COMMAND NAME:

        ZOOM

USAGE:
        ZOOM X <time1> <sig_name_pos1> <time2> <sig_name_pos2>
        ZOOM XY <time1> <time2>
        ZOOM FIT X
        ZOOM FIT XY
        ZOOM REFRESH
        ZOOM OUT
	ZOOM IN

        This command allows the user to manipulate the waveform display.

                X:
        This option allows the user to zoom only in the x direction
        whilst leaving the number of signals displayed the same (see
        also the WAVEFORM command).

                XY:
        This option allows the user to specify a window for viewing by
        selecting two points via mouse and/or keyboard.

        Points may be specified by entering time and the signal name or number
        from the keyboard. Alternatively, a LEFT MOUSE BUTTON click in the
        Overview or graphics window can be used.

        Rubberbanding will show the user the extent of the new viewing window
        in both the Overview and graphics windows.  Moving the mouse anytime 
        after the first point is entered (regardless of the method of entry)
        engages the rubberbanding, allowing the user to explore different
        window sizes before deciding on a new view.
        
                FIT X:
        Will display the signals which are currently displayed in their
        entirety, modifying the extent of the time axis to ensure the 
        longest database signal is fully displayed.

                FIT XY:
        Will display all signals in the database in their entirety,
        modifying the extent of the time axis to ensure the longest 
        database signal is fully displayed.

                REFRESH:
        Refreshes the display.

                IN:
        This option allows the user to enlarge the display by the factor 1.625.
        Repeatedly pressing the LEFT MOUSE_BUTTON will continue to zoom in.
 
                OUT:
        This option allows the user to reduce the display by the factor 
        1/1.625. Repeatedly pressing the LEFT MOUSE_BUTTON will continue 
        to zoom out.

        NOTE: views cannot extend into negative time nor may they extend above
        the first signal in the database.
