Abstract: A method of improving printer throughput by selecting a print velocity based on the characteristics of a line to be printed. Incorporated into an application program are all available printing velocities to be used for printing. As each line to be printed is buffered, it is analyzed. Based on the analysis, an optimum velocity is selected by the program for causing a printing of the line.

Abstract: A fiber-optic receiver invention includes an improved edge detector which receives the input current pulse from a photo diode located at the output of an optical fiber link. The edge detector differentiates the input waveform and provides a sequential positive going and negative going pulse combination at its output. The output of the edge detector is applied to the input of a switched threshold comparator circuit. The switched threshold comparator senses the differentiated waveform signal and provides complementary output signals which are the desired data output waveforms. At the same time, the switched threshold comparator applies the output waveform to an emitter-coupled differential amplifier having an unbalanced collector circuit. The emitter-coupled differential amplifier has a first transistor connected between a current and the reference input to a differential comparator.

Abstract: A microsequencer includes at least two program counters which access microinstructions stored in a memory system. A first program counter is cyclicly incremented to sequentially access microinstructions of a principal microprogram. When a particular microinstruction is accessed which indicates that a subroutine will be the next program to be executed, a branched-from address, representing the microinstruction calling the subroutine, is retained in the first program counter. An address representing the first instruction of the subroutine is loaded into a second program counter. The second program counter is then cyclicly incremented to sequentially access microinstructions associated with the subroutine. After the subroutine has been executed, the first program counter is re-enabled and cyclicly incremented so that the execution of the principal program is resumed in an orderly manner.

Abstract: A method of, and placing help information on a convenient but unneeded portion of a screen. Help information, when called, is placed on the screen adjacent an operating point, and positioned such that needed information adjacent the point is not covered up or blocked from view.

Abstract: A method of modifying a graphics data stream for improving printer throughput. The data stream is scanned and nulls preceding printable data are converted to text spaces. Text spaces are recognized by the printer to cause a printhead included in the printer to move directly to the first printable data position rather than homing first.

Abstract: A method of, and system for, building a screen and retrieving related portions of the screen through single button depression. The order with which various portions are built in building a screen is used upon recall of the screen and selection of one portion for controlling selection of related portions. Consider a wheel which is built by building a hub, spokes, rim, and tire in order. Later recall of the wheel and selection of the spokes will permit selection of either the hub or rim upon single button depression.

Abstract: Automatic gain control in a digital signal processor. An incoming electrical signal is sampled and multiplied by a gain factor with the resulting product compared to a constantly changing maximum value. If the magnitude of the changing maximum value lies outside a predetermined range of values, then the gain factor is adjusted proportionally to the error calculated by the amount the maximum value is outside the threshold range. In an alternative embodiment, the gain is adjusted according to whether or not one of the resulting products lies outside such upper and lower threshold range. The running maximum value decays with time in order to allow the automatic gain control to rack a signal which slowly weakens in strength. A time dependent factor enables the gain to be adjusted much more radically when a signal is first received.

Abstract: A CMOS flip-flop circuit is disclosed which enables a single side pull-down operation for inputting test signals during a test mode and alternately a dual side push-pull operation for inputting data signals during the normal use of the circuit. A pair of inverter circuits selectively feed complementary data signals to opposite sides of a bistable circuit so that the circuit operates in the push-pull manner thereby decreasing the switching time of the flip-flop. A pair of transmission gates, which are coupled to outputs of the inverter circuits, electrically isolate any noise appearing at a data input from the bistable circuit. During a test mode of the flip-flop, a test signal is fed into one side of the bistable circuit and facilitates a single side pull-down operation of the flip-flop. Two such flip-flop circuits are concatenated in a push-pull cascaded connection to provide a shift register latch.

Abstract: This invention enables voice energy to be distinguished from energy due to other sources such as telephone call progress signals. A portion of the audio spectrum is divided into a high and into a low frequency band and the energy content of these bands is examined. The audio energy of a signal is passed through a set of filters and compared. A frequency boundary crossing of an input signal subsequent to filtering is used to signify the receipt of a voice signal. By operating in this manner, voice, whose predominant frequency switches in a random fashion from being greater than to less than a cutoff frequency, can be distinguished from other signals either below or above the cutoff frequencies of the filters. The detection of voice energy is not begun until a predetermined threshold of energy has been received for a specified period of time. This specified period of time need not be continuous after a ringback signal is received.

Abstract: A data signal appearing at an input node of a bus transceiver is transmitted to an output node thereof during a clock cycle. During a second phase of the clock cycle, the data signal is captured in a latch of the transceiver and continues to be transmitted to the output node. Additionally, a receiver is enabled to the detect the transmitted data signal at the output node and to transmit the detected data signal to the input node. Thereafter, the detected data signal can be sensed by an external circuit.

