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Re: Y3K for PDP-11 Operating Systems

From glen herrmannsfeldt <gah@ugcs.caltech.edu>
Newsgroups alt.sys.pdp11, comp.sys.dec, vmsnet.pdp-11
Subject Re: Y3K for PDP-11 Operating Systems
Date 2011-05-27 00:54 +0000
Organization A noiseless patient Spider
Message-ID <irmsov$kjp$1@dont-email.me> (permalink)
References (8 earlier) <irilvv$p6t$1@Iltempo.Update.UU.SE> <944mhrF19qU1@mid.individual.net> <mddk4de2s77.fsf@panix5.panix.com> <irka34$sqr$1@dont-email.me> <8muWrc1fNvZf@eisner.encompasserve.org>

Cross-posted to 3 groups.

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In vmsnet.pdp-11 Bob Koehler <koehler@eisner.nospam.encompasserve.org> wrote:

(snip)
>   I've done a lot of direct access in Fortran, and never had to worry
>   about the disk block size.  I was suprized to discover that the
>   IBM Fortran H Extended Enhanced I/O subsystem would do direct access
>   on a veriable-length record file, but not a fixed length record file.
>   Perhaps IBM figured they only had to do the harder part.

I am surprised, too.  The Fortran G and H direct access requires
a fixed record length.  Just to be sure, while the record length is
fixed, you are allowed to choose any length you want between 1 and
the disk track size.  It just uses BDAM, which goes directly to the
disk hardware, which has the ability to format the track to any
record length you want.  On first open, the system formats the whole
file to the specified length.  I am pretty sure that is still supported,
though there is a recommendation to use VSAM instead.

The disk hardware writes blocks similar to the way data is written
on 9-track tape.  Well, not exactly.  The format is called CKD,
Count-Key-Data.  Each block has a count field (with key length
and data length), an optional key (for keyed access filed), and
data field.  In between, there is an inter-block gap, just like
on tape.  BDAM uses unblocked files, so one physical block per record.

VSAM formats the CKD disk in fixed size blocks, such as 4K, and
then uses the resulting data similar to other fixed block disk
systems.  

-- glen

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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

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