>These days perhaps, but in the Good Old Days of 14" ten-disk platters on
>mainframes, if the power failed they'd spin for about 15 minutes!  Very
>eerie to be in a computer room illuminated by emergency lights, with no
>sound but the very quiet whine from half a dozen disk drives.  Normally
>they'd be braked to a halt, so it was only in a power failure that it
>would happen.

Hmm, all the Winchester drives I dealt with had brakes that came on with 
power drop. The platter drives I dealt with all did an auto retract by 
dumping a charged cap across the voice coil on power down. I do remember 
they took a while to spin down even on a normal "unload" operation.

The one I always found impressive was the CDC 300MB removable platter drive 
that was OEM'd to a lot of companies. The spindle motor in that would be 
large enough to power a small car. From a standing start it was something 
like 15 seconds to online when you pushed the start button. 

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