Abstract: A periodic process scheduling method which includes receiving requests for periodical execution of processes each with a period of execution and execution time, securing allocation time for the shortest process to be executed in respective periods of execution, securing another allocation time for part of a process if full execution time of the process cannot be secured within the respective periods of execution, and starting execution of the process in secured allocation time. A data transfer management method for reducing collision in data transfer which includes storing data length of packets being transferred in a predetermined transmission time interval, storing the predetermined transmission time interval, accumulating a quantity of packets to be transferred in the predetermined transmission time interval, and limiting quantity of packets to be transferred to not be greater than data length.

Abstract: A data transfer management method and apparatus for reducing collision during data transfer. The invention stores a data length (m) in byte units of a plurality of packets capable of being transferred in a predetermined transmission time interval, stores the predetermined transmission time interval (t), accumulates the quantity of the packets to be transferred on a communication stream in the predetermined transmission time interval, and limits the quantity of the packets to be transferred to a value not greater then the data length (m).

Abstract: A process executing method capable of performing multiprocessing by using a shared resource without impairing periodical drivability of processes designed for executing continuous media processing. When a process requests the use of the shared resource, abortion of that process is first disabled by the process itself by using an abort disable function and then preemption of the same process is disabled by means of a preempt control module, whereupon the process enters a processing executed by using the shared resource. Upon completion of the processing for the shared resource, the process is immediately set to a preempt-enabled state by means of a preempt control module. After completion of all the processings, the abort-disabled state is finally cleared by using a disabled-abort clear function.

Abstract: A movable connector is provided which is more compact, reduces the attachment area on the board, increases the strength of attachment to the board, and increases the reliability of electrical connections. The movable connector has an insulating housing, contacts held in the vicinity of the mating portion of this housing, and retention legs (metal attachment members) held in the housing and fastened to the board. Each retention leg has a mounting portion mounted on the housing, and an attachment portion attached to the board and connected to the mounting portion in a position that is removed from the surface of the circuit board in the upward direction. Since the contacts and retention legs are flexible with respect tot he housing, a movable connector is obtained that can move over the surface of the board so that any positional deviation with the mating connector can be absorbed.

Abstract: The shielding arrangement of the present invention is equipped with a conductive inner shell (10) that has opening (11) for receiving a mating connector (40), and an outer shell (20) that encloses parts of inner shell (10). The outer shell serves to resist outward force applied by the inserted mating connector to the inner shell during mating by having bent sections (22) extending inward near an edge to engage the conductive inner shell (10).

Abstract: A data transfer management method for effectively reducing collision in data transfer includes the steps of storing a data length (M) of a plurality of packets capable of being transferred in a predetermined transmission time interval, storing the predetermined transmission time interval (t), accumulating the quantity of the packets to be transferred on a communication stream in the predetermined transmission time interval, and limiting the quantity of the packets to be transferred to a value not greater than the data length.

Abstract: Before starting data transfer, the sender node sends the CONNECT message requesting security of hardware resources necessary for data transfer to the receiver node. Each node relaying the CONNECT message secures the CPU time and bandwidth necessary for data transfer and sends the CONNECT message to the receiver node. Upon receipt of the CONNECT message, the receiver node reserves the CPU time necessary for data reception and then sends the ACCEPT command to the sender node. The sender node receives the ACCEPT command and then sends a data packet.

Abstract: A process executing method capable of performing multiprocessing by using a shared resource without impairing periodical drivability of processes designed for executing continuous media processing. When a process requests the use of the shared resource, abortion of that process is first disabled by the process itself by using an abort disable function and then preemption of the same process is disabled by means of a preempt control module, whereupon the process enters a processing executed by using the shared resource. Upon completion of the processing for the shared resource, the process is immediately set to a preempt-enabled state by means of a preempt control module. After completion of all the processings, the abort-disabled state is finally cleared by using a disabled-abort clear function.

Abstract: There is disclosed an optical data storage medium in which the weather resistance of the semitransparent reflective film is improved and the adhesive property between the semitransparent reflective film and a substrate is enhanced, and which has a higher reliability. In an optical data storage medium (6), on the side on which a reproduction light (8) is incident, a first information layer (9) is located while on the side opposite to the side on which the reproduction light (8) is incident, a second information layer (10) is located. A semitransparent reflective film (3) of first information layer (9) is AgPdCu alloy thin films containing 0.5 to 3.0 weight % Pd and 0.1 to 3.0 weight % Cu or AgPdTi alloy thin films containing 0.5 to 3.0 weight % Pd and 0.1 to 3.0 weight % Ti. At the wavelength 650 nm, the optimum film thickness of AgPdCu alloy thin film is 5 to 18 nm and the optimum film thickness of AgPdTi alloy thin film is 10 to 25 nm.

Abstract: A magnetron sputtering apparatus for forming a thin metal film on one of the major surfaces of a light-transmitting disc-shaped substrate as a disc substrate for an optical disc as mutually intersecting magnetic fields are applied by a magnetic field application unit provided at back of a target. The apparatus includes a center mask tightly contacted with the outer peripheral portion of one major surface of the disc substrate on which the thin film is formed for masking the center portion of the substrate and an outer peripheral mask tightly contacted with the outer peripheral portion of the one major surface of the disc substrate on which the thin film is formed for masking the outer peripheral portion. The outer peripheral mask is separated from and independent of the center mask.

