Apple PowerBook (2400c) - Manual (Page 22)

m You can also put your computer to sleep by closing and latching the display.
When the computer is in sleep, a small green light flashes in the center of
the latch.
For information on other ways of putting the computer to sleep, see the
“Batteries & Power” topic of Mac OS Guide, available in the Guide (h)
menu. (You can learn more about using Mac OS Guide in Chapter 2 of
this manual.)
Automatic sleep
If you don’t use the computer for several minutes, it goes to sleep
automatically. This conserves battery power.
To wake the computer, press any key on the keyboard (except Caps Lock).
The screen will reappear as it was before the computer went to sleep.
You can control the automatic sleep feature. For more information on sleep
and automatic sleep, see the “Batteries & Power” topic of Mac OS Guide,
available in the Guide (h) menu. (You can learn more about using Mac OS
Guide in Chapter 2 of this manual.)
Sleep indicator
21 Getting Started