Groups | Search | Server Info | Keyboard shortcuts | Login | Register


Groups > comp.sys.dec > #530

Re: Y3K for PDP-11 Operating Systems

From Rich Alderson <news@alderson.users.panix.com>
Newsgroups alt.sys.pdp11, comp.sys.dec, vmsnet.pdp-11
Subject Re: Y3K for PDP-11 Operating Systems
Date 2011-05-27 14:51 -0400
Organization PANIX Public Access Internet and UNIX, NYC
Message-ID <mddvcwwou3u.fsf@panix5.panix.com> (permalink)
References (11 earlier) <mddk4de2s77.fsf@panix5.panix.com> <irka34$sqr$1@dont-email.me> <mddvcwxkylh.fsf@panix5.panix.com> <irmpml$rm0$2@dont-email.me> <irn54h$87p$1@Iltempo.Update.UU.SE>

Cross-posted to 3 groups.

Show all headers | View raw


Johnny Billquist <bqt@softjar.se> writes:

> You are all missing the point with regards to disks here. It don't 
> matter what the OS presents you with. That is an abstraction layer. The 
> actual, physical disk use disk blocks. Not a stream of bytes. (Well, 
> there were actually some disks in the old days who almost did, but that 
> is another story, and besides, it's not totally a stream of bytes even 
> for those).

No, as a matter of fact, we are *not* missing the point:  Disk access is
in blocks.  On the PDP-10 under Tops-10, TOPS-20 and TENEX (and probably
ITS, those blocks are 128 words long (plus some overhead for parity,
checksums and the like that are invisible to the programmer), while on
IBM System/360 family systems, the size of the block is under programmer
control but is still the addressable unit of storage on the disk.

The abstraction layer from the OS may or may not hide block size from you.
Tops-10, for example, does not.  TENEX/TOPS-20 presents disk data to the
programmer in 512-word (4 block) pages (or in bytes or byte-strings or
integers or floating-point numbers, depending on system call, but the OS
buffers are in pages).

Prior to the introduction of virtual memory to IBM's computers, the OS
never hid the block size from you.  With the advent of VSAM (Virtual
Storage Access Method), disks could be blocked at something other than
the programmer's whim, though the older access methods could still be
used as well.

But in none of these cases does the OS force the view of a disk as a
stream of bytes.

-- 
Rich Alderson                                   news@alderson.users.panix.com
    the russet leaves of an autumn oak/inspire once again the failed poet/
    to take up his pen/and essay to place his meagre words upon the page...

Back to comp.sys.dec | Previous | NextPrevious in thread | Next in thread | Find similar


