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From: barkdoll@cattell.psych.upenn.edu (Ed Barkdoll)
Newsgroups: comp.sys.ibm.pc
Subject: Re: MS Fortran v 5.0 error trapping
Message-ID: <1457@cattell.psych.upenn.edu>
Date: 26 Jul 89 21:31:42 GMT
References: <319@maytag.waterloo.edu>
Reply-To: barkdoll@cattell.psych.upenn.edu.UUCP (Ed Barkdoll)
Organization: University of Pennsylvania
Lines: 27

In article <319@maytag.waterloo.edu> dmurdoch@watstat.waterloo.edu (Duncan Murdoch) writes:
>
>I've just bought Microsoft Fortran version 5.0, in order to work with a function
>minimizing program that was written for a mainframe.  My program works, mostly,
>but occasionally aborts with overflows or out of range values.  On the HP3000
> ...
>In the MS Fortran manual, the only mention of error trapping that I can find
>has to do with I/O errors.  Is it really impossible to trap calculation errors
>in MS Fortran?
>
>Duncan Murdoch
	In MS fortran 4.1 you can handle so called floating point exceptions
by calling LCWRQQ. Page 363 of the manual states:

"The LCWRQQ procedure sets the control word to a given value.  LCWRQQ has the 
following declaration:
SUBROUTINE LCWRQQ(CW)
INTEGER*2 CW

The integer*2 argument passed to LCWRQQ is known as the 'users control word'"


	According to page 362 passing a control word value of 4926 should
disable overflow and zero divide errors.  I haven't tried it myself so I can't
vouch for it and the call may be different for fortran 5.0

	Edwin Barkdoll [barkdoll@cattell.psych.upenn.edu]