A mouse controller includes a platform mounted on a base for a range of
movement in a plane relative to the base of at least 1/2 inch (12.5 mm)
in each of two different directions (preferably mutually perpendicular
directions). A pair of flat, elongated coils (Lorentz voice coils) are
mounted on the platform with their longitudinal axes extending one in
each of the two directions. Each of the coils cooperates with at least
one magnet fixed to the base. The sizes of the magnets and of the coils
and the relative positions of the cooperating coils and magnets are made
or their operation controlled so that, in the range of relative movement
between the platform and base, preselected forces between the coils and
the magnets may be generated by a control computer. Preferably the
projected area of the field from each of the permanent magnets onto the
coil with which it cooperates will be substantially constant regardless
of the position of the platform within the range so that the same current
is required to generate the same force anywhere within the range. The
control computer is programmed to activate the coils to controllably
apply forces to the platform and thereby to facilitate movement of the
platform and feed back tactile sensations to the operator.