Thread

Y3K for PDP-11 Operating Systems "Jerome H. Fine" <everyone@nospam.com> - 2011-04-04 09:12 -0400
  Re: Y3K for PDP-11 Operating Systems billy@MIX.COM - 2011-04-30 22:27 +0000
    Re: Y3K for PDP-11 Operating Systems "Jerome H. Fine" <everyone@nospam.com> - 2011-05-01 10:01 -0400
      Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-01 10:27 -0700
        Re: Y3K for PDP-11 Operating Systems "Jerome H. Fine" <everyone@nospam.com> - 2011-05-01 20:53 -0400
  Re: Y3K for PDP-11 Operating Systems glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2011-05-01 21:16 +0000
    Re: Y3K for PDP-11 Operating Systems "Jerome H. Fine" <everyone@nospam.com> - 2011-05-01 20:54 -0400
      Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-01 21:07 -0700
        Re: Y3K for PDP-11 Operating Systems "Jerome H. Fine" <everyone@nospam.com> - 2011-05-02 09:37 -0400
          Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-02 08:39 -0700
      Re: Y3K for PDP-11 Operating Systems glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2011-05-02 05:15 +0000
  Re: Y3K for PDP-11 Operating Systems jjh <jjhudak@gmail.com> - 2011-05-02 18:20 -0700
    Re: Y3K for PDP-11 Operating Systems koehler@eisner.nospam.encompasserve.org (Bob Koehler) - 2011-05-03 08:18 -0500
      Re: Y3K for PDP-11 Operating Systems "Jerome H. Fine" <everyone@nospam.com> - 2011-05-03 12:51 -0400
        VAXTREK koehler@eisner.nospam.encompasserve.org (Bob Koehler) - 2011-05-03 12:50 -0500
        Re: Y3K for PDP-11 Operating Systems Henry Crun <mike@rechtman.com> - 2011-05-03 21:39 +0300
          Re: Y3K for PDP-11 Operating Systems "Jerome H. Fine" <everyone@nospam.com> - 2011-05-03 15:56 -0400
          Re: Y3K for PDP-11 Operating Systems onedbguru <onedbguru@yahoo.com> - 2011-05-03 15:52 -0700
            Re: Y3K for PDP-11 Operating Systems billig999@cs.uofs.edu (Bill Gunshannon) - 2011-05-04 00:07 +0000
              Re: Y3K for PDP-11 Operating Systems "Richard B. Gilbert" <rgilbert88@comcast.net> - 2011-05-04 01:16 -0400
                Re: Y3K for PDP-11 Operating Systems billg999@cs.uofs.edu (Bill Gunshannon) - 2011-05-04 13:01 +0000
                Re: Y3K for PDP-11 Operating Systems "Richard B. Gilbert" <rgilbert88@comcast.net> - 2011-05-04 10:19 -0400
                Re: Y3K for PDP-11 Operating Systems kludge@panix.com (Scott Dorsey) - 2011-05-04 10:58 -0400
                Re: Y3K for PDP-11 Operating Systems billg999@cs.uofs.edu (Bill Gunshannon) - 2011-05-04 16:33 +0000
                Re: Y3K for PDP-11 Operating Systems "Richard B. Gilbert" <rgilbert88@comcast.net> - 2011-05-04 21:51 -0400
                Re: Y3K for PDP-11 Operating Systems G Cornelius <cornelius@eisner.decus.org> - 2011-05-06 13:08 -0500
                Re: Y3K for PDP-11 Operating Systems "Richard B. Gilbert" <rgilbert88@comcast.net> - 2011-05-06 14:47 -0400
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@update.uu.se> - 2011-05-06 16:13 -0600
                Re: Y3K for PDP-11 Operating Systems Rich Alderson <news@alderson.users.panix.com> - 2011-05-07 21:00 -0400
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-07 19:51 -0600
                Re: Y3K for PDP-11 Operating Systems "Richard B. Gilbert" <rgilbert88@comcast.net> - 2011-05-08 07:19 -0400
                Re: Y3K for PDP-11 Operating Systems Rich Alderson <news@alderson.users.panix.com> - 2011-05-09 17:32 -0400
                Re: Y3K for PDP-11 Operating Systems Rob Brown <mylastname@gmcl.com> - 2011-05-09 09:40 -0600
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-09 09:43 -0600
                Re: Y3K for PDP-11 Operating Systems vandys@vsta.org - 2011-05-09 21:47 +0000
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-09 16:05 -0600
