An impulse cartridge having multiple charges that are independently activatable. The core is substantially free of cavitations, voids, and fillers. Each of the calendars can have a primary color for display; and, secondary colors are automatically determined based on the primary color for the user interface elements associated with a calendar. Also, an application for reproducing data enables to identify an error, enabling to avoid the application falling into a non-executable condition or the system falling into a hung-up condition. In redundant systems it also simplifies the direct vs.