Abstract: In this programmable logic array (PLA), internal array lines are shared by several sets of input array lines. Each set of input lines operates on a separate time phase. This PLA construction is denser than some other arrangements of multiple PLAs, and some of its components are reduced in number as compared with multiple independent PLAs for the same functions. A new pipelined multiplier is disclosed as one application for the PLA of this invention. In another application for this PLA, the array lines are shared where the array locations that are otherwise required for don't care states have been eliminated and a denser construction is provided.

Abstract: A digital data display system including a testcase generator which generates testcase programs. Testcase programs include primary data which may be displayed in alphanumeric or graphic form and secondary data which is used to provide a visible check that the primary data has been displayed correctly. The generator also includes checking code with each testcase program so that the tests are self-checking.

Abstract: A text terminal in which a text stream received on a communication link is segmented by a segmenter into chained variable-length segments which are stored in a random access text store. Each segment can contain at most one extended formatting command. Segments have slack areas to allow the subsequent insertion of text. A text editor receives keystroke signals from a keyboard and modifies the stored text stream, new segments being created as necessary for extended formatting commands or when slack areas are full. An interpreter/formatter is invoked when a received text stream has been segmented or when the stored text stream has been modified to format and map the stored text stream into a refresh buffer driving a cathode ray tube (CRT) display. The interpreter/formatter maintains a status index with condensed versions of the extended formatting commands stored in the text stream. Formatting is inhibited by the editor if it receives a keystroke requiring modification of the stored text.

Abstract: A new bus permits processing elements (PE's) to communicate with other PE's entirely under the control of each PE without a separate bus controller. Each PE has means for broadcasting its priority code on a contention portion of the bus and for sampling the bus after a delay in which it has received the codes from other PE's. Each PE holds its priority code on the bus for a further delay during which other PE's can sample the priority code. The PE's resolve contention for access to the information portion of the bus in a multi stage contention sequence. System usage, made possible by peer-to-peer distribution of bus access control, includes dynamic driven priority schemes, a variety of operating modes and hence flexible multiplexing of message traffic.

Abstract: In a bipolar transistor storage array, the single emitter terminal of each transistor is connected to a bit line. Each bit line is connected to a sense amplifier that provides a low impedance connection to a current source or voltage reference point. The low impedance circuit helps to provide fast switching for a write operation and a noise immune storage operation. The emitter connection and the sense amplifier construction simplify the conversion of the array or part of the array to a read only storage function.

Abstract: A multi-stage, multi-function, arithmetic and logic unit for a data processing system is formed with only a small number of components. Some of the functions (Sum and Exclusive OR) are performed within each stage. For other functions (AND and OR), some of the components of one stage cooperate with different components of the next stage in an arrangement that reduces the total number of components for each stage. For these functions, the output appears shifted one bit position to the left and is then re-shifted one bit position to the right by a conventionally available shifter.

Abstract: An interactive data retrieval apparatus in which a data base store is searched by content using search keys entered by an operator. Dedicated hardware includes a plurality of search modules and apparatus for clocking the byte-wide data stream read from the data store through successive search modules. In each module, the data is compared with an entered search key. When a match is found between the data stream and the search keys, the data record is displayed to the operator. The apparatus can detect near matches to allow for misspellings etc. In one embodiment of the search module, a plurality of comparison cells perform byte-equality operations on search key data stored in a search key register and the data stream. In a second embodiment, an associative store contains the n-character search key, the associative store being addressed by each character in the data stream as it is clocked past its data port.

Abstract: An apparatus and a method to automatically locate defects and to automatically insert and personalize dummy lines in a PLA having latches controlling the cross points of the AND and OR array. Upon occurrence of an error in the PLA, a check signal is generated which interrupts normal operation of the PLA and which initiates a test procedure. The cross point latches are automatically loaded with test patterns and the output of the PLA is analyzed to locate the defective part, for example, a damaged cross point transistor, short circuited or open line. The dummy lines are repersonalized automatically to replace lines which are defective themselves or which are connected to defective crosspoints.

