[comp.sys.ibm.pc] Do ST251/4096 have auto-parking mechanism?

yao@euler.uucp (Wei-Hsin Yao) (03/31/89)

Hi, folks, thanks for your help about the information
of Seagate ST225/4096.  I think some of you might
be interested in this information:

Mark davis@cs.uncc.edu said:
|Both  251 and 4096 have auto-park.  There are important differences
|though.  The 251 has a stepper motor.  The 4096 has a voice coil 
|mechanism, which is superior technology, is quieter, etc.

irish@Sun.COM said: 
|ST251 did not have shock mounts.  ST 251 failed Power Cycling.

Adam ads4@tank.uchicago.edu wrote:
|I own an ST251-1 and enjoy it immensely (I run a BBs off of that and a ST225)

air@anableps.berkeley.edu sent me the following information:

|PART #		STORAGE		SPEED		PRICE
|		IN		IN
|		MEGABYTES	MILISECONDS	
|ST225		21.4		65		299
|ST125		21.4		40		339
|ST125-1	21.4		28		399
|ST251		42.8		38		499
|ST251-1	42.8		28		559
|ST4096		80		28		799	FULL HEIGHT
|
|                           st251  and    st4096
|recoverable read errors   1per10^10 bits read  
|nonrecoverable read errors 1per10^12 bits read
|seek errors              1per 10^6 seeks
|Service life:  Five years

john@wa3wbu.uu.net said: 
|Both the ST-251 & ST-4096 are auto-parking. They park in different
|ways however. The ST-251 uses a stepper-motor positioner. When you
|remove power it automatically starts rotating the heads toward the inner
|hub. Once they reach the hub, a stopper bangs against a stop until the power
|dies off. This takes about 3 seconds and produces a slight vibrating sound
|which is perfectly normal and does not harm the drive.
|
|   The ST-4096 uses a voice-coil positioner. When power is removed from
|this drive a stored pulse throws the carraige/head mechanism out to the
|inner-most cylinder and a electro-magnet latch locks them there. When
|you power up the drive the next time, the selenoid releases and allows
|the heads to be free again.

Greg ccastgw@prism.gatech.edu said:
|Both the 251-1 and 4096 have auto-park on power off.  As far as reliability
|goes, I can't really say.  They're sure to be better than the 238R.
|(I just recovered from my first crash on it yesterday.  Not fun.)


I myself have a Seagate 225 for about one year, not many complaints,
just too slow.  I tried some software, the acess time of my ST225
is about 80 ms, especially when I run LaTeX.....
Anyway, I think I will not only consider Seagate's HD, but also
Toshiba or Mitsubishi's.

Again, Thanks for all your help!

Wei
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   Wei Hsin  YAO                    Internet: yao@euler.berkeley.edu
				
   Dept of ME, UC Berkeley          Phone #:(415) 642-0935
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