Abstract: A computer system including at least one processor and a cache subsystem, in which computer system locked cycles are generated, include a jumper assembly for operatively connecting the at least one processor and the cache subsystem so as to render locked cycles cacheable if the computer system includes only one processor and non-cacheable if the computer system includes more than one processor. A method according to the present invention includes the steps of determining whether there is one or more than one processor in a computer system, and then rendering locked cycles cacheable or non-cacheable accordingly.

Abstract: A circuit board having a thermal relief pattern for isolating heat generated during soldering of components thereon. The circuit board comprises (1) a substantially planar insulating substrate, the substrate having a via therethrough and (2) a substantially planar conductive layer located over the substrate, the via passing through the layer, the layer having a thermal relief pattern comprising a plurality of apertures located about the via, the plurality of apertures cooperating to restrict heat flow across the thermal relief pattern, each of the plurality of apertures having a boundary with the conductive layer free of discontinuities to inhibit edge effect electromagnetic resonance, the plurality of apertures defining a plurality of corresponding conductive bands in the conductive layer and between the plurality of apertures, the conductive bands cooperating to provide a predetermined minimum level of electrical conduction across the thermal relief pattern.

Abstract: An apparatus for docking a portable data processing unit is provided in which a cylindrically shaped, pivotal support member is attached to a base member for supporting the portable unit. An interface card extends from a cavity within the support member and is configured to electrically and mechanically engage within a card interface slot of the portable data processing unit. In addition to providing an electrical interface between the docking apparatus and the portable data processing unit, the interface card provides a mechanical guide for guiding the portable data processing unit into the support member and provides additional support for the portable data processing unit when engaged within the cavity of the support member. The docking unit is tiltable relative to the base member to accommodate a suitable viewing angle.

Abstract: A fastener for securing a printed circuit board to a chassis includes a body portion, legs depending from the body portion, the legs being adapted for removable attachment within holes in the chassis, a hook for slidably engaging a slot on a printed circuit board inserted thereon, and a grounding element for providing an electrical connection between the printed circuit board and a shield on the chassis. The fastener described herein enables one chassis design to accommodate a variety of sizes of printed circuit boards merely by forming holes at particular points on the chassis, thereby avoiding the expense of redesigning a chassis to accommodate a new printed circuit board.

Abstract: A method and apparatus which provides bi-directional communication between a video monitor and a computer system unit. This enables the video monitor to inform the system unit of its capabilities without user involvement and also enables the system unit to directly control or adjust all the functions of the video monitor. In the preferred embodiment, a monitor/mouse interface provides bi-directional communication between the video monitor and the system unit. The monitor/mouse interface connects to the mouse and video connectors or the back of the system unit and in turn connects to the mouse and video monitor. The interface includes separate data paths from the system unit to the mouse and video monitor, respectively. Monitor control software is included in the system unit which can be used to control or adjust the output of the video monitor.

Abstract: A sensor circuit for monitoring the operation of a fan in an electronic device includes a current sensor that produces a voltage signal proportional to the magnitude of the current flowing through the fan. The proportional voltage signal is filtered to extract an rms dc signal that then is compared with a minimum and maximum voltage threshold in two voltage comparators. If the voltage of the filtered signal exceeds the maximum threshold value, or is less than the minimum threshold value, a fan failure signal is generated and transmitted to an external monitoring unit. The sensor circuit can be implemented with a standard two-wire fan and interface connector.

Abstract: A pen-operable computer which also functions as a fully keyboard-operable computer. The keyboard contains an independent power supply, and is linked to the main chassis only by an infrared interface. The system chassis is very compact, but includes a full-width docking bay into which the keyboard can be latched for storage. When keyboard interface is desired, the user takes the keyboard module out of its docking bay and uses it in whatever position is most comfortable. When keyboard interface is not desired, the user simply snaps the keyboard module back into its docking bay for safe storage and/or transport.

Abstract: A small computer having a card interface slot in a side of the computer. An inserted electronic card, the connector on its inserted end mates firmly with a connector at the inner end of the recess behind the slot. The user ejects an inserted card by sliding a slider which is positioned in a shallow recess on the bottom of the computer, near the slot. The slider is connected to an ejector which actually presses against the inner end of the card. By moving the slider with his thumb, the user can push the card out far enough to disengage the contacts of the card, and then can readily remove the card by hand or allow it to drop out.

Abstract: A two-computer system and method wherein data is transferred between the computers as complete disk images rather than as files. The transfer is made between the parallel ports of the two computers, for greater speed; amd RLL data compression is used to increase the effective rate of data transfer.

