Useful changes by Jeremy C B Nicoll 

             a) my version of !Scaler, which contains
                1) a new !boot file to set sprites

                2) code to modify mouse sensitivity
                   when scaler is started up (that's
                   in !run) and tell you that scaling
                   is now on.

                3) supplied code has a module named
                   "MouseScale" and armalyser source
                   output named "MouseScale/s".  When
                   both are copied to a 10-character
                   FS, the source file replaces the
                   module.  So I've renamed the source
                   to "source" and left the module with
                   the real name.

             b) a trivial mini-app called !ScalerOff
                which turns !Scaler off and sets the
                original mouse sensitivity.