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Sender: "piclist-bounces@mit.edu" Date: Thu, 28 May 2020 16:39:20 -0700 Subject: Re: [EE]:: Reversing Sinclair's amazing 1974 calculator hack - half the ROM of the HP-35 | & Some HP35 links Thread-Topic: [EE]:: Reversing Sinclair's amazing 1974 calculator hack - half the ROM of the HP-35 | & Some HP35 links Thread-Index: AdY1Srk8Lm2K4a+GRG6DX2gyZEBuaQ== Message-ID: <20200528233920.GD3423@laptop.org> References: List-Help: List-Subscribe: , List-Unsubscribe: , In-Reply-To: Reply-To: Microcontroller discussion list - Public. Accept-Language: en-US X-MS-Exchange-Organization-AuthAs: Anonymous X-MS-Exchange-Organization-AuthSource: TS500.efplus4.local X-MS-Has-Attach: X-Auto-Response-Suppress: All X-MS-Exchange-Organization-SenderIdResult: TempError X-MS-Exchange-Organization-PRD: mit.edu X-MS-TNEF-Correlator: received-spf: Pass (protection.outlook.com: domain of laptop.org designates 209.85.210.173 as permitted sender) receiver=protection.outlook.com; client-ip=209.85.210.173; helo=mail-pf1-f173.google.com; dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=laptop-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=hw53IyMiksvXxmnKFF7zxI6+NOZivsG3b3Wxkbpcq6k=; b=v2gaAW4SupdIPwFwZO472RnSL+T50pIKYrNduMxBUQS7RoK/xSWJXC0u/vprcVXTxz bfm3IZLXyD3H+85S4HmqBwqtZH18dJGa9JArSWu4m46QDv2pIQbfRCRzIXPwJd5QtDKX ixU/WlE/RqtVpgBhvt/1SWI1xGC1reMb1C6POlIlEI3unmF+htH6vh1+HZkC2VsvtZcX 5XMoc2yUdSKsV+5IUmUNb/PlwTcGZGJ6qzepLfX19w1Q9o5wnsCLBZqQcoaLtrqiAWs/ new3I+BD3W1vCWFdDxFDD6aK0+UVPkgZXYnR1ODlPFxSVd4nHvITLEfS1PVFjtUqkYEQ PUlA== authentication-results: spf=pass (sender IP is 209.85.210.173) smtp.mailfrom=laptop.org; mit.edu; dkim=pass (signature was verified) header.d=laptop-org.20150623.gappssmtp.com; mit.edu; dmarc=bestguesspass action=none header.from=laptop.org;compauth=pass reason=109 user-agent: Mutt/1.9.4 (2018-02-28) errors-to: piclist-bounces@mit.edu list-id: "Microcontroller discussion list - Public." list-post: x-beenthere: piclist@mit.edu x-mailman-version: 2.1.6 x-received: by 2002:a62:7bc8:: with SMTP id w191mr5910048pfc.30.1590709165251; Thu, 28 May 2020 16:39:25 -0700 (PDT) x-topics: [EE] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 On Thu, May 28, 2020 at 02:17:17PM -0500, John Gardner wrote: > ... https://www.jwz.org/doc/worse-is-better.html >=20 > ! The anecdote paragraph that starts "Two people, one from MIT and another from Berkeley", reminds me of EINTR, interrupted system call, which is something that can happen rarely on UNIX and Linux when you ask the operating system to read or write exactly this many bytes from a file descriptor or network socket. Most code doesn't anticipate it. These programs work 99% of the time, and fail ingloriously at the first sign of it, usually when an operating system is heavily loaded. Some code checks for the condition, and retries the operation. When used on a heavily loaded operating system, these programs bring the system further to its knees. i.e. exactly what was requested. --=20 James Cameron http://quozl.netrek.org/ --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .