the other equipment within the base housing is facilitated from a space standpoint by the vertical stacking of the hard disk drive atop the CD ROM drive within the base housing. To dissipate the operating heat from these components within the base housing, a heat spreader plate is interposed between the CD ROM drive and the overlying hard disk drive, and the high heat-generating components—namely, the modem, the AC/DC converter, the PCMCIA card bay structure, and the computer processor—are closely grouped together, with the AC/DC converter in thermal communication with a second heat spreader plate.

Abstract: A method for sampling the performance of a computer system is provided. The computer system includes a plurality of functional units. The method selects transactions to be processed by a particular functional unit of the computer system. State information is stored while the selected transactions are processed by the functional unit. The state information is analyzed to guide optimization.

Abstract: An apparatus and method for multi-threaded transaction status management tracks elapsed time from the receipt of multiple independent transaction requests utilizing a unique transaction number included in the descriptor of a longer than a predetermined time are invalidated. The transaction number is also used as an index to stored authentication information and the transaction number is included in a response header and is used to access the stored information to authenticate the response.

Abstract: A technique handles load instructions within a data processor that includes a cache circuit having a data cache and a tag memory indicating valid entries within the data cache. The technique involves writing data to the data cache during a series of four processor cycles in response to a first load instruction. Additionally, the technique involves updating the tag memory and preventing reading of the tag memory in response to the first load instruction during a first processor cycle in the series of processor cycles. Furthermore, the technique involves reading tag information from the tag memory during a processor cycle of the series of four processor cycles following the first processor cycle in response to a second load instruction.