An apparatus and methodology for use in a signal measurement system having a graphical user interface. The apparatus constructed and arranged to simultaneously render on a display of pixels a main waveform display and a magnified waveform display is disclosed. The main waveform display is adapted to have displayed therein one or more waveforms and associated data on a first graticule with a background while the magnified waveform display is adapted to have displayed therein a magnified view of a region of the main waveform display on a second graticule with a background. The region of the main waveform display to be magnified is defined by a graphically-controllable selection window positioned over the main waveform display to encompass the region. Preferably, the operator-controllable selection window has a position and extent that may be graphically manipulated.

An apparatus and methodology for use in a signal measurement system having a graphical user interface. The apparatus constructed and arranged to simultaneously render on a display of pixels a main waveform display and a magnified waveform display is disclosed. The main waveform display is adapted to have displayed therein one or more waveforms and associated data on a first graticule with a background while the magnified waveform display is adapted to have displayed therein a magnified view of a region of the main waveform display on a second graticule with a background. The region of the main waveform display to be magnified is defined by a graphically-controllable selection window positioned over the main waveform display to encompass the region. Preferably, the operator-controllable selection window has a position and extent that may be graphically manipulated.

A digital engine analyzer has an oscilloscope display screen operable in single-trace and dual-trace modes and in live and freeze modes, and having signal pickup leads for respectively acquiring different input signal waveforms from the engine and digitizing them for storage and display. When the freeze mode is entered, the last-displayed screen display format is frozen, and can then be reconfigured by the user by altering one or more of the number of traces, the signal plotted on each trace, the engine sweep of each trace, the scale and the scale offset for each trace and, in the case of a cylinder sweep, the displayed cylinder. In dual trace screen display formats, the user can also select for display on trace 2 a waveform pattern selected from a stored library of patterns.

A method of displaying continuously acquired measurement data in a display with a fixed number of pixels is provided. Measurement data is provided at a predetermined fixed sample rate independent of a pixel rate which is equal to or less than the sample rate. The measurement data is convened to pixel data which includes the minimum, maximum, and the average of the measurement data gathered and the pixel data is plotted to the pixels at a pixel rate. At the end of the fixed number of pixels of the display, the pixel values are compressed to half the fixed number of pixels and the pixel rate is halved, thereby doubling the time scale. This process can continue indefinitely, requiring no operator intervention or prior knowledge to set a total measurement time. Furthermore, the sample rate is independent of the pixel rate so that a tradeoff of sample rate and total measurement time need not be made.

Video magnification apparatus modifies (shrinks or enlarges) video graphic images in a horizontal and vertical direction during a transfer of video graphics data signals from a graphics memory to a television screen. A first magnification modifying device modifies the magnification of a graphic by a vertical magnification factor by generating graphic line address output signals that selectively prevent a transmission of predetermined horizontal lines of the graphic upon the reception of a vertical magnification factor that is less than unity. The first device also causes a transmission of predetermined horizontal lines of the graphic to be selectively repeated upon the reception of a vertical magnification factor that is greater than unity. A second magnification modifying device is responsive to the transmissions of the horizontal lines of the graphic indicated for transmission by the output signals of the first magnification modifying means for modifying the magnification of the graphic in a horizontal direction by a horizontal magnification factor. The second magnification modifying device selects N predetermined pixels of each received X pixel group that are multiplexed into a transmitting X pixel group for transmission in each output signal of the apparatus for a magnification factor equal to or less than unity. Still further, the second device repeats pixels of each received X pixel group a number of times corresponding to an integer magnification factor that is greater than unity for transmission in each output signal of the apparatus.