pam1@ra.MsState.Edu (Phillip A. McReynolds) (10/27/90)
After recently running optimize for QEMM, I found that I could not park my hard drive heads (ST238R drive with ST11 controller) since something no longer recognized my controller type. Is there much serious danger in leaving my heads unparked? What is the reason for this monkey-business anyway? Is there a way around this problem (without giving up the convenient ability to load TSR's into high memory)? = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Phillip A. McReynolds, sophist@brainiac.raidernet.com Licensed Philosopher org: Phillip's Philosophy Shop, Inc. (MPA Certified) "Quality Philosophy Products Since 1990" = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
buck@granite.cr.bull.com (Kenneth J. Buck) (10/29/90)
In article <795@ra.MsState.Edu> pam1@ra.MsState.Edu (Phillip A. McReynolds) writes: >Is there much serious danger in leaving my heads unparked? This brings up a more general question upon which I am uninformed. Do some/all/none hard drives in use these days support autoparking heads, or is it still something that must be done manually? It seems that this is something which should be able to be done automatically upon machine shutdown (when the drive or controller detects power loss, or something). I would have thought that by now, all drives would do this. What is the _real_ story here, please?
poffen@sj.ate.slb.com (Russ Poffenberger) (10/30/90)
In article <795@ra.MsState.Edu> pam1@ra.MsState.Edu (Phillip A. McReynolds) writes: >After recently running optimize for QEMM, I found that I could not park my >hard drive heads (ST238R drive with ST11 controller) since something no >longer recognized my controller type. > >Is there much serious danger in leaving my heads unparked? > >What is the reason for this monkey-business anyway? Is there a way around >this problem (without giving up the convenient ability to load TSR's into >high memory)? > When I ran optimize in QEMM, it hung up my system on the third pass, and trashed part of my CMOS setting. I had to re-program my CMOS to get things working. Russ Poffenberger DOMAIN: poffen@sj.ate.slb.com Schlumberger Technologies UUCP: {uunet,decwrl,amdahl}!sjsca4!poffen 1601 Technology Drive CIS: 72401,276 San Jose, Ca. 95110 (408)437-5254
jcburt@ipsun.larc.nasa.gov (John Burton) (10/30/90)
In article <1990Oct29.143743.23911@granite.cr.bull.com> buck@granite.cr.bull.com (Kenneth J. Buck) writes: >In article <795@ra.MsState.Edu> pam1@ra.MsState.Edu > (Phillip A. McReynolds) writes: >>Is there much serious danger in leaving my heads unparked? > >This brings up a more general question upon which I am uninformed. >Do some/all/none hard drives in use these days support autoparking heads, or >is it still something that must be done manually? > >It seems that this is something which should be able to be done automatically >upon machine shutdown (when the drive or controller detects power loss, or >something). I would have thought that by now, all drives would do this. > >What is the _real_ story here, please? The *real* story is the differences in technologies... The answer to your head parking question is yes and no... There are two basic technologies for head positioning, stepper motor and voice coil. Stepper motor head positioning is the cheapest and is used on most of the lower priced hard disks. When the power goes off, the heads just stay where they are, unless additional hardware is used to pull the heads back to their parking space (unlikely). Voice coil is more expensive (but IMHO well worth the extra price) and by default autoparks the heads on power down (when the power is removed from the voice coil, an electromagnet, the heads move back to a base position). If you can afford it, voice coil head positioning is the way to go. You get automatic head parking and you *don't* have the problems of head misalignement due to thermal expansion of the platters that can occur with stepper motor. Many disk technicians suggest regular low level formatting of stepper motor disks as a preventive maintenance. With voice coil, its not needed. just my thoughts on the subject... John Burton (jcburt@cs.wm.edu) (jcburt@ipsun.larc.nasa.gov)