Preferences

There are only two preferences in MacFoil, accessed by choosing "Preferences..." under the Edit menu:

Default Units chooses the units to use for all new documents. The default is inches, but if you usually work in millimeters, set this preference and all new documents will use millimeters instead.

Dynamic Redraw sets whether to redraw automatically when the plot parameters change. (Frankly, I don't know why you'd want to turn this off, but I thought I should give you the option.) If turned off, you need to click the "Plot" button (or hit the return or enter key) to redraw after making changes.