Abstract: A digital power management system for an analog-to-digital converter operates to cause the sample rate of the analog-to-digital converter to function at an original desired frequency so long as changing input signals are present. Whenever activity at the input of the analog-to-digital converter ceases to change, the system automatically decreases the clock signal sampling rate to a slower clock frequency, or shuts down the application of clock signals. This conserves power until a change in the analog input is detected, whereupon the system automatically increases the sample clock frequency back to the original frequency.

Abstract: An improved leaf removal system is disclosed for removing leaves and the like through the floor drain of a swimming pool. conventional recirculation system for the pool. This is accomplished by providing a leaf removal chamber adjacent the pool, with a water outlet from the bottom of the chamber to the pool. The floor drain is interconnected by means of a pipe to a water inlet near the upper end of the chamber, and this inlet is located beneath the water level of the pool. A strainer basket is removably placed between the water inlet and the water outlet in the chamber. Return water for the pool is supplied to an entrainment nozzle connected to the water outlet in the chamber to cause a venturi effect to draw water, along with leaves and other debris, from the floor drain into the water inlet of the chamber, from which such water is returned to the pool, along with return water supplied to the entrainment nozzle.

Abstract: A joystick system is designed to provide a modified digital representation of the setting of a joystick potentiometer. The system operates to compensate for non-linearities and offsets in the joystick response, or may be used to enhance or vary the joystick response to a non-linear form. This is accomplished by supplying the output voltage of the joystick to an analog-to-digital converter, the output of which then is supplied to a lookup table. The lookup table output is provided to a counter. In one mode of operation, the counter counts down to zero at some multiple of a sample rate. When the counter reaches a zero count, the time interval representative of the joystick position is indicated; and the corrected or enhanced position is indicated by this output.

Abstract: A loudspeaker system comprises a housing consisting of three interconnected sealed enclosures. The primary sealed enclosure has an aperture in it in which a loudspeaker is mounted in a sealed relationship. This enclosure is interconnected with an intermediate sealed enclosure located between it and a third or output enclosure. The intermediate sealed enclosure has an aperture communicating between it and the interior of the primary sealed enclosure. A first passive plate is movably mounted in this aperture in sealed relationship. A second passive plate is movably mounted in an aperture between the second enclosure and the output enclosure in sealed relationship to form a sealed airspace between the first and second passive plates. The output enclosure has a port in it for communication with the air surrounding the enclosures.

Abstract: A cache memory system operates without requiring valid bits in the external cache tag RAM by employing a system controller as a writeback cache controller for control of the cache data/tag memory and the system main memory. The system controller receives signaling information from a CPU through a host bus to indicate when to pre-load the cache memory or to flush (disable) the cache memory while maintaining memory coherencey by causing the cache controller to write back all modified lines in the cache memory to the main memory.

Abstract: An integrated circuit test apparatus employs a main test circuit load board which has a circular array of relay card mounts located on it. Auxiliary relays, operated in conjunction with the load board, are mounted in groups on individual relay circuit cards, each card including several relays. The relay circuit cards have connectors on first and second edges thereof; and the connectors on the first edges interconnect with the corresponding receptacles on the relay card mounts. A customized configuration board load ring for the particular integrated circuit device under test (DUT) then is placed over the second edges of the relay circuit cards to interconnect with spring-loaded connectors on these edges to effect the configuration for the operation of the particular DUT which is undergoing test at any given time.

Abstract: An ergometrically improved keyboard data input device particularly suited for computers includes a housing adapted to underlie the palm of the hand of an operator in a relaxed, natural, concave position; so that the fingertips of each finger extend substantially vertically downward through an aperture in the top of the housing. Data input keys are mounted on a data input key support member located inside the housing, beneath the aperture. The keys are arranged in groups of data input keys in three dimensional patterns at each of the fingertip positions of the hand of the operator. The device includes a provision for raising and lowering the key support member within the housing, relative to the aperture. Actuators also independently move the opposite ends of the key support member back and forth within the housing, relative to the aperture, to adjust the locations of the groups of keys relative to the portion underlying the palm of the hand of a user to compensate for hands of different sizes.

Abstract: A closure system for a sliding main door and a sliding screen door system of the type typically used in houses and some commercial buildings operates to permit three modes of operation of the sliding screen door and the sliding main door relative to one another. In a first mode of operation handles on the doors freely pass by one another and the two doors may be operated completely independently of one another. The handle on the sliding screen door is capable of movement to different vertical positions; and in another position, cooperating surfaces on the two handles cause the sliding screen door always to be closed when the main door is closed. When the main door is opened, however, the sliding screen door in this mode is capable of movement back and forth independently of the main door to the extent of the opening of the sliding main door.

Abstract: A system is provided for digitizing the setting of a potentiometer of the type used in an analog joystick for computer games. The analog output of the potentiometer is applied to one of two inputs of a voltage comparator. When a readout of the joystick position is desired, a "write" input is applied to a counter to permit it to commence counting at a predetermined frequency from an initial or zero count. The digital outputs of the counter are coupled to the inputs of a digital-to-analog converter, the output of which is coupled to the second input of the voltage comparator. When the count in the counter produces a voltage at the output of the digital-to-analog converter corresponding to the voltage setting of the potentiometer, the comparator provides an output signal. The time delay from the time the write pulse occurs until this signal is obtained is representative of the potentiometer setting.