                Re: Y3K for PDP-11 Operating Systems vandys@vsta.org - 2011-05-09 23:05 +0000
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-09 17:20 -0600
                Re: Y3K for PDP-11 Operating Systems vandys@vsta.org - 2011-05-10 00:12 +0000
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-09 19:36 -0600
                Re: Y3K for PDP-11 Operating Systems glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2011-05-10 02:01 +0000
                Re: Y3K for PDP-11 Operating Systems koehler@eisner.nospam.encompasserve.org (Bob Koehler) - 2011-05-10 08:31 -0500
                Re: Y3K for PDP-11 Operating Systems John Wallace <johnwallace4@yahoo.co.uk> - 2011-05-10 09:56 -0700
                Re: Y3K for PDP-11 Operating Systems koehler@eisner.nospam.encompasserve.org (Bob Koehler) - 2011-05-10 12:50 -0500
                Re: Y3K for PDP-11 Operating Systems G Cornelius <cornelius@eisner.decus.org> - 2011-05-11 11:04 -0500
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-04 10:02 -0700
                Re: Y3K for PDP-11 Operating Systems koehler@eisner.nospam.encompasserve.org (Bob Koehler) - 2011-05-04 12:20 -0500
                Re: Y3K for PDP-11 Operating Systems glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2011-05-04 18:10 +0000
                Re: Y3K for PDP-11 Operating Systems John Wallace <johnwallace4@yahoo.co.uk> - 2011-05-04 12:21 -0700
                Re: Y3K for PDP-11 Operating Systems MetaEd <metaed@gmail.com> - 2011-05-04 15:06 -0700
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-04 20:17 -0700
                Re: Y3K for PDP-11 Operating Systems koehler@eisner.nospam.encompasserve.org (Bob Koehler) - 2011-05-10 08:20 -0500
                Re: Y3K for PDP-11 Operating Systems koehler@eisner.nospam.encompasserve.org (Bob Koehler) - 2011-05-10 08:29 -0500
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-10 09:29 -0600
                Re: Y3K for PDP-11 Operating Systems G Cornelius <cornelius@eisner.decus.org> - 2011-05-10 12:16 -0500
                Re: Y3K for PDP-11 Operating Systems koehler@eisner.nospam.encompasserve.org (Bob Koehler) - 2011-05-10 12:45 -0500
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-10 15:34 -0600
                Re: Y3K for PDP-11 Operating Systems koehler@eisner.nospam.encompasserve.org (Bob Koehler) - 2011-05-10 12:58 -0500
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-10 15:36 -0600
    Re: Y3K for PDP-11 Operating Systems "Jerome H. Fine" <everyone@nospam.com> - 2011-05-03 12:38 -0400
  Re: Y3K for PDP-11 Operating Systems paramucho@hotmail.com (paramucho) - 2011-05-03 11:28 +0000
    Re: Y3K for PDP-11 Operating Systems "Jerome H. Fine" <everyone@nospam.com> - 2011-05-03 12:09 -0400
    Re: Y3K for PDP-11 Operating Systems billy@MIX.COM - 2011-05-23 03:41 +0000
      Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-22 21:51 -0700
        Re: Y3K for PDP-11 Operating Systems jjh <jjhudak@gmail.com> - 2011-05-23 07:47 -0700
          Re: Y3K for PDP-11 Operating Systems billg999@cs.uofs.edu (Bill Gunshannon) - 2011-05-23 15:04 +0000
            Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-23 15:52 -0700
              Re: Y3K for PDP-11 Operating Systems billg999@cs.uofs.edu (Bill Gunshannon) - 2011-05-24 00:16 +0000
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-23 17:40 -0700
                Re: Y3K for PDP-11 Operating Systems billg999@cs.uofs.edu (Bill Gunshannon) - 2011-05-24 12:58 +0000
                Re: Y3K for PDP-11 Operating Systems glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2011-05-24 14:02 +0000
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-24 07:36 -0700
                Re: Y3K for PDP-11 Operating Systems billg999@cs.uofs.edu (Bill Gunshannon) - 2011-05-24 16:42 +0000
