[Simh] Simh Digest, Vol 166, Issue 21
Peter Allan
petermallan at gmail.com
Wed Nov 8 09:19:11 EST 2017
Thanks for the suggestion Larry, but the way that simh is set up for a VAX
780, there are two massbuses and the disks (RP or RM) go on the first
massbus, while the tape drives go on the second. You have no choice about
that.
Cheers
Peter Allan
On 8 November 2017 at 01:36, <simh-request at trailing-edge.com> wrote:
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> Today's Topics:
>
> 1. Re: TE16 CRC Errors (Johnny Billquist)
> 2. Re: TE16 CRC Errors (Paul Koning)
> 3. Re: TE16 CRC Errors (Johnny Billquist)
> 4. Re: TE16 CRC Errors (Larry Baker)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Wed, 8 Nov 2017 01:49:05 +0100
> From: Johnny Billquist <bqt at softjar.se>
> To: simh at trailing-edge.com
> Subject: Re: [Simh] TE16 CRC Errors
> Message-ID: <050102c6-9d68-cf61-2f5a-7e75a5eb7391 at softjar.se>
> Content-Type: text/plain; charset=utf-8; format=flowed
>
> I actually don't think he has a mixed massbus. I don't think you could
> even configure simh for this. Simh have a very simplistic view on
> hardware configurations.
> You don't configure massbuses, and put devices on them. You normally
> just configure the devices, and all the bus and controller
> configurations come implicit from that.
>
> So, if you specify a massbus disk, you'll get a corresponding massbus.
> And for tapes, you'll get another one.
> Both configured appropriately for that specific type of device you have
> hooked to it.
>
> In RSX land, only M+ supported mixed massbus, as you mention. Not sure
> when/if VMS did. Not sure how much of anything else that might have
> supported it either.
>
> Johnny
>
> On 2017-11-08 00:57, Larry Baker wrote:
> > Peter,
> >
> > My reading of your hardware setup sounds like what was called a
> > "Mixed-MASSBUS" configuration, that is, mixing disks and tapes on the
> > same MASSBUS. PDP-11 RSX-11M-Plus supported Mixed-MASSBUS. We
> > dual-ported all our disks and used the MASSBUS that came with our tape
> > drives that way. I think Mixed-MASSBUS support was unusual. I do not
> > remember if VMS 3.0 supported Mixed-MASSBUS. If not, what you are
> > seeing might be the result.
> >
> > Larry Baker
> > US Geological Survey
> > 650-329-5608
> > baker at usgs.gov <mailto:baker at usgs.gov>
> >
> >
> >
> >> On 7 Nov 2017, at 12:54:40 PM, simh-request at trailing-edge.com
> >> <mailto:simh-request at trailing-edge.com> wrote:
> >>
> >> ------------------------------
> >>
> >> Message: 4
> >> Date: Tue, 7 Nov 2017 20:54:31 +0000
> >> From: Peter Allan <petermallan at gmail.com <mailto:petermallan at gmail.com>
> >
> >> To: "simh at trailing-edge.com <mailto:simh at trailing-edge.com>"
> >> <simh at trailing-edge.com <mailto:simh at trailing-edge.com>>
> >> Subject: Re: [Simh] Simh Digest, Vol 166, Issue 12
> >> Message-ID:
> >> <CAJCrz55fv2uBE5PhmtboUXL5Yzt8CpyiYhn1CyGxgHZHbXEkyw at mail.gmail.com
> >> <mailto:CAJCrz55fv2uBE5PhmtboUXL5Yzt8CpyiYhn1CyGxgHZHbXEkyw@
> mail.gmail.com>>
> >> Content-Type: text/plain; charset="utf-8"
> >>
> >> In order to try to understand why I am having trouble reading a
> simulated
> >> tape with a simulated TE16 tape drive on a simh VAX 780, I have tried
> >> several configurations.
> >>
> >>
> >> Firstly, a point of clarification. The problem that I came across was in
> >> finishing the installation of VMS 3.0. This was necessary in order to be
> >> able to install VMS 1.5 using DSC2, but I have no problem with the
> >> installation of VMS 1.5 itself. VMS 1.5 is a red herring - the problem
> is
> >> with VMS 3.0.
> >>
> >>
> >> I had configured a VAX 780 in simh with three RP06 disk drives and two
> >> TE16
> >> tape drives. I was using TE16 tape drives rather than TS11 really just
> >> because when I was the system manager of a real 780, it had two TE16
> tape
> >> drives.
