OSDev.org

Is there a way to determine if an optional command is supported on the selected ATA interface? For example, how can I make sure if the Sleep command is supported on my HDD?

I'd appreciate it if somebody could help me with this.

There is Identify Device command which returns a lot of information (512bytes). There are Power Management bit, so it means that if PM is present, sleep function should work

xsix,

That wouldn't work with ATA-1 drives, would it?

i don't know, but it should. Here is the code for implementing this command and getting data back http://www.geocities.com/siliconvalley/2072/atapi.htm . Check out on your old ATA-1 drive, if you don't own one, read, read and one more time, read =)