From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: tuhs-bounces@minnie.tuhs.org X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.6 required=5.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE, T_DKIM_INVALID autolearn=ham autolearn_force=no version=3.4.1 Received: from minnie.tuhs.org (minnie.tuhs.org [45.79.103.53]) by inbox.vuxu.org (OpenSMTPD) with ESMTP id 4737c461 for ; Mon, 2 Jul 2018 09:57:11 +0000 (UTC) Received: by minnie.tuhs.org (Postfix, from userid 112) id 54741A1DE3; Mon, 2 Jul 2018 19:57:10 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 94CB9A183B; Mon, 2 Jul 2018 19:56:38 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=fail reason="key not found in DNS" (0-bit key; unprotected) header.d=kev009.com header.i=@kev009.com header.b=EWfMQpJk; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id 9C9DAA183B; Mon, 2 Jul 2018 19:56:35 +1000 (AEST) Received: from mail-io0-f170.google.com (mail-io0-f170.google.com [209.85.223.170]) by minnie.tuhs.org (Postfix) with ESMTPS id CA341A183A for ; Mon, 2 Jul 2018 19:56:34 +1000 (AEST) Received: by mail-io0-f170.google.com with SMTP id s26-v6so14209381ioj.4 for ; Mon, 02 Jul 2018 02:56:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kev009.com; s=google; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=9BMB4bXTy0ppfZrbWcM9m2dz3Q5E0uFuxA/HfxQZzY0=; b=EWfMQpJkPrctHSYCzJKKg4OWzupE/uPRG7BPZ0sXzjwe2mNbcqZ8C1Asj0fWGzR3wd SF22I+HE/3OBDAYRWFnJacbljMQ0tcdrMeFm2kuUhJftfMP1RLAodVBEyQJAy2hqnYGY Og91J1nLGyTCZLenlVM53vj/rvZhlZCKvhzgo= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=9BMB4bXTy0ppfZrbWcM9m2dz3Q5E0uFuxA/HfxQZzY0=; b=MsoYIRxv5QwsqgCc1v8Wz/MTxhSxH9w6dAKMdO8v75Vtk6LfYNR5ysLkTJxfHLtjKb xYh8KX8P6HIwl02bF2SnbYkhxWRwFh2yU4SDfZ5YyL/7AkK0mHhd8g4i7piOgjYTc/wl XmYLpD0z52mnAUc0+xBBkXynwNTuJ0SD82vKA/gtxPZNqKyCMAX78fXhSZB6uXFKgV0M fbKVSfqTAQydvqQWkA2SkzWZMGHS8BIX6qyRRX5fBJQuiKIzhGImqJW1XOjHlpyAVjAw fvUCm4G2+yZSUbW+3lAstXy/3mI9c56ZpfiHaT2b37cylqJJb1uINHxJtehUzlwkjf9l 7FDw== X-Gm-Message-State: APt69E0Mz4zwN1y83a65bXY4UiE1MbUUY2AfvXycNrVPcjWn4wxhr6yq 4uVnwgua9sUvpkPAIaS08wTJPxiVWnlkAATUSSQQyQ== X-Google-Smtp-Source: AAOMgpdiJ9FuXhLDoctVDkHtTAjUv7J2sEZZGOwkznpQtpOz809iGdr+JMCSkangeT2oJk+3X2pIx4oQtPcv88uR4as= X-Received: by 2002:a6b:2381:: with SMTP id j123-v6mr21267383ioj.251.1530525394140; Mon, 02 Jul 2018 02:56:34 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a02:5343:0:0:0:0:0 with HTTP; Mon, 2 Jul 2018 02:56:33 -0700 (PDT) In-Reply-To: <285b5c9f6210cfbc4f2ff3a84c11e674cc230879@webmail.yaccman.com> References: <201806301824.w5UIOO71062430@tahoe.cs.Dartmouth.EDU> <285b5c9f6210cfbc4f2ff3a84c11e674cc230879@webmail.yaccman.com> From: Kevin Bowling Date: Mon, 2 Jul 2018 02:56:33 -0700 Message-ID: To: Steve Johnson Content-Type: text/plain; charset="UTF-8" Subject: Re: [TUHS] AT&T Hardware (3B2) X-BeenThere: tuhs@minnie.tuhs.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: The Unix Heritage Society mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: The Eunuchs Hysterical Society , Doug McIlroy Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" I have several working 3B2s and a non-working 3B1 aka UNIX PC/ 7300. Your story sounds more like a 3B1 where Convergent Technologies was the ODM (original design mfg). I've seen Convergent branded 7300s in collections or for sale. The various 3b2 models are a relatively simple backplane design, the cards are all discrete chips on small boards that aren't very dense integration vs other contemporary systems. I couldn't see more than a few manual reworks being more cost effective than reving the PCBs on it, especially because it was a "serious system". Wikimedia has a good pic of the first model, 3B2-300, main board https://upload.wikimedia.org/wikipedia/commons/3/3d/3b2-300-motherboard.jpg One thing I've desired are contemporary pictures of the 3B5, 3B15 and 3B20 if anyone knows of intact machines. On Sun, Jul 1, 2018 at 6:29 AM, Steve Johnson wrote: > The 3B2 was designed for AT&T by Convergent Technologies. I later worked > with several people at Convergent, one of whom had a framed circuit board on > his wall. It was a wonder to behold -- the board had wires all over it that > were added later, and nearly a dozen "bugs" -- in the days of discrete logic > chips, a bug was when you took another chip and glued it, upside down, on > top of an existing chip and then ran wires to the pins in the air. As I > recall, the story was that the first demo of the 3B2 happened roughly six > weeks after the initial request, using the board on the wall. Now, that's > what should really be in the computer museums... > > In those days, if there was floating point it was a separate chip, and the > 3B2 had none. Floating-point instructions caused a fault, which meant a > context switch to the OS, where the instruction was emulated and then the > program returned. The performance, as I recall was about 800 FLOPS - > dismal. We fixed the compiler so it would generate calls to subroutines > that did the floating point operations, and the performance improved by over > an order of magnitude -- still dismal, but no longer ridiculous... > > One of the events that led me to leave AT&T was that they fired the head of > the benchmarking group at Indian Hill, a most competent woman, because they > didn't like the results she was presenting. When a company's information > channels stop functioning reliably, it's time to leave... > > Steve > > > > ----- Original Message ----- > From: > "Doug McIlroy" > > To: > > Cc: > > Sent: > Sat, 30 Jun 2018 14:24:24 -0400 > Subject: > Re: [TUHS] AT&T Hardware > > > Anent 3B's: Last time I visited Paul Allen's Living Computer Museum > the only working Unix on display was running on a 3B2. Apparently > the machine was robust if nothing else. > > doug