The Parameters of each fractal algorithm are described by
a short title, which appears above the entry field for
each of the (up to) four parameters.

Parameters that don't apply to a given fractal type will have
no title, and the entry field will be inaccessible.

For information on what the parameters mean, see the description
of the fractal in question in the "Fractal Types" help data
selectable from the main menu Help menu.

When entry is complete, select OK, or press Enter.
To exit with no changes, select Cancel, or press Escape.
To see the default (built-in) values, press Default.
To proceed with the default values, press Default, then OK.
Exiting with OK will cause the fractal to be recalculated
with the new parameters.