Use the Prism.editor resource to specify the editor that Prism is to invoke when you choose the Edit or Email selection from the Utilities menu (or issue the corresponding commands).
Use the resource Prism.editGeometry to specify the X geometry string for the editor created by the Edit selection from the Utilities menu. The geometry string specifies the number of columns and rows, and the left and right offsets from the corner of the screen.
You can also change the settings of these resources via the Customize utility; see " Using the Customize Utility" for more information.