Function Key ResourcesFunction key resources (of the
'FKEY'resource type) are Command-Shift-number key combinations that are captured and processed by the
WaitNextEventfunction. The screen utility resource (a function key resource with resource ID 3) produces a picture of the main screen, contained in a
'PICT'file, when the user presses Command-Shift-3. The
'FKEY'resource IDs 0 through 4 are reserved for future use by Apple Computer, Inc. The
WaitNextEventfunction is described in the chapter "Event Manager" in Inside Macintosh: Macintosh Toolbox Essentials.