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 autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 25820 invoked from network); 19 Sep 2023 15:51:08 -0000 Received: from minnie.tuhs.org (2600:3c01:e000:146::1) by inbox.vuxu.org with ESMTPUTF8; 19 Sep 2023 15:51:08 -0000 Received: from minnie.tuhs.org (localhost [IPv6:::1]) by minnie.tuhs.org (Postfix) with ESMTP id C4E5440963; Wed, 20 Sep 2023 01:51:04 +1000 (AEST) Received: from mail-lj1-x234.google.com (mail-lj1-x234.google.com [IPv6:2a00:1450:4864:20::234]) by minnie.tuhs.org (Postfix) with ESMTPS id 0DD284095D for ; Wed, 20 Sep 2023 01:50:58 +1000 (AEST) Received: by mail-lj1-x234.google.com with SMTP id 38308e7fff4ca-2b962535808so93290971fa.0 for ; Tue, 19 Sep 2023 08:50:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1695138656; x=1695743456; darn=tuhs.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=9TALhs0G3dYvQ24n3SLqlzPf/xHZg8gisnoliazqqgo=; b=K2KNfKmsyrol/MY+htK+Uje7sEEVrWURwQsUyTrHs3qGJMPuqizyHIn087IydG8m+6 TOgKdbCiLByMMkFgbMrSXkUjKwoEQHCbcTYOmmW83Puc0MPnwssHLfvVHp3VC4TzzLtV acnvqWzfQavF0G52WlHzDQQbmnH6MYqrEGk60YMfG3K9oNLJYGYW28e91uI3sYS9dxjI 7SxwjAqRPwNISqNAdCF1EapML6JhhswAiCfw+6gR6P5fv+gZIsHeJBoZGZr+Gl+UbXqc 39be/BKV85dHRX2Xy4QQMjF5liLHjd8nlN0kpbZ1m/J7iIkJDn6EyEXgiSczQBkR3iRF 3TDw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1695138656; x=1695743456; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=9TALhs0G3dYvQ24n3SLqlzPf/xHZg8gisnoliazqqgo=; b=oxAGdx9z9rv2CVkS4Ct7a0Zu74Mnd05fAEJcNk5VMnOy6F0RoYP9nd695P/V85LkLp aW/cHZLGXvEHY2ixLMfENvD5/K0SFlF2u31auqUaA9xyadpJOfbHcTDv6t7ZNj5NnR1l bra6RXdMfIGBG1SJDErmm4BrhDDHsFjBJl6JvteZjSHJvCw9JJjfOaESdOSV0b6uG1PO p57NMf/4FuAUAyMWug8IFoZYcUOUYBN4ZDtWaSReWvQzNRW+uQSbeT2SzyZtKBqtly5e jBgrks2dNRIn78/qnupz5EhYFsoi02YV1/P3iHnItk6VlQX+qUvQCa2OftAzlrKaoUdg kT9Q== X-Gm-Message-State: AOJu0Yw7sPgJFK6r7vOULEaICP41Ena8lKoYK6A4Fm30c/plK/CHNqdD +VJX7ptd7kfwojI52QjnPI9u46ZBBkiiqZ9thEM= X-Google-Smtp-Source: AGHT+IGvDHK64NsSeubysRYGOKKl1QGFjQvNrf6E9TiVkjUFlhIKsSesOOku6GF7cI1Y5+1Nr9f22PYCX5jjJz8feNM= X-Received: by 2002:a2e:9a88:0:b0:2bf:fd7c:c82f with SMTP id p8-20020a2e9a88000000b002bffd7cc82fmr7263154lji.22.1695138655699; Tue, 19 Sep 2023 08:50:55 -0700 (PDT) MIME-Version: 1.0 References: <87246EC9-0AC8-404E-A8DD-508AB046018B@planet.nl> In-Reply-To: From: Dan Cross Date: Tue, 19 Sep 2023 11:50:19 -0400 Message-ID: To: Paul Winalski Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Message-ID-Hash: I5Z4DXPQVKOPNWPXDT32OSIZYMBQTTNZ X-Message-ID-Hash: I5Z4DXPQVKOPNWPXDT32OSIZYMBQTTNZ X-MailFrom: crossd@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: Paul Ruizendaal , "tuhs@tuhs.org" X-Mailman-Version: 3.3.6b1 Precedence: list Subject: [TUHS] Re: CRC calculation in the 1980s List-Id: The Unix Heritage Society mailing list Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: On Tue, Sep 19, 2023 at 11:34=E2=80=AFAM Paul Winalski wrote: > For what it's worth, the VAX had a table-driven CRC instruction. It > wasn't very popular because on most VAX models it was actually slower > than by-hand coding. It is one of the instructions dropped from the > microVAX instruction set used on all later VAXen, where it was > emulated by the operating system. I thought that was a general polynomial root finder instruction that used Horner's Method? Obviously it could be used in CRC calculations, but I remember it being more general. I also remember reading about it in the VAX architecture manual and thinking, "wow, that's...something." - Dan C.