delorie.com/archives/browse.cgi   search  
Mail Archives: djgpp/1997/05/17/13:54:44

From: "Charles