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_MESSAGE,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 2661 invoked from network); 27 Sep 2023 02:47:06 -0000 Received: from minnie.tuhs.org (50.116.15.146) by inbox.vuxu.org with ESMTPUTF8; 27 Sep 2023 02:47:06 -0000 Received: from minnie.tuhs.org (localhost [IPv6:::1]) by minnie.tuhs.org (Postfix) with ESMTP id 7A92A40964; Wed, 27 Sep 2023 12:46:55 +1000 (AEST) Received: from bosmailout09.eigbox.net (bosmailout09.eigbox.net [66.96.189.9]) by minnie.tuhs.org (Postfix) with ESMTPS id 318A540963 for ; Wed, 27 Sep 2023 12:46:47 +1000 (AEST) Received: from bosmailscan06.eigbox.net ([10.20.15.6]) by bosmailout09.eigbox.net with esmtp (Exim) id 1qlKZa-0006ki-8d for tuhs@tuhs.org; Tue, 26 Sep 2023 22:46:46 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=osta.com; s=dkim; h=Sender:In-Reply-To:From:References:To:Subject:Reply-To: MIME-Version:Date:Message-ID:Content-Type:Cc:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=U2jcvY3Sh2Dv8QhNW2dYc1uQGpjk0nvB2oJ/ARI7R5o=; b=gEHCaI1w6Y5m0HCo4O4r8AsYwm 7C3g6i9uJVoFQ34oIzyLouFAMdMyXZIuTr1ZgvGFrvo6uX7JUy2gKRO7aPoPhKp2ltxPHpHUFbBoN jT+G9PCxSg6gPLzlM96cwPUKiQvr1rwqbyMnMWASPPGBxFyNJMB6FZMimQbn0sSLzCSpTTKI6YUHK 7+De215byywb7SmbL9TBG3f/+oSf1bOdmL6O9tPTbpors4GnEtSrlYxEjfqCndrimtyQEsRENw56b Aowtpu1hYRfRF75PTn6n01WW1uFrpwoH5Hc1m4mn71l/wz3MiDGeN6CZ/XolpgXQi2wsolfhOmmUH qmBNhCLw==; Received: from [10.115.3.33] (helo=bosimpout13) by bosmailscan06.eigbox.net with esmtp (Exim) id 1qlKZZ-0003SM-UR for tuhs@tuhs.org; Tue, 26 Sep 2023 22:46:45 -0400 Received: from bosauthsmtp17.yourhostingaccount.com ([10.20.18.17]) by bosimpout13 with id qqmi2A0050N5uqq01qmlgg; Tue, 26 Sep 2023 22:46:45 -0400 X-Authority-Analysis: v=2.3 cv=G76H7+s5 c=1 sm=1 tr=0 a=f4kFLigMKr8AH7rIJ//qJA==:117 a=7yVU7b3yyQQPX44ivRY3zA==:17 a=zNV7Rl7Rt7sA:10 a=r77TgQKjGQsHNAKrUKIA:9 a=1QKRkxQp_7GXvOMP5ZEA:9 a=QEXdDO2ut3YA:10 a=ze1yajpOAAAA:8 a=TfIwjIho-qtWdf2yYJsA:9 a=kbRMpT-5HOZIojz_:21 a=_W_S_7VecoQA:10 a=5kY_Wwz69C95-IfV1DmU:22 Received: from 047-047-085-078.biz.spectrum.com ([47.47.85.78]:61635 helo=[172.16.0.118]) by bosauthsmtp17.eigbox.net with esmtpa (Exim) id 1qlKZW-0000NA-Gf for tuhs@tuhs.org; Tue, 26 Sep 2023 22:46:42 -0400 Content-Type: multipart/alternative; boundary="------------gU6riilwkPFXWO2IirNFg3iV" Message-ID: <1eaf63bd-5394-a692-ad42-c8dd5c1a741c@osta.com> Date: Tue, 26 Sep 2023 19:46:41 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.15.1 Content-Language: en-US To: tuhs@tuhs.org References: <202309260137.38Q1btZU325043@darkstar.fourwinds.com> From: Heinz Lycklama Organization: Open Systems Technology Associates In-Reply-To: <202309260137.38Q1btZU325043@darkstar.fourwinds.com> X-EN-UserInfo: ffc85f53e1d6cf32f4fdb09be51357ac:931c98230c6409dcc37fa7e93b490c27 X-EN-AuthUser: heinz@osta.com Sender: Heinz Lycklama X-EN-OrigIP: 47.47.85.78 X-EN-OrigHost: 047-047-085-078.biz.spectrum.com Message-ID-Hash: 46GMHKSRLYX7NM5VPT5KZY5NG3LU6FVQ X-Message-ID-Hash: 46GMHKSRLYX7NM5VPT5KZY5NG3LU6FVQ X-MailFrom: SRS0=4DBTVG=FL=osta.com=heinz@eigbox.net X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.6b1 Precedence: list Reply-To: heinz@osta.com Subject: [TUHS] Re: Known Specimens of Pre-5ESS UNIX Telephone Switching Software? List-Id: The Unix Heritage Society mailing list Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: This is a multi-part message in MIME format. --------------gU6riilwkPFXWO2IirNFg3iV Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit To answer Jon's following question (2 minutes later): ------------------------------------------------------------------------ Oh yeah, and I think that this is why Heinz wrote MERT, but he should know more than me about it. ------------------------------------------------------------------------ Yes, my Dept. in MH was involved in the early days of digital switching and the need for real-time response was certainly recognized. But MERT was not developed with a specific telephony project in mind. I was mostly involved in software in support of current projects being done in the Dept. We started the MERT project at the time that DEC announced their PDP-11/45 mini-computer in the early 1970's because it supported 3 separate address spaces - system, supervisor, and user. This enabled us to run operating system environments with different user application program needs, specifically real-time under control