Abstract: Automatic gain control (AGC) is provided in a digital signal processor environment. A predetermined threshold value, a predetermined automatic gain control value, and a predetermined count threshold value are established and stored in a data memory associated with a signal processor. Each incoming signal sample that is received is multiplied by the AGC value with the product being temporarily stored in the data memory. The absolute value of the resulting product is taken and added to the predetermined threshold value. If the result of this operation results in a signal processor overflow, then the AGC value is reduced and stored back into the data memory. The adjustment period of the AGC value is chosen to be well under the allowable distortion time for speech, dual tone multi-frequency reception, and modem operation.

Abstract: A method of, and system for, accurately manipulating objects on a screen to obtain a desired layout. Objects are called or built and then manipulated in terms of rotation and/or displacement. Accurate manipulation is facilitated by displaying a readout of the extent of rotation and/or displacement. Upon obtaining a desired layout, the layout is stored, printed, used to drive a process, etc.

Abstract: A method of determining character width for proportional spacing printing based on information contained in a dot pattern table. For a selected character, the character dot pattern in the table is analyzed to determine leading blanks and the actual character width. To obtain an overall width for printing, a number of trailing blanks equal to the number of leading blanks is added to the number of leading blanks and the actual character width. As such, a character suitable for proportional spacing printing is in effect built.

Abstract: A memory array associated with a display can be accessed in either one of two substantially orthogonal directions. The memory array is structured so that it may be accessed, such as for reading or writing, in either the horizontal or vertical direction. Pel position representations in the array are arranged so that vertically sequential pel positions in a given column are represented by data in sequential memory modules rather than by data in the same memory module. Likewise, horizontally sequential pels in a given row are represented by data in sequential modules rather than in the same module. The memory array is comprised of a plurality of separate memory modules and is structured so that both x and y directional accessing into and out of the array is accomplished on a bit addressable x,y field. This enables any bit string in the array to be addressed and to be read from or written into the array in either the x or y direction.

Abstract: A bus communication system is disclosed which provides low bus acquisition latency while supporting large block data transfers. A first device, which has control of a communication bus, detects a request for control of the bus during a transfer of the data to a second device. The first device then determines whether the transfer of data can be completed within a predetermined time period. A suspend signal is generated and transmitted to the second device in the event that the transfer of data cannot be completed within the predetermined period of time. The second device, in response to the suspend signal, sends to the first device, a plurality of control words which sets forth the information that the servant unit will require from the bus master to identify and resume the message at a later time. The first device stores the control words and relinquishes control of the bus.

Abstract: A method of reducing the need for a reverse indexing capability during multi-pass printing. In environments permitting narrow line spacings, requiring multiple passes to print a line, and where platen indexing is by full head height increments, indexing for completing printing for one line may result in an overshooting of a subsequent print line. Without reverse indexing capabilities, the subsequent line cannot be printed at a proper location or on the subsequent print line. A solution to reduce the occurrence of this problem is to index the platen only to the extent necessary to complete printing of a line on a subsequent pass.

Abstract: A method of, and system for, controlling a view of window information upon editing the information. The view is controlled based on mode selection. For normal information input operations, information scrolling is selected. Related existing information adjacent the newly input information will be viewable, but remote information will eventually be scrolled out of the window. For those instances where all existing information is to remain viewable upon input of additional information, border scrolling will result in a varying of the size of the window.

Abstract: A current pulse signal, which is generated by an optical detector, is fed to an input of an edge detector circuit. The current pulse signal is converted into a differentiated voltage pulse signal having a negative going pulse corresponding to a positive going slope of the input signal and a positive going pulse corresponding to the negative going slope of the input waveform. The positive differentiated pulse has a rise amplitude which is larger than its fall amplitude so that its most positive down level has a relatively positive absolute voltage value. Correspondingly, the negative differentiated pulse has a fall amplitude which is greater than its rising amplitude so that its most negative up level is more negative in absolute value than a nominal median zero voltage reference level.

Abstract: An M-bit binary counter is disclosed having M sequentially ascending binary value stages, the first stage being the lowest significant bit. In accordance with the invention, each stage above the least significant bit stage has a subsequent value decoder which has the function of determining the effect of lower order carry bits on higher order stages with a minimum of signal delay. The decoder includes the feature of using natural threshold FET devices in a transfer gate configuration to perform logical AND functions so as to minimize gate delays in decoding a carry condition for higher order stages. A selective up-counting or down-counting function is also disclosed.