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When the battery power is down and the unit not plugged in the computer is forced into a sleep mode requiring pushing the start button when power is re-connected. The initial desktop screen appears to be greyed out and is unresponsive with a timer bar which, when the timing sequence is complete restores an active desktop. I can't find any reference to this phenomenon in the OSX literature I have. Any pointers to where I can get more information? Perhaps I am using the wrong search criteria?

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Thanks for asking this. I saw it for the first time yesterday after letting my Macbook run down overnight. I wondered whether it might have hibernated even though I have safe-sleep turned off. – JRobert May 28 '10 at 18:10

This is analogous to hibernation where the contents of the RAM are cached to the hard drive. This allows for the unit to be completely off, but without any loss to currently used data. This only occurs in extreme battery situations.

Apple calls it Safe Sleep.

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Thanks, the answer will do nicely. I have taken the MascOS Support Essentials course for OSX 10.6 and interestingly, it was not mentioned in the book nor at the classroom course. I expect others that I may be called upon to assist will occasionally come up with the same question. – Don MacLachlan May 30 '10 at 21:26
@Don MacLachlan - If you'd like to accept this as the correct answer, you can click the check mark icon under the voting to the left of this question. – MDMarra May 30 '10 at 23:14

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