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_INVALID,DKIM_SIGNED, MAILING_LIST_MULTI,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 12203 invoked from network); 9 Sep 2022 17:27:59 -0000 Received: from minnie.tuhs.org (50.116.15.146) by inbox.vuxu.org with ESMTPUTF8; 9 Sep 2022 17:27:59 -0000 Received: from minnie.tuhs.org (localhost [IPv6:::1]) by minnie.tuhs.org (Postfix) with ESMTP id 14F7B422C0; Sat, 10 Sep 2022 03:27:54 +1000 (AEST) Received: from mail-io1-f51.google.com (mail-io1-f51.google.com [209.85.166.51]) by minnie.tuhs.org (Postfix) with ESMTPS id AA13E422BE for ; Sat, 10 Sep 2022 03:27:49 +1000 (AEST) Received: by mail-io1-f51.google.com with SMTP id r134so1977549iod.8 for ; Fri, 09 Sep 2022 10:27:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dartmouth.edu; s=google1; h=to:subject:message-id:date:from:mime-version:from:to:cc:subject :date; bh=hQxF9Al8eCiGgvui5umizSbBQRl/tgwU3mTEcRdJFxA=; b=BoqghADlLotLRQ7cdIAKsyanrk6orzWyJRIwEdINoVMwQ22jdQ3pqgOV9C8LEBah/B eoGg1WbV8j8mDYwoA2+uVlyPICNVf0dJLnhLJIg68bX9Sgtz9j1DgGDg3EDTBHG7mS4W vPWga3DuomqfEjM6PaTaaS0EbJT8ys39zX6cFZGrrXlbDEtS78QxdqeFGs8aKpIACWGQ 91IhlBQSS22HaawpHXCL2+tepd1wdxYojhYM8xKe0t0i4qwDLRwIj7gQ3pwSSaTTSUrC zjAsCXgTvTnah8x/TvHJ4DsJx0tzc1xfTWO/REyaihDjcRZdPfqrlR0c258weldGtMsL tH6w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=to:subject:message-id:date:from:mime-version:x-gm-message-state :from:to:cc:subject:date; bh=hQxF9Al8eCiGgvui5umizSbBQRl/tgwU3mTEcRdJFxA=; b=IRmAKW4vLiFPy1IAppI5hinoVrkH/v1OBqUBRFTkpOGlooOJe/O1E6OSFGV4Kz8DzX 3r6o2+Q8oXjFNAWD3mRpuhMnZbGn9/Rq8N6E/1idIdo8xx58qfKVHruCs3ug+MKdqpvR dV1WYU4GDAGCxljXqu2tnzI4oFkEBVR0tCBfS2EDEZM7Zx6wCI1xQOdA2QUaM5XULWL+ Uq5mNVI2lgcaHvbHxeI25BimLkUY0HqDi6Hc2BeGYQsu+2+HbSVFLa4MbbgdnlxOdqnT J0kvCzyX+r10cdQQ8fM3T1QDc0mbx+wh1HBM5QpSc/jpqA190bQTfyoTf6tLfWkc98NM oVnw== X-Gm-Message-State: ACgBeo3t5uLzLbkL4pqLkrbARBRC9wNVUzZpT9vVu4M7xwjfHYgkPfkO 5gCKfgIkabTaIwkR0pvWC1ChC4NlcQGsycO6LN8uEXpxjsEWRQ== X-Google-Smtp-Source: AA6agR47FEDHEunZC1gdO7nfOzkpCtNBHpZGNiZuFptqtwfhEofk2G26b6CjEjwLhP+FCK/B+MK7vqKkBwzEa3cM0eI= X-Received: by 2002:a02:3c12:0:b0:34a:1d2f:6b5a with SMTP id m18-20020a023c12000000b0034a1d2f6b5amr7731720jaa.173.1662744407410; Fri, 09 Sep 2022 10:26:47 -0700 (PDT) MIME-Version: 1.0 From: Douglas McIlroy Date: Fri, 9 Sep 2022 13:26:31 -0400 Message-ID: To: TUHS main list Content-Type: text/plain; charset="UTF-8" Message-ID-Hash: HOG4K2GFKQ37LTAYRRWO7W56MO6YQ2DC X-Message-ID-Hash: HOG4K2GFKQ37LTAYRRWO7W56MO6YQ2DC X-MailFrom: douglas.mcilroy@dartmouth.edu X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; header-match-tuhs.tuhs.org-0; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.6b1 Precedence: list Subject: [TUHS] Re: Does anybody know the etymology of the term "word" as in collection of bits? List-Id: The Unix Heritage Society mailing list Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: > Doug or anyone, why do bit pointers make sense? Why? Bit-addressing is very helpful for manipulating characters in a word-organized memory. The central idea of my ancient (patented!) string macros that underlay SNOBOL was that it's more efficient to refer to 6-bit characters as living at bits 0,6,12,... of a 36-bit word than as being characters 0,1,2,... of the word. I've heard that this convention was supported in hardware on the PDP-10. In the IBM 7020 floats and ints were word-addressed. But those addresses could be extended past the "decimal point" to refer to bits. Bits were important. The computer was designed in parallel with the Harvest streaming "attachment" for NSA. Harvest was basically intended to gather statistics useful in code-breaking, such as frequency counts and autocorrelations, for data typically encoded in packed 5- to 8-bit characters. It was controlled by a 20-word "setup" that specified operations on rectangular and triangular indexing patterns in multidimensional arrays. Going beyond statistics, one of the operations was SQML (sequential multiple lookup) where each character was looked up in a table that specified a replacement and a next table--a spec for an arbitrary Turing machine that moved its tape at byte-streaming speed! Doug