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=-0.4 required=5.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 bf57df55 for ; Thu, 21 Jun 2018 20:39:57 +0000 (UTC) Received: by minnie.tuhs.org (Postfix, from userid 112) id B6B4FA1832; Fri, 22 Jun 2018 06:39:56 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 1C229A181C; Fri, 22 Jun 2018 06:39:30 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b=o3Vpeb0u; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id CE1B1A1817; Fri, 22 Jun 2018 06:39:26 +1000 (AEST) Received: from mail-lf0-f67.google.com (mail-lf0-f67.google.com [209.85.215.67]) by minnie.tuhs.org (Postfix) with ESMTPS id D683CA1816 for ; Fri, 22 Jun 2018 06:39:25 +1000 (AEST) Received: by mail-lf0-f67.google.com with SMTP id e13-v6so6261150lfc.1 for ; Thu, 21 Jun 2018 13:39:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=F44TwhrCwniOw5EbfU1KC/bsCOPV7QVLuMJGpCXgqRg=; b=o3Vpeb0ukqdllFM/Z/yiNecJKSLH2BfiJ9Y4SFJFcZgsMEZCUigKXMSX6fKuykUXWb cokKD2lqC7332SRuv1GriJIEaEVL3C0cRA8eU2jNOVkojaKHyiB7p3TijN/h78Y3+y9a XacRZZ0Lho1Xrq356/mOvrVPoZDZo8DYS8RDj5Qfak8PpcslWZJHpIE8HwWFs+EfzO72 mhFWcLU0N9H9BYnzi6500Kx2mViCbocAuIFmUX+lHvCZcIJjvjdj9z2GFHetlVGE2IfE fK0FNRxqxUjO6a99x5XX9AFSmo6rbOk5QRuzkBnt/Iw+Y2x0t8oNe9aIVOQ+G3rCw83s OubA== 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:content-transfer-encoding; bh=F44TwhrCwniOw5EbfU1KC/bsCOPV7QVLuMJGpCXgqRg=; b=dIjWjp0V2TBmFE+IGuHAopwYgfwPUtzVhMdhzY9s39GBLN2YsWOswLad4RuHcram5C UbT0Ad3VFgPrnpLmY+D43xap2avZSoQJaW0wNX4v+30f7gaegpx4XVDUWbU4qp0eY5Kb vxd1OiuORTpoqXki7hNjxYAVNvhFLynclFAR2gcQMJT4tg6q9WI3CTlS+L2yBkoLEOqo mymbHyj2rP3Yn7FVq5oCJWRmpEfN5ZzNpbiCKzE5ETbwXsGSVHFJcXs6ouNlme0m/g1W hmupGySD84bfKgGKTRHFmQMZeKJqcYUlawLqBWs2KHMTMyjK1/nAh7Gpbu3bIQeZW8rS ssLQ== X-Gm-Message-State: APt69E0p+13+lJFydhNWBAtYuyi8rn/ZuCU8RUXgHACd181UabuFZ5Dd QmUw7ePFVewsR6sgfB9sB0E1aIU3EKzsR4xxEDQ= X-Google-Smtp-Source: ADUXVKI5X5xZxoQo351MURB6TQ3lFVIZwkWqrI5WZCLUVkhC8Lu681S2gV/kNifsWFvBfLMmFvhaNQ3jhFfsSfaBYdI= X-Received: by 2002:a2e:120b:: with SMTP id t11-v6mr17574785lje.57.1529613563999; Thu, 21 Jun 2018 13:39:23 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a2e:104c:0:0:0:0:0 with HTTP; Thu, 21 Jun 2018 13:39:23 -0700 (PDT) In-Reply-To: References: <20180619204536.GA91748@server.rulingia.com> <20180620050454.GC91748@server.rulingia.com> <20180620081032.GF28267@eureka.lemis.com> <20180621030505.GA89671@server.rulingia.com> From: Paul Winalski Date: Thu, 21 Jun 2018 16:39:23 -0400 Message-ID: To: Arrigo Triulzi Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Subject: Re: [TUHS] Old mainframe I/O speed (was: core) 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 Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" On 6/21/18, Arrigo Triulzi wrote: > On 21 Jun 2018, at 16:00, Paul Winalski wrote: > [...] >> for the microcode to customers. There were several hacks in there to >> slow down the disk I/O so that it didn't outperform the model 30. > > Is this the origin of the lore on =E2=80=9Cthe IBM slowdown device=E2=80= =9D? > > I seem to recall there was also some trickery at the CPU level so that yo= u > could =E2=80=9Cfield upgrade=E2=80=9D between two models by removing it b= ut a) I cannot find > the source and b) my Pugh book is far and cannot scan through it. I don't know about that for IBM systems, but DEC pulled that trick with the VAX 8500 series. Venus, the successor to the 11/780, was originally to be called the 11/790 and was done in ECL by the PDP-10 folks. The project suffered many delays and badly missed its initial market window. It eventually was released as the VAX 8600. It had a rather short market life because by that time the next generation CPU, codenamed Nautilus and implemented in TTL, was nearly ready for market and offered comparable performance. There was also a slower and lower cost system in that series codenamed Skipjack. When it finally came time to market these machines, it was found that the product line needed a reduced cost version of Skipjack. Rather than design a new CPU, they just put NOPs in the Skipjack microcode to slow it down. The official code name for this machine was Flounder, but within DEC engineering we called it "Wimpjack". Customers could buy a field upgrade for Flounder microcode that restored it to Skipjack performance levels. -Paul W.