Abstract: A signal processing system for a spectrum analyzer presents a three-dimensional display of a signal in the form of a display of an independent variable, such as frequency, versus a selected property of the signal, such as power, where the selected property is represented as a distribution of values for each independent variable interval in the form of intensity variation on the display. The independent variable is divided into m slots, and the selected property is sampled k times for each slot. A histogram for each slot is built up in a buffer representing the number of samples occurring at each of n power levels. The histogram is transferred to a display memory column by column for each slot, and after all the slots have been processed the display memory is read out onto a display device, such as a CRT, in a raster scan format with the intensity of each pixel element being a function of the number or samples at that power level within that frequency interval.

Abstract: A hand-held inertial mouse provides input data to a computer from which the computer can determine the translational and angular displacement of the mouse. The mouse includes accelerometers for producing output signals of magnitudes proportional to the translational acceleration of the mouse in three non-parallel directions. Pairs of these accelerometers are positioned to detect acceleration along each axis of a cartesian coordinate system such that an angular acceleration of the mouse about any axis of rotation causes representative differences in the magnitudes of the output signals of one or more of these accelerometer pairs. The translational velocity and displacement of the mouse is determined by integrating the accelerometer output signals and the angular velocity and displacement of the mouse is determined by integrating the difference between the output signals of the accelerometer pairs.

Abstract: Quadraphonically encoded left end right signals are fed to separate left and right signal phase shifters the outputs of which are fed to three variable gain amplifiers for each of the four corner loudspeakers of a quadraphonic playback system and also to three comparators which function to control operation of the variable gain amplifiers in such manner as to cancel cross talk by altering the decoding coefficients of the cross talk bearing channels.