X-Authentication-Warning:	delorie.com: mail set sender to djgpp-bounces using -f
Message-ID:	<40341587.891B0EB8@yahoo.com>
From:	CBFalconer <cbfalconer AT yahoo DOT com>
Organization:	Ched Research
X-Mailer:	Mozilla 4.75 [en] (Win98; U)
X-Accept-Language:	en
MIME-Version:	1.0
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Cross Platform Incompatabilites? - code fragments
References:	<3 DOT 0 DOT 1 DOT 16 DOT 20040216231142 DOT 38e7a7cc AT earthlink DOT net> <c0t2ef$gsf$1 AT nets3 DOT rz DOT RWTH-Aachen DOT DE> <2719-Tue17Feb2004213034+0200-eliz AT elta DOT co DOT il> <c0vftb$5ft$1 AT nets3 DOT rz DOT RWTH-Aachen DOT DE> <ud68c4g4f DOT fsf AT elta DOT co DOT il> <403391FA DOT 119903C6 AT yahoo DOT com> <3791-Wed18Feb2004204649+0200-eliz AT elta DOT co DOT il>
Lines:	39
Date:	Thu, 19 Feb 2004 02:00:44 GMT
NNTP-Posting-Host:	12.76.134.71
X-Complaints-To:	abuse AT worldnet DOT att DOT net
X-Trace:	bgtnsc05-news.ops.worldnet.att.net 1077156044 12.76.134.71 (Thu, 19 Feb 2004 02:00:44 GMT)
NNTP-Posting-Date:	Thu, 19 Feb 2004 02:00:44 GMT
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp
Reply-To:	djgpp AT delorie DOT com

Eli Zaretskii wrote:
> From: CBFalconer <cbfalconer AT yahoo DOT com>
> > >
> > > I thought about something like that, but this could only have
> > > effect on programs that trigger exceptions, no?
> >
> > Such as events triggered by the timers, giving time slices to
> > other processes, etc.
> 
> I don't think so.  Do you have examples?

No.  I do remember cases in the CP/M days when certain evil bioses
in the Osborne I altered and did not save some Z80 registers
"because CP/M doesn't use them".  This created havoc, and I
carefully wrote my CP/M replacement to protect those values.

> 
> A multitasking, multiprocessing OS should save and restore the state
> of the FPU between context switches.  IIRC, Windows indeed does that,

Glad to hear it, but I greatly mistrust MS.

> except in the exceptional conditions, when a program triggered an FP
> exception in the x87.  That's why I suggested, at the beginning of
> this thread, to turn on the SIGFPE generation (it is usually masked
> off by the DJGPP startup code).  The OP replied that doing so didn't
> make any difference, so it seems like this problem is not the reason
> for the different behavior.
> 
> Hans-Bernhard also mentioned the effects on the FPU precision, but I
> don't think this could be relevant unless the program in point fiddles
> with the default precision of the FPU, which I think is not the case.


-- 
Chuck F (cbfalconer AT yahoo DOT com) (cbfalconer AT worldnet DOT att DOT net)
   Available for consulting/temporary embedded and systems.
   <http://cbfalconer.home.att.net>  USE worldnet address!

- Raw text -