Abstract: One or more domains are independently clocked with separate clocks. Each clock is an asynchronous stop/start clock implementing a self-tuning clocking methodology. Domain circuit speed is monitored and the clock adjusted to tune the domain to run at near maximum speed. Inter-domain data transfers are performed by a four-way handshaking method. In effect the clock period of the respective clocks during the data transfer becomes the slower period of the two domains' clock periods. An inter-domain arbiter is implemented at each domain for deciding which domain's request is to be granted during an immediate clock period. Data input to a domain is tracked to determine when data is present. When no data is present, the domain's clock is stopped.

Abstract: A display device is achieved using a simplified optical system which generates an expanded exit pupil without compromising magnification or resolution. Modulated light from a source is converged toward a focal point by an optics subsystem. A scanning subsystem deflects the converging light, and thus the focal point, along a raster pattern to define a curved intermediate image plane. An exit pupil expanding apparatus defines a curved surface which coincides with the curved image plane. Impinging light rays at a given instant in time span a given incidence angle. Exiting light rays span a larger angle. As a result, the exiting light spans a larger surface area of an ensuing eyepiece. In turn an expanded exit pupil occurs beyond the eyepiece. Embodiments of the expanding apparatus include a curved diffractive optical element, fiber optic face plate, lens array and diffuser. The diffractive optical element generates multiple exit pupils, while the other embodiments generate enlarged exit pupils.

Abstract: A tub structure underlying a first well in a semiconductor integrated circuit is charge pumped to increase electron collection efficiency in the tub structure. A charge pumping circuit applies the biasing voltage via a second well. The current in the tub structure is monitored to determine when to pump charge into the tub structure. The pumping biases the n-tub to voltages as high as twice the supply voltage magnitude, (2V.sub.cc). The tub current is compared to a minimum current threshold and a maximum current threshold. The charge pump is disabled when the tub current exceeds the maximum threshold and is turned on before the tub current goes below the minimum threshold. The maximum threshold is for keeping the tub structure from exhibiting an undesirable standby current. The minimum threshold is to keep the tub structure biased enough to achieve a desired electron collection efficiency.

Abstract: Two piezoelectric sensors are mounted on the back of a spring-plate of a mechanical resonance scanner on respective sides of a center line coinciding with an axis of rotation. As the scanner mirror rotates back and forth the two sensors are accelerated and decelerated at a 180.degree. phase difference. Each sensor's output voltage crosses a zero level when the acceleration is unchanging. A differential amplifier detects the zero crossings for motion along the axis of rotation. Common mode rejection eliminates the non-rotational accelerations associated with external vibrations and shocks, and prevents masking the mirror's zero-crossings.

Abstract: A system has multiple subsystems and a test signal source resident upon a common substrate. A first subsystem interfaces with an off-substrate functional tester during a test. The test signal source generates a first signal during the test for input to the second subsystem. The second subsystem responds performing an operation independent of operation and current state of the first subsystem. The functional tester verifies the independent operation of the first and second subsystems.

Abstract: A pen-based direct-drive manipulator enables precision manipulation and force display of a control point within three degrees of freedom. The control point exhibits substantially no backlash, very low friction and very low inertia making it useful as a force display. The manipulator also has a very high force generation bandwidth allowing high frequency force components to be displayed. A parallel actuator structure controls motion over two degrees of freedom in a horizontal plane. The parallel structure is a redundant structure including three chains in parallel coupled at the control point. The redundant structure provides a uniform force capability throughout the manipulator workspace. A pair of rotational actuators rotate the parallel structure about an axis to approximate a linear motion along a third axis. The rotational actuators provide a third degree of freedom for the control point. Motion about the third axis is substantially decouple from motion about the horizontal plane.

