Groups > sci.electronics.design > #453355

Re: big drives

From	Don Y <blockedofcourse@foo.invalid>
Newsgroups	sci.electronics.design
Subject	Re: big drives
Date	2017-03-24 01:31 -0700
Organization	A noiseless patient Spider
Message-ID	<ob2lb8$3a5$1@dont-email.me> (permalink)
References	<rpn2dc9nqndp7glvfi5pdedb8ujgmf7pln@4ax.com> <fPqdnafUM7f-00nFnZ2dnUU7-c-dnZ2d@earthlink.com> <ob1kua$u3q$1@dont-email.me> <s1l9dcdfp3uc4rnfdu8bt7g64r70ff0ggo@4ax.com>

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On 3/24/2017 1:14 AM, upsidedown@downunder.com wrote:
> On Thu, 23 Mar 2017 16:18:12 -0700, Don Y
> <blockedofcourse@foo.invalid> wrote:
>
>> On 3/23/2017 3:38 PM, Michael A. Terrell wrote:
>>> John Larkin wrote:
>>>>
>>>> I just happened to open my recycle bin and there was 42 Gbytes of
>>>> junk.
>>>>
>>>> I remember 256 Kbyte hard drives.
>>>
>>>    Don't you mean a floppy drive?
>>
>> My first *hard* disk had a capacity of 256K words (words were 12b).
>> The "disk" (i.e., the actual storage medium) weighted 100 pounds.
>> The (single) platter was 14 inches in diameter, IIRC.  There were
>> 16? head assemblies arranged around the drive -- the only access
>> delay was rotational (wait for the data to move under the appropriate
>> head; no need to MOVE the heads!)
>
> With multiple heads on a single surface sounds like a "cache" disk in
> which you stored frequently used files (such as program or parameter
> files) while the actual bulk (application) data was stored on disks
> with much greater capacity.

No, just old technology.  I.e., the head assemblies were large enough to
be visible with naked eye.  It takes a lot less engineering to make a
fixed head drive than to design an actuator to position the movable
head assembly (no servos involved).  For a fixed head disk, you only
worry about rotation delays to access the desired word (the controller
had a 20 bit "address register" that allowed you to select the starting
address of a 1MW disk subsystem with one word granularity so you could
treat it as "slow RAM")

And, when you're dealing with a machine that has 4096 words of "memory",
256K words is *huge*!

(e.g., the same multiplier applied to a 64K address space would yield
4M addresses -- a fair size for a winchester on something like an early
Z80, 10 years later!)

> I have used some single platter 14" removable disks with about 1 MB
> capacity, but they were only a few kilograms.

