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Y3K for PDP-11 Operating Systems

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  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

Page 3 of 8 — ← Prev page 1 2 [3] 4 5 6 7 8  Next page →

#428

In vmsnet.pdp-11 vandys@vsta.org wrote:
> In alt.sys.pdp11 Johnny Billquist <bqt@softjar.se> wrote:
>> I know that for some things, actually coding using more primitive 
>> instructions on the (older) VAXen turned out to be faster than to use 
>> the fancy instructions, but I would not have thought that was true for 
>> things like MOVC or LOCC, but I might very well be wrong.
 
> I'm pretty sure we ended up with a hand coded bcopy() back in the day.
> It might've been that we could do optional initial odd, and then move
> as words.  I think I heard that later Vaxen microcode would do that too.

I remember stories from near the beginning of the 11/780 about
the polynomial expansion and bounds check instructions being
slower than doing either without those instructions.

I wouldn't be surprised if the string instructions were slower,
but I don't remember any stories about them.

-- glen

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#430

In article <iqa6a7$gu8$1@dont-email.me>, glen herrmannsfeldt <gah@ugcs.caltech.edu> writes:
> 
> I remember stories from near the beginning of the 11/780 about
> the polynomial expansion and bounds check instructions being
> slower than doing either without those instructions.

   On the 11/780, the speed of several of those instructions depended on 
   whether or not you had a floating point accelerator.  The FPA actually 
   did a lot of integer and address arithmatic, in addition to floating
   point.

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#433

On May 10, 2:31 pm, koeh...@eisner.nospam.encompasserve.org (Bob
Koehler) wrote:
> In article <iqa6a7$gu...@dont-email.me>, glen herrmannsfeldt <g...@ugcs.caltech.edu> writes:
>
> > I remember stories from near the beginning of the 11/780 about
> > the polynomial expansion and bounds check instructions being
> > slower than doing either without those instructions.
>
>    On the 11/780, the speed of several of those instructions depended on
>    whether or not you had a floating point accelerator.  The FPA actually
>    did a lot of integer and address arithmatic, in addition to floating
>    point.

I remember one of my 1980s customers whose hardware service was done
by a 3rd party. Their 2*78x cluster had a problem in that one node
wouldn't mount one of the shared disks. They'd been waiting for their
fixit folks to sort this for months, no progress. Then one day the
other 78x failed, leaving them unable to produce vehicles (cars, and
an IT company in this picture which is now part of HP, work it out).
As a favour, DEC Field Circus came in, ran the usual diagnostics, and
within minutes it emerged that an FPU fault had been preventing the
disk being mounted on the original dodgy 785. It was a bit of a
surprise to me to see an FPU involved in mounting a disk, but
apparently it shouldn't have been a surprise.

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#436

In article <696a284f-1e28-499f-bcec-bb21ccf7cbc9@l14g2000pro.googlegroups.com>, John Wallace <johnwallace4@yahoo.co.uk> writes:
> 
> I remember one of my 1980s customers whose hardware service was done
> by a 3rd party. Their 2*78x cluster had a problem in that one node
> wouldn't mount one of the shared disks. They'd been waiting for their
> fixit folks to sort this for months, no progress. Then one day the
> other 78x failed, leaving them unable to produce vehicles (cars, and
> an IT company in this picture which is now part of HP, work it out).
> As a favour, DEC Field Circus came in, ran the usual diagnostics, and
> within minutes it emerged that an FPU fault had been preventing the
> disk being mounted on the original dodgy 785. It was a bit of a
> surprise to me to see an FPU involved in mounting a disk, but
> apparently it shouldn't have been a surprise.

   The FPA for the VAX-11/780, and I believe for the 785, was part of
   the data path between RAM and CPU.  When the CPU fetched and
   instruction that was implemented in the FPA, the FPA executed it,
   presented an instruction to store the result, and padded with NOPs
   to maintain instruction alignment.

   When the FPA went bad, all kinds of screw ups could happen.  I was
   quite suprized to find an FPA bug that created incorrect behaviour
   in our applications by dropping bits, but allowed VMS itself to
   run all day long.  We finally found the bug by running the Fortran
   compiler repeatedly to put a load on the CPU.  From time to time
   it would die, and we were able to see that a RET had gone to the
   wrong address, one bit different from the saved PC.

   Pulling the FPA made everything work correctly.  We ran without it
   for a couple of days until the replacement showed up (third party
   maintenance, didn't keep one in stock).

   

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#444

Bob Koehler wrote:
>    The FPA for the VAX-11/780, and I believe for the 785, was part of
>    the data path between RAM and CPU.  When the CPU fetched and
>    instruction that was implemented in the FPA, the FPA executed it,
>    presented an instruction to store the result, and padded with NOPs
>    to maintain instruction alignment.

