Abstract: A data processing system such as a personal computer includes a plurality of expansion connectors for receiving adapter cards. A non-volatile memory stores programmable option select (POS) data that is stored when the system is configured. A Power On Self Test (POST) operation is performed during which adapters are checked to determine if any have been added, moved or removed, since a previous system configuration. If any have been so altered, the system may be placed in operation with all adapters enabled except for those which were altered.

Abstract: A data processing system includes a processor for accessing a memory in either a direct mode or an indirect mode. The memory includes at least two memory banks and two decoders for decoding bank addresses. The decoders produce bank select signals. In direct mode, the decoder outputs are generated according to which bank is addressed. In interleave mode, the two decoder outputs are ANDed to select both banks covering the address range of the selected banks.

Abstract: A personal computer housing has a plurality of air intake openings located around the sides and front. A fan is mounted at the rear of the housing and sucks or draws coolant air through the intakes and exhausts the air to the rear. A bulk power supply is mounted along one side of the housing and is cooled by air flow through adjacent intakes. A plurality of I/O or expansion cards are located along the opposite side of the housing and cooled by air flowing through adjacent side intakes. A plurality of system cards including a processor card and memory cards, are located in parallel, rearwardly extending rows directly between at least some of the front intakes and the fan. A DC/DC regulator card is mounted over the system cards and has a heat sink provided with rearwardly extended cooling fins aligned in the direction of air flow from front to rear.

Abstract: Apparatus and method for increasing efficiency of command execution from a host processor over an SCSI bus. Arbitration, selection and message out functions of SCSI protocol are implemented using a background arbitration state machine. Additional protocol functions are implemented in a foreground state machine. When the host processor issues a command for access to the SCSI bus, the background state machine can be programmed before the foreground machine completes the protocol function for a previous command. Thus, the background state machine is ready to arbitrate for access to the bus at the very next bus free condition.

Abstract: A data processing device has a battery compartment in which a battery is fastened by a releasible latch. A manually actuated eject button is used to release the battery. A light is source is placed in or near the eject button and provides, when illuminated, a light signal warning the user not to eject the battery. The eject button is covered by a door, and both the door and button are designed for two handed operation which, in addition to preventing accidental actuation of the button, forces the user to concentrate attention on the eject button and warning light.

Abstract: A wireless stylus includes a pocket clip having a latch which, upon insertion into a storage compartment within a digitizer, engages a cam. The cam has a shape that causes the latch to move into engagement with a keeper as the stylus is pushed into the compartment and then released. The keeper holds the stylus in a stored position. The latch is released upon first pushing the stylus and then releasing it. Biasing means engages the stylus and moves it against the keeper and ejects the stylus outwardly from the storage compartment allowing the stylus to be grasped and withdrawn from the tablet. The storage compartment is open at opposite ends and has two cams, one at each end of the compartment so that the stylus, at the convenience of the user, can be inserted into either end for storage.

Abstract: A digitizer tablet has a base integrated with a heat sink. The base includes a flat portion which surrounds the heat sink. The sink is recessed relative to the flat portion and includes a flat upper surface on which a thermal pad is mounted. A planar member overlies the base and has a plurality of heat generating modules mounted on the underside thereof, the modules being pressed into the thermal pad to establish a thermal conduction whereby heat flows from the modules through the thermal pad and into the heat sink. The underside of the heat sink is recessed and has a plurality of cooling pins which provide a relatively large area. The pins are cooled by natural air convection and radiation, and lie within the recess to prevent body contact with portions other than the tips thereof. Bosses mount the planar member on the base and coact with fasteners to press the modules against the thermal pad.

Abstract: Light responsive elements of a color imaging array are arranged in basic groupings of four aligned elements, which groupings included two luminance-responsive elements that alternate with individual elements for two other basic colors. These groupings are repeated along a line and are shifted by one element in each adjacent line. As a result of intermixing color-responsive elements in this way, high-spatial-frequency luminance sampling is achieved for all directions on the array and closely repeated patterns of elements are achieved for all three basic colors in both fields of the array (here assuming a two-field interlaced readout array). Because closely repeated sampling occurs for all colors in both fields of such an array, the field-to-field color flicker, that can occur when intermixed color sampling is attempted using an interlaced-readout imaging array, is avoided.

