Abstract: The invention provides techniques for changing the quantization used in multiple generations of selected complexity of data quantization such that the errors incurred in subsequent generations are substantially the same as the error incurred in a generation given the same complexity of data. To this end, in a preferred embodiment, quantizing factors are selected from a preselected finite non-degenerative set of quantizing factors provided in the form of arrays of a periodic series of individual quantizer values, wherein a special numerical relationship is maintained between corresponding quantizer values in successive arrays. A different quantizing factor may be selected for each generation of compression/decompression as required by changing data complexity as when performing a layering process during the generations.

Abstract: A preferred embodiment of an electromagnetically controlled scanning magnetic transducer is described having two confronting core poles defining a physical transducing gap therebetween. A control winding is associated with each core pole. A control current applied to each control winding selectively saturates a portion of each core pole facing a record medium. Each saturated face portion defines an adjacent unsaturated highly permeable face portion. The highly permeable face portions of each core pole overlap across the gap to define a transducing zone. The information signal and control windings are arranged relative to one another to obtain information signal and control flux paths extending perpendicular to one another.

Abstract: A video image is extracted and stored as a geometric figure by generating a binary pixel map of the image. The binary pixel map contains one bit for each pixel in the image, representative of the value of a characteristic feature of that pixel relative to a threshold range. A crack following algorithm locates the border of a group of contiguous pixels all having the same binary value. This border defines the boundaries of the scanned image. It is smoothed by a recursive adaption technique to generate one or more polygons related to the shape of the image.

Abstract: A magnetic transducer has a transducing gap that is wider than that used for transferring information signals with respect to a magnetic record medium. A magnetic control flux is applied to the transducer to enable a selected segment of the transducing gap, which defines a transducing zone, for transferring information signals with respect to a selected path along the magnetic record medium. Registration of the transducing zone over the selected path is maintained by varying the applied magnetic control flux to thereby move the transducing zone along the wider transducing gap so as to compensate for deviations between the path traced by the transducing zone over the magnetic record medium and the selected path.

Abstract: Apparatus is described for coupling magnetic flux defining information between a first body of magnetic material and a second body of magnetic material having a magnetic flux path therein. A third body of magnetic material having a transducing zone is included and disposed to be magnetically proximate the first body of magnetic material to couple flux to or from the same, and to have a portion thereof magnetically proximate the magnetic flux path within the second body of magnetic material to provided coupling of flux to or from such flux path. In specific embodiments described, the first body of magnetic material is a magnetic storage medium such as a layer of hard magnetic material of a tape, and the second body of material is a transducer core of a soft magnetic material.

Abstract: A magnetic transducer arrangement includes a core with a gap and a body of magnetically anisotropic material in which a signal transfer region is defined. Control flux flows across the gap of the core and through the body in opposite directions. The two oppositely directed flux flows influence one another and tend to cancel each other to define a null zone. This null zone, in which the flow of control flux is very low, is sensitive to flux emanating from an adjacent magnetic storage medium and therefore defines the signal transfer region. By varying the relative proportions of control flux flowing in the opposite directions, the location of the null zone can be varied along the width of the magnetic transducer to thereby scan the signal transfer region. The flux which is coupled from the magnetic storage medium into the null zone of the body does not flow through the magnetic core in a manner similar to a fringing flux.

Abstract: A slave device detecting system utilizes the past history of devices connected to a data bus to optimize the time required to re-establish communications. Whenever a master controller senses a condition that requires an assessment of devices on the bus, it examines the addresses of previously connected devices at more frequent time intervals than it does for addresses that were not previously associated with connected devices. In a preferred approach, all valid addresses can be examined in a sequential fashion, and the address of the previously connected device can be examined at every fifth or tenth position in the sequence. With such a technique, a device will be detected much faster once it has returned to the bus.

Abstract: An electromagnetically controlled scanning magnetic transducer has two magnetic core portions with confronting poles defining a transducing gap. A control winding is arranged in each core portion to provide a control flux therein. The control flux saturates a region of the transducer face of each core portion, adjacent to the gap. The saturated regions define adjacent unsaturated highly permeable regions which overlap at the gap to obtain a transducing zone. The transducing zone can be altered, moved, scanned or otherwise positioned along the transducer width by electromagnetically controlling the location and size of the saturated face regions.

Abstract: To expand the interrupt capabilities of a microprocessor system without restructing system architecture, intermediate levels of priority are created for a given interrupt request. Plural interrupts can be handled on one interrupt request line to thereby permit execution of a number of functions that is greater than the number of interrupt lines. A system controller which provides this capabitlity can monitor the various functions during their execution, as well as arbitrate among plural interrupts so as to maintain the priority which has been assigned to them.

Abstract: To produce a simulated airbrush spray pattern comprising a random pattern of pixels in a video image, multiple source arrays defining random variations of one or more video image parameters are created. Each time that an airbrush spray pattern is to be generated on a video display, the source arrays are individually retrieved and used to control the characteristics of corresponding pixels in the video image. The arrays are varied on a regular basis to create a random pattern in the image that simulates the effects of an airbrush spray. Various modifications can be used to create particular effects and position dependent textures, such as the short, random streaks that are produced by chalk.