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-24 11:17 -0700
                Re: Y3K for PDP-11 Operating Systems billg999@cs.uofs.edu (Bill Gunshannon) - 2011-05-24 20:07 +0000
                Re: Y3K for PDP-11 Operating Systems Rich Alderson <news@alderson.users.panix.com> - 2011-05-24 21:07 -0400
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-25 03:34 -0700
                Re: Y3K for PDP-11 Operating Systems billg999@cs.uofs.edu (Bill Gunshannon) - 2011-05-25 15:46 +0000
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-25 16:00 -0700
                Re: Y3K for PDP-11 Operating Systems Fritz Wuehler <fritz@spamexpire-201105.rodent.frell.theremailer.net> - 2011-05-26 17:50 +0200
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-26 09:53 -0700
                Re: Y3K for PDP-11 Operating Systems Fritz Wuehler <fritz@spamexpire-201105.rodent.frell.theremailer.net> - 2011-05-26 22:20 +0200
                Re: Y3K for PDP-11 Operating Systems billg999@cs.uofs.edu (Bill Gunshannon) - 2011-05-28 18:01 +0000
                Re: Y3K for PDP-11 Operating Systems Rich Alderson <news@alderson.users.panix.com> - 2011-05-25 20:58 -0400
                Re: Y3K for PDP-11 Operating Systems glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2011-05-26 01:23 +0000
                Re: Y3K for PDP-11 Operating Systems koehler@eisner.nospam.encompasserve.org (Bob Koehler) - 2011-05-26 08:01 -0500
                Re: Y3K for PDP-11 Operating Systems glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2011-05-27 00:54 +0000
                Re: Y3K for PDP-11 Operating Systems Rich Alderson <news@alderson.users.panix.com> - 2011-05-26 16:15 -0400
                Re: Y3K for PDP-11 Operating Systems glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2011-05-26 23:56 +0000
                Re: Y3K for PDP-11 Operating Systems Rich Alderson <news@alderson.users.panix.com> - 2011-05-27 14:37 -0400
                Re: Y3K for PDP-11 Operating Systems glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2011-05-27 00:02 +0000
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-26 20:17 -0700
                Re: Y3K for PDP-11 Operating Systems Rich Alderson <news@alderson.users.panix.com> - 2011-05-27 14:51 -0400
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-27 12:48 -0700
                Re: Y3K for PDP-11 Operating Systems Rich Alderson <news@alderson.users.panix.com> - 2011-05-27 14:35 -0400
                Re: Y3K for PDP-11 Operating Systems "Jerome H. Fine" <everyone@nospam.com> - 2011-05-25 21:14 -0400
                Re: Y3K for PDP-11 Operating Systems glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2011-05-26 01:32 +0000
                Re: Y3K for PDP-11 Operating Systems "Jerome H. Fine" <everyone@nospam.com> - 2011-05-26 16:39 -0400
                Re: Y3K for PDP-11 Operating Systems Fritz Wuehler <fritz@spamexpire-201105.rodent.frell.theremailer.net> - 2011-05-26 17:50 +0200
                Re: Y3K for PDP-11 Operating Systems Rich Alderson <news@alderson.users.panix.com> - 2011-05-24 21:01 -0400
                Re: Y3K for PDP-11 Operating Systems koehler@eisner.nospam.encompasserve.org (Bob Koehler) - 2011-05-26 07:53 -0500
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-26 09:59 -0700
                Re: Y3K for PDP-11 Operating Systems Fritz Wuehler <fritz@spamexpire-201105.rodent.frell.theremailer.net> - 2011-05-26 10:03 +0200
                Re: Y3K for PDP-11 Operating Systems paramucho@hotmail.com (paramucho) - 2011-05-26 14:21 +0000
                Re: Y3K for PDP-11 Operating Systems billy@MIX.COM - 2011-05-26 18:50 +0000
                Re: Y3K for PDP-11 Operating Systems paramucho@hotmail.com (paramucho) - 2011-05-27 11:58 +0000
