The 'ZOOM MODE' allows you to magnify selected square sections of the tree display area within the main window.
Click on the <PZoom> button of the main window or press the 'F4' key on the keyboard to activate the 'ZOOM MODE'. In the latter case, the cursor has to be placed within the tree display area.
Define and magnify a section:
Position the cursor to define the first corner of the square to magnify. Keep the left mouse button pressed and move the cursor to define size and position of the region to magnify. Release the button.
Increase/reduce the zoom scale:
To gradually increase or reduce the zoom scale click the left or right mouse button while the cursor is located within the tree display area of the 'ARB_NT' window.
Alternatively you may use CTRL+Mouse-Wheel (this works independent of the currenly select mode).