Abstract: DMA adapters which perform programmed data transfer operations in response to descriptors are programmed by information in the same descriptors (and adapter logic responsive to that information) to perform various ancillary control functions relative to addressable I/O devices that conventionally would be addressed and controlled directly by a host (higher level) system processor (e.g., the processor that prepares the descriptors). The ancillary control functions are variable programmably in number (e.g., in the disclosed embodiment, one descriptor can define 0, 1 or 2 discrete ancillary control operations) and effects produced by each operation are programmably variable (e.g., ancillary operation can be used by the adapter to alter states of addressed devices; for example, to prepare a device that has been transferring data in one direction, in a half-duplex mode, for transferring data in the opposite direction, or to switch to a full duplex mode, etc.).

Abstract: Digital signals defining a bit mapped primary image are stored in a data processing system and displayed on a color monitor. These signals are processed by breaking down or separating the primary image into a set of areas where the pixels within each area have the same color. The set of areas is then analyzed to select a group of a minimum number of subgroups, which group contains all of the different areas. Different color/dither patterns are assigned to represent the different subgroups. Then, a derivative bit mapped image is produced in which the assigned representations are used, and the derivative image is then printed or displayed.

Abstract: An inteferometer is provided with a light source forming a first collimated beam shaped to illuminate an area and a second collimated beam shaped to illuminate a narrow line. Both of these beams are split into orthogonally-polarized sub-beams, which are diverted outward and inward within a compound Wollastom prism. The images of these beams are focussed on a test surface through an objective lens, with a real splitting point being projected to the rear focal plane of the objective lens. With light reflected off the test surface and projected back through the compound Wollastom prism, interference patterns are generated on the surface of a line sensor, which is typically used with illuminated narrow lines split by the compound prism and projected onto a moving test surface, and on the surface of an area sensor, which is typically used with area illumination projected onto a stationary test surface. Autofocus and automatic phase angle correction servomechanisms are also provided within the interferometer.

Abstract: A processor stores descriptors without explicit linkages, in non-contiguous memory locations, and sequentially hands them off to an adaptor which manages scheduling and processing of data transfers defined by the descriptors. Each descriptor is handed off in a request signalling process in which the processor polls the availability of a request register in the adaptor, and writes the address of a respective descriptor to that register when it is available. The adapter then schedules processing of the descriptor whose address is in the request register. The adapter manages a "Channel Descriptor Table" (CDT), which defines the order of processing of descriptors designated by the requests. In effect, the CDT defines a linked list queue into which the adapter installs descriptors, in the sequence of receipt of respective requests. Using the CDT information, the adapter retrieves successively queued descriptors and controls performance of operations (data transfer or other) defined by them.

Abstract: A network adapter and wiring scheme makes use of existing plain old telephone service (POTS) wiring to provide support between analog devices within the subscriber premise and an Integrated Digital Service Network (ISDN). Moreover, the network adapter and wiring scheme provides further support between digital devices within the premise and the ISDN while concurrently supporting analog devices.

Abstract: A method and apparatus for testing circuit boards uses a pair of probes to contact the various nodes on the circuit board. A single one of the pair of probes may be used to deposit a charge at a being tested net and checking for the presence of a charge at subsequent nets to determine whether a short condition exists. Moreover, the pair of probes is used to contact two nodes of a network being tested to measure the resistance within the network being tested; the measured resistance being compared to a nominal resistance, to determine whether an open condition exists. In addition, the pair of probes may be used to measure the resistance between networks in order to verify or determine whether a short condition exists between networks.

Abstract: A dual quad flexure carriage and assembly, for receiving a sensing probe, is used for scanning the sensing probe across a target surface. The flexure carriage is a unitary structure providing flat motion for the sensing probe during the scanning procedure, while further compensating for thermal creep. The dual quad flexure assembly comprises the dual quad flexure carriage along with piezo actuators and control systems to provide highly linear orthogonal motion.

Abstract: A portable paperless parcel tracking system capable of reading bar codes on packages, capturing signatures and alphanumeric data related to the parcels when entered into a touch panel display, disabling manual or finger touch entry when a stylus is near the surface of the display, storing the parcel related data electronically and transmitting the data to a host at a convenient time.

Abstract: Groups of DCVS (Differential Cascode Voltage Switch) circuits are interconnected by single-track data transfer connections. Each group contains one or more DCVS tree circuits, through which data signals propagate only on dual-track connections. In each group, at least one DCVS tree circuit is configured as an input boundary tree, and at least one tree circuit is configured as an output boundary tree. All data inputs externally applied to a group, are transferred only through input boundary trees of the group, and all data outputs transferred out of a group leave the group only through output boundary trees of the group. If a group has only a single tree, that tree serves as input and output boundary tree of the group. Each input boundary tree of each group has one or more associated primary shift register latch (SRL) circuits through which all external data inputs to that tree are transferred. Such external data inputs are received through the single-track connections mentioned above.

Abstract: A debris control system is provided for an electron-beam drilling apparatus having a chamber encompassing a drilling area and a calibration area. The debris control system includes a calibration-area shielding assembly which shields a calibration area of such apparatus from drilling-generated debris and an isolation assembly which isolates drilling-generated debris within such drilling area.

Abstract: A touch screen display is automatically calibrated during periods of active use or extended periods of non-use. Calibration contacts are cemented or embedded to the surface of a touch sensitive panel, and electrically connected to a reference during calibration. The reference is either electrical ground or a resistive, capacitive, or inductive load.

Abstract: A non-contact, step-wise method for automatically positioning a sensing probe, having a vibrating cantilever and tip, above a target surface utilizing acoustic and Van der Waals interactions respectively during an approach method. The sensing probe is lowered to a substantially optimized tip to target surface distance. The system utilizes the interaction of forces between the vibrating cantilever and target surface to automatically position the sensing probe above the target surface.