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From: chkg@ptsfa.UUCP (Chuck Gentry)
Newsgroups: comp.unix.xenix
Subject: Re: XENIX and math coprocessors
Message-ID: <3235@ptsfa.UUCP>
Date: Wed, 15-Jul-87 13:33:16 EDT
Article-I.D.: ptsfa.3235
Posted: Wed Jul 15 13:33:16 1987
Date-Received: Fri, 17-Jul-87 06:40:46 EDT
References: <1859@Shasta.STANFORD.EDU>
Reply-To: chkg@ptsfa.UUCP (Chuck Gentry)
Distribution: na
Organization: Pacific * Bell, San Ramon, CA
Lines: 25
Keywords: XENIX, coprocessors
Summary: Yes, it supports the 80x87

In article <1859@Shasta.STANFORD.EDU> boesch@Shasta.UUCP (Brian Boesch) writes:
>
>----
>
>We have SCO Xenix 286 and I would likt to know it the C compiler supports
>the 287 coprocessor. I looked in the manuals and there is no mention of
>the coprocessor in the CC sections of the manual.
>
The 8087, 80287, and 80387 are all supported by the related version of XENIX.
I believe that it is the kernel that provides the floating point support.  The
compiler "assumes" that the coprocessor exists in the system when generating
code.  If no coprocessor is present, the kernel will emulate the routine.  If
a coprocessor is present, the floating point instruction is executed. 
(Makes your code portable between machines.)

The coprocessor is mentioned in the manual: "Run Time Environment", Operating
System Release Notes.  Depending on your version, you'll find the info on:
V2.1.0 Page 8, V2.2.1 Page 43.  During boot time, Xenix will tell you if
a math coprocessor is present.  (There are also references in the
Hardware Dependent Misc. section, and the MASM section in Programmer's Guide,
system development tools, User's section 2-5.  It seems my copy does not 
have these pages. They are mentioned in various places in the manual.)

Chuck Gentry
{lll-lcc,quantel,ihnp4}!ptsfa!pbcesar!chkg