Abstract: Mixed color effects in a character graphics display system are achieved by providing font characters comprising several character cells with different patterns which can selectively be read simultaneously to different color registers, thereby determining the color in which each character cell is to be displayed. The system also provides characters comprising only a single character cell which can selectively be directed to any of the color registers. A control system interprets color bits in a control word in accordance with the type of character being accessed.

Abstract: An electromagnetic lateral convergence assembly includes a generally-annular, planar magnetic core (optionally found as a laminate) having integral pole pieces extending toward the center of the annulus. Electrical coils are mounted on selected pole pieces for producing a convergence-compensating magnetic field within the center of the annulus. The coils are secured to a printed circuit board to hold the core in spaced parallel relationship to the board. Optionally a purity assembly including a planar magnetic core having a number of electrical coils for producing a rotatable, variable, linear field is mounted on the other side of the printed circuit board.

Abstract: The data processing system consists of a plurality of interconnected data processing subsystems one of which is a service subsystem devoted to servicing the remainder of the system and provides communication between the operator and the system to facilitate maintenance. A plurality of power supply units provide electrical power for the system, together with power supply means dedicated to the service subsystem to start up.The service subsystem includes a power adapter unit with measuring and logic circuits which cooperate with a power control microprogram to control and monitor the plurality of power supply units. The power adapter unit collects analog and digital data from the plurality of power supply units and distributes digital data to the plurality of power supply units in a multiplex mode as directed by the power control microprogram.

Abstract: A three color gun cathode ray tube has convergence correction signals derived from digital signals stored in a digital data store. The screen of the tube is divided into a plurality of areas and a digital correction signal derived for each area. The system is arranged so that when the three beams are scanning a particular area the digital correction signal associated with that area is read out from the digital store, passed through a digital to analog converter and then applied to the convergence coils of the tube.

Abstract: A method of convergence correction in a three beam color cathode ray tube dividing the screen into a plurality of discrete areas. Digital values for convergence factor signals are derived for a predetermined number of the discrete areas and a spreading algorithm is used to derive digital values for the remaining areas. The resulting digital values are stored in a digital store and used to provide convergence correction factor signals during operation of the tube.

Abstract: A display system is described in which left to right or right to left mode may be displayed without character inversion. A read/write store is added between a display buffer and a CRT. This store stores one complete scan line of character slice bytes in sequence. The bytes may be read out either in a normal sequence or in a reversed sequence for display. As bytes are read in parallel, the orientation of individual characters is unchanged.One line of control data or selected lines may always be displayed in left to right mode, while the remainder of the display is in right to left mode.

Abstract: A circuit associated with a telephone line to detect line status includes a first detector sensitive to the line current phase, a second detector sensitive to the ringing voltage phase, and two pulse generators of the same frequency as the ringing voltage, appearing at the positive and negative zero-crossings of the ringing voltage, respectively. When only the ringing current is applied to the line, only the signals from both detectors and one generator are simultaneously present (once per period). When the called subscriber lifts his handset, the signals from both detectors and the other generator are also simultaneously present once per period. These pulse coincidences are detected and processed by an appropriate logic.

Abstract: The disclosed supply utilizes the capability of two-way power flow, from a DC source to the load and from the load to a DC source, so as to be able to track a desired output wave form while running reactive loads. This method of operation requires minimum filtering for loads of various power factors and transient characteristics. Two equal and opposite DC sources, such as batteries, furnish and accept current, through switches, to and from an inductor-capacitor filter to which the load is connected. A feed-back circuit compares the voltage furnished to the load with a reference of the desired output wave shape, so as to control the switches in such manner as to force the output voltage to follow that wave form.

Abstract: A display system is shown which has a source of coded information in display mapped format and includes plural devices for decoding and utilizing the information in accordance with its position in that mapped format. In the illustrated embodiment, the source includes a refresh buffer and the utilization devices include an attribute decoder and a character generator. A character row counter controls gating which causes the apparatus to treat bytes of data, having attribute format, truly as attributes or as addresses of members of an extra, graphical character set of the character generator.

Abstract: The method of winding a cathode ray tube, magnetic deflection yoke. The yoke is formed with an annular core with non-electrically conductive, non-magnetic end caps. The end caps have a series of hook members separated by slots, with the slots of one end cap aligned with those of the opposite end cap and the hook members defining radially outwardly displaced annular channels in the respective caps. To wind the yoke, wire is fed under tension axially through the core and a slot in one end cap, then radially outward between a pair of adjacent hooks around and along one of the channels behind a predetermined number of hooks, thence radially inward between a separate pair of hooks and axially in the opposite direction toward the second end cap where the same procedure is repeated until a bundle of wire turns is formed on the yoke in a predetermined pattern.

Abstract: A data entry system suitable for entry/exit (attendance) recording includes a terminal unit having identity card reading means, adapted to be connected via an extension line to a central apparatus such as a computer controlled telephone line switching system having data handling capabilities. The terminal unit includes a buffer to store the data read from the identity card prior to requesting service from the line switching system and includes a locally generated signal to indicate that the card was correctly read and means responsive to a signal from the central system to indicate that the data was accepted. The card forms a component of the system and is encoded in such fashion that the manner of its use indicates whether entry or exit information is being recorded, and the terminal unit is responsive to the information entered by the card and the response of the central system to provide appropriate logical output at the terminal, such as the activation of an automatic door lock.

Abstract: A switching exchange of the space switching type is adapted to provide interconnection of the lines of a communication network, each line being able to provide several multiplex channels, each channel being different from the other ones in the frequency domain, in the time domain or in any other way. The control unit of a switching exchange of the space switching type is adapted to enable the system to interconnect more than two lines of the multiplex type together, by the provision of complementary logic which determines for any new connection of multiplex lines whether the required connection is possible or not in accordance with the state of the network when this request occurs. This operation is carried out by checking what are the lines which would be interconnected should the required connection be made, and whether the use of the transmission channels in the assembly of said lines, as it is in the initial state, will cause interference between the channels when the required connection is made.

Abstract: A power translating circuit of the general kind utilized in transformer coupled transistor switching regulators has a source of DC, the primary of a transformer and a switching transistor in series. To protect the transistor from excessive power dissipation during its turnoff transition, a surge diverting path including a diode poled oppositely to the transistor is provided in parallel with the transistor, the diode being in forward conduction at the beginning of turnoff of the transistor and becoming back-biased as the transistor turns off, the reverse conductivity of the diode during its recovery serving as a temporary path diverting some of the power dissipation at turnoff away from the transistor.

Abstract: A method and apparatus for monitoring and controlling a plurality of power supplies in a computer or similar complex electronic apparatus provides the steps of normalizing each power supply output according to a common nominal val ue, comparing the normalized values to a reference having values according to the normalized upper and lower limits specified for each power supply, and conducting a quantative measurement of out-of-tolerance test values. The specific upper and lower tolerance values for each normalized output are stored in digital form and the measurement of an out-of-tolerance reading is by comparison to a digital ramp extending only from the specific maximum or minimum tolerance threshold which is exceeded. The testing of plural power supplies having the same upper or lower normalized tolerance can be conducted as a group of tests against the same reference.

Abstract: A push pull inverter has a pair of chopper transistors connected to opposite ends of a center tapped primary of an output transformer and off drive clamps for turning the chopper transistors off alternately under the control of an oscillator. On drive is provided entirely by feedback derived from a secondary winding on the transformer and coupled to the base circuits of the chopping transistors. When the oscillator causes one transistor to be clamped off, the resulting reversal of polarities in the transformer delivers on-drive to the other transistor base. Since the off-switching of the first transistor causes the on-switching of the second transistor in a sequential manner, the two can never be on at the same time, despite the effects of minority carrier storage in the switching transistors.

Abstract: An acoustic feedback control to be installed in every extension provided with a loud speaker and a microphone in a digital telephone system. Each extension is provided with a coder and a decoder of the syllabic compression type which therefore have quantizing steps varying with the voice level at the input of the transmission channels between two extensions. A comparator receives the step information from the coder and decoder and prevents the decoder step from increasing when the coder step exceeds the decoder step.

Abstract: Two-way links communication capability between time-division multiplexed subsystems is provided via dual time division address and data busses correlated by a recirculating memory having sections respectively associated with the address busses. Addresses on the address busses are recognized by the individual subsystems and further decoded to gate data to and from the busses data according to time slots assigned to terminal devices in the subsystems. The dual bus arrangement provides a full-duplex link in the sense that there is simultaneous communication via the two data busses, one each way.