Abstract: A system and method for performing an operation within limits upon a shared value stored in an actual value location. The method provides a plurality of memory locations, two of the memory locations being first and second reservation memory locations, and two of the memory locations being limit memory locations containing limit values. An operand is obtained and the operation is performed upon an affected reservation register using the operand. A resulting value is compared to the limit values in the limit memory locations and if the resulting value is not within the values in the limit memory locations, an inverse operation is performed to restore the affected reservation register and a failure is reported. Else the operation is performed to update the actual value location, the operation is performed to update an unaffected reservation register, and a success is reported.

Abstract: A method for enhancing concurrency in a multiprocessor computer system is described. Various tasks in a computer system communicate using commonly accessible mailboxes to access valid data from a location in the mailbox. A task holding the valid data places that data in a mailbox, and other tasks read the valid data from the mailbox. The task that inputs the valid data into the mailbox is caused to notify other tasks addressing the mailbox that the valid data is contained therein. Thus, no central coordination of mailbox access is required. Further, busy waits for valid data are minimized and the ressources of tasks and processors are used more efficiently. By coordinating several lists associated with each mailbox, conflicts in accessing data and delays in obtaining data are also minimized.

Abstract: A lock-free list for use with a computer system. The lock-free list includes a list storage structure comprising at least two sublists, each of a plurality of list elements being sequentially assignable to one of the at least two sublists in such manner that a plurality of assigned list elements is partitionable across the at least two sublists, an indicator for indicating whether each of the at least two sublists is empty or in use, an indicator for indicating whether a list element is being removed from each of the at least two sublists, an indicator for recording an order of the at least two sublists into which the plurality of assigned list elements are assigned, and an indicator for recording for each of the at least two sublists, a write address location and a read address location.

Abstract: A system and method for performing an operation within limits upon a shared value stored in an actual value location. The method provides a plurality of memory locations, two of the memory locations being first and second reservation memory locations, and two of the memory locations being limit memory locations containing limit values. An operand is obtained and the operation is performed upon an affected reservation register using the operand. A resulting value is compared to the limit values in the limit memory locations and if the resulting value is not within the values in the limit memory locations, an inverse operation is performed to restore the affected reservation register and a failure is reported. Else the operation is performed to update the actual value location, the operation is performed to update an unaffected reservation register, and a success is reported.

Abstract: Parallel digital computers which include randomization of tasks among processors, assignment of tasks via indications stored in main memory units accessible by all processors, randomization of data locations among the memory units, the use of a conflict free network for communicating between processors and memory units, and various combinations thereof.

Abstract: An array of binary elements suitable for alphanumeric or graphic displays are electrostatically actuated. The elements have a flexible member overlying a stator member. The flexible member has a bulge which is transferred along the element by sequential de-energization of a plurality of electrostatic electrode regions. Transfer of the bulge linearly shifts the flexible member with respect to the stator member to alter the state or to change appearance, light transmission, or electrical characteristics of the element.

Abstract: Arrays of electrostatic elements arranged in columns and rows are used for switching purposes and for memory devices. Electrostatically attracted members, for each element, when actuated, complete a capacitance device to render that element capable of retaining a charge. Whether or not the element is a capacitance device is sensed by a high frequency signal. Permanent memories can be made by substitution of a pattern of conductor areas for the attractable members. The attractable members, when attracted, form a capacitance switching device or matrix of switches.

Abstract: A shared memory computer method and apparatus having a plurality of sources, a memory manager, and memory units in which the memory locations of data items are randomly distributed. The memory manager includes a translation module for locating data items in the memory units and a temporary storage buffer for storing at least a portion of messages between sources and the memory units with respect to data items.

Abstract: A shared memory computer method and apparatus having a plurality of sources, a memory manager, and memory units in which the memory locations of data items are randomly distributed. The memory manager includes a translation module for locating data items in the memory units and a temporary storage buffer for storing at least a portion of messages between sources and the memory units with respect to data items.

Abstract: An electromechanical display element is provided for use in light reflective and light transmissive display arrays. The display element has a moveable electrode electrostatically controllable between a curled position removed from a stationary electrode, and an uncurled position overlying the stationary electrode to modify the light reflective or transmissive character of the display element. Embodiments of the moveable electrodes are provided which readily can be manufactured for use in either type of array. Stationary electrodes having a plurality of discrete conductive regions are provided to facilitate the control of display elements in an array. Embodiments of dielectric insulators and external circuitry are provided which avoid operating problems and manufacturing complexities associated with residual electric polarization.

Abstract: Method for selectively interrogating decoding devices which are located at remote stations. In one embodiment, a number of transponders which make up a final group within a larger group of transponders, all attached to a common line running from a central station, are selected and simultaneously caused to retransmit modified interrogation signals in accordance with certain informational characteristics and the identity of each transponder retransmitting. The final group of transponders, which include respective decoding devices, chosen to be interrogated is selected by first sending a number n of tones of a larger group of tones m down a branch line to partially activate some of the decoding devices. These tones are followed by a smaller number of tones k chosen from the group n to which only the decoding devices in the final group respond.