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=-1.0 required=5.0 tests=MAILING_LIST_MULTI, T_SCC_BODY_TEXT_LINE,UNPARSEABLE_RELAY autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 6236 invoked from network); 16 Feb 2022 14:56:12 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 16 Feb 2022 14:56:12 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id 72C7C9D044; Thu, 17 Feb 2022 00:56:09 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 7B7B89D036; Thu, 17 Feb 2022 00:54:22 +1000 (AEST) Received: by minnie.tuhs.org (Postfix, from userid 112) id 63B749D036; Thu, 17 Feb 2022 00:54:20 +1000 (AEST) Received: from mail-wr1-f52.google.com (mail-wr1-f52.google.com [209.85.221.52]) by minnie.tuhs.org (Postfix) with ESMTPS id 9D5569D035 for ; Thu, 17 Feb 2022 00:54:19 +1000 (AEST) Received: by mail-wr1-f52.google.com with SMTP id d27so3908255wrb.5 for ; Wed, 16 Feb 2022 06:54:19 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:references:date:in-reply-to :message-id:user-agent:mime-version:content-transfer-encoding; bh=driEH3Wjg+auxsNiOYxZIqh9AVbo886+yVXq4xMISj8=; b=E27sWdS3V9mI731Anj+OLSz1dtnB+JCWfJAU0UHkCAsgX3Yeg7KZm/2TI1UEIV6n8P MEdG39ws6jhMzOfsGaDVb1Ezbedmc++RX3nxrYT70bmko00UqsHuSbRY7R2dqDKv7GhO eS/cm3sDl7+huNs/wlrF4YeuLt4G1CHepm7My+l87khuAHa5FlivciX7LJCuQF5f8GDR ijGKHug50TRYZ2fwmDtn4uA2/x1FIhFDU0zvIHz/ueDL94owRwjBUf98lhLobCIfYYzo 736GeFd6w0IwLG+HSfgfjDcSIElVdeKH2YhNH80phtn72Y2UeqjvsUx7LCfU4HQMdB2Q 2+0w== X-Gm-Message-State: AOAM532KZOKrvHNjYaABa81BSF3MPqBwHeApQxm50viRCb8OAx130mG4 7lurRJExBZu7urXckSpK5TvAnk7+FB8= X-Google-Smtp-Source: ABdhPJyT/BTgkwDa0zTyv6fJ7QWa5ML7+8WpSuxzbPpQcV9m6L2bhfJECiEnRqlTg/FaIsuysrxedw== X-Received: by 2002:a05:6000:108b:b0:1e3:222a:25dd with SMTP id y11-20020a056000108b00b001e3222a25ddmr2685063wrw.481.1645023257997; Wed, 16 Feb 2022 06:54:17 -0800 (PST) Received: from rhea.home.vuxu.org ([2a01:4f8:c010:17cd:ea6a:64ff:fe4d:ff9e]) by smtp.gmail.com with ESMTPSA id 1sm11920184wrz.75.2022.02.16.06.54.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Feb 2022 06:54:16 -0800 (PST) Received: from localhost (rhea.home.vuxu.org [local]) by rhea.home.vuxu.org (OpenSMTPD) with ESMTPA id 4f0823a5; Wed, 16 Feb 2022 14:54:16 +0000 (UTC) From: Leah Neukirchen To: markus schnalke References: <202202160754.21G7sbUa011318@freefriends.org> <1nKFRN-4IZ-00@marmaro.de> Date: Wed, 16 Feb 2022 15:54:16 +0100 In-Reply-To: <1nKFRN-4IZ-00@marmaro.de> (markus schnalke's message of "Wed, 16 Feb 2022 09:13:33 +0100") Message-ID: <8735kig8vb.fsf@vuxu.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [TUHS] Lorinda Cherry X-BeenThere: tuhs@minnie.tuhs.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: The Unix Heritage Society mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: tuhs@minnie.tuhs.org Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" markus schnalke writes: > Hoi. > > [2022-02-16 00:54] arnold@skeeve.com >> Dave Horsfall wrote: >> > >> > You know you're a greybeard if you can remember why the DC sequence=20 >> > "99k2vp8opq" was so popular... >> > >> > -- Dave >>=20 >> I guess I'm not enough of a greybeard: >>=20 >> $ dc >> 99k2vp8opq >> 1.4142135623730950488016887242096980785696718753769480731766797379907\ >> 32478462107038850387534327641572 >> 1.3240474631771674622042627661154672512575174353366027242235650231664\ >> 2753102603147144252257620301035270505416503 >>=20 >> I recognize the first value as the square root of two. What is >> the second value? > > Decoding the program with the manpage: > > 99k set scaling factor to 99 (i.e. 99 digits on output) > 2v square root of 2 > p print it (but leave it on the stack) > 8o switch to octal output > p print the same value (now in octal) > q quit > > More interesting is the question why you need sqrt(2) in octal? Apparently it was a popular benchmark back in the day: https://www.tuhs.org/Archive/Documentation/AUUGN/AUUGN-V05.1.pdf > Tim Long: Quick Benchmarks of the Machines on Display > A simple cpu-bound benchmark was run on each of the machines on display. > The benchmark was "echo 99k2vp8opq I /bin/time dc > /dev/null=E2=80=99. I= t uses dc > (the desk calculator) to calculate the square root of 2 to 99 decimal pla= ces, > and to "print" the result in decimal and then in octal. The results are in > fact never printed, being piped to /dev/null. The user time is all that is > compared. > This benchmark has been applied to a large number of machines=C2=B0 It has > (up until now) been useful because most manufacturers have not optimised = dc, > so the results are not likely to have been distorted by attempts to optim= ise > for benchmarks. > The results were: > DoEo UNITY (DE-68K) 11.3 sec > Plexus P/25 14.1 sec > NCR Tower 21.3 sec > Wicat 150WS 27.3 sec > Unison 32.6 sec > By comparison, a VAX 11/780 clocks about 5 to 6 secs, VAX750 9 sec, PDPIIs > range from 27 secs (11/23) to 6 secs (11/70), PDP ii/34s range from 12 to= 19 > secs depending upon the presence of a cache. Perkin-Elmer range from 12o5 > secs (32/10) to 7=C2=B09 secs (32/40)o I looks like V7 dc used 100-limbs internally, so printing in decimal was fast, but printing in octal required conversion. --=20 Leah Neukirchen https://leahneukirchen.org/