Abstract: A test-mode latching circuit residing on an integrated circuit with test circuitry and operational circuitry has an enable state and a disable state. In the enable state, a test key is able to be latched so as to trigger a test mode. In the disable state test key inputs are not latched, and thus, test modes are not entered. Initially the circuit is readily enabled so that the IC can be tested upon fabrication. The circuit is locked in a disable state before external sale. A re-enable circuit is present to preclude inadvertent switching of the latching circuit back into the enable state during customer operation. Safeguards are implemented to avoid inadvertently re-enabling the latching circuit. To re-enable the latching circuit, an out-of-spec voltage is applied to an anti-fuse capacitor or programmable logic circuit while an out-of-spec voltage of the same or another signal is detected at a field device. In one embodiment, the state switches to the enable state in response to the out-of-spec voltage.

Abstract: A cache for improving access to optical media includes a primary cache comprising RAM and a secondary cache comprising a portion of hard disk memory. Multiple aspects of the invention are defined: (1) Cache data discrimination: Discrimination methodology is implemented for determining when data should not be cached. Under certain conditions, caching of data is less likely to improve access time. (e.g., when the transfer rate is already exceeding a critical sustained throughput rate; when an estimated time to complete a CD-ROM data request is within a specific percentage of the estimated time to complete a hard drive disk request). (2) Secondary cache fragmentation avoidance: To keep the access time to secondary cache faster than the access time to the optical media, fragmentation of the secondary cache (i.e., hard disk) is minimized.

Abstract: A cache for improving access to optical media includes a primary cache comprising RAM and a secondary cache comprising a portion of hard disk memory. Multiple aspects of the invention are defined: (1) Cache data discrimination: Discrimination methodology is implemented for determining when data should not be cached. Under certain conditions, caching of data is less likely to improve access time. (e.g., when the transfer rate is already exceeding a critical sustained throughput rate; when an estimated time to complete a CD-ROM data request is within a specific percentage of the estimated time to complete a hard drive disk request). (2) Secondary cache fragmentation avoidance: To keep the access time to secondary cache faster than the access time to the optical media, fragmentation of the secondary cache (i.e., hard disk) is minimized.

Abstract: A closed-environment wet-abrasive blasting system includes a vacuum device for recovering a waste stream of water, abrasive particulate and surface debris. The waste stream is filtered resulting in cleaned water recycling through the system. During operation, water is pumped from a water holding tank to a blast head. Also, abrasive particulate is forced from canister to the blast head. The abrasive material and water form a blast stream which impacts on a surface to treat the surface. The blast head is held to the surface during use by the suction force and defines a work volume over the surface under treatment. In effect, the blast head defines a closed environment in which abrasive particulate water and surface debris do not escape into the surrounding environment, but instead is captured. The vacuum force pulls the surface debris, abrasive particulate and water (i.e., waste stream) from the blast head along a vacuum hose into a recovery tank.

Abstract: A substantially balanced, five-axis, direct drive mini-robot provides repeatable micro-manipulation to micron precision. Dynamic forces of each link are nearly decoupled from the dynamic forces of remaining links. The robot is generally formed as a shoulder, arm and wrist assembly. At the shoulder a linear actuator drives the robot in a linear horizontal movement along a first axis (e.g., z axis). Two additional actuators at the shoulder provide revolute motion to rotate the arm in an xz plane (e.g., for lateral motion) and a yz plane (e.g., for vertical motion), respectively. A fourth actuator provides rotational motion to move an end-effector (manipulator) at the wrist through a yaw motion. A fifth actuator, positioned at the shoulder and linked to the wrist, provides rotational motion to move the end-effector through a pitch motion.

Abstract: A scan conversion method is implemented to achieve real-time scan conversion at video rates. Scan conversion tasks include vector point identification processing, distance derivation processing and interpolation processing. An active image area is defined in response to user inputs. For a given set of user adjustments there is a fixed active image area of the display screen. In addition, there is a fixed positional relationship between output pixel locations of the active image and corresponding input vector points of the active image. Whenever the user makes adjustments, these relationships change becoming fixed again until another user-initiated change. Whenever the relationships change, vector identification processing and distance derivation processing is re-done to define these relationships. Interpolation processing is performed each frame only for output pixels within the active image area. The active image area is divided into groups of output pixels.

