Article View: comp.sys.atari.st
Article #27261Re: MWC and VAX floating-point format
From: manis
Date: Fri, 19 Jun 1987 14:57
Date: Fri, 19 Jun 1987 14:57
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In article <8706171715.AA08471@orville.arpa> rowley@ORVILLE.ARPA.UUCP (Karl
Rowley) writes:
>VAX double-precision format is identical to single-precision format, except
>that the mantissa is extended. The IEEE format does not have this property.
Actually (not really being an expert in these matters) I believe that what
MWC uses is the old PDP-11 format. VAXen nowadays have 4 (!) formats, of
which MWC appears to use F (single) and D (old double) precision. Not having
the VAX G format (less than double, but with more exponent bits) is something
of a lose, in that one gets possibly more precision, but no more range.
Since I rarely use floating point, I don't care that much. However, not
having the same format as used by other ST languages is a bit of an
annoyance, as is the inability to support coprocessors.
>Of course, IEEE format is superior in many ways, and doesn't have its bytes
>all flipped around.
They could have done *much* worse. The 370 has its own floating point format.
-----
Vincent Manis {seismo,uw-beaver}!ubc-vision!ubc-cs!manis
Dept. of Computer Science manis@cs.ubc.cdn
Univ. of British Columbia manis%ubc.csnet@csnet-relay.arpa
Vancouver, B.C. V6T 1W5 manis@ubc.csnet
(604) 228-6770 or 228-3061
"To lose one parent, Mr Worthing, may be regarded as a misfortune; but
to lose both looks like carelessness." -- Oscar Wilde
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: arc1-ca.pugleaf.net!utzoo!utgpu!water!watmath!clyde!rutgers!ames!ptsfa!ihnp4!alberta!ubc-vision!ubc-cs!manis From: manis@ubc-cs.UUCP Newsgroups: comp.sys.atari.st Subject: Re: MWC and VAX floating-point format Message-ID: <1475@ubc-cs.UUCP> Date: Fri, 19-Jun-87 10:57:18 EDT Article-I.D.: ubc-cs.1475 Posted: Fri Jun 19 10:57:18 1987 Date-Received: Sun, 21-Jun-87 04:59:37 EDT References: <8706171715.AA08471@orville.arpa> Reply-To: manis@ubc-cs.UUCP (Vincent Manis) Distribution: world Organization: UBC Department of Computer Science Lines: 29