> >>
> >>
> >> All of this has been done on a host system running CentOS 5 (for simh
> >> 3.8-1) and CentOS 6 (for simh 4.0).
> >>
> >>
> >> To remind you of the problem, I started the installation of VMS 3.0 by
> >> booting stand-alone backup and restoring a saveset from a tape that I
> >> downloaded from the University of Stuttgart. The first phase went fine
> and
> >> when I rebooted the 780, the system asked which device contained the
> >> installation media so that it could automatically complete the
> >> installation
> >> of VMS. I entered MTA0: and this is where things went wrong. Wilm
> >> suggested
> >> I should trying using a TS11 drive (MSA0) rather than a TE16 drive and
> >> this
> >> did indeed work, but this left me wondering why?
> >>
> >>
> >> I have tried to restore a BACKUP saveset from a tape to a disk using
> >> several configurations. I have tried:
> >>
> >> - Two difference versions of simh, 3.8-1 and 4.0
> >>
> >> - Three different versions of VMS, 3.0, 4.6 and 7.3
> >>
> >> - Different simulated tapes
> >>
> >> - The two different simulated tape drives, TS11 and TE16
> >>
> >> The results have surprised me.
> >>
> >> 1) Changing the version of simh makes no difference to the results.
> >>
> >> 2) I only get a problem in restoring a saveset from tape when
> running
> >> VMS 3.0 as the operating system. Everything works fine with VMS 4.6
> >> and 7.3.
> >>
> >> 3) I have tried different tapes, but if the system is going to
> >> fail to
> >> do a restore operation, it does it with all of the tapes containing
> BACKUP
> >> savesets that I tried.
> >>
> >> Following a suggestion from Kevin Handy, I tried to copy the savesets
> from
> >> tape to disk, but the copy failed on the VMS 3.0 system when using a
> TE16
> >> tape drive.
> >>
> >>
> >> My experiments indicate that there is a problem with VMS 3.0 when using
> >> TE16 tape drives. However, this seems so unlikely, not least because the
> >> sequence of operations that I have gone through is what hundreds
> >> (thousands
> >> probably) of system managers must have done to install VMS 3.0 on real
> >> hardware, including my predecessor with “my own” 780.
> >>
> >>
> >> This leaves me stumped, but at least I have narrowed the problem down
> >> and I
> >> am able to do the installation of VMS 3.0 (which lets me do the
> >> installation of 1.5) by using a TS11 drive.
> >>
> >>
> >> The only thing I can think of is to wonder if the way that VMS handled
> >> TE16
> >> (i.e. massbus) tape drives changed between VMS 3 and VMS 4 and that
> >> somehow
> >> there is a bug in simh that only rears its head on the earlier version.
> I
> >> confess this is a stab in the dark.
> >>
> >>
> >> Anyone got a bright idea about this?
> >>
> >>
> >>
> >> Cheers
> >>
> >>
> >> Peter Allan
> >>
> >>
> >>
> >
> >
> >
> > _______________________________________________
> > Simh mailing list
> > Simh at trailing-edge.com
> > http://mailman.trailing-edge.com/mailman/listinfo/simh
> >
>
>
> --
> Johnny Billquist || "I'm on a bus
> || on a psychedelic trip
> email: bqt at softjar.se || Reading murder books
> pdp is alive! || tryin' to stay hip" - B. Idol
>
>
> ------------------------------
>
> Message: 2
> Date: Tue, 7 Nov 2017 19:54:18 -0500
> From: Paul Koning <paulkoning at comcast.net>
> To: Johnny Billquist <bqt at softjar.se>
> Cc: simh at trailing-edge.com
> Subject: Re: [Simh] TE16 CRC Errors
> Message-ID: <2ED1EDE6-B204-4E0F-9955-275E67BA405D at comcast.net>
> Content-Type: text/plain; charset="utf-8"
>
>
>
> > On Nov 7, 2017, at 7:49 PM, Johnny Billquist <bqt at softjar.se> wrote:
> >
> > I actually don't think he has a mixed massbus. I don't think you could
> even configure simh for this. Simh have a very simplistic view on hardware
> configurations.
> > You don't configure massbuses, and put devices on them. You normally
> just configure the devices, and all the bus and controller configurations
> come implicit from that.
> >
> > So, if you specify a massbus disk, you'll get a corresponding massbus.
> And for tapes, you'll get another one.
> > Both configured appropriately for that specific type of device you have
> hooked to it.
> >
> > In RSX land, only M+ supported mixed massbus, as you mention. Not sure
> when/if VMS did. Not sure how much of anything else that might have
> supported it either.
