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Re: Y3K for PDP-11 Operating Systems

Message-ID <4DC4390F.9040401@eisner.decus.org> (permalink)
Date 2011-05-06 13:08 -0500
From G Cornelius <cornelius@eisner.decus.org>
Organization Dis
Newsgroups comp.os.vms, alt.sys.pdp11, comp.sys.dec, vmsnet.pdp-11
Subject Re: Y3K for PDP-11 Operating Systems
References (8 earlier) <H9mdnUTgT5LYfF3QnZ2dnUVZ_uOdnZ2d@giganews.com> <92d114Fhm7U1@mid.individual.net> <KsmdnY-dhd7k_VzQnZ2dnUVZ_vqdnZ2d@giganews.com> <92ddfkF764U1@mid.individual.net> <tY2dnego1pM4n1_QnZ2dnUVZ_o-dnZ2d@giganews.com>

Cross-posted to 4 groups.

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Richard B. Gilbert wrote:
> I have no PDP-11.  I had one at work many long years ago.  I don't miss it.

You must never have worked on an -8!

A 22-bit PDP-11 with RSX-11M+ (I/D space, supervisor mode libraries)
was a huge improvement over the sad little 18-bit beasts (physical
address, of course). And memory resident overlays at least meant
that you did not have to wait for more than a single system call's
overhead for additional segments of your overlaid program to be
accessed. But, oh, the task builder overlay description language
files you had to manage!

The 18-bit physical address space was a broken concept from the
beginning: "Hey, we have all this 18/36 bit stuff already built
for the 10- and 20-series, let's give the 11's two entire bits
of extended physical address!"  To go to 22 bits your device
drivers still had to go through the 18 bit atrocity, with the
extra two bits tucked into the CSR somewhere, just so they could
address a set of "Unibus mapping registers" to extend the map
from 18 bits to 22 bits. In retrospect it all seems to have been
rather poor planning.

If in fact your code fit into the address space and did not need
32 bit arithmetic, it could be fast.  The first time I started
working in a group that had VAXen I noticed two 750's sitting
off to the side because they had not been able to handle the
application load.  Their replacement: a pair of 11/84's.
Granted, this was specialized in that the language interpreter
had to do a lot of single byte operations, resulting in the
initial versions, on 750's at least, being rather inefficient.
Sometimes extra bits just mean extra overhead.

George

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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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