Abstract: A disk array architecture which supports compound RAID configurations and which can automatically switch between various RAID configurations in case of drive failures to prevent data loss and retain data redundancy. In the preferred embodiment, the disk array system of the present invention begins operation with an array configuration that implements a maximum of data redundancy using all of the available disk drives. As drive failures occur, the disk array system automatically reconfigures one or more of the drives to other RAID configurations which utilize less data redundancy and thus require a lesser number of drives. This automatic reconfiguration occurs until the least amount of redundancy remains, or no redundancy remains. In this manner, the disk array system initially takes advantage of all of the available drives for maximum performance and redundancy while still retaining a high level of fault tolerance.

Abstract: A system is disclosed for providing a supplemental front lighting system for a liquid crystal display. Retractable light sources are provided adjacent to the LCD. The light sources may be placed in a closed position for compactness when storing the system or when ambient lighting is adequate. The light sources may be placed in an open position when supplemental lighting of the LCD is desired. A grazing incidence reflecting film having a micro replicated surface is applied to the front surface of the LCD to increase light transmission and to collimate and direct light toward the LCD. Multifaceted microstructures arranged in longitudinal columns on the front surface of the film reduce reflection of light at glancing angles, thereby providing for improved and even lighting across the entire LCD.

Abstract: A pointing device or mouse which monitors motion in both the X and Y directions as well as in the yaw or rotational direction. The pointing device hence monitors three degrees of freedom and thus provides a more accurate indication of the position of the device. One embodiment comprises a pointing device which includes two motion indicators or mouse balls integrated into the bottom of the device which detect change of motion or position in one X and two Y directions. Separate Y measurements are made for each of the respective balls because yaw or rotation of the device causes the line movements for the two balls to differ. The two balls are preferably a distance L apart, and the rotation and translation of the respective balls are measured by the change in position with reference to a center point between the two balls. The two mouse balls generate signals indicating positive or negative motion in the respective directions.

Abstract: This invention relates to the general area of data integrety in digital computers. In particular it relates to digital computer systems having parity checked systems busses and ECC checked memory. This invention increases the performance of such systems by reducing the memory latency incurred in the ECC to parity conversion process.

Abstract: A portable computer system with a special connector, on the motherboard, into which a field-installable boot card can be inserted. The special motherboard connector is wired so that the operator, by setting connections on the field-installable boot card, can bypass the boot memory on the motherboard and force the computer to boot from the memory on the boot card. This permits a technician, in the field, to temporarily override the internal nonvolatile memory which holds the basic system software. This permits recovery of a system in which the basic system software has been corrupted. Preferably the motherboard boot memory is a flash EPROM, and can be rewritten, by setting appropriate jumpers on the boot card, after the computer has booted from the boot card. The motherboard connector is preferably located on the motherboard, and is accessible through a removable cover. This connector can also preferably be used for temporary attachment of a diagnostic display card.

Abstract: An improved liquid crystal display (LCD) is provided having a static random access memory located within each liquid crystal control cell and between each display electrode and corresponding bit and word lines. The memory cell, or storage cell, includes a pass-gate transistor which, upon activation via word line, forwards bit line video data to a memory circuit, such as a latching circuit, placed between the pass-gate transistor and the display electrode. The latching circuit may consist of two thin-film transistors connected as cross-coupled inverters for latching video data upon the display electrode for virtually an indefinite period of time or until the pass-gate transistor is again activated. By utilizing a storage cell with buffer capability adjacent each display electrode, problems associated with large data line current can be minimized. Moreover, the static memory can rid the host processor of having to continuously refresh the LCD active matrix.

Abstract: A system for refreshing selected portions of a dynamic access memory (DRAM) subsystem of a computer. A memory controller of the present invention includes a RAM device for storing a plurality of region descriptors used to inhibit the refresh of address ranges of the DRAM that do not contain valid data, thereby conserving energy required to refresh the entire DRAM. The controller includes logic circuitry connected between a refresh period timer and the RAM device for inhibiting receipt by a RAS generator of a refresh pulse when a generated refresh address falls within the refresh address range defined by the region descriptor. A refresh address output by a refresh address counter compared to the region descriptors in the RAM device, and if the region descriptors indicate that the row addressed by the refresh address does not contain valid data, the RAS generator is inhibited from producing a RAS pulse.

Abstract: Disclosed are a circuit and method for providing automatic termination for a small computer systems interface ("SCSI") bus. The circuit resides within a bus controller comprising (1) a control circuit for controlling transmission of data on a bus and for providing an interface between the bus and a computer system for communication of the data therebetween and (2) a first bus port and a second bus port, each of the first and second bus ports permitting a device to be coupled thereto for communication with the control circuit via the bus, the bus controller being at an end of the bus when a single one of the first and second bus ports is coupled to a device and being in a middle of the bus when both the first and second bus ports are coupled to devices.

Abstract: A battery charging/data transfer structure is provided for use in conjunction with a handheld computer to charge its battery and serve as an infrared data exchange interface between the handheld computer and a data input/output device such as a desktop computer. The structure includes a support housing having an inset well area configured to receive and releasably hold a portion of the handheld computer in a docked orientation. With the handheld computer in this docked orientation a battery charging contact member in the well area contacts a charging area on the received computer portion and transfers battery-charging electrical energy thereto.

Abstract: A method and apparatus which enables devices connected to a bus to detect and take advantage of the early arrival of bus signal inputs. A signal arrival encoder circuit included in a device encodes the arrival time of a signal input whose early arrival is desired to be detected. The arrival time of the signal at issue is categorized according to a desired degree of precision or granularity depending upon the complexity of the encoder used in the respective embodiment. The encoded signal arrival information is then used by the respective device to determine when to sample the other respective input signal. By detecting the early arrival of this input, the device is not required to wait for the worst case signal arrival time to utilize the information. This considerably increases system performance.