It is interesting that in the EV4 Alphas, at least, you could consider
floating point and load/store as a single unit, in that when issuing
instructions - the EV4 was dual-issue - only one load/store/FP class
instruction could be issued in a clock cycle, but it could be issued
simultaneously with, say, an integer arithmetic instruction.

George

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#390

On 2011-05-04 06:01, Bill Gunshannon wrote:
> In article<H9mdnUTgT5LYfF3QnZ2dnUVZ_uOdnZ2d@giganews.com>,
> 	"Richard B. Gilbert"<rgilbert88@comcast.net>  writes:
>> On 5/3/2011 8:07 PM, Bill Gunshannon wrote:
>>> In article<7d287cc3-4605-49a0-826e-fb92fc14e98d@j28g2000vbp.googlegroups.com>,
>>> 	onedbguru<onedbguru@yahoo.com>   writes:
>>>> On May 3, 2:39 pm, Henry Crun<m...@rechtman.com>   wrote:
>>>>> On 03/05/11 20:51, Bob Koehler wrote:
>>>>>
>>>>>>     >Bob Koehler wrote:
>>>>>
>>>>>>>> In article<bdd4fd3d-bb52-43fb-ad9c-746b901f4...@gu8g2000vbb.googlegroups.com>, jjh<jjhu...@gmail.com>     writes:
>>>>>
>>>>>>>> To make sure I understand, y3K =3D 3000, it is 2011 now...um that is 989
>>>>>>>> years from now...or roughly  12.5 lifetimes....I seriously don't think
>>>>>>>> that anyone in the year 3000 will want to know anything about DEC hw
>>>>>>>> or sw.
>>>>>
>>>>>>> You obviously have not read the historical documents.
>>>>>
>>>>>> I am curious, I have not read the historical documents.
>>>>>> Can you please post a link?
>>>>>
>>>>>> As for Y3K for RT-11, since the date is presently managed
>>>>>> up to 2099 as of V05.07 of RT-11, dates starting in 2100
>>>>>> become the next problem.  And since adding support only
>>>>>> for an additional 128 years seems like a complete waste of
>>>>>> time, then 3000 CE was chosen as the next minimum step.
>>>>>> In practice, at least an additional 4000 years would probably
>>>>>> be added, more than enough to handle dates until the rules
>>>>>> for the CE (Commercial Events, Common Era, Christian Era
>>>>>> or Gregorian - all are identical and have a 400 year cycle)
>>>>>> Calendar requires a rule change to handle years which are
>>>>>> less than the current 365.2418 days.
>>>>>
>>>>>> So Y3K is really just Y2.1K if that makes a difference.
>>>>>
>>>>> IIRC there was an article by someone from DEC who promised that RSTS would be
>>>>> patched to accept five-digit years before the year 9999. However I doubt that
>>>>> current versions would be supported until then...
>>>>>
>>>> question... who cares??? I can almost guarantee that none of us will
>>>> be here in 2099... and by that time you might be using neural-net
>>>> technology that will make the PDP look like a TRS80.
>>>
>>> Hey, just what xfdo you think was wrong with the TRS80?
>>>
>>
>> Other than primitive hardware and primitive software?  It was a good
>> machine in its day but its day is LONG GONE!
>>
>
> Now that's funny, here.  Just how is the Z80 more primitve than the PDP-11?
> And software?  At least 5 different OSes.  Wide language support.  Many
> commercial applications.
>
> And, at this point it is probably debatable which one between the TRS80
> and PDP-11 has more users on both real hardware and emulators.  I have
> quite a bit of both.

Actually, I know of plenty of PDP-11 systems still running critical 
applications in the industry. I have not seen a TRS-80 in the wild in 20 
years.

I'd it's not even a competition between these two machines. :-)

That said, the Z80 is more primitive in lots of ways. The instruction 
set is way more limited. You don't even have an MMU for the machine, and 
there is no way of doing a protected system where user applications 
can't do "bad" things, like turning off interrupts... There are a lot of 
things more primitive on the Z80. But I still use Z80 in products. It's 
a nice CPU for doing embedded things. So that architecture is still very 
much alive as well. Probably more alive than the PDP-11, since you can 
buy new Z80 cpus anywhere, but you'll have a very hard time finding a 
new PDP-11 anywhere, although you have commercial emulators for the latter.

	Johnny

-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt@softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol

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#392

In article <ips0r8$6jh$1@Iltempo.Update.UU.SE>, Johnny Billquist <bqt@softjar.se> writes:
> 
> That said, the Z80 is more primitive in lots of ways.