Abstract: A digital data display in which each display unit includes a random access, read/write character definition buffer store and a screen buffer. The character definitions and screen buffer for each picture to be displayed are constructed in a remote host central processing unit. In order to minimize the time that a user has a blank screen while new character definition and screen buffer data is sent from the c.p.u. to the display unit, this information is sent in groups relating to rows of character cells on the screen and a coherent picture is displayed growing from the top downwards, giving a roller blind effect. Data relating to the first significant row is sent initially followed by groups of character definitions and screen buffer data, the size of the groups dependent upon the characteristics of the transmission buffer.

Abstract: Program instruction TPI (Test Pending Interruption) and associated data processor sequence controls for its execution enable interruption handling programs to operate in a shortened recursive mode relative to interruptions pending while such programs are in control of a data processor system. Execution of a TPI instruction sets a condition code distinguishing between pendency and non-pendency of a request for interruption in one associated class of interruptions. If an interruption request in that class is pending, the instruction execution controls clear (terminate) it. If more than one request is pending, a selected one is cleared. The selection is based on a predetermined priority ordering. Interruption code information is stored by the execution controls, indicating the source of the cleared request. The interruption handling program branches on the condition code and the interruption code information, to attend to the interruption task associated with the cleared request.

Abstract: A resolution standard for a scanning electron microscope has clusters of palladium in a sea urchin form. The clusters are widely scattered on a substrate so that a cluster can be acquired easily for a resolution test. The tips of the spines on the clusters are on the order of 50 Angstroms and they present a sharp clear image to an electron microscope that is operating properly. A process for forming the clusters is also disclosed.

Abstract: Articles of a thermoplastic having an improved level of electromagnetic shielding are molded from plastic pellets that have a core of metalized glass fibers that are arranged to partially disperse through the molded article as individual fibers and partially to remain in clumps of generally aligned closely contacting fibers. The clumps have approximately the length of an individual fiber but they are substantially wider than an individual fiber. Improved conductivity is attributed to increased electrical bridging between fibers that is provided by the width of the clumps of fibers.

Abstract: In a cell-organized graphic display apparatus a set of canonical or standard cells is stored in a character generator. A data processor loads character codes into a character buffer and attribute bits into an attribute buffer. Lines to be displayed are computed on a cell-by-cell basis by the processor using pairs of canonical cells and the computed character codes are stored in the character buffer and attribute bits representing displacements of the required canonical cells are loaded into the attribute buffer. During accessing of the character generator, an adder shifts the bit patterns in accordance with the attribute bits. Optionally a second character buffer, a second character generator and a logic mixer are used to allow logical combining of cell images in accordance with attribute bits.

Abstract: Signals to the base of a bipolar transistor and to the gate of a parallel - connected FET are timed to turn on the two transistors simultaneously and to turn off the bipolar transistor before the FET. The shorter switching time of the FET is combined with the low resistance of the bipolar transistor to provide a switch that is particularly useful in a switched-type power supply with increased switched frequency.

Abstract: A new polling apparatus for units on a shared bus of a data processing system operates with a relatively slow multi signal line request bus and a relatively slow local counter. The local counter divides each time slot into a few sub-slots. Each sub-slot is assigned to two or more units in a priority sequence and during a sub-slot the assigned units contend for access to the bus by raising signals on particular lines of the request bus according to their priority within the sub-slot.

Abstract: A cover for a video record has a generally unbroken rectangular perimeter. A record player has permanent magnets that cooperate with paramagnetic inserts in the record cover to open the cover for loading and unloading a recording disk. The player has a clamp mechanism that enters the opened cover to clamp the disk for these operations.

Abstract: Articles of a thermoplastic having an improved level of electromagnetic shielding are molded from plastic pellets that have a core of metalized glass fibers that are arranged to partially disperse through the molded article as individual fibers and partially to remain in clumps of generally aligned closely contacting fibers. The clumps have approximately the length of an individual fiber but they are substantially wider than an individual fiber. Improved conductivity is attributed to increased electrical bridging between fibers that is provided by the width of the clumps of fibers.