Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!ux1.cso.uiuc.edu!tank!ncar!asuvax!mcdphx!mcdchg!ddsw1!ddsw1!karl
From: karl@ddsw1.MCS.COM (Karl Denninger)
Newsgroups: comp.sys.ibm.pc
Subject: Re: COBOL, power cycles, and hard disks
Keywords: COBOL for PCs, acceptable power cycling, manual disk parking
Message-ID: <[25451d0c:6247.3]comp.ibmpc;1@ddsw1.MCS.COM>
Date: 25 Oct 89 03:00:04 GMT
References: <4005@cbnewsc.ATT.COM> <6626@pt.cs.cmu.edu>
Lines: 29

>-----
>Response 2 of 2 (6247) by ralf at b.gp.cs.cmu.edu on Tue 24 Oct 89 17:24
>[Ralf Brown]
>(13 lines)
>
>In article <4267@ncsuvx.ncsu.edu> unkydave@shumv1.ncsu.edu (David Bank)
>writes:
>}depends on the hard disk. Check with the manufacturer to find
>}out. Generally speaking, RLL drives are intrinsically auto-park,
>}while most MFM drives are not.
>
>My MFM ST4051 is most definitely autopark.  I think the deciding factor is
>whether the head positioner is a stepper motor (nonparking) or voice coil
>(autoparking).

Not true.  The difference is whether the maker decided to make the drive
autopark, and has little relevance other than that.

Seagate drives 40MB and up (251, 277R, etc) all autopark.  4038's autopark. 
MOST smaller drives do NOT autopark (238, 225, etc).

I have never seen a voice-coil positioner that did not autopark, so you can
use that as a guide.  It is not a tell-all, however, as the 251/277R series
of Seagates is definately a stepper device, and it DOES park the heads when
the power is turned off.

--
Karl Denninger (karl@ddsw1.MCS.COM, <well-connected>!ddsw1!karl)
Public Access Data Line: [+1 312 566-8911], Voice: [+1 312 566-8910]
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