From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=5.0 tests=DKIM_INVALID,DKIM_SIGNED, HTML_FONT_LOW_CONTRAST,HTML_MESSAGE,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 25050 invoked from network); 20 Dec 2021 16:31:59 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 20 Dec 2021 16:31:59 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id C2FE99CE4B; Tue, 21 Dec 2021 02:31:57 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 9EA8D9490D; Tue, 21 Dec 2021 02:30:47 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=ccc.com header.i=@ccc.com header.b="kk4SkHSs"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id BCA519490D; Tue, 21 Dec 2021 02:30:43 +1000 (AEST) Received: from mail-qv1-f52.google.com (mail-qv1-f52.google.com [209.85.219.52]) by minnie.tuhs.org (Postfix) with ESMTPS id 1E6AF9461A for ; Tue, 21 Dec 2021 02:30:40 +1000 (AEST) Received: by mail-qv1-f52.google.com with SMTP id g15so8511580qvi.6 for ; Mon, 20 Dec 2021 08:30:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ccc.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=xgZY5EgWwQPfAbqD/XREZZYHuvdr1RGBVLLlFm+wAcM=; b=kk4SkHSs9O9rhzteI81HxFQH9u+Wc9AJGW1R3aCjRoUIIDyDUCASiaptm0FUEjAmOF 0+fsv9inkzicG7RJm74cflkgD544JuoUDGOjyjlywlzxzFq1vcHwZkIqjnbSwY5b/b9J rBZat6kj3WjA/KgJqvXIwQzgFynFNjkQdkof4= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=xgZY5EgWwQPfAbqD/XREZZYHuvdr1RGBVLLlFm+wAcM=; b=wEBfPxwfueSqby2QFbv5k7TzxrHWQMy1JFAcSHizoOT18nDSYWst+oZjF6PWGXAWhw +j4jiV98gm6Xc8KWt6BEGnx8ac+cIkge2X5R99ylxSgzGgghI3jFV+3wUPk2U91AWckc IVbfaR37G8yWhEIn5npdesmKwiDgJW0gCmBgCMgBDvN7vgyUDHxSHbNMLGcV4DAyyhVE 26NdovzC2b7YcqZjZyzbTQ/SQ2ay0brsaxcjEb/WxnvE24/1iDFjsLcsZctywp7GMo7d JbIczAN8/bQJwIwu+dWx3CoYBr1biuawyi8Tp6QXmVGpMaxqIVsIwa2we8WQtL1SFFF3 W08g== X-Gm-Message-State: AOAM533Yip//LKq2J2IPzBfKJryeLr2z7Ef/xfCqK0dH6j5nKFY4CGWH QN0DmBL1GGhCbvY4QQ5eGVVFy7VQCOuHACQHnjv0Vn/wa8bdJYgiilQ= X-Google-Smtp-Source: ABdhPJw0MYnM0Gou/5crXsp+qQ9ine/bjtAusjNu5MGiNNvznzu+0GDFltzA7jIc1mwuHdfBWA+Atjj9oMaIhkPrfdU= X-Received: by 2002:a05:6214:2589:: with SMTP id fq9mr13721226qvb.38.1640017838798; Mon, 20 Dec 2021 08:30:38 -0800 (PST) MIME-Version: 1.0 References: <55817161-038A-4358-8D4D-2D938578583A@planet.nl> In-Reply-To: From: Clem Cole Date: Mon, 20 Dec 2021 11:30:12 -0500 Message-ID: To: Dave Plonka Content-Type: multipart/alternative; boundary="000000000000b50e6205d3966863" Subject: Re: [TUHS] PDP 11/23 running UNIX version 6 at VCF Midwest! X-BeenThere: tuhs@minnie.tuhs.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: The Unix Heritage Society mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: TUHS main list , Paul Ruizendaal Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" --000000000000b50e6205d3966863 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Dave/Paul First Sixth Edition does not have support for either the 11/23 or a floppy. So your issues might be found in either place. Where did you get the modifications? Maybe: https://www.hamartun.priv.no/v6unix.html Your guess WRT to floppy being the source, would be where I started to poke. Frankly, early UNIX when ported to a system with a floppy has a lot of issues [we did this at Tektronix in the early late 1970s for the magnolia and some of its siblings). Take a look at the physical floppy - you will notice a lack of magnetic material near the center of the diskette. This is the i-list and v6 (and v7) hits it pretty hard. Caching of the inodes