Abstract: A system for testing a digital counter of mn stages, in which the counter is organized into m segments, each of n bits, includes a two input exclusive OR gate connected between each of the m segments. One of the two inputs of each exclusive OR gate is obtained from the carry output of a lower order one of the m segments, and the output of each exclusive OR gate is connected to the carry input of the next higher order one of the m segments. The other inputs to the exclusive OR gates are obtained from a test signal enable input, which is driven high (binary "1") for the test mode of operation. The counter is fully exercised in the test mode in a parallel operation, with full testing of the carry bits from one segment to the next, without any interruption in the clock signal input stream.

Abstract: A golf club head cover for use with golf clubs having graphite shafts has a generally hollow, cylindrically shaped head cover for the head of a golf club. The head cover has a closed upper end and an open lower end. The head cover is made of a first member of a semi-cylindrical shape; and this member has an elongated shaft protector secured to it externally from the closed upper end and extending beyond the open lower end of the first member. The portion of the shaft protector which extends beyond the open bottom of the first member has closure elements on it for closing the shaft protector around a shaft of a golf club.

Abstract: A mold for forming hollow blow molded containers is made in multiple sections to create a cavity in the shape of the desired container when the mold is in the closed position. A recess is formed in the inner surface of at least one of the sections of the mold body, and a removable insert is designed to be placed in the recess. The insert may carry design indicia on it; and it is held in place by a set screw extending through the top of the mold body section in which it is located. Thus, insertion and removal of different inserts may be accomplished without disassembling the mold.

Abstract: A link system controller is interposed between a PCI bus and the CPU data bus and memory data bus of a personal computer system to ensure that the transfer of data from the PCI bus to the CPU data bus occurs on different clock signals from the transfer of data from the PCI bus to the memory data bus. This is accomplished by an authorizing circuit, which alternately enables a CPU bus interface controller and a memory data bus controller in response to alternating clock signals. This prevents simultaneous switching of the devices on both the CPU data bus and the memory data bus, to reduce the generation of noise below an acceptable threshold; so that the operation of the IC system device is not impaired.

Abstract: An interferometer particularly suitable for testing the flatness of transparent plano-parallel test pieces employs an extended spatially non-coherent light source. The source is directed to a first beam splitter at an angle of incidence other than normal; and the beam is split into first and second spatially non-coherent divergent wavefronts. A reference surface reflects the first wavefront and a surface under test reflects the second wavefront. A second beam splitter receives and recombines the first and second reflected spatially non-coherent wavefronts; and an interference detector is located to receive the combined reflected wavefronts to produce the interferogram. The distance traveled by the wavefronts from the first beam splitter to the detector is equal, and the optical characteristics of the light path traveled by both wavefronts is the same.

Abstract: A method and system are designed to guarantee availability of ownership of an ISA bus by a bus mastering or a direct memory access device in a system also including a PCI bus. This is accomplished by placing a lock on the PCI bus through a bridge device to a configuration read of a PCI configuration space register. Once the lock is established, other PCI devices are prevented from locking any other resource on the PCI bus. The PCI configuration space exists outside of the memory or I/O ranges to which an ISA resident device can generate access. Consequently, whenever the ISA resident device generates its access, it is to a device known not to be in a locked state. Consequently, the bus transaction is capable of completion within the time limit expected by the ISA resident device.

Abstract: A link system controller is interposed between a PCI bus and the data bus and memory data bus of a personal computer system to normally allow transfer of write information from the PCI bus to DRAM memories on the memory data bus. Whenever a request is made for the transfer of data to the CPU data bus, a CPU bus interface controller requests release of the system from the DRAM controller. The DRAM controller then grants permission or releases control to the CPU bus interface whenever the DRAM controller is not writing data out to the DRAM data bus. When this release is effected, the transfer of write data to the memory data bus is prevented and transfer of data to the CPU data bus is enabled. This prevents simultaneous switching of the devices on both the CPU data bus and the memory data bus, to reduce the generation of noise; so that the operation of the IC system device is not impaired.

Abstract: A trigger safety lock for guns comprises a rigid plug, typically made of aluminum or rigid plastic, designed with a central portion configured to frictionally fit into the space between the rear of the trigger of the gun and the trigger guard. The plug prevents depression of the trigger to fire the gun. The plug has an ejector extension on one side of the central portion, which extends laterally beyond the trigger guard for engagement by a user to force the plug out of the space behind the trigger. The dimensions of the extension are such that it freely passes through the space. The ejector extension has a hole through it for receiving a locking device to positively lock the trigger when the gun is in storage. A flange on the opposite side of the central portion of the plug overlaps at least part of the trigger or trigger guard and engages the trigger or trigger guard when the central portion is located in the space behind the trigger.

Abstract: A comparator used in an enhanced N-WELL pad voltage tracking circuit for high (5 Volts) voltage-tolerant buffers is designed to eliminate current leakage when the input/output is tristated and is being driven externally by a weak voltage source. This is accomplished by comparing the pad voltage supplied from the external source to a reference voltage that is a predetermined amount (VTP) less than the low internal voltage source (VDD). Thus, switchover for tracking of the N-WELL voltage tracks very closely the voltage VDD, reducing the differential voltage between the N-WELL and the pad on the pull-up driver for the system, thereby keeping the driver off and eliminating leakage current. The reference voltage is generated either by a diode voltage drop or by a weak source follower.

Abstract: A joystick system provides a digital representation of the setting of a joystick potentiometer. The voltage of the joystick is supplied to an analog-to-digital converter, the output of which then is used to load a counter. In one mode of operation, the counter counts down to zero at some multiple of the sample rate. When the counter reaches zero, the time interval representative of the joystick position is indicated; and this output is indicative of the joystick position. In an alternative mode of operation, the counter is used as a data latch and the joystick position is digitally read from the counter, which keeps the data latched until the next sample cycle from the joystick position.