Abstract: A method of transferring multimedia data from an input device to an output device in a computer system having a plurality of input/output devices. An application program specifies an origination and destination of multimedia data transfer and orders multimedia data transfer start. A periodic driven program conducts multimedia data transfer in accordance with the order given by the application program. The application program can conduct other processing irrespective of the multimedia transfer state after giving the transfer start order. The periodic driven program operates with a predetermined period, divides multimedia data, and transfers the multimedia data in a plurality of periods.

Abstract: A motor control method stops rotation of a motor which rotates in a forward direction by applying a brake signal for rotating the motor in a reverse direction. The motor control method detects a power supply voltage, and corrects a brake signal applying time for which the brake signal is applied to the motor depending on the detected power supply voltage.

Abstract: To reduce an overhead of the interrupt on a processor associated with packet send and receive control in a network, a packet send command chaining unit is provided. Based on the control field in each packet send command, a send node controls an interrupt request to the processor in the packet level and sends a packet set with the control information to a receive node. Based on the control field in the received data packet, the receive node controls a receive circuit interrupt request, thereby reducing the number of times the interrupt on the instruction processor is caused for each packet send and receive operation.

Abstract: A frequency synthesizer generates, through setting of a frequency control value, a reference clock having a frequency necessary to read data from a medium. When reading data from an arbitrary position on the medium, a setting control unit sets in the frequency synthesizer a frequency control value corresponding to the zone position, thereby allowing the frequency synthesizer to control a reference clock frequency, and sets in a single or a plurality of processing units other than the frequency synthesizer a predetermined control value corresponding to the read position on the medium. A settling wait processing unit calculates a settling time T1 required for a frequency of the frequency synthesizer to become stable and a setting processing time T2 necessary for the setting control of the other processing unit, and defines as a wait time Tw a difference (T1-T2) between the settling time T1 and the setting processing time T2, during which wait time Tw a migration to the subsequent processing is kept waiting.

Abstract: A scheduling method of a periodic process of a computer system for keeping the execution interval of each process group constant as far as possible in the case where a plurality of process groups including periodically executed processes are executed in parallel. If a group master process of each process group specifies a wakeup interval period and a required CPU time per period and requests allocation of a CPU time, then a CPU allocation time of a specified process group is secured so as not to collide with a CPU allocation time of another process group, and a scheduling table is created so as to maintain the specified wakeup interval period. In response to arrival of time when one of the process groups should be waked up, a kernel process or a scheduler conducts wakeup by changing execution priority of a process belonging to this process group to highest priority ("raised") in the system, and thereafter maintains the highest priority for CPU allocation time consecutively allocated.

Abstract: A linear waveguide 12 is formed on a substrate 11. A non-linear waveguide 13 whose refractive index may vary depending on an electric field intensity of a light is formed in contact with or at a given distance from the linear waveguide 12. These waveguides form a branch structure. The linear waveguide 12 is the original optical transmission path, while the non-linear waveguide 13 is a bypass for an inicident light with an electric field intensity higher than a set value. Adjusting the refractive indices of the linear waveguide 12 and the non-linear waveguide 13 by, for example, selection of materials, can make the incident light 14 transmitted through the linear waveguide 12 when its intensity is below the set value or through the non-linear waveguide 13 when its intensity is equal to or higher than the set value.

Abstract: A method which detects an actuator offset amount for an optical disk device is disclosed. The device reproduces signals by forming a spot of a light beam from an optical system on an optical disk and has an actuator for moving the spot in a radial direction of the optical disk. The method includes the steps of controlling a driving signal supplied to the actuator so as to keep the spot at a predetermined position on a moving path of the spot, detecting the driving signal which keeps the spot at the predetermined position, and storing the driving signal as the actuator offset amount. A device for carrying out the method is also disclosed.

Abstract: A method of transferring multimedia data from an input device to an output device in a computer system having a plurality of input/output devices. An application program specifies an origination and destination of multimedia data transfer and orders multimedia data transfer start. A periodic driven program conducts multimedia data transfer in accordance with the order given by the application program. The application program can conduct other processing irrespective of the multimedia transfer state after giving the transfer start order. The periodic driven program operates with a predetermined period, divides multimedia data, and transfers the multimedia data in a plurality of periods.

Abstract: An optical disk apparatus is downsized. The optical disk apparatus comprises an optical disk drive mechanism having a rotating mechanism for rotating an optical disk and an optical head for optically reading data on the optical disk, and a circuit board. An analog circuit and a digital circuit are mounted upon a single surface on one side of the circuit board of the optical disk drive mechanism. This analog circuit includes a drive circuit for driving the optical head, and a read circuit for creating read data from detection signals of the optical head.

Abstract: In a computer system in which nodes are connected to each other via a network, transmission and reception buffers of sender and receiver processes are prepared as resident areas in a main storage. A node of a receiver side notifies, prior to initiation of a communication, a physical address of a data reception area of the node to a node on a sender side. In the node on the sender side, the reported physical address is added to transmission data to transfer a resultant item. On the receiver side, reception data is written in a location of the main storage at the physical address. In the receiver node, the double buffering is employed to prevent an overwriting operation of another node onto the data reception area. The respective nodes achieve partial synchronization with adjacent nodes in chain, thereby automatically establishing synchronization between all nodes.