Abstract: A mirror-type beam steering apparatus employs at least one flexible mirror support member having, generally, the shape of the Greek letter lambda. Each such member has a pair of flexible leg sections that slant toward one another and are truncated into an interconnecting section. The diverging ends of the leg sections are fixed and an optical beam steering mirror is mounted to the interconnecting section. With this arrangement, a "virtual pivot" occurs at the intersection of the leg section axis (although the legs themselves do not intersect), and torque components applied to deflect the mirror result in rotation of the mirror about the virtual pivot axis. In preferred forms of the invention, the mirror's center of gravity is located on the virtual pivot axis, thereby reducing the inertial resistance to rotation and improving steerer performance.

Abstract: Primary color filters which also pass infrared are employed in cooperation with a broad-spectral-response, image sensing apparatus to provide a color video camera which has an extended range of operation at low light levels. The image beam which reaches the image sensing apparatus is selectively controlled by a regulatable infrared filtering device in cooperation with such primary color filters. Upon detecting a normal light level, the infrared filtering device responds by blocking infrared. At low light levels, on the other hand, infrared blocking is negated and infrared passes through some or all of the primary color filters to augment the faint visible light components which are imaged on the image sensing apparatus.

Abstract: A carrier plate for use in mounting a pair of magnetic heads at diametrically opposite sides on a rotatable head drum section facilitates positioning adjustments to remove dihedral head positioning error. Independent dihedral position adjustment is made possible by virtue of a specially shaped slot in the carrier plate, which slot is characterized by two guide edges that are perpendicular to the head pair axis and are adapted to closely engage a shaft or other axis-identifying means associated with the drum section. Such guide edges in cooperation with the shaft permit relative movement between the carrier plate and drum section in a direction to correct dihedral error while blocking movement in directions which would disturb other alignment geometries. In a preferred implementation, the carrier plate has a generally disc-like form.

Abstract: A magnetic head drum includes an upper section that carries a set of magnetic heads and rotates at a preselected head speed, and a stationary lower section that is characterized by a reduced diameter step formed along the tape wrap path thereover (e.g., a helical path for a helical scan recorder). Because of the reduced diameter step, tape pressure is shifted from the lower drum section to the upper drum section which, by virtue of its rotation, produces a low friction air bearing. The reduction in diameter to produce the above-described step, moreover, results in a shoulder or ledge along the lower edge of the tape wrap path, which shoulder serves as a guide for the tape, and promotes accurate tape tracking over the drum.The amount of reduction in diameter for the lower drum section is not chosen arbitrarily, but is preferably within a range of 1 to 6 mils. In this range, a desirable balance is achieved between reduction in frictional drag and limiting of forces tending to distort the tape.

Abstract: An information processing method and apparatus, which is adapted to use, for example, in the recording of color image information, calls for sampling a set of basic colors (e.g., green, red, and blue) at rates which are proportioned according to the resolving power of the human visual system respective of color, and arranging the resulting samples to produce a sequential video signal. In one implementation, green, red, and blue color image information is sampled at respective rates decreasing progressively from green to red to blue in producing a sequential signal which is recorded, and on playback a luminance signal for, say, a television display is derived from the sequential signal based only on the relatively high frequency (preferably both green and red but not blue) sample information. Moreover, to improve image registration with such customized sampling, delays are selectively interposed in the individual color signals in accordance with their respective sampling frequencies.

Abstract: A mirror-type light beam deflector or steerer utilizes a hinged mounting linkage to couple a beam deflecting mirror to a mirror driving apparatus. In a preferred form, flexible hinges are employed to avoid any introduction of play or looseness between the mirror and mirror driver.

Abstract: A method and apparatus are disclosed for retrieving magnetically recorded information by optical means. The magnetic recording is irradiated by a beam of coherent light whose plane of polarization is periodically varied. The light which is transmitted or reflected from the recording medium is analyzed in order to retrieve the magnetically recorded information.

Abstract: An exposure control apparatus for use in photographic printers assigns the originals which are received for printing to groups or sets, for example, according to filmstrip membership, and bases the printing exposure for each such original, at least in part, on characteristics determined for a corresponding set taken as a whole. In a presently preferred apparatus, the exposures for individual frames from a filmstrip are controlled in accordance with the average optical density for the overall filmstrip in selectively weighted combination with individual frame, optical density characteristics.