Compare Files Display:  This feature allows you to make bit by bit comparasons of individual files.  The comparison in only made when the files have the same length.  You can choose one file to be the base and all other files are compared to it.  Use the mouse to set the base by clicking on one of the buttons in the left most column.

Don't forget to use the mouse and the tool tip help to review the functions associated with the buttons on the toolbar. The toolbar changes depending upon what the currently selected window contains.