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- Path: sparky!uunet!zaphod.mps.ohio-state.edu!malgudi.oar.net!uoft02.utoledo.edu!dsouth
- From: dsouth@uoft02.utoledo.edu (Dale Southard Jr.)
- Newsgroups: comp.sys.mac.hardware
- Subject: Re: PB HD Warning
- Message-ID: <1992Aug13.143813.9388@uoft02.utoledo.edu>
- Date: 13 Aug 92 14:38:12 EST
- References: <892@emoryu1.cc.emory.edu> <1992Aug13.015723.8181@talon.ucs.orst.edu> <hp48sx.713716719@wuarchive.wustl.edu>
- Distribution: usa
- Organization: University of Toledo, Computer Services
- Lines: 28
-
- In article <hp48sx.713716719@wuarchive.wustl.edu>, hp48sx@wupost.wustl.edu (HP48SX Archive Maintainer) writes:
- > I am not sure how the 2" drives are designed, but many 3.5" drives do a
- > park when they receive the SCSI STOP command. And I think this is what
- > the 2" drives do as well. Is there a spin-down-without-parking-heads
- > mode at all ?
-
- Doubtful -- spin-down-without-parking-head is the hard drive equiv. of
- suicide. It would mean the the heads were going to land on the platter
- (death and destruction etc etc). All of the modern mechanisms that I am
- aware of park heads automatically on spin-down (or power loss for that matter,
- the heads are ususally extracted from the platter by the spring force in the
- case of a voice-coil mechanism, no current in the coil, nothing to hold the
- heads over the platter -- I am not sure how the stepper motor designs
- accomplish it). In fact, I believe that most mechanisms also park after a
- few seconds of inactivity.
-
- On my powerbook 170, I can HEAR the heads park -- there is a faint click from
- the drive as it sleeps, or after a few seconds without disk activity.
-
- I think the "DON'T MOVE IN SLEEP MODE" warnings are due to the possibility
- of waking the hard drive accidently -- not because of unparked heads (which
- again, would already have done the damage when the disk stopped spinning).
-
- --
- /* Dale Southard Jr. Sr. Rigger */
- /* University of Toledo AFF/I SL/I */
- /* dsouth@uoft02.utoledo.edu D-11216 */
- /* Department of Chemistry -- "Just another skydiving grad student." */
-