was added later, but was thought to do on the 11s due to lack of address space [you need to BSD 2.X later versions and generally need support for separate I/D 11 and a lot more physical memory]. I thought I remember that the 11/23 is a 11/40 class processor, not a 45 class so it lacks the '17th' bit as it were, although I think it can support more the 256K bytes of memory, but again it takes hacking V6 to enable and use it. One thing you could do is put the kernel image on simh [ https://github.com/simh/simh] or Ersatz11 [http://www.dbit.com/] and try it with an 11/40 and an RK05 emulator instead of the 11/23 and floppy since 11/40 with an RK05 and RP03/04 were the native distribution. Then try to change processors, and finally disks on the emulation. BTW: it if works fine with an emulated floppy [I would not be surprised if it does] I would look at the driver. I would think that it is possible for the floppy driver is causing the 11/23 to have missed interrupts with how the spl()/splx() calls are working [which can get tricky and easy to be 'almost right']. One other thought, I'm pretty sure that Noel's V6+ system from MIT can support a 23 but I don't know about floppies, you might try his image. Check out gunkies - https://gunkies.org/wiki/UNIX_Sixth_Edition, but Noel might reply here directly with more info. Have fun. Clem =E1=90=A7 On Mon, Dec 20, 2021 at 10:45 AM Dave Plonka wrote: > Hi Paul > > We talked about this a bit more in the comments on the video, with > Gavin doing some experiment afterwards. > > While at the show, one experiment we did was to redirection the > bas(1)ic program's output to a file and what we found was that (a) > characters would still sometimes be lost (which is how we determined > it's not due to a serial communications, directly and (b) the dropped > characters would coalesce together into a small run. > > Gavin's speculation at the time was that the floppy driver > interfered/interrupted the bas' output somehow, since we noticed there > was also disk activity coinciding roughly in time with a bout of > dropped characters. > > What is unusual about Gavin's machine (at the time of this video) is > that everything was on floppies - including root, tmp, etc. because he > did not have a functioning fixed disk yet. It may be a configuration > that was rarely used, e.g., scratch space for bas on floppy. (We found > bas seems to read the source code from the file system even at > runtime.) > > Any insights welcome - esp. if you can put them in the comments there. > > Peace, > Dave > > On Sun, Dec 19, 2021 at 11:25 AM Paul Ruizendaal wrote: > > > > While doing some end of year retrocomputing revisiting, I thought some > > of you might enjoy this - there is hope for the next generation(s)! ;) > > https://www.youtube.com/watch?v=3D_Zyng5Ob-e8 > > > > > > > > Thanks for that video link! > > > > I noticed the bit at the end about V6 and the occasional dropped > character and that this was not a serial line issue. I have the same issu= e > in my V6 port to the TI-990 and always assumed that it was a bug I > introduced myself when hacking the tty driver. > > > > Does anyone remember, was this a real life bug back in 6th edition back > in the 1970=E2=80=99s? Maybe only showing at higher baud rates? > > > > Paul > > > > > -- > > dave@plonka.us http://www.cs.wisc.edu/~plonka/ > --000000000000b50e6205d3966863 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Dave/Paul

