Abstract: An alarm console is provided which selectively generates audio signals in an ordered priority basis when there is a simultaneous request for two or more tone signals. The priority is from voice paging, highest priority; test mode, to test individually selected alarm tones; keyboard tone selection; automatic priority tone in response to a detected condition; automatic non-priority signal tone in response to a detected condition; and a lowest priority signal which typically comprises background music.

Abstract: A communication controller for a distributed processing system has a number of data processing stations in which messages are exchanged among the stations over a communication channel. The controller includes a communications processing unit which manages the transmission and receipt of messages. A program is provided for the communications processing unit which responds to an inbound message addressed to the associated station with its poll flag asserted to cause the station to immediately contend for use of the channel. No other station can contend for use of the channel at this time because their corresponding communication processing units responded to such inbound message as being addressed to another station. This causes a predetermined time interval to start. Each of the other units then awaits expiration of the interval before attempting to contend for use of the channel.

Abstract: Interface unit for handling translation of message signals between a communication channel and a communications processor. The processor and interface unit are embodied in a data processing station of which a plurality of such stations are arranged along the communication channel. The interface unit includes a microstate machine which under program control directs the operations of message transmission, message receipt, and communication channel contention.

Abstract: This controller may be used to direct operations of a remote station impact line printer whose data source is a host computer. The controller includes a microprocessor (CPU), a memory large enough to accomodate a plurality of lines of textual data, and host computer and printer interfaces arranged in a firmware implementation. A multiline buffering feature includes capability for receipt of incomplete lines and printing of partial lines. An overstrike feature includes capability for printing more than one character at the same print point (e.g., underlining, or "0") without intervening horizontal escapement commands such as backspace or carriage return.

Abstract: An electron beam deflection circuit useful in cathode ray tube displays which employ television scanning principles. The deflection circuit is characterized by transformer coupling between a source of horizontal drive signal and a switching transistor for the horizontal deflection coil. Energy stored in the transformer during the scan and retrace time is utilized during the scanning time to provide base current to the switching transistor. In addition, the transformer has a second primary winding connected in the emitter circuit of the switching transistor in a manner to allow positive feedback. The positive feedback enhances and sustains the base current during scanning time and controls its magnitude. The circuit is advantageous in that it eliminates the need for precise waveshaping circuits at the input to the switching transistor and lowers the power requirements for the circuits which precede the switching transistor.

Abstract: A computer system having two busses which are shared by one or more processors, one or more memories, one or more input/output channels and a bus control mechanism. One of the busses is used for the transmission of original messages from the processors and/or I/O channels to the memories or the bus control mechanism. The other bus is used for the transmission of reply messages by the memories or the bus control mechanism to the senders of original messages requiring a reply. The bus control mechanism includes a first control means for controlling priority and usage of the first bus and a second control means, independent of the first control means, for controlling reply message traffic over the second bus. The reply message control means is arranged to handle reply message traffic on a priority basis and a time availability basis so as to prevent hang up of the reply message bus.

Abstract: A print hammer mechanism with a flexible interposer selectively moveable from a normal position into the path of a rotating impeller tooth which engages the interposer driving it and the associated hammer toward a print line to impact a print medium with a type die on a moving carrier. The interposer is flexible in the plane of motion of the hammer and the impeller tooth which allows slower and more controlled acceleration of the hammer and enhances the wear of the materials used to fabricate the hammer, interposer and impeller tooth. Uncontrolled oscillation of the flexible interposer and, hence, multiple strikes and multiple rebounds from the print hammer back stop are prevented by means of a mechanical linkage which captivates the interposer to the hammer for travel with the hammer but also allows the interposer to move from its normal position into the path of the impeller tooth and to return to its normal position.

Abstract: An apparatus and arrangement is disclosed for controlling the sharing of an electronic memory between a number of memory users, at least one of which requires transfers of blocks of data on a high priority basis. Access to the memory is controlled by means of a modified time division multiplexing scheme whereby a set of time slots is assigned for performing memory accesses requested by high priority memory users, but, during times in which no high priority users are using the memory, these time slots may be used by other memory users in the order of pre-assigned priorities. Independent output data paths are provided for the respective high and low priority data transfers.

Abstract: Electronic display system in which a single memory is timeshared by a plurality of display units each including a cathode ray tube (CRT) television monitor capable of displaying a frame of characters in the form of one or more lines as well as a central processing unit and a number of input/output units. Character codes representing the characters in each character line being displayed are stored in blocks of storage locations in the memory, one character line per memory block. A plurality of frame display programs, one for each display element, are stored in separate blocks of storage locations. Each program specifies the order in which the character lines are to be displayed by its corresponding display element. A refresh control unit common to all of the display units includes a basic line counting means which is employed to sequentially execute the frame display programs in retrieving the character codes from the memory and loading them into unit line buffers for the various display units.

Abstract: A print hammer mechanism with a flexible interposer selectively moveable from a normal position into the path of a rotating impeller tooth which engages the interposer driving it and the associated hammer toward a print line to impact a print medium with a type die on a moving carrier. The interposer is flexible in the plane of motion of the hammer and the impeller tooth which allows slower and more controlled acceleration of the hammer and enhances the wear of the materials used to fabricate the hammer, interposer and impeller tooth. Uncontrolled oscillation of the flexible interposer and, hence, multiple strikes and multiple rebounds from the print hammer backstop are prevented by means of a mechanical linkage which captivates the interposer to the hammer for travel with the hammer but also allows the interposer to move from its normal position into the path of the impeller tooth and to return to its normal position.

Abstract: An improved method is disclosed for manufacturing a keyswitch assembly which includes a plurality of switches in a predefined arrangement on the face of an insulative circuit board and which also has a protective, insulative coating over the switches and board face. Each of the switches includes a pair of spaced contacts on the board face and a resilient, deformable, electrically conductive actuating element which can be selectively deformed to provide an electrical circuit between the two contacts. The method is performed with the aid of a planar template having a plurality of apertures positioned in a predefined arrangement corresponding to the arrangement of the switches on the circuit board. As an initial step, an insulative sheet, eventually forming the coating, is placed on a flat surface and the template is placed on top of the sheet so that the sheet is sandwiched between the template and the surface.

Abstract: A method of preparing an alignment disc pak in which first and second signals of different frequencies f1 and f2 are recorded in eccentric bands at a selected track on the disc such that the playback signal will consist of three components having frequencies f1, f2 and (f1-f2). One frame of the playback signal is first displayed with one beam of a multibeam oscilloscope on the display surface thereof such that the (f1-f2) signal component appears as a "cat's eye" pattern. The delay time base time marker is then employed to measure the time base of one of the cat's time marker is further employed to produce first and second narrow timing bands on either side of the intermediate crossover of the cat's eye pattern by erasing the recorded signals on the disc only in those radial sectors of the disc corresponding in position to two positons of the time marker on the scope as defined by the formula (Gc - Sp/2 .+-. 0.2.

Abstract: A keyswitch assembly including a circuit board having a plurality of circuits, each circuit terminating with a pair of first and second contacts, and a curved, resilient contact plate associated with each pair of contacts having at least a portion of its periphery in communication with one of the pair of contacts, the plate being selectively deflectable so that it communicates with the other contact to close the respective circuit. The contact plates are fixed in position by a retaining element comprising a film formed by a layer of thermoplastic material bonded to a flexible sheet of insulative material, the thermoplastic material being bonded to the resilient plates and circuit board thereby maintaining the former in correct position relative to the latter. The method of manufacturing the assembly includes precisely locating the plates over the pairs of contacts, placing the retaining element over the circuit board an applying pressure to the assembly at an elevated temperature for a predetermined time.

Abstract: A ballistic print hammer assembly which includes a pivotally mounted print hammer driven by an electromagnetic actuator, characterized by low cost and ease of manufacture, high velocity and short dwell time. A rigid pivot upon which the hammer is mounted is simply secured to one side of a frame member. One end of the hammer is disposed in a slot of the armature of the electromagnetic actuator. The stator of the actuator is arranged to be inserted (by means of screw threads) from the other side of the frame member through an aperture so that the armature fits within the actuator stator cavity. An impression control spring is further disposed in a central cavity of the armature to continually produce a biasing force on the hammer which in the free-flight condition of the hammer is a decelerating force.

Abstract: A keyswitch assembly including a circuit board having a plurality of circuits, each circuit terminating with a pair of first and second contacts, and a curved, resilient contact plate associated with each pair of contacts having at least a portion of its periphery in communication with one of the pair of contacts, the plate being selectively deflectable so that it communicates with the other contact to close the respective circuit. The contact plates are fixed in position by a retaining element comprising a film formed by a layer of thermoplastic material bonded to a flexible sheet of insulative material, the thermoplastic material being bonded to the resilient plates and circuit board thereby maintaining the former in correct position relative to the latter. The method of manufacturing the assembly includes precisely locating the plates over the pairs of contacts, placing the retaining element over the circuit board and applying pressure to the assembly at an elevated temperature for a predetermined time.

Abstract: Apparatus for feeding data processing record cards seriatim from the bottom of a stack to a data sensing station or the like including a pair of oscillating picker members for displacing a record card from the bottom of the stack, and a pair of sector rollers for intermittently gripping the displaced card and moving it at right angles to the direction of displacement to the nip of a set of feed rollers. Both the picker members and sector rollers are driven from a common source, the picker members being harmonically driven through a unique coupling device including a pair of flexural elements mounted at right angles to each other to give a universal action.