The Unix Heritage Society mailing list
 help / color / mirror / Atom feed
From: jnc@mercury.lcs.mit.edu (Noel Chiappa)
To: tuhs@tuhs.org
Cc: jnc@mercury.lcs.mit.edu
Subject: [TUHS] Re: Attempting To Build NOSC and BBN UNIXs + ARPANET code
Date: Wed, 12 Oct 2022 15:38:56 -0400 (EDT)	[thread overview]
Message-ID: <20221012193856.7FE9618C077@mercury.lcs.mit.edu> (raw)

    > From: Michael Casadevall

    > sys4.c is entirely corrupted, and part of impio.c is cut off

The copy on MIT-CSR (the origin of the copy at TUHS) has the same issues. I
doubt it's possible to recover them from that system; you'll have to find
some other way to recover them (perhaps through a dump of the BBN system), or
re-code them (as you did with sys4.c).

    > I do need to do a readthrough for the VDH driver ... I think that might
    > be for the radio links to Hawaii and the UK? 

No. Read BBN 1822.

The LH and DH bit-serial physical interfaces only work up to about 1000 feet
or so. (Less for LH; DH is logically idential to LH, but uses differential
pairs - the LH is single-sided). VDH is, in the bottom layer, simply a
synchronous serial link, allowing the host to be up to hunreds of miles from
the IMP.


    > From: Lars Brinkhoff

    > Another it adding emulators for various IMP interfaces. I.e. you will
    > not get anywhere without adding one of IMP11A, ACC, or VDH to SIMH.

Did VDH PDP-11's have a special VDH interface, or did they simply use an
off-the-rack DEC synchronous serial interface like a DU11? (More of them
here:

  http://gunkies.org/wiki/Category:DEC_Synchronous_Serial_Interfaces

if anyone wants.) Looking at net_vdh.h, it seems to be a "VDH-11C"

Looking online, the VDH-11 seems to be an ACC prodict, but I wasn't able to
find anything out about it at all. (I have some hardcopy manuals for other
ACC IMP interface products, and I was going to look in them to see if any of
them listed its manual in a 'see also', but I can't find them.)

I'm not sure why people did just use an off-the-rack DEC synchronous serial
interface; maybe the VDH11 did a BBN specific CRC, or something (in addition
to using DMA; mostr DEC sync interfaces didn't, IIRC)?

Anyway, you don't want to use VDH.

	Noel

             reply	other threads:[~2022-10-12 19:39 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-12 19:38 Noel Chiappa [this message]
2022-10-13  5:50 ` Lars Brinkhoff
  -- strict thread matches above, loose matches on Subject: below --
2022-10-14 20:30 Noel Chiappa
2022-10-14 11:55 Paul Ruizendaal
2022-10-14 16:08 ` Phil Budne
2022-10-14 16:37   ` Clem Cole
2022-10-14 19:06     ` Warner Losh
2022-10-14 18:47 ` Lars Brinkhoff
2022-10-11 15:08 Paul Ruizendaal
2022-10-10 18:33 [TUHS] " Michael Casadevall
2022-10-10 19:48 ` [TUHS] " Lars Brinkhoff
2022-10-10 20:31   ` Michael Casadevall
2022-10-11  5:31     ` Lars Brinkhoff
2022-10-11 12:57       ` Michael Casadevall
2022-10-11 13:57         ` Lars Brinkhoff
     [not found]           ` <CAJq=PCV7o_kMvRLXXK9prddmyvf0hAodX+NuqqVF=49iCYt63w@mail.gmail.com>
2022-10-11 19:58             ` Lars Brinkhoff
2022-10-10 20:31 ` Clem Cole
2022-10-10 20:48   ` Michael Casadevall
2022-10-10 21:37     ` Clem Cole

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20221012193856.7FE9618C077@mercury.lcs.mit.edu \
    --to=jnc@mercury.lcs.mit.edu \
    --cc=tuhs@tuhs.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).