Abstract: A plurality of program processors, shared memory, dual port memory, external cache memory and a control processor form a multiprocessor system. A shared memory bus links the program processors, shared memory, dual port memory and external cache memory. Program processor I/O occurs through a pair of serial I/O channels coupled to one port of the dual port memory. A write generate mode is implemented for updating cache by first allocating lines of shared memory as write before read areas. For such lines, cache tags are updated directly on cache misses without reading from memory. A hit is forced for such line, resulting in valid data at the updated part and invalid data at the remaining portion. Thus, part of the line is written to and the rest invalidated. The invalid portions are not read, unless preceded by a write operation. The mode reduces the number of bus cycles by making write misses more efficient.

Abstract: A system has multiple subsystems and a test signal source resident upon a common substrate. A first subsystem interfaces with an off-substrate functional tester during a test. The test signal source generates a first signal during the test for input to the second subsystem. The second subsystem responds performing an operation independent of operation and current state of the first subsystem. The functional tester verifies the independent operation of the first and second subsystems.

Abstract: Full-duplex, concurrent voice and non-voice communication over the public switched telephone network (PSTN) is maintained by a communication interface apparatus. A voice only connection is established between two sites initially. Concurrent voice/non-voice connection then is established by pressing an engage button on the communication interface apparatus at each site. Voice communication is temporarily lost, while the connection changes from a phone-to-phone voice-only link to an interface-to-interface voice/non-voice data link. The communication interface apparatus includes a digital signal processor for converting and compressing digital voice data into a voice data packet, a modem for maintaining communication over the PSTN and a micro-controller for managing the establishment and maintenance of concurrent voice and non-voice data communication.

Abstract: A strain gauge exhibits temperature offset errors and span errors which vary from device to device and vary as a function of temperature. A digitally-compensated strain-gauge apparatus executes embedded calibration and compensation programs for improving accuracy over a wide temperature range. Pressure measurement error bands are reduced to approximately to 0.03% of full scale for a 5 psi device over a 0.degree. C. to 50.degree. C. temperature range. A calibration program defines parameters for compensating for such errors. During field operation, a compensation program uses the calibration parameters to generate a more accurate pressure measurement. According to the compensation scheme, current normalized voltage and bridge impedance are derived from the raw data. A first-pass temperature estimate then is derived from the result. The derived first-pass temperature estimate is plugged into a temperature offset error function to find the temperature offset error at the estimated temperature.

Abstract: A color-mapped display sub,stem efficiently combines palettes of multiple images into a single shared palette. As each image already received a degree of distortion during conventional palette selection, it is desirable to minimize further distortion during the palette combination method of this invention. A pairwise nearest neighbor (PNN) technique is used for combining colors from respective palettes to minimize further distortion. For a final 256-color shared palette, up to 256 (n-1) individual vector merges are performed (where n is the number of image palettes being combined). In one embodiment, two vectors are chosen at each step that yield the lowest increase in distortion when merged. A mean squared error distortion measure of gamma-corrected values defined in YIQ space is used to compare distortion. Searching time at each step is reduced from O(N.sup.2) to O(N), while also eliminating the need for extensive recalculation of color pair distortions between steps.

Abstract: A line fishing apparatus having a generally bulbous head and tapered tail is inserted inside a fish used for bait. Before the apparatus is inserted, the apparatus slides freely along the fishing line. The bulbous head portion is shaped to fit the inner dimensions of the bait's mouth. When the bait's mouth is closed around the apparatus, a bumper portion sticks out from the mouth protecting the head of the fish from striking bottom. As the apparatus is inserted, the tail portion is pushed through the bait's stomach toward the bait's tail. The apparatus tail portion is curved along an arc as it tapers to a distal end. The curvature forces the bait to curve along its length. As a result, when the line is pulled through the water, a swinging or spinning action is induced. The swimming motion generally resembles that of a live, injured fish.