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Re: modern computers and S/360 model 20

From Dan Espen <dan1espen@gmail.com>
Newsgroups alt.folklore.computers
Subject Re: modern computers and S/360 model 20
Date 2020-08-30 20:37 -0400
Organization A noiseless patient Spider
Message-ID <rihgnt$6f5$1@dont-email.me> (permalink)
References (1 earlier) <rigrfd$qq3$1@gal.iecc.com> <rih00v$455$1@dont-email.me> <rih7vu$23ak$2@gal.iecc.com> <rih9d2$55n$1@dont-email.me> <egaokflor3k3ab094chdj2vsn5osm6ajph@4ax.com>

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J. Clarke <jclarke.873638@gmail.com> writes:

> On Sun, 30 Aug 2020 18:32:02 -0400, Dan Espen <dan1espen@gmail.com>
> wrote:
>
>>John Levine <johnl@taugh.com> writes:
>>
>>> In article <rih00v$455$1@dont-email.me>,
>>> Dan Espen  <dan1espen@gmail.com> wrote:
>>>>I found the variable block sizes a real problem.
>>>>If you pick a really large block size for the benefit of one
>>>>program, all the other programs reading that file must use the
>>>>same block size.  Which could be a problem if a program is storage
>>>>constrained.  Back in the 14xx days one program might read one sector
>>>>at a time, another might attempt to read the whole cylinder.
>>>>
>>>>It looks like IBM has tried to adapt using 4K blocks with VSAM and PDS/E.
>>>
>>> Not at all by coincidence, 4K is also the virtual memory page size.
>>> Modern operating systems treat file I/O and paging together, moving
>>> data back and forth between disk and main memory as needed.
>>
>>Yes, I was going to try to get into that.
>>As I understand it, IBM has an array of buffering techniques in play,
>>DB2 has something, IMS has something, they're all over the place.
>>
>>Unix deals with it at a single level, the entire filesystem gets cached
>>as best it can.
>>
>>I don't know if IBM is trying to consciously move toward that or not.
>
> There's also the matter that 4K is the physical sector size on
> virtually all disks currently in production.
>
> Seagate provides a discussion of that transition here:
> <https://www.seagate.com/tech-insights/advanced-format-4k-sector-hard-drives-master-ti/>

I'm reading this and thinking, hey this is pretty interesting.

Then I realize my last hard drive went out of service 2 or 3 years ago.

Hard drive, meet punched card.

