Abstract: A method for maintaining coherent data in a multiprocessor system having a plurality of processors coupled to main memory, where each processor has an internal cache which is externally unreadable outside the processor. The method includes requesting data associated with a memory location in main memory and determining if an external cache coupled to an application specific integrated circuit associated with a second processor contains a reference to the requested data. A snoop cycle is performed on the second processor if the external cache has a reference to the requested data, whereupon a determination is made as to whether the requested data has been modified.

Abstract: A tactile feedback switching mechanism having a plurality of switching states. The tactile feedback switching mechanism includes a plunger switch having a plunger. When the plunger is displaced a given distance the switch changes state. A covering lies at least over the plunger switch and includes a border section and a deformation section. The covering may be formed from an elastic material such as an elastomer. When a user depresses the plunger, confirmation of a change in the state of the switch can be tacitly sensed by a change in resistance provided by the covering. The resistance of the covering changes by deformation of the deformation portion of the covering while the plunger is depressed.

Abstract: A user-controlled input device for use with a computer system is disclosed. The user controlled input device controls at least three-dimensional movement in a three-dimensional virtual space defined by a three axis coordinate system. The device includes a controller body and at least a pressure controlled button joystick coupled to the controller body. Displacement of the button joystick in a first direction translates into directional movement at least about a first axis. The button joystick includes a force sensor wherein an output signal is produced by the button joystick that is proportional to the force placed on the button joystick. The output signal is translated by a computer program into a rate of motion that is proportional to the pressure that is supplied by the user of the input device. In certain embodiments, a second button joystick is coupled to the controller body to control directional movement about a second and a third axis.

Abstract: A tactile feedback switching mechanism having a plurality of switching states. The tactile feedback switching mechanism includes a plunger switch having a plunger. When the plunger is displaced a given distance the switch changes state. A covering lies at least over the plunger switch and includes a border section and a deformation section. The covering may be formed from an elastic material such as an elastomer. When a user depresses the plunger, confirmation of a change in the state of the switch can be tacitly sensed by a change in resistance provided by the covering. The resistance of the covering changes by deformation of the deformation portion of the covering while the plunger is depressed.

Abstract: A console-type ruggedized computer system has a console with components, and an image producing apparatus for displaying images based upon electronic signals received from the components of the console. The computer system further includes at least one shock absorber coupling the image producing apparatus to the console. The (at least one) shock absorber is capable of attenuating shock to the image producing apparatus.

Abstract: A disk system includes a disk cage having a spring and an interior wall that forms a disk drive chamber. The disk system also includes a disk drive removably coupled within the disk drive chamber. The spring in the disk cage preferably is coupled with the interior wall and extends into the disk drive chamber to form a receiving chamber. The spring contacts the disk drive to dampen disk drive vibration.

Abstract: A method for image stabilization of at least two digital images is disclosed. In such an embodiment, a first digital image having a plurality of pixels and at least a second image having a plurality of pixels are provided. Each pixel has an associated address for display and is representative of a color. Either a user of the system provides a color match range or the system provides a predetermined color matched range. A pixel is selected within the first digital image. Preferably the pixel is one that represents an item within the image that is either blurry due to movement of the item or appears jittery due to camera movement. Due to the vast number of available colors a pixel selected in a first image can be matched to a pixel in a second image within a range. The range allows for compensation due to lighting changes. Once the pixel in the first image is selected it can be compared to all pixels within the second image.

Abstract: An apparatus for transmitting a set of documents from a server computer to a client computer utilizes a document list of document identifiers for automatically and repetitively transmitting selected documents from the server computer to the client computer. To that end, the apparatus first receives a first download request from the client computer. Once the request is received, then the document list is accessed to identify the identifier of a first document in the document list. Once identified, the first document and a controller are transmitted to the client computer. The controller controls the client computer to transmit a second download request to the server computer after a predetermined condition is satisfied. The predetermined condition may be the passing of a predetermined amount of time and the controller is a tag with in the first document.