startup screen

The Macintosh startup sequence for Apple Macintosh (or Mac) computers includes hardware tests and diagnostics which can trigger the startup chimes and/or other instances of success or failure of the startup routines.
The startup sequence provides auditory and visual symbols of the computer's status and condition as it powers up, providing users with immediate feedback on the machine's soundness. Additionally, they allow the user to quickly identify any potential problems and take any appropriate actions to rectify faults.

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