From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=0.3 required=5.0 tests=MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE,RDNS_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.2 Received: (qmail 20404 invoked from network); 20 Mar 2020 18:43:42 -0000 Received-SPF: pass (minnie.tuhs.org: domain of minnie.tuhs.org designates 45.79.103.53 as permitted sender) receiver=inbox.vuxu.org; client-ip=45.79.103.53 envelope-from= Received: from unknown (HELO minnie.tuhs.org) (45.79.103.53) by inbox.vuxu.org with ESMTP; 20 Mar 2020 18:43:42 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id 5CCFF9D569; Sat, 21 Mar 2020 04:43:38 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id E81229CD83; Sat, 21 Mar 2020 04:43:09 +1000 (AEST) Received: by minnie.tuhs.org (Postfix, from userid 112) id 7DE609CD83; Sat, 21 Mar 2020 04:43:07 +1000 (AEST) Received: from cfcl.com (cpepool4cmts2-144.sanbrunocable.com [24.143.248.144]) by minnie.tuhs.org (Postfix) with ESMTP id 12F179CD73 for ; Sat, 21 Mar 2020 04:43:07 +1000 (AEST) Received: from spot.local (spot.local [IPv6:fe80::c25:43c7:e8ba:a938]) by cfcl.com (Postfix) with ESMTP id 930A8B49AF3 for ; Fri, 20 Mar 2020 11:43:06 -0700 (PDT) From: Rich Morin Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Mac OS X Mail 13.0 \(3608.40.2.2.4\)) Date: Fri, 20 Mar 2020 11:43:05 -0700 References: <202003132331.02DNVaxN061501@tahoe.cs.Dartmouth.EDU> <7ec47fd97b1a3d383ffed428f21f5287@firemail.cc> <6D9CA6C2-BDF2-4BCA-9503-0F8415C594C9@guertin.net> <211b9d54-573c-05d3-2c60-e15a9fc0b86b@tnetconsulting.net> <202003201640.02KGerlG470796@darkstar.fourwinds.com> To: TUHS main list In-Reply-To: <202003201640.02KGerlG470796@darkstar.fourwinds.com> Message-Id: X-Mailer: Apple Mail (2.3608.40.2.2.4) Subject: Re: [TUHS] The most surprising Unix programs 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: , Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" Back in the 70's, I bought an HP-67 for some ridiculous amount of money. = I only wrote one significant program on it, but I think folks here = might find the idea interesting. My X-Ray astronomy project at NRL = (HEAO A1) was using a CDC 3800 for data analysis. The machine had = 48-bit words and used octal to display binary values. I decided to = write a program to convert the binary representation of a floating point = number into the numeric value. For starters, it had to accept a pair of 24-bit values, expressed in = (mock) octal. That is, when I entered 12345, it was actually 12345(8), = not 12345(10). So, the program had to turn these values back into real = integers. It then pulled out the exponent and mantissa, did the = appropriate calculations, and displayed the floating-point value. It = worked, but it wasn't all that fast. As I recall, it took about 30 = seconds... -r