   Nintendo Game Boy was a Z80.  Game Boy 2 had a Z80 so it could play
   Game Boy cartridges.  I don't think the new 3-D Game Boy has a Z80,
   but I'm not sure.

   DEC LA120 console had Z80 in them.  We had an LA120 in front of
   a PDP-11/34 and were not sure which had more computing power.

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#394

In vmsnet.pdp-11 Bill Gunshannon <billg999@cs.uofs.edu> wrote:

(snip, someone wrote)
>> Other than primitive hardware and primitive software?  It was a good 
>> machine in its day but its day is LONG GONE!
 
> Now that's funny, here.  Just how is the Z80 more primitve than the PDP-11?
> And software?  At least 5 different OSes.  Wide language support.  Many
> commercial applications.
 
> And, at this point it is probably debatable which one between the TRS80
> and PDP-11 has more users on both real hardware and emulators.  I have
> quite a bit of both.

As I understand it, processors based on the Z80, though maybe not
made by Zilog, are used in many current products, such as the popular
TI graphing calculators in the TI-81 family.

I don't know that I ever heard of a PDP-11 being used in a
popular calculator.

-- glen

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#395

On May 4, 7:10 pm, glen herrmannsfeldt <g...@ugcs.caltech.edu> wrote:
> In vmsnet.pdp-11 Bill Gunshannon <billg...@cs.uofs.edu> wrote:
>
> (snip, someone wrote)
>
> >> Other than primitive hardware and primitive software?  It was a good
> >> machine in its day but its day is LONG GONE!
> > Now that's funny, here.  Just how is the Z80 more primitve than the PDP-11?
> > And software?  At least 5 different OSes.  Wide language support.  Many
> > commercial applications.
> > And, at this point it is probably debatable which one between the TRS80
> > and PDP-11 has more users on both real hardware and emulators.  I have
> > quite a bit of both.
>
> As I understand it, processors based on the Z80, though maybe not
> made by Zilog, are used in many current products, such as the popular
> TI graphing calculators in the TI-81 family.
>
> I don't know that I ever heard of a PDP-11 being used in a
> popular calculator.
>
> -- glen

It's only a few years since the Z80 was a reasonably ubiquitous
processor in cellphones, though it was well hidden and there weren't
many associated jobs for Z80 programmers or Z80 system designers.
Obviously the various flavours of ARM are now the default choice in
that market.

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#396

On Wed, May 4, 2011 at 13:10, glen herrmannsfeldt
<gah@ugcs.caltech.edu> wrote:
> I don't know that I ever heard of a PDP-11 being used in a popular
> calculator.

According to Bob Supnik, there were some hundreds of thousands of
T-11 microprocessors shipped. Not an earthshaking quantity, but I
was interested to see that the applications included the arcade
video game "Paperboy" by Atari.

http://simh.trailing-edge.com/semi/t11.html

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#398

On 2011-05-04 15:06, MetaEd wrote:
> On Wed, May 4, 2011 at 13:10, glen herrmannsfeldt
> <gah@ugcs.caltech.edu>  wrote:
>> I don't know that I ever heard of a PDP-11 being used in a popular
>> calculator.
>
> According to Bob Supnik, there were some hundreds of thousands of
> T-11 microprocessors shipped. Not an earthshaking quantity, but I
> was interested to see that the applications included the arcade
> video game "Paperboy" by Atari.
>
> http://simh.trailing-edge.com/semi/t11.html

There are a bunch of arcade games that had a T-11 in them, including 
some 3-player car race game that I can't remember the name of right now.

	Johnny

-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt@softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol

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#429

In article <92raajFe87U1@mid.individual.net>, vandys@vsta.org writes:
> 
> I think it was most competetive when you used multiple of its more optimized
> instructions.  For instance, my recollection is that the single-instruction
> bulk string ops ran slower than the hand coded move/loop constructs.  (Most
> of my time was on 750's and the odd 780, and this no doubt changed as DEC
> fleshed out their Vax line.)

   Out experiences on 11/780 were the opposite of that, until we got MV II, 
   where those instructions were emulated.

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#431

In article <iqa4rr$ebl$1@Iltempo.Update.UU.SE>, Johnny Billquist <bqt@softjar.se> writes:
> 
> Hmm. Memory alignment issues... Good point.
> Otherwise, I'm also pretty sure that a function like strcpy() is much 
> better to do on your own, as the VAX really don't have a good way of 
> implementing that. Doing first a LOCC to get the length, and then a MOVC 
> to move the string will surely be less efficient than just doing a MOV 
> followed by a conditional branch to loop... Obviously, for C stuff, 
> anything dealing with strings is opposed to how a VAX wants things. :-)

   I never did understand why the VAX C RTL did a LOCC first, instead of a
   MOVTUC with a straight-through translation table and null escape
   charater.  I assumed MOVTUC was even slower.

