Setting History Depth
By default older lines are discarded from the event list to stay within a specified History depth. To change History depth, click the History toolbar button, choose History Depth on the View menu, or press Ctrl+H.
This action opens the Event List History Depth dialog box.
Type or select a new value in the History Depth box or click Default to restore the default value of 50,000 lines.
Type or select 0 in the History Depth box to retain an unlimited number of lines in the display.
Note
Turning off Auto Scroll temporarily sets the History Depth to an unlimited number of lines so that new items will continue to appear in the display.