Thread

big drives John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-21 10:21 -0700
  Re: big drives bitrex <bitrex@de.lete.earthlink.net> - 2017-03-21 13:47 -0400
    Re: big drives George Herold <gherold@teachspin.com> - 2017-03-21 12:42 -0700
      Re: big drives dagmargoodboat@yahoo.com - 2017-03-21 12:55 -0700
        Re: big drives George Herold <gherold@teachspin.com> - 2017-03-21 13:37 -0700
          Re: big drives bill.sloman@ieee.org - 2017-03-21 21:51 -0700
            Re: big drives George Herold <gherold@teachspin.com> - 2017-03-22 07:26 -0700
  Re: big drives Winfield Hill <hill@rowland.harvard.edu> - 2017-03-22 03:38 -0700
    Re: big drives Don Kuenz <g@crcomp.net> - 2017-03-22 14:23 +0000
      Re: big drives David Brown <david.brown@hesbynett.no> - 2017-03-22 16:43 +0100
        Re: big drives Don Kuenz <g@crcomp.net> - 2017-03-22 18:35 +0000
          Re: big drives David Brown <david.brown@hesbynett.no> - 2017-03-23 10:24 +0100
            Re: big drives Don Kuenz <g@crcomp.net> - 2017-03-23 16:11 +0000
              Re: big drives krw@notreal.com - 2017-03-23 13:05 -0400
                Re: big drives Don Kuenz <g@crcomp.net> - 2017-03-23 17:39 +0000
                Re: big drives krw@notreal.com - 2017-03-23 21:05 -0400
                Re: big drives Don Kuenz <g@crcomp.net> - 2017-03-24 03:01 +0000
                Re: big drives krw@notreal.com - 2017-03-23 23:09 -0400
                Re: big drives Don Kuenz <g@crcomp.net> - 2017-03-24 04:15 +0000
                Re: big drives krw@notreal.com - 2017-03-24 22:34 -0400
      Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-22 12:25 -0700
        Re: big drives dplatt@coop.radagast.org (Dave Platt) - 2017-03-22 13:57 -0700
          Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-22 16:03 -0700
        Re: big drives krw@notreal.com - 2017-03-22 20:29 -0400
  Re: big drives tabbypurr@gmail.com - 2017-03-22 04:36 -0700
    Re: big drives Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> - 2017-03-22 08:57 -0400
      Re: big drives Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-03-22 11:59 -0400
        Re: big drives krw@notreal.com - 2017-03-22 13:23 -0400
          Re: big drives Jon Elson <jmelson@wustl.edu> - 2017-03-22 16:38 -0500
            Re: big drives krw@notreal.com - 2017-03-22 20:31 -0400
            Re: big drives gray_wolf <g_wolf@nospam.com> - 2017-03-23 20:59 -0500
            Re: big drives gray_wolf <g_wolf@nospam.com> - 2017-03-23 21:00 -0500
        Re: big drives Robert Baer <robertbaer@localnet.com> - 2017-03-23 22:21 -0800
    Re: big drives John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-22 07:51 -0700
      Re: big drives krw@notreal.com - 2017-03-22 13:23 -0400
      Re: big drives Robert Baer <robertbaer@localnet.com> - 2017-03-23 22:19 -0800
      Re: big drives tabbypurr@gmail.com - 2017-03-24 04:26 -0700
        Re: big drives John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-24 08:38 -0700
    Re: big drives Jon Elson <jmelson@wustl.edu> - 2017-03-22 16:37 -0500
      Re: big drives John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-22 16:07 -0700
        Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-22 16:21 -0700
          Re: big drives John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-22 16:45 -0700
            Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-22 23:21 -0700
              Re: big drives John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-24 13:06 -0700
                Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-24 16:56 -0700
                Re: big drives John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-24 17:35 -0700
                Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-24 21:47 -0700
      Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-22 16:19 -0700
        Re: big drives John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-22 16:50 -0700
          Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-22 17:58 -0700
            Re: big drives John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-22 21:00 -0700
              Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-22 22:50 -0700
                Re: big drives John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-23 08:27 -0700
                Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-23 12:25 -0700
      Re: big drives tabbypurr@gmail.com - 2017-03-24 04:31 -0700
        Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-24 06:38 -0700
          Re: big drives John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-24 08:41 -0700
            Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-24 11:38 -0700
              Re: big drives John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-24 13:55 -0700
              Re: big drives tabbypurr@gmail.com - 2017-03-24 17:14 -0700
                Re: big drives John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-24 17:41 -0700
                Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-24 18:00 -0700
  Re: big drives Joerg <news@analogconsultants.com> - 2017-03-23 09:35 -0700
  Re: big drives "Michael A. Terrell" <mike.terrell@earthlink.net> - 2017-03-23 18:38 -0400
    Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-23 16:18 -0700
      Re: big drives Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-03-23 18:29 -0400
        Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-23 18:38 -0700
          Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-23 18:54 -0700
            Re: big drives pcdhobbs@gmail.com - 2017-03-23 19:16 -0700
              Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-23 19:28 -0700
                Re: big drives pcdhobbs@gmail.com - 2017-03-23 19:55 -0700
                Re: big drives krw@notreal.com - 2017-03-23 23:04 -0400
                Re: big drives pcdhobbs@gmail.com - 2017-03-23 22:00 -0700
                Re: big drives John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-24 08:46 -0700
                Re: big drives krw@notreal.com - 2017-03-24 22:38 -0400
                Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-23 22:22 -0700
                Re: big drives pcdhobbs@gmail.com - 2017-03-23 23:08 -0700
                Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-24 00:21 -0700
                Re: big drives John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-24 09:00 -0700
                Re: big drives David Brown <david.brown@hesbynett.no> - 2017-03-24 17:14 +0100
                Re: big drives tabbypurr@gmail.com - 2017-03-24 09:19 -0700
                Re: big drives David Brown <david.brown@hesbynett.no> - 2017-03-24 17:47 +0100
                Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-24 12:01 -0700
                Re: big drives Jasen Betts <jasen@xnet.co.nz> - 2017-03-24 20:30 +0000
                Re: big drives John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-24 14:06 -0700
                Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-24 11:55 -0700
                Re: big drives "Michael A. Terrell" <mike.terrell@earthlink.net> - 2017-03-25 04:00 -0400
                Re: big drives upsidedown@downunder.com - 2017-03-24 22:18 +0200
                Re: big drives John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-24 14:15 -0700
                Re: big drives Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-03-25 13:21 +0200
                Re: big drives John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-25 07:54 -0700
                Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-25 10:53 -0700
                Re: big drives upsidedown@downunder.com - 2017-03-25 23:11 +0200
                Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-25 15:14 -0700
                Re: big drives upsidedown@downunder.com - 2017-03-26 12:18 +0300
                Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-26 03:33 -0700
                Re: big drives Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-03-26 16:36 -0400
                Re: big drives John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-26 14:13 -0700
                Re: big drives Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-03-25 21:04 +0200
                Re: big drives pcdhobbs@gmail.com - 2017-03-24 19:03 -0700
                Re: big drives John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-24 08:53 -0700
                Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-24 12:12 -0700
                Re: big drives John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-24 14:20 -0700
                Re: big drives krw@notreal.com - 2017-03-24 22:43 -0400
                Re: big drives John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-24 20:10 -0700
                Re: big drives krw@notreal.com - 2017-03-24 23:23 -0400
                Re: big drives John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-24 22:25 -0700
                Re: big drives Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-03-25 13:23 +0200
        Re: big drives John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-23 19:36 -0700
      Re: big drives upsidedown@downunder.com - 2017-03-24 10:14 +0200
        Re: big drives Don Y <blockedofcourse@foo.invalid> - 2017-03-24 01:31 -0700
    Re: big drives John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-23 16:21 -0700
      Re: big drives "Michael A. Terrell" <mike.terrell@earthlink.net> - 2017-03-24 08:54 -0400

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