Sleeping, Restarting, & Shutting Down
The Apple menu (Figure 61) offers several options that change the work state of your computer:
Figure 61 Four commands under the Apple menu let you change the work state of your computer.
Sleep puts the computer into a state where it uses very little power. The screen goes blank and the hard disk may stop spinning.
Restart instructs the computer to shut down and immediately start back up.
Shut Down closes all open documents and programs, clears memory, and cuts power to the computer.
Log Out closes all open documents and closes all open documents and programs and clears memory. Your computer remains running until you or someone else logs in. I discuss all of these commands on the following pages.
Mac OS X also includes a screen saver, which automatically starts up when your computer is inactive for five minutes. Don't confuse the screen saver with System or display sleepit's different. To display the screen again, simply move the mouse or press any key. You can customize screen saver settings with the Screen Effects preferences pane, which is covered in Mac OS X Advanced: Visual QuickPro Guide.
If your computer's keyboard includes a power key, pressing it displays a dialog with buttons for the Restart, Sleep, and Shut Down commands (Figure 62). This feature, how ever, does not work with all Mac OScomputer mod els.
Figure 62 Pressing the power key on some Mac OS computers displays a dialog like this one.
Do not restart or shut down a computer by simply flicking off the power switch. Doing so pre vents the computer from properly closing files, which may result in file corruption and related problems.
To put your computer to sleep
Choose Apple > Sleep (Figure 61).
Press the power key on the keyboard.
In the dialog that appears (Figure 62), click Sleep.
Not all computers support sleep mode. If your computer does not support sleep mode, the Sleep command will not appear on the Apple menu.
When you put your computer to sleep, everything in memory is preserved. When you wake the computer, you can quickly continue working where you left off.
Sleep mode is an effective way to conserve the battery life of a Power Book or iBook without turning it off.
By default, Mac OS X automatically puts a computer to sleep when it is inactive for 20 minutes. You can change this setting in the Energy Saver preferences pane, which is discussed in detail in Mac OS X Advanced: Visual QuickPro Guide.
To wake a sleeping computer
Press any keyboard key. You may have to wait several seconds for the computer to fully wake.
It's much quicker to wake a sleeping computer than to restart a computer that has been shut down.
On some computer models, pressing or certain other keys may not wake the computer. When in doubt, press a letter keythey always work.
To restart your computer
Choose Apple > Restart (Figure 61).
In the dialog that appears (Figure 63), click Restart or press or .
Figure 63 This dialog appears when you choose the Restart command from the Apple menu.
Press the Power key on the keyboard.
In the dialog that appears (Figure 62), click Restart.
Restarting the computer clears memory and reloads all system files.
To shut down your computer
Choose Apple > Shut Down (Figure 61).
In the dialog that appears (Figure 64), click Shut Down or press or .
Figure 64 This dialog appears when you choose the Shut Down command from the Apple menu.
Press the Power key on the keyboard.
In the dialog that appears (Figure 62), click Shut Down or press or ..
On most computers, the Shut Down command will cut power to the computer as part of the shut down process. If it doesn't, a dialog will appear onscreen, telling you it's safe to turn off your computer. You can then use the power switch to cut power to the computer. Down command from the Apple menu.