   The need to find that null character, in any case, always seemed to be 
   one more reason to use a better HLL.

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#432

On 2011-05-10 07.29, Bob Koehler wrote:
> In article<iqa4rr$ebl$1@Iltempo.Update.UU.SE>, Johnny Billquist<bqt@softjar.se>  writes:
>>
>> Hmm. Memory alignment issues... Good point.
>> Otherwise, I'm also pretty sure that a function like strcpy() is much
>> better to do on your own, as the VAX really don't have a good way of
>> implementing that. Doing first a LOCC to get the length, and then a MOVC
>> to move the string will surely be less efficient than just doing a MOV
>> followed by a conditional branch to loop... Obviously, for C stuff,
>> anything dealing with strings is opposed to how a VAX wants things. :-)
>
>     I never did understand why the VAX C RTL did a LOCC first, instead of a
>     MOVTUC with a straight-through translation table and null escape
>     charater.  I assumed MOVTUC was even slower.

I'm pretty sure that on later machines, MOVTUC is an emulated 
instruction, so you don't want to use it unless you really want the 
special features. For the simple C string case, having that translation 
table is a small memory cost, but it also hurts performance.
But from a purity point of view, yes, MOVTUC should also be able to do it.

>     The need to find that null character, in any case, always seemed to be
>     one more reason to use a better HLL.

:-)

	Johnny

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#434

Johnny Billquist wrote:
> On 2011-05-10 07.29, Bob Koehler wrote:
>>     I never did understand why the VAX C RTL did a LOCC first, instead
>>     of a MOVTUC with a straight-through translation table and null escape
>>     character.  I assumed MOVTUC was even slower.
> 
> 
> I'm pretty sure that on later machines, MOVTUC is an emulated
> instruction, so you don't want to use it unless you really want the
> special features. For the simple C string case, having that translation
> table is a small memory cost, but it also hurts performance.
> But from a purity point of view, yes, MOVTUC should also be able to do it.

References to a 1-1 MOVTUC table are basically wasted memory
accesses, and, in fact, will be mostly cache misses until a
significant proportion of the table has been loaded.  Not to
mention having flushed information out of cache, resulting in
likely cache misses later.  Also: these are per-byte cache misses,
where actual data fetches should load four, eight, or even more
soon to be used bytes into cache whenever a miss occurs.

George

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#435

In article <iqbllp$u0i$1@Iltempo.Update.UU.SE>, Johnny Billquist <bqt@softjar.se> writes:
> 
> I'm pretty sure that on later machines, MOVTUC is an emulated 
> instruction, so you don't want to use it unless you really want the 
> special features. For the simple C string case, having that translation 
> table is a small memory cost, but it also hurts performance.
> But from a purity point of view, yes, MOVTUC should also be able to do it.

   IIRC, LOCC and MOVCx are in the same VAX instruction subset as
   MOVTUC.  And the rules were you can do all of a subset in hardware,
   or none of the subset in hardware, but you couldn't break it up.

   For example, IIRC, MV II did none of the string instructions in 
   hardware.

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#439

On 2011-05-10 11.45, Bob Koehler wrote:
> In article<iqbllp$u0i$1@Iltempo.Update.UU.SE>, Johnny Billquist<bqt@softjar.se>  writes:
>>
>> I'm pretty sure that on later machines, MOVTUC is an emulated
>> instruction, so you don't want to use it unless you really want the
>> special features. For the simple C string case, having that translation
>> table is a small memory cost, but it also hurts performance.
>> But from a purity point of view, yes, MOVTUC should also be able to do it.
>
>     IIRC, LOCC and MOVCx are in the same VAX instruction subset as
>     MOVTUC.  And the rules were you can do all of a subset in hardware,
>     or none of the subset in hardware, but you couldn't break it up.
>
>     For example, IIRC, MV II did none of the string instructions in
>     hardware.

The MVII don't follow later rules about what to emulate and what to do 
in hardware. Those rules came later, and perhaps partly as an analysis 
after the MVII. As such, the MVII do not have LOCC in hardware, nor 
CMPCx, or a bunch of other string instructions that are "now" required. 
But it does have some other instructions that are very optional.

But actually, MOVTUC is in the group of instructions never required to 
be implemented, and which can be handpicked one by one, so it's not even 
in a group of instructions.