                Re: Y3K for PDP-11 Operating Systems billy@MIX.COM - 2011-05-27 17:23 +0000
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-26 10:04 -0700
                Re: Y3K for PDP-11 Operating Systems Fritz Wuehler <fritz@spamexpire-201105.rodent.frell.theremailer.net> - 2011-05-27 03:30 +0200
                Re: Y3K for PDP-11 Operating Systems kludge@panix.com (Scott Dorsey) - 2011-05-26 22:17 -0400
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-26 20:26 -0700
                Re: Y3K for PDP-11 Operating Systems John Wallace <johnwallace4@yahoo.co.uk> - 2011-05-30 14:09 -0700
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-30 18:15 -0700
                Re: Y3K for PDP-11 Operating Systems jjh <jjhudak@gmail.com> - 2011-05-31 11:02 -0700
                Re: Y3K for PDP-11 Operating Systems koehler@eisner.nospam.encompasserve.org (Bob Koehler) - 2011-05-31 15:54 -0500
                Re: Y3K for PDP-11 Operating Systems glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2011-05-31 21:37 +0000
                Re: Y3K for PDP-11 Operating Systems "Jerome H. Fine" <everyone@nospam.com> - 2011-05-24 22:59 -0400
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-25 03:51 -0700
                Re: Y3K for PDP-11 Operating Systems "Jerome H. Fine" <everyone@nospam.com> - 2011-05-25 08:36 -0400
                Re: Y3K for PDP-11 Operating Systems "Tom Lake" <tlake@twcny.rr.com> - 2011-05-25 13:25 -0400
                Re: Y3K for PDP-11 Operating Systems "Jerome H. Fine" <everyone@nospam.com> - 2011-05-25 14:01 -0400
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-25 11:44 -0700
                Re: Y3K for PDP-11 Operating Systems Rich Alderson <news@alderson.users.panix.com> - 2011-05-25 21:20 -0400
                Re: Y3K for PDP-11 Operating Systems Rob Brown <mylastname@gmcl.com> - 2011-05-26 10:53 -0600
                Re: Y3K for PDP-11 Operating Systems Rich Alderson <news@alderson.users.panix.com> - 2011-05-26 16:27 -0400
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-26 20:27 -0700
                Re: Y3K for PDP-11 Operating Systems "Jerome H. Fine" <everyone@nospam.com> - 2011-05-26 16:38 -0400
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-26 21:44 -0700
              Re: Y3K for PDP-11 Operating Systems paramucho@hotmail.com (paramucho) - 2011-05-24 12:02 +0000
        Re: Y3K for PDP-11 Operating Systems "Jerome H. Fine" <everyone@nospam.com> - 2011-05-23 10:48 -0400
          Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-23 15:46 -0700
            Re: Y3K for PDP-11 Operating Systems billg999@cs.uofs.edu (Bill Gunshannon) - 2011-05-24 00:19 +0000
              Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-23 17:43 -0700
              Re: Y3K for PDP-11 Operating Systems "Jerome H. Fine" <everyone@nospam.com> - 2011-05-25 14:41 -0400
          Re: Y3K for PDP-11 Operating Systems billy@MIX.COM - 2011-05-24 02:54 +0000
            Re: Y3K for PDP-11 Operating Systems billg999@cs.uofs.edu (Bill Gunshannon) - 2011-05-24 13:03 +0000
              Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-24 07:39 -0700
                Re: Y3K for PDP-11 Operating Systems billy@MIX.COM - 2011-05-24 15:10 +0000
                Re: Y3K for PDP-11 Operating Systems Johnny Billquist <bqt@softjar.se> - 2011-05-24 08:48 -0700
                Re: Y3K for PDP-11 Operating Systems billg999@cs.uofs.edu (Bill Gunshannon) - 2011-05-24 16:54 +0000
              Re: Y3K for PDP-11 Operating Systems billy@MIX.COM - 2011-05-24 14:42 +0000
                Re: Y3K for PDP-11 Operating Systems billg999@cs.uofs.edu (Bill Gunshannon) - 2011-05-24 16:56 +0000
                Re: Y3K for PDP-11 Operating Systems "Jerome H. Fine" <everyone@nospam.com> - 2011-05-25 14:05 -0400

csiph-web