5.2 Mouse

left button
pops up the small magnifying glass, as long as the button is down.
middle button
pops up the medium magnifying glass, as long as the button is down.
right button
pops up the big magnifying glass, as long as the button is down.
Shift + left button
change the arrow cursor for a crossbar cursor and enter 'setting home position' mode. Home position is set when the button is released. Usefule with the 'Keep Home' feature.