MOVCx and LOCC on the other hand are in the required group of 
instructions. So they are not even optional.

(Check chapter 11 of the VARM (DEC STD 032))

	Johnny

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#437

In article <4dc972d1$0$73606$815e3792@news.qwest.net>, G Cornelius <cornelius@eisner.decus.org> writes:
> Johnny Billquist wrote:
> 
> References to a 1-1 MOVTUC table are basically wasted memory
> accesses, and, in fact, will be mostly cache misses until a
> significant proportion of the table has been loaded.  Not to
> mention having flushed information out of cache, resulting in
> likely cache misses later.  Also: these are per-byte cache misses,
> where actual data fetches should load four, eight, or even more
> soon to be used bytes into cache whenever a miss occurs.

   Caches have got large, and most likely misses would all be resolved once
   early in program execution.

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#438

On 2011-05-10 11.58, Bob Koehler wrote:
> In article<4dc972d1$0$73606$815e3792@news.qwest.net>, G Cornelius<cornelius@eisner.decus.org>  writes:
>>
>> References to a 1-1 MOVTUC table are basically wasted memory
>> accesses, and, in fact, will be mostly cache misses until a
>> significant proportion of the table has been loaded.  Not to
>> mention having flushed information out of cache, resulting in
>> likely cache misses later.  Also: these are per-byte cache misses,
>> where actual data fetches should load four, eight, or even more
>> soon to be used bytes into cache whenever a miss occurs.
>
>     Caches have got large, and most likely misses would all be resolved once
>     early in program execution.

The cache warmup is an issue, since most strings aren't that long, and 
the MOVTUC will probably not hit that many locations that many times 
when implementing a strcpy(). So performance hit is probably very 
measurable.

And the table will most of the time probably not be around in the cache 
by the next time strcpy() got called. Even though caches have grown 
large, so have programs.

	Johnny

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#365

[Multipart message — attachments visible in raw view] — view raw

 >jjh wrote:

>To make sure I understand, y3K = 3000, it is 2011 now...um that is 989
>years from now...or roughly  12.5 lifetimes....I seriously don't think
>that anyone in the year 3000 will want to know anything about DEC hw
>or sw.
>I can't even begin to imagine any commercial organization running RT11
>in the year 3000....(hmmmm Nomad?)
>  
>
I can't imagine any commercial organization running RT-11 in the year 
3000!!!!!!!!!

However, with SIMH written in "C" and therefore portable, the PDP-11
emulator could survive that long.

On the other hand, RT-11 currently has an absolute limit of December 
31st, 2099.
The 16 bit word is able to hold all dates starting from January 1st, 
1972.  There seems
little use to writing all the code that would extend the years by 128 or 
up to 2227
and devote exactly one additional bit in some other word to do so when 
an additional
10% more effort using a whole additional byte or word will extend the 
date to an
almost unlimited future, certainly beyond 3000.

The original RT-11 date definition used only 14 bits of the 16 bit date 
word and
covered just 28 years.  Using the extra 2 bits added another 100 years 
until 2099.
It would have taken about 25% more effort to have added Y3K compliance at
the same time, but that would have required extra thought around 1998 and
time was getting very short.

>Computing technology will have probably undergone 4 or 5 radical
>technology changes.  I am almost sure no one will want to learn
>RT-11.  What for?  I don't want to learn IBM 1130 assembler or PDP1
>assembler for that matter. (and it has only been 40 years...)
>Then again, it would be interesting to see what happens if the borg
>assimilates a PDP11 running RT11...
>  
>
I agree as well. If that is the case, then if anyone is interested
in RT-11 just to try it out, it would be nice to be Y3K compliant
since it is extremely unlikely anyone would bother after 2099.

>This does bring up an interesting issue...I have several near pristine
>DEC systems and I wonder who will want them in 25-30 years?
>I doubt any museums will be around that will showcase the stuff.
>I've tried to get a number of engineering students over the last 10
>years to 'play' with them, and the general reaction is 'that junk? -
>what can I do with it...lol'
>  
>
The mouse seems to be an essential method of interfacing
these days.  However, I suspect that within another 30 years,
voice interaction will become the standard interface.  As
Kirk's chief engineer remarked during one episode when
he had to use a keyboard (the computers available during
the original Startrek series did not have mice), "back to
basics" or something like that.

I still use a DOS box and the keyboard when I am writing and
testing the code for a DLL to interface with Ersatz-11 when I
need something special for RT-11..  Is there any other way?

>In summary, I have no interest in spending time in this area.
>I have other types of crossword puzzles to keep me busy....
>
I found it is more fun the write code for RT-11.

Jerome Fine

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