of one supervisor and time-sharing applications in another supervisor, to start with. Hence its name - Multi-Environment Real Time (MERT). Once we had MERT up and running on the PDP-11/45 and PDP-11/70 computers, some projects in other Bell Labs locations involved in telephony projects started building their projects on the MERT system. The DMERT system was developed later on by projects at yet another Bell Labs location. Heinz On 9/25/2023 6:37 PM, Jon Steinhart wrote: > segaloco via TUHS writes: >> Hello, my studies lately bring me to the question: Are there any extant >> examples of telephone switching software, built on UNIX, from the various >> parts of the Bell System prior to the introduction of the 5ESS and 3B20D? >> My focus veers earlier as some 5ESS/3B20D/DMERT technology is still in >> active use, that sleeping dragon can lie. >> >> What's gotten me curious is reading about 1ESS in a BSTJ volume I >> picked up, noting the particulars on how previous concerns of manual and >> electro-mechanical systems were abstracted into software. Even without >> surviving examples, were previous systems such as the 1ESS central >> control ever ported to or considered for porting to UNIX, or was the >> hardware interface to the telco lines too specific to consider a future >> swap-out with, say, a PDP11 running arbitrary software? Columbus's SCCS >> (switching, not source code) also comes to mind, although all I know that >> survives of that is the CB-UNIX 2.3 manual descriptions of bits and pieces. >> >> By the way, it's funny, I have UNIX to thank for my current experiments >> with telephones and other signalling stuff, what with making me study the >> Bell System more generally. It's starting to come full circle in that I >> want to take a crack at reading dialing, at least pulse, into some sort >> of software abstraction on a SBC that can, among other things, provide a >> switching service on top of a UNIX-like kernel. I don't know what I'd do >> with such a thing other than assign work conference call rooms their own >> phone numbers to dial with a telephone on a serial line...but if I can even >> get that far I'd call it a success. One less dependency on the mobile... >> >> - Matt G. > Heinz might know something about this. If I remember correctly, one of the > projects in his group was SS1, an all-digital exchange. I have some vague > memory of him and Carl poring over some gigantic switch statement looking > for a bug - the long distance code wasn't sending the ST pulse and as a > result all of the key pulse senders at the Berkeley Heights telephone > exchange were taken off line and needed a technician to go in and manually > reset them. They were not amused. Fortunately, they and BTL were both > children of Ma Bell. > > If my memory serves me correctly, the system had a pair of PDP-11/10s that > ran Hal Alles's digital filter code, a PDP11/70 behind the whole thing, > Harry Breece's active replacement circuitry for the hybrid transformers, > and some huge insanely fast wire-wrapped boards designed by John Sheets > that did TDM switching. > > Jon --------------gU6riilwkPFXWO2IirNFg3iV Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: 7bit To answer Jon's following question (2 minutes later):
Oh yeah, and I think that this is why Heinz wrote MERT,
but he should know more than me about it.
Yes, my Dept. in MH was involved in the early days of digital switching
and the need for real-time response was certainly recognized.
But MERT was not developed with a specific telephony project in mind.
I was mostly involved in software in support of current projects
being done in the Dept. We started the MERT project at the
time that DEC announced their PDP-11/45 mini-computer in
the early 1970's because it supported 3 separate address
spaces - system, supervisor, and user. This enabled us to
run operating system environments with different user
application program needs, specifically real-time under
control of one supervisor and time-sharing applications
in another supervisor, to start with. Hence its name -
Multi-Environment Real Time (MERT). Once we had MERT up
and running on the PDP-11/45 and PDP-11/70 computers, some
projects in other Bell Labs locations involved in telephony projects
started building their projects on the MERT system. The
DMERT system was developed later on by projects at yet
another Bell Labs location.

