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_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FROM,MAILING_LIST_MULTI, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 21003 invoked from network); 19 Dec 2023 21:31:57 -0000 Received: from minnie.tuhs.org (50.116.15.146) by inbox.vuxu.org with ESMTPUTF8; 19 Dec 2023 21:31:57 -0000 Received: from minnie.tuhs.org (localhost [IPv6:::1]) by minnie.tuhs.org (Postfix) with ESMTP id 4C83043E7A; Wed, 20 Dec 2023 07:31:52 +1000 (AEST) Received: from mail-pf1-x434.google.com (mail-pf1-x434.google.com [IPv6:2607:f8b0:4864:20::434]) by minnie.tuhs.org (Postfix) with ESMTPS id 299E843E79 for ; Wed, 20 Dec 2023 07:31:45 +1000 (AEST) Received: by mail-pf1-x434.google.com with SMTP id d2e1a72fcca58-6d9389583edso837302b3a.0 for ; Tue, 19 Dec 2023 13:31:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1703021504; x=1703626304; darn=tuhs.org; h=cc:to:subject:message-id:date:from:references:in-reply-to :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=pF9a9+vxHfS6GMK1Skj19Mqz7Ik1MNlreEhAEBrPxEg=; b=K00+iC8YF+aSTlllvqvkNf+cR7vJMLZczIN9pW3M5KRt4C2MZwjOxdMEw1g/KojbmZ Nsrn8E9LFp64hkkdUW7OziAE8FDiyPPoj3R8ET1iIaMU/K4msxhYVdVd0QHNTKfTPXIk MIKTaBrV8anfLq3mvL5LNE8bQXSs2xSBsYRRcFgGj2OnOTe8cu3wgKwOpHY8FRg+zZaL Pid5/8JnpiaGv6SDSFJ3sCZmeg6/oU4sliy5TOZyd0oEoXyhGEBJHSTeZQwUzLnMrzTi HBw2RLkh895XpfYccUVSYdeSy4/2aOHSRnioI2eq5yaLuMSomctoNtVya6IOR8zUGX24 RTGA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1703021504; x=1703626304; h=cc:to:subject:message-id:date:from:references:in-reply-to :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=pF9a9+vxHfS6GMK1Skj19Mqz7Ik1MNlreEhAEBrPxEg=; b=AUc9DSHUPP+ASFSS6oSl87te9OwYfCZQ+KOqMp9VHdRKxd1NX1XmrU6mxFGBGXKcNy nXeHVru3lU6lCCX2SnyPA0aDEiVnaal3qjAoT949ulreNAlOqzilYgGVjdkLisagukZk ulX1dILA8GtZTwU9BEBMRzFGbNpC9Fzr3e+hAdfgSpRegnpjEsxr6mezSrDhE8BeY7QE NtXMl3wF6BlyAFeWsERAf5nc/oImbLuH/vYHW2/1bOzWn2hs5d0VUxqp/Y+QoS7nKQjj 4nhKgD2ONv17n9GaVcTK4RvgtJZGjKKeOA1QW1iVJ+jZHv0TJgStmYyKmqab7FKIyO0S I8VA== X-Gm-Message-State: AOJu0YwuKLAxItp0epQwnpncm+Q3E/StP3kjYEpJFyPOMGAc5wa4BhZM 0QzcdjJDQuCiZO0/P9KhdJYxE3I7iM+9WejZUQ3OTGPh X-Google-Smtp-Source: AGHT+IELz5gmJ4gU8mvipp4D1H1ijIf4Cti8ePjsGc08XYusG73iFaPrx26L5F6EYKm+UOo9gLdy1sKWIqugG4X1jAw= X-Received: by 2002:a05:6a00:1148:b0:6ce:515a:1dfb with SMTP id b8-20020a056a00114800b006ce515a1dfbmr22336211pfm.26.1703021504346; Tue, 19 Dec 2023 13:31:44 -0800 (PST) MIME-Version: 1.0 Received: by 2002:a05:6a10:844e:b0:52a:96f1:6718 with HTTP; Tue, 19 Dec 2023 13:31:43 -0800 (PST) In-Reply-To: References: <93ef58b9-b058-4463-b0e6-d2f2f2bf5a55@loomcom.com> <76f6ae7e-20e1-41fa-9fe4-cc22015411bf@mhorton.net> From: Paul Winalski Date: Tue, 19 Dec 2023 16:31:43 -0500 Message-ID: To: Clem Cole Content-Type: text/plain; charset="UTF-8" Message-ID-Hash: ZHOTNAYQG53QBEAOWXROBTH7VA5NLKW4 X-Message-ID-Hash: ZHOTNAYQG53QBEAOWXROBTH7VA5NLKW4 X-MailFrom: paul.winalski@gmail.com 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 CC: Tom Lyon , The Eunuchs Hysterical Society X-Mailman-Version: 3.3.6b1 Precedence: list Subject: [TUHS] Re: Compatibility question List-Id: The Unix Heritage Society mailing list Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: On 12/19/23, Clem Cole wrote: > Tom smiled while reading that man page: "It is assumed that the TN print > train is being used." > I have to wonder how many younger programmers know what a print train is, For the edification of those who don't know, the 1403 line printer and its brothers worked like this. There was a (removable and switchable) horizontal cartridge that sat midway in the printer, laid out horizontally across the paper, behind an ink-soaked cloth band located between the print train and the paper. Behind the paper was a series of 132 hammers (one per column of print). The cartridge contained a single chain of type that was spun at high speed. Whenever the position of a desired character passed in front of its desired colu, that column's hammer struck the back of the paper and thus printed the character. There were several print trains available, just as there were several typeballs for the IBM Selectric typewriter. One of these used a space character ' ' both for the space and for the underscore '_'. This was the origin of using underscores to represent spaces in program identifiers. The other way to do line printing is to have a rotating drum with the full character set for each column. This is the way the DEC line printers worked. Of course there were minor inaccuracies in the timing of the hammers, and with the drum-based printers this resulted in wavy lines. There were inaccuracies in the print train-style printers, too, but waviness in the columns is not as noticeable to the eye as waviness in the lines. Coming from the IBM world, I considered the DEC printers total junk. > Paul -- you left out the other "feature" -- the noise, which was still > deafening even with a model N1 and its cover. Yes, the 1403 was very loud. The pitch of the noise varied with the sequence of characters being printed. Some IBM hacker (yes, they existed) came up with a deck of cards that, when printed, played "Anchors Aweigh" on the 1403. IBM field service wasn't very keen on this hack because it put a lot of wear-and-tear on the print train. -Paul W.