First Sixth Edition does= not have support for either the 11/23 or a floppy.=C2=A0 So your issues mi= ght be found in either place.=C2=A0 Where did you get the modifications? Ma= ybe:=C2=A0https://www.= hamartun.priv.no/v6unix.html=C2=A0 Your guess WRT to floppy being the s= ource, would be where I started to poke.=C2=A0

Frankly= , early UNIX when ported to a system with a floppy has a lot of issues [we = did this at Tektronix in the early=C2=A0late 1970s for the magnolia and som= e of its siblings).=C2=A0 =C2=A0Take a look at the physical floppy - you wi= ll notice a lack of magnetic material near the center of the diskette.=C2= =A0 This is the i-list and v6 (and v7) hits it pretty hard.=C2=A0 =C2=A0Cac= hing of the inodes was added later,=C2=A0but was thought to do on the 11s d= ue to lack of address space [you need to BSD 2.X later versions and general= ly=C2=A0need support for separate I/D 11 and a lot more physical memory].

I thought I remember that=C2=A0the 11/23 is a 11/40 cla= ss processor, not a 45 class so it lacks the '17th' bit as it were,= although=C2=A0I think it can support more the 256K bytes of memory, but ag= ain it takes hacking V6 to enable and use it.

One thi= ng you could do is put the kernel image on simh [https://github.com/simh/simh] or Ersatz11 [http://www.dbit.com/] and try it with an 11/40 and = an RK05 emulator instead of the 11/23=C2=A0 and floppy since 11/40 with an = RK05 and RP03/04 were the native distribution.=C2=A0 =C2=A0 Then try to cha= nge=C2=A0processors, and finally disks on the emulation.=C2=A0 =C2=A0 BTW: = it if works fine with an emulated floppy [I would not be surprised if it do= es] I would look at the=C2=A0driver.=C2=A0 =C2=A0I would think that it is p= ossible for the floppy=C2=A0driver is causing the 11/23 to have missed inte= rrupts with how the spl()/splx() calls are working [which can get tricky an= d easy to be 'almost right'].

One other though= t, I'm pretty sure that Noel's V6+ system from MIT can support a 23= but I don't know about floppies, you might try his image.=C2=A0 Check = out gunkies - https= ://gunkies.org/wiki/UNIX_Sixth_Edition, but Noel might reply here direc= tly with more info.=C2=A0

Have fun.
Clem
=

=C2=A0=C2=A0
3D""=E1=90=A7

On Mon, Dec 20, = 2021 at 10:45 AM Dave Plonka <dave@plo= nka.us> wrote:
Hi Paul

We talked about this a bit more in the comments on the video, with
Gavin doing some experiment afterwards.

While at the show, one experiment we did was to redirection the
bas(1)ic program's output to a file and what we found was that (a)
characters would still sometimes be lost (which is how we determined
it's not due to a serial communications, directly and (b) the dropped characters would coalesce together into a small run.

Gavin's speculation at the time was that the floppy driver
interfered/interrupted the bas' output somehow, since we noticed there<= br> was also disk activity coinciding roughly in time with a bout of
dropped characters.

What is unusual about Gavin's machine (at the time of this video) is that everything was on floppies - including root, tmp, etc. because he
did not have a functioning fixed disk yet. It may be a configuration
that was rarely used, e.g., scratch space for bas on floppy. (We found
bas seems to read the source code from the file system even at
runtime.)

Any insights welcome - esp. if you can put them in the comments there.

Peace,
Dave

On Sun, Dec 19, 2021 at 11:25 AM Paul Ruizendaal <pnr@planet.nl> wrote:
>
> While doing some end of year retrocomputing revisiting, I thought some=
> of you might enjoy this - there is hope for the next generation(s)! ;)=
> https://www.youtube.com/watch?v=3D_Zyng5Ob-e8<= br> >
>
>
> Thanks for that video link!
>
> I noticed the bit at the end about V6 and=C2=A0 the occasional dropped= character and that this was not a serial line issue. I have the same issue= in my V6 port to the TI-990 and always assumed that it was a bug I introdu= ced myself when hacking the tty driver.
>
> Does anyone remember, was this a real life bug back in 6th edition bac= k in the 1970=E2=80=99s? Maybe only showing at higher baud rates?
>
> Paul
>


--

dave@plonka.us=C2= =A0 http://www.cs.wisc.edu/~plonka/
--000000000000b50e6205d3966863--