Abstract: Using a relatively simple four piece conversion kit consisting of a replacement control bracket, and vertically enlarged top housing portion, drive bay and expansion card cage replacement structures, a relatively small frame personal desktop computer is converted to a larger frame computer having upgraded expansion card and drive installation capacities. The upgrading process is effected simply by removing the existing top housing portion, drive bay, expansion card cage and control panel bracket, installing the replacement drive bay, expansion card cage and control panel bracket on the existing bottom side portion of the computer, and then operatively connecting the vertically enlarged top housing portion to the existing housing base wall. Other than the four components of the conversion kit, all of the components in the original computer are reused in the resulting upgraded computer.

Abstract: A memory apparatus using conventional DRAMs which uses a ternary representation of stored data. Each DRAM memory cell can thus store three states. The ternary storage memory apparatus includes a binary to ternary converter which receives a first number of binary bits of data during a write operation and generates a second lesser number of data values or voltages using a ternary representation. A second number of memory storage elements are coupled to the binary to ternary converter and store the respective voltage using the above ternary representation. During reads, a ternary to binary converter reads the voltages stored in the memory elements and converts these voltages into the original first number of binary bits that were originally written into the memory storage elements. This allows the use of existing DRAM while considerably increasing the DRAM's memory storage density.

Abstract: Synchronous switching inverter and regulator suppress rf emissions, and FET push-pull switching for the inverter provides high efficiency power transfer by sinusoidal transformer operation. Feedback control for both pass transistors switching and duty cycles insures overall synchronous behavior.

Abstract: An optimal routing methodology for routing high I/O density packages which minimizes the number of PCB layers required. One feature of this routing methodology comprises treating respective I/O that are routed at the top layer of the package as surface mount technology (SMT) pads without dropping vias within the BGA grid, as is commonplace in the industry. This facilitates the use of fewer escapes and allows for more efficient use of the available space. Signal lines on the top layer of the package which must be routed to other layers of the PCB are connected to vias outside of the area of local high signal density on the printed circuit board. The placement of vias outside the area of local high density, i.e., in a depopulated area, reduces the number of layers necessary in the PCB to properly route the signals. This placement also facilitates the use of filtering capacitors to meet EMI requirements. In addition, all voltage pins are placed on the innermost or outermost grids and have clearanced vias.

Abstract: Disclosed is an access door for computer systems comprising an outer case containing an electronic component of the computer system that is capable of generating heat during the operation of the computer system. The outer case has an aperture in its surface proximate the component to allow external access into the outer case. The access door is capable of assuming a closed position where it closes the aperture, covers the component and forms a part of the outer. The access door is also capable of being placed in an open position wherein the component is externally exposed through the aperture. The access door includes a heat sink having a heat receiving portion positioned to mechanically contact a surface of the component to allow transmission of heat from the component to the heat receiving portion.

Abstract: Disclosed is a diagnostic procedure for identifying and sizing computer memory, which, in the preferred embodiment of the invention, comprises SIMMs. The procedure comprises the steps of (1) testing a plurality of memory locations in the unit by writing and reading bit patterns to memory locations in succession to determine whether any of the memory locations contains any responding bits and (2) stipulating the unit to be present when a number of the memory locations having any responding bits reaches a predetermined minimum number. The procedure is uniquely designed to detect memory which is not fully functional.

Abstract: Disclosed are an apparatus and method for testing a direct memory access ("DMA") controller. The apparatus comprises (1) a virtual control device including a virtual control latch, the virtual control device coupled to a request input of the DMA controller and capable of transmitting a signal to the DMA controller representing a request to transfer data and (2) a virtual input/output ("I/O") device including a virtual I/O latch, an acknowledgement output of the DMA controller coupled to the virtual I/O device, the virtual I/O latch capable of storing the data for use by the DMA controller. In its preferred embodiment, the present invention operates within the confines of IBM-compatible personal computer architecture, allowing DMA controller functionality to be tested directly.

Abstract: To facilitate a grounding connection between a circuit board and a chassis upon which it is to be mounted, a spaced series of unlined mounting holes are formed through the substrate portion of the circuit board between its top and bottom sides, and spaced series of grounding vias are formed through the substrate and positioned in a circular arrays around each of the mounting holes. Annular layers of a metallic plating material are formed on the opposite sides of the circuit board substrate, around the top and bottom ends of the unlined mounting holes, with the plating material being extended along the interior side surfaces of the vias between associated top and bottom annular plating material layers.

Abstract: A webbed boss is integrally formed on and projects outwardly from the nominal surface of a wall portion of an injection molded plastic part and has a specially designed cross-section along its length that increases the strength of the boss, in both bending and twisting modes, without increasing the tendency of creating a sink mark on the cosmetic side surface of the wall portion beneath the boss. Representatively, along its length the boss has a generally cross-shaped cross section defined by four webs that meet, at inner cross-sectional ends thereof, at a square junction area of the boss. Each boss has an outer side edge portion with a thickness at the nominal wall side surface of about 60% of the wall portion thickness. From such outer side edge portion, the opposite sides of each of the bosses taper inwardly to the junction area in a manner such that the maximum thickness of the junction area parallel to the nominal side surface is about 60% of the wall portion thickness.