>
> RSTS definitely did not. It does support mixed RP/RM massbus, which is
> more usual but not universal either, I think. But no mixing disk and tape.
>
> paul
>
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>
> ------------------------------
>
> Message: 3
> Date: Wed, 8 Nov 2017 02:01:25 +0100
> From: Johnny Billquist <bqt at softjar.se>
> To: Paul Koning <paulkoning at comcast.net>
> Cc: simh at trailing-edge.com
> Subject: Re: [Simh] TE16 CRC Errors
> Message-ID: <730c93d6-b392-ed29-7ca3-4fcd3499500b at softjar.se>
> Content-Type: text/plain; charset=windows-1252; format=flowed
>
> On 2017-11-08 01:54, Paul Koning wrote:
> >
> >
> >> On Nov 7, 2017, at 7:49 PM, Johnny Billquist <bqt at softjar.se
> >> <mailto:bqt at softjar.se>> wrote:
> >>
> >> I actually don't think he has a mixed massbus. I don't think you could
> >> even configure simh for this. Simh have a very simplistic view on
> >> hardware configurations.
> >> You don't configure massbuses, and put devices on them. You normally
> >> just configure the devices, and all the bus and controller
> >> configurations come implicit from that.
> >>
> >> So, if you specify a massbus disk, you'll get a corresponding massbus.
> >> And for tapes, you'll get another one.
> >> Both configured appropriately for that specific type of device you
> >> have hooked to it.
> >>
> >> In RSX land, only M+ supported mixed massbus, as you mention. Not sure
> >> when/if VMS did. Not sure how much of anything else that might have
> >> supported it either.
> >
> > RSTS definitely did not. It does support mixed RP/RM massbus, which is
> > more usual but not universal either, I think. But no mixing disk and
> tape.
>
> Thanks. I was wondering about RSTS/E, but didn't dare saying something
> definitive. That it allows mixing of RM/RP is nice. I think in plain
> -11M, even that might not be allowed, but I would have to go and check
> and refresh my memory.
> M+ allows any kind of combinations.
>
> Johnny
>
> --
> Johnny Billquist || "I'm on a bus
> || on a psychedelic trip
> email: bqt at softjar.se || Reading murder books
> pdp is alive! || tryin' to stay hip" - B. Idol
>
>
> ------------------------------
>
> Message: 4
> Date: Tue, 7 Nov 2017 17:36:07 -0800
> From: Larry Baker <baker at usgs.gov>
> To: <petermallan at gmail.com>
> Cc: simh <simh at trailing-edge.com>
> Subject: Re: [Simh] TE16 CRC Errors
> Message-ID: <20474D0E-0006-4307-BD99-0AFFB7C525F7 at usgs.gov>
> Content-Type: text/plain; charset="utf-8"
>
> Peter,
>
> I answered my own question. The VAX/VMS Version 1.6 SPD (
> http://www.bitsavers.org/www.computer.museum.uq.edu.au/pdf/
> AE-C770D-TE%20VAX-VMS%20Operating%20System,%20Version%201.6%20SPD%2025.1.
> 4.pdf) specifically states Mixed-MASSBUS configurations were supported:
>
>
> NOTE:
>
> MASSBUS disk drives and magnetic tape transports can be attached to the
> same MASSBUS.
>
>
> Your predicament remains a mystery.
>
> Larry Baker
> US Geological Survey
> 650-329-5608
> baker at usgs.gov
>
>
>
> > On 7 Nov 2017, at 3:57:13 PM, Larry Baker <baker at usgs.gov> wrote:
> >
> > Peter,
> >
> > My reading of your hardware setup sounds like what was called a
> "Mixed-MASSBUS" configuration, that is, mixing disks and tapes on the same
> MASSBUS. PDP-11 RSX-11M-Plus supported Mixed-MASSBUS. We dual-ported all
> our disks and used the MASSBUS that came with our tape drives that way. I
> think Mixed-MASSBUS support was unusual. I do not remember if VMS 3.0
> supported Mixed-MASSBUS. If not, what you are seeing might be the result.
> >
> > Larry Baker
> > US Geological Survey
> > 650-329-5608
> > baker at usgs.gov <mailto:baker at usgs.gov>
> >
> >
> >
> >> On 7 Nov 2017, at 12:54:40 PM, simh-request at trailing-edge.com <mailto:
> simh-request at trailing-edge.com> wrote:
> >>
> >> ------------------------------
> >>
> >> Message: 4
> >> Date: Tue, 7 Nov 2017 20:54:31 +0000
> >> From: Peter Allan <petermallan at gmail.com <mailto:petermallan at gmail.com>
> >
> >> To: "simh at trailing-edge.com <mailto:simh at trailing-edge.com>" <
> simh at trailing-edge.com <mailto:simh at trailing-edge.com>>
> >> Subject: Re: [Simh] Simh Digest, Vol 166, Issue 12
> >> Message-ID:
> >> <CAJCrz55fv2uBE5PhmtboUXL5Yzt8CpyiYhn1CyGxgHZHbXEkyw at mail.
