Apple Macintosh PowerBook 145 - Manual (Page 127)

More about automatic sleep
The Battery Conservation slider controls two different power
conservation features: system sleep and hard disk sleep.
m System sleep is a state in which your computer uses only the
power it needs to maintain the contents of RAM. (The
contents of RAM include any open programs and documents,
and various control panel settings such as the clock time.)
m Hard disk sleep stops your computer’s internal hard disk from
spinning when it isn’t being used.
If system sleep is in effect, so is hard disk sleep.
The table indicates how the battery conservation settings
correspond to sleep times.
Minutes before sleep if you choose:
Performance
Conservation
System 15 8 4 1
Hard disk 15 4 2 0.5
Using the battery conservation options
The Battery Conservation section of the PowerBook control panel
includes a button labeled Options. Click this button to see more
options that affect your computer’s power consumption.
Don’t sleep when plugged in
If the power adapter is plugged in, you can prevent automatic
sleep by clicking “Don’t sleep when plugged in.”
Chapter 7: Power Management 111