Inside Macintosh: Devices /

Chapter 6 - Power Manager / Power Manager Reference

Power Manager Dispatch Routines / Controlling the Hard Disk

HardDiskPowered

You can use the HardDiskPowered function to find out whether the internal hard disk is on.

Boolean HardDiskPowered();

DESCRIPTION

The HardDiskPowered function returns a Boolean value indicating whether or not the internal hard disk is powered up. A value of true means that the hard disk is on, and a value of false means that the hard disk is off.

ASSEMBLY-LANGUAGE INFORMATION

The trap is _PowerMgrDispatch ($A09E). The selector value for HardDiskPowered is 6 ($06) in the low word of register D0. The Boolean result is returned in the low word of register D0.