> gmail.com <mailto:CAJCrz55fv2uBE5PhmtboUXL5Yzt8CpyiYhn1CyGxgHZHbXEkyw@
> mail.gmail.com>>
> >> Content-Type: text/plain; charset="utf-8"
> >>
> >> In order to try to understand why I am having trouble reading a
> simulated
> >> tape with a simulated TE16 tape drive on a simh VAX 780, I have tried
> >> several configurations.
> >>
> >>
> >> Firstly, a point of clarification. The problem that I came across was in
> >> finishing the installation of VMS 3.0. This was necessary in order to be
> >> able to install VMS 1.5 using DSC2, but I have no problem with the
> >> installation of VMS 1.5 itself. VMS 1.5 is a red herring - the problem
> is
> >> with VMS 3.0.
> >>
> >>
> >> I had configured a VAX 780 in simh with three RP06 disk drives and two
> TE16
> >> tape drives. I was using TE16 tape drives rather than TS11 really just
> >> because when I was the system manager of a real 780, it had two TE16
> tape
> >> drives.
> >>
> >>
> >> All of this has been done on a host system running CentOS 5 (for simh
> >> 3.8-1) and CentOS 6 (for simh 4.0).
> >>
> >>
> >> To remind you of the problem, I started the installation of VMS 3.0 by
> >> booting stand-alone backup and restoring a saveset from a tape that I
> >> downloaded from the University of Stuttgart. The first phase went fine
> and
> >> when I rebooted the 780, the system asked which device contained the
> >> installation media so that it could automatically complete the
> installation
> >> of VMS. I entered MTA0: and this is where things went wrong. Wilm
> suggested
> >> I should trying using a TS11 drive (MSA0) rather than a TE16 drive and
> this
> >> did indeed work, but this left me wondering why?
> >>
> >>
> >> I have tried to restore a BACKUP saveset from a tape to a disk using
> >> several configurations. I have tried:
> >>
> >> - Two difference versions of simh, 3.8-1 and 4.0
> >>
> >> - Three different versions of VMS, 3.0, 4.6 and 7.3
> >>
> >> - Different simulated tapes
> >>
> >> - The two different simulated tape drives, TS11 and TE16
> >>
> >> The results have surprised me.
> >>
> >> 1) Changing the version of simh makes no difference to the results.
> >>
> >> 2) I only get a problem in restoring a saveset from tape when
> running
> >> VMS 3.0 as the operating system. Everything works fine with VMS 4.6 and
> 7.3.
> >>
> >> 3) I have tried different tapes, but if the system is going to
> fail to
> >> do a restore operation, it does it with all of the tapes containing
> BACKUP
> >> savesets that I tried.
> >>
> >> Following a suggestion from Kevin Handy, I tried to copy the savesets
> from
> >> tape to disk, but the copy failed on the VMS 3.0 system when using a
> TE16
> >> tape drive.
> >>
> >>
> >> My experiments indicate that there is a problem with VMS 3.0 when using
> >> TE16 tape drives. However, this seems so unlikely, not least because the
> >> sequence of operations that I have gone through is what hundreds
> (thousands
> >> probably) of system managers must have done to install VMS 3.0 on real
> >> hardware, including my predecessor with “my own” 780.
> >>
> >>
> >> This leaves me stumped, but at least I have narrowed the problem down
> and I
> >> am able to do the installation of VMS 3.0 (which lets me do the
> >> installation of 1.5) by using a TS11 drive.
> >>
> >>
> >> The only thing I can think of is to wonder if the way that VMS handled
> TE16
> >> (i.e. massbus) tape drives changed between VMS 3 and VMS 4 and that
> somehow
> >> there is a bug in simh that only rears its head on the earlier version.
> I
> >> confess this is a stab in the dark.
> >>
> >>
> >> Anyone got a bright idea about this?
> >>
> >>
> >>
> >> Cheers
> >>
> >>
> >> Peter Allan
> >>
> >>
> >>
> >
>
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>
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>
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>
> End of Simh Digest, Vol 166, Issue 21
> *************************************
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