Heinz

On 9/25/2023 6:37 PM, Jon Steinhart wrote:
segaloco via TUHS writes:

Hello, my studies lately bring me to the question: Are there any extant
examples of telephone switching software, built on UNIX, from the various
parts of the Bell System prior to the introduction of the 5ESS and 3B20D?
My focus veers earlier as some 5ESS/3B20D/DMERT technology is still in
active use, that sleeping dragon can lie.

What's gotten me curious is reading about 1ESS in a BSTJ volume I
picked up, noting the particulars on how previous concerns of manual and
electro-mechanical systems were abstracted into software.  Even without
surviving examples, were previous systems such as the 1ESS central
control ever ported to or considered for porting to UNIX, or was the
hardware interface to the telco lines too specific to consider a future
swap-out with, say, a PDP11 running arbitrary software?  Columbus's SCCS
(switching, not source code) also comes to mind, although all I know that
survives of that is the CB-UNIX 2.3 manual descriptions of bits and pieces.

By the way, it's funny, I have UNIX to thank for my current experiments
with telephones and other signalling stuff, what with making me study the
Bell System more generally.  It's starting to come full circle in that I
want to take a crack at reading dialing, at least pulse, into some sort
of software abstraction on a SBC that can, among other things, provide a
switching service on top of a UNIX-like kernel.  I don't know what I'd do
with such a thing other than assign work conference call rooms their own
phone numbers to dial with a telephone on a serial line...but if I can even
get that far I'd call it a success.  One less dependency on the mobile...

- Matt G.

Heinz might know something about this.  If I remember correctly, one of the
projects in his group was SS1, an all-digital exchange.  I have some vague
memory of him and Carl poring over some gigantic switch statement looking
for a bug - the long distance code wasn't sending the ST pulse and as a
result all of the key pulse senders at the Berkeley Heights telephone
exchange were taken off line and needed a technician to go in and manually
reset them.  They were not amused.  Fortunately, they and BTL were both
children of Ma Bell.

If my memory serves me correctly, the system had a pair of PDP-11/10s that
ran Hal Alles's digital filter code, a PDP11/70 behind the whole thing,
Harry Breece's active replacement circuitry for the hybrid transformers,
and some huge insanely fast wire-wrapped boards designed by John Sheets
that did TDM switching.

Jon

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