From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham
	autolearn_force=no version=3.4.4
X-Google-Thread: 103376,c4cb2c432feebd9d
X-Google-Thread: 1094ba,c4cb2c432feebd9d
X-Google-Thread: 101deb,15c6ed4b761968e6
X-Google-Attributes: gid103376,gid1094ba,gid101deb,public
X-Google-Language: ENGLISH,ASCII-7-bit
Path: 
 g2news2.google.com!news4.google.com!sn-xt-sjc-15!sn-xt-sjc-09!sn-post-sjc-02!sn-post-sjc-01!supernews.com!corp.supernews.com!not-for-mail
From: "Shmuel (Seymour J.) Metz" <spamtrap@library.lspace.org.invalid>
Newsgroups: comp.lang.ada,comp.lang.fortran,comp.lang.pl1
Subject: Re: ONES COMPLEMENT (was: Ada vs Fortran for scientific applications)
Date: Tue, 18 Jul 2006 10:05:42 -0300
Organization: Atid/2
Message-ID: <44bceab6$29$fuzhry+tra$mr2ice@news.patriot.net>
References: <mubcg.13522$fb2.853@newssvr27.news.prodigy.net>
      <epcs4e.qb8.ln@hunter.axlog.fr>
      <tHkcg.6937$kR6.484@trnddc05>
      <0ugu4e.4i7.ln@hunter.axlog.fr>
      <PkHcg.90575$Fs1.7198@bgtnsc05-news.ops.worldnet.att.net>
      <To_cg.10095$S7.4017@news-server.bigpond.net.au>
      <%P_cg.155733$eR6.26337@bgtnsc04-news.ops.worldnet.att.net>
      <6H9dg.10258$S7.9150@news-server.bigpond.net.au>
      <XVadg.76594$_S7.45873@newssvr14.news.prodigy.com>
      <1hfv5wb.1x4ab1tbdzk7eN%nospam@see.signature>
      <20060712.7A4E6E0.D028@mojaveg.lsan.sisna
      <20060717.7A4ADD0.10B1A@mojaveg.lsan.sisna.com>
Mail-Copies-To: nobody
X-CompuServe-Customer: Yes
X-Coriate: interspeed.co.nz
X-Ecrate: tanandtanlawyers.com
X-Pose: George Cox
X-Punge: Micro$oft
X-Sanguinate: The MVS Guy
X-Terminate: SPA(GIS)
X-Tinguish: Mark Griffith
X-Treme: C&C,DWS
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
X-Newsreader: MR/2 Internet Cruiser Edition for OS/2 v2.67/60 
X-Complaints-To: abuse@supernews.com
Xref: g2news2.google.com comp.lang.ada:5792 comp.lang.fortran:12175
 comp.lang.pl1:2025
Date: 2006-07-18T10:05:42-03:00
List-Id: <comp.lang.ada>

In <20060717.7A4ADD0.10B1A@mojaveg.lsan.sisna.com>, on 07/17/2006
   at 06:26 PM, mojaveg@mojaveg.lsan.sisna.com (Everett M. Greene)
said:

>"robin" <robin_v@bigpond.com> writes:

>> Some implementations of ones complement used two forms of
>> zero 

FSVO "some" equal to "all".

>>which required two tests.

That  makes no sense.

>A properly designed 1s complement machine would not
>generate -0 in normal arithmetic operations.

0+(-0)?

>Thus, no need to perform a program check for -0.

I never saw a need to test for it regardless. Every 1s complement
machine I know of lets you test for zero in a single instruction.

>> How many machines now offer ones complement arithmetic?

Before the S/360 captured the market there were large numbers of
machines in the lines started with the CDC 160, CDC 6660 and the
UNIVAC 1107. The shift seemed to be a copycat issue more than a
technological one.

-- 
Shmuel (Seymour J.) Metz, SysProg and JOAT  <http://patriot.net/~shmuel>

Unsolicited bulk E-mail subject to legal action.  I reserve the
right to publicly post or ridicule any abusive E-mail.  Reply to
domain Patriot dot net user shmuel+news to contact me.  Do not
reply to spamtrap@library.lspace.org