Abstract: A circuit board design featuring a fine pitch ball grid array ("BGA") having a simplified construction. The circuit board comprises: (1) an insulating substrate, the substrate having a via therethrough, (2) a conductive layer located over the substrate, the via passing through the layer and laterally uninterrupted through the circuit board, (3) a first solder having a first melting point located within and substantially blocking the via and (4) a second solder having a second melting point located over the blocked via, the second melting point lower than the first melting point, the first solder remaining substantially solid and preventing the second solder from substantially entering the via when the first and second solders are heated to a temperature between the first and second melting points. The present invention eliminates precision drilling required by current blind via BGA pad designs.

Abstract: A memory channel array configuration wherein two or more memory channels are used for data transfer and data is striped across each of the memory channels. In addition, one or more redundant memory channels, preferably a single dedicated parity channel, are used for error correction. In the preferred embodiment the memory channel configuration utilizes RAMBUS based memory channels, and thus the present invention provides error correction for a RAMBUS based memory system. Also, the use of multiple memory channels in conjunction with data striping across each of the channels allows for much higher data transfer bandwidths than is available using prior art implementations of RAMBUS technology.

Abstract: An interconnect structure is provided for converting or adapting select signals sent between a printed circuit board (PCB) and an electrical component. The interconnect structure comprises an adapter card placed between the PCB and the electrical component, wherein the adapter card includes one or more pass-through vias and non pass-through vias extending completely through the adapter card in parallel spaced relation to one another. Pass-through vias are used to couple signals having critical timing paths between the electrical component and the PCB without substantially modifying or changing the critical path switch points. The pass-through vias also provide connection of signals of non critical timing between the PCB and the component. A signal converter may be used to convert non-critical signals and place those signals at select pins upon the electrical component.

Abstract: To facilitate the registered connection between a BGA package and an associated multi-tiered circuit board, a spaced series of vias are formed transversely through the board substrate between its opposite first and second sides. A spaced series of relatively shallow, circularly cross-sectioned socket areas, offset from the vias, are also formed on the first side of the circuit board. The sockets have diameters slightly larger that those of the generally ball-shaped leads of the BGA package, and are positioned on the same centerline pattern as the leads. After the vias and sockets are formed, a metal plating material is deposited on their interiors and around their open ends on the first board side, with the plating being extended across the first board side between associated socket and via pairs.

Abstract: A printed circuit board mounting apparatus for securing a printed circuit board within a chassis includes a track affixable to the chassis and a locking mechanism affixable to the printed circuit board. The track, which includes a plurality of locking points, is slidably received within the locking mechanism, which engages the track at any of the several locking points to secure the track within the locking mechanism. The mounting apparatus described herein enables the chassis to accommodate printed circuit boards of different sizes without mechanical modification of the chassis.

Abstract: An interconnect sheet for connecting multiple layers of a circuit board for the manufacture of high interconnect density PWBs. The interconnect sheet preferably comprises an area array grid of 0.003 inch solder columns having a 0.006 inch pitch. The interconnect sheet is preferably used to attach two or more multi-layer boards by placing one sheet at every interconnect surface. This interconnect mechanism has an advantage of redundancy of contact and therefore lower susceptibility to failure than other methods. The interconnect sheet of the present invention also offers a large tolerance for registration error without shorting adjacent pads. The preferred method of fabrication of the interconnect sheet begins with creating equally spaced holes through a 0.5 ounce double sided laminate comprising a dielectric sheet and copper plates on either side of the dielectric. These holes are filled with solder paste and the sheet undergoes a baking process to shrink the paste.

Abstract: A device in which functions of both a conventional mouse and a numerical data entry keypad are integrated into a single unit is disclosed. A conventional mouse ball is disposed on the bottom of the device. Pointer select buttons are disposed on a forward portion of the top of the device and numerical entry keys are disposed on a rearward portion of the top of the device. A microprocessor responsive to the ball, buttons, and keys, generates appropriate signals for input to a single I/O port in a computer. A hood is also provided which is hingedly attached to the device between the forward and rearward portions thereof such that it is rotatable between a first position in which the numerical data entry keys are rendered accessible, thereby enabling the device to function as a numerical keypad, and a second position, in which the numerical data entry keys are rendered inaccessible, thereby enabling the device to function as a conventional mouse.

Abstract: A system for inductively coupling power and data to a portable electronic device. A portable device, such as a personal digital assistant, is powered or recharged via an inductive link between the device and a support unit, thereby eliminating the need for cabling or other connections therebetween. The same inductive link is also used to transfer data signals between the device and a second electronic device, for example, a conventional desktop computer. The support unit includes a primary winding of a transformer, a power amplifier and a modulator. The portable device includes a secondary winding connected in parallel with the input of a rectifier, the output of which is connected to a battery charging circuit, and to a modem, which is further connected to the device microprocessor. Placement of the device on the support unit effects the inductive coupling when the primary and secondary windings are in proximity to one another.

Abstract: Disclosed are a circuit and method for remote diagnosis of personal computers. The method comprises the steps of (1) confirming an existence and a proper operation of a modem coupled to the personal computer, the step of confirming performed in a central processing unit ("CPU") of the personal computer and in a diagnostic environment independent of a normal operating system of the personal computer, (2) receiving an indication of a selection of diagnostic routines to be performed from a remote location via the modem and (3) performing selected ones of the diagnostic routines as a function of the selection. The present invention allows an experienced technician located remotely from the computer to interact as though seated in front of it, to thereby allow remote diagnosis of even critical faults that prevent the computer from booting.