Abstract: Magnetic record media are described that have an overlying or underlying magnetically saturable high permeability keeper layer in addition to a high coervicity magnetic layer in which magnetic signals are stored. These media are used in magnetic signal processing devices whose transducers are capable of generating a keeper layer-saturating bias flux. In signal reproduction the bias flux magnetically forms a saturation zone in the nature of virtual gap in the keeper layer that directs signal flux between the media and the transducer.

Abstract: A time base corrector including a frame memory and a memory control. The memory control is microprocessor based and calculates the starting addresses of memory areas at which video data will be written to or read from the frame memory and the starting times of those sequences. The memory control receives information concerning the configuration of the time base corrector, the input video field sequence, the desired output video field sequence, timing components of the input and reference clock signals, TV standard, and operator commands to make these calculations. The results of the control are time base corrections for horizontal and vertical phase errors, horizontal and vertical positioning control, color frame sequencing, color correction of chroma phase, configuration delay adjustment, and other advantageous operations.

Abstract: Magnetic transducer-keeper combination embodiments of the invention are described. Each has a magnetic core defining a physical gap and a thin magnetic keeper arranged in close proximity of the core to bridge the gap. A magnetic flux from the gap saturates the keeper inan area bridging the gap, thereby forming a signal transducing zone in the keeper. The keeper is maintained stationary and the core moved or scanned with respect to the same, thereby moving or scanning the transducing zone in the keeper.

Abstract: A dynamic head position tracking control for a magnetic tape playback system employs a detected dither signal to determine the elevational position of a pair of magnetic transducing heads relative to tracks of recorded information being scanned by the heads. This detection is carried out at several locations along the lengths of the tracks being scanned, and a value is stored for each of the locations. Based upon the stored information, an estimation is made of a position value for the first location along the length of the tracks. This estimation is determined from a weighted extrapolation of the following two samples taken during the scan of the track. The elevational position of the heads is then dynamically controlled in accordance with the actual and estimated head position values.

Abstract: Apparatus and method for detecting a sync signal in parallel data which has been reconstituted from serial data. The first occurrence of digital bits which corresponds to a predefined sync signal is recognized and causes the circuitry to shift to a mode of operation in which subsequent sync signals will be recognized if and only if they occur within a predetermined "window" around the expected position of the sync signal. The sync signal is used re-align the parallel data so that the bits are grouped into meaningful words.

Abstract: A serial data communication system including a microprocessor and an asynchronous communication interface adapter (ACIA) implementing a SMPTE Supervisory Protocol for Digital Interface Control. The system detects the beginning of a break character as the first framing error which occurs after the last word of a data block has been detected. The receive clock of the ACIA is disabled in response to the start of break detection by the software reset of a bistable device which disables a receive clock gate. The framing error detection circuit of the ACIA is additionally disabled by the termination of the receive clock signal. The end of the break character is detected as the space to mark transition before the start of the first word in the data block. The receive clock is enabled by setting the bistable device with the end of break transition thereby detecting the termination of the break character and enabling the receive clock gate.

Abstract: A silicon nitride layer is prepared on the surface of a silicon substrate by carrying out a surface reaction on the substrate in a vacuum chamber that contains an electrode which is capacitively coupled to an rf generator. A second electrode within the chamber, or a metal wall of the chamber itself, is connected to ground. The silicon substrates to be treated are placed on one of the electrodes to be in electrical and physical contact therewith, and a reagent gas that contains nitrogen is introduced into the chamber. An rf voltage is then applied between the electrodes to ionize and activate the gas, and cause ions and other active species thereof to be directed into the silicon substrate. The nitrogen ions and other active species that are created as a result of the application of the rf power can be directed at the surface of a number of wafers simultaneously.

Abstract: Two insulating layers may be employed to define boundaries of junctions in transistor structures useful in integrated circuit fabrication. The junctions may overlie one another, have approximately equal areas, and terminate in the insulating layers.

Abstract: A lead frame that is suited for use on array types of integrated circuit packages to provide a high degree of compliance for absorbing mechanical stress induced by thermal changes includes a series of individual terminal elements that are connected in a strip form by means of break tabs disposed between adjacent elements. Each terminal element provides two spaced, generally parallel mounting surfaces that are resiliently connected to one another by means of an integral intermediate section. While the terminal elements are interconnected in strip form, one of the mounting surfaces of each element can be bonded to an associated attachment region on the semiconductor substrate. After all of the terminals of the strip have been so bonded, the break tabs between adjacent terminals can be removed to thereby separate the terminals from one another. The package which then results contains discrete compliant terminals which are suitable for subsequent surface attachment to the printed circuit board.

Abstract: A new automatic tracking method is disclosed for the accurate positioning of a magnetic head with information previously recorded on the magnetic tape. If a moveable magnetic head is used, the position thereof is first normalized. Thereafter tracking is automatically adjusted based on a repetitive sampling process in which the results are mathematically averaged to determine a precise center position. Finally, new video material is physically positioned on the magnetic track according to a single offset error measurement and this offset error is stored and used in all subsequent edit operations.