A telescope paddle appears on the MOPRA workstation
screen during system startup (if ENLIST IR has been typed). This
paddle consists of a 3 
3 grid with NSEW boxes labelled
accordingly. The first mouse button (the left one for a righthanded
setup) is used to offset the telescope by clicking on the appropriate
box. All eight outer boxes respond in the obvious way. The first
mouse button does not respond to clicks in the central square. The
default telescope offset is 1.0 arcsec. This offset can be increased
in factors of two by clicking the second (middle) mouse button in the
central square. Similarly, it is decreased by clicking the third
mouse button in the central square. The second and third mouse
buttons do not respond to clicks in any other squares.