-- 
Dan Espen

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Thread

S/360 model 20 Dan Espen <dan1espen@gmail.com> - 2020-08-30 00:27 -0400
  Re: S/360 model 20 John Levine <johnl@taugh.com> - 2020-08-30 18:34 +0000
    Re: S/360 model 20 Dan Espen <dan1espen@gmail.com> - 2020-08-30 15:51 -0400
      Re: modern computers and S/360 model 20 John Levine <johnl@taugh.com> - 2020-08-30 22:07 +0000
        Re: modern computers and S/360 model 20 Dan Espen <dan1espen@gmail.com> - 2020-08-30 18:32 -0400
          Re: modern computers and S/360 model 20 J. Clarke <jclarke.873638@gmail.com> - 2020-08-30 18:38 -0400
            Re: modern computers and S/360 model 20 Dan Espen <dan1espen@gmail.com> - 2020-08-30 20:37 -0400
        Re: modern computers and S/360 model 20 Bob Eager <news0073@eager.cx> - 2020-08-31 08:54 +0000
          Re: paging, modern computers and S/360 model 20 John Levine <johnl@taugh.com> - 2020-08-31 16:36 +0000
            Re: paging, modern computers and S/360 model 20 scott@slp53.sl.home (Scott Lurndal) - 2020-08-31 16:57 +0000
            Re: paging, modern computers and S/360 model 20 Bob Eager <news0073@eager.cx> - 2020-08-31 17:21 +0000
              Re: paging, modern computers and S/360 model 20 scott@slp53.sl.home (Scott Lurndal) - 2020-08-31 18:10 +0000
              Re: paging, modern computers and S/360 model 20 Quadibloc <jsavard@ecn.ab.ca> - 2020-08-31 16:10 -0700
                Re: paging, modern computers and S/360 model 20 Bob Eager <news0073@eager.cx> - 2020-09-01 14:14 +0000
                Re: paging, modern computers and S/360 model 20 Bill Findlay <findlaybill@blueyonder.co.uk> - 2020-09-01 17:41 +0100
                Re: paging, modern computers and S/360 model 20 Bob Eager <news0073@eager.cx> - 2020-09-02 08:34 +0000
          Re: modern computers and S/360 model 20 usenet@only.tnx (Questor) - 2020-09-02 07:04 +0000
    Re: S/360 model 20 Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2020-09-01 04:40 +0000
      Re: S/360 model 20 Quadibloc <jsavard@ecn.ab.ca> - 2020-08-31 22:10 -0700
        Re: S/360 model 20 Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2020-09-01 19:09 +0000
          Re: S/360 model 20 Dan Espen <dan1espen@gmail.com> - 2020-09-01 15:41 -0400
            Re: S/360 model 20 Jon Elson <elson@pico-systems.com> - 2020-09-03 10:44 -0500
              Re: S/360 model 20 Dan Espen <dan1espen@gmail.com> - 2020-09-03 11:51 -0400
                Re: S/360 model 20 Niklas Karlsson <anksil@yahoo.se> - 2020-09-03 16:41 +0000
              Re: S/360 model 20 J. Clarke <jclarke.873638@gmail.com> - 2020-09-03 12:46 -0400
                Re: S/360 model 20 drb@ihatespam.msu.edu (Dennis Boone) - 2020-09-03 13:32 -0500
                Re: S/360 model 20 Dan Espen <dan1espen@gmail.com> - 2020-09-03 14:44 -0400
                Re: staying up, S/360 model 20 John Levine <johnl@taugh.com> - 2020-09-03 22:28 +0000
          Re: S/360 model 20 hancock4@bbs.cpcn.com - 2020-09-03 11:09 -0700
            Re: S/360 model 20 Peter Flass <peter_flass@yahoo.com> - 2020-09-03 11:48 -0700
            Re: S/360 model 20 Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2020-09-03 19:49 +0000
              Re: S/360 model 20 Dave Garland <dave.garland@wizinfo.com> - 2020-09-04 10:06 -0500
                Re: S/360 model 20 Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2020-09-04 16:13 +0000
            Re: S/360 model 20 J. Clarke <jclarke.873638@gmail.com> - 2020-09-03 17:30 -0400
            Re: S/360 model 20 John Levine <johnl@taugh.com> - 2020-09-03 22:55 +0000
            Re: S/360 model 20 Robin Vowels <robin.vowels@gmail.com> - 2020-09-03 19:44 -0700
              Re: S/360 model 20 Quadibloc <jsavard@ecn.ab.ca> - 2020-09-04 23:27 -0700
      Re: S/360 model 20 hancock4@bbs.cpcn.com - 2020-09-01 11:03 -0700
      Re: S/360 model 20 Jon Elson <elson@pico-systems.com> - 2020-09-03 10:42 -0500
        Re: S/360 model 20 hancock4@bbs.cpcn.com - 2020-09-03 11:12 -0700
          Re: S/360 model 20 Peter Flass <peter_flass@yahoo.com> - 2020-09-03 11:48 -0700
          Re: S/360 model 20 Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2020-09-03 19:49 +0000
            Re: S/360 model 20 hancock4@bbs.cpcn.com - 2020-09-10 11:37 -0700
              Re: S/360 model 20 Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2020-09-10 23:34 +0000
                Re: S/360 model 20 Peter Flass <peter_flass@yahoo.com> - 2020-09-10 18:06 -0700
                Re: S/360 model 20 Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2020-09-11 20:41 +0000
                Re: S/360 model 20 Peter Flass <peter_flass@yahoo.com> - 2020-09-11 16:21 -0700
                Re: S/360 model 20 Terry Kennedy <terry-groups@glaver.org> - 2020-09-11 17:26 -0700
                Re: S/360 model 20 Bob Eager <news0073@eager.cx> - 2020-09-12 09:30 +0000
              Re: S/360 model 20 Quadibloc <jsavard@ecn.ab.ca> - 2020-09-10 20:39 -0700
                Re: S/360 model 20 Quadibloc <jsavard@ecn.ab.ca> - 2020-09-10 20:46 -0700
          Re: S/360 model 20 J. Clarke <jclarke.873638@gmail.com> - 2020-09-03 17:41 -0400
    Re: S/360 model 20 hancock4@bbs.cpcn.com - 2020-09-01 11:00 -0700
      Re: S/360 model 20 Quadibloc <jsavard@ecn.ab.ca> - 2020-09-01 17:05 -0700
        Re: S/360 model 20 J. Clarke <jclarke.873638@gmail.com> - 2020-09-01 20:25 -0400
          Re: S/360 model 20 Quadibloc <jsavard@ecn.ab.ca> - 2020-09-10 20:44 -0700
            Re: S/360 model 20 J. Clarke <jclarke.873638@gmail.com> - 2020-09-11 00:30 -0400
              Re: S/360 model 20 Peter Flass <peter_flass@yahoo.com> - 2020-09-11 06:48 -0700
              Re: S/360 model 20 drb@ihatespam.msu.edu (Dennis Boone) - 2020-09-11 11:02 -0500
                Re: S/360 model 20 Peter Flass <peter_flass@yahoo.com> - 2020-09-11 11:18 -0700
              Re: S/360 model 20 "Kerr-Mudd,John" <notsaying@127.0.0.1> - 2020-10-03 10:29 +0000
                Re: S/360 model 20 Peter Flass <peter_flass@yahoo.com> - 2020-10-03 07:38 -0700
                Re: S/360 model 20 scott@slp53.sl.home (Scott Lurndal) - 2020-10-03 16:17 +0000
                Re: S/360 model 20 drb@ihatespam.msu.edu (Dennis Boone) - 2020-10-04 11:24 -0500
        Re: S/360 model 20 Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2020-09-02 00:50 +0000
      Re: S/360 model 20 Jon Elson <elson@pico-systems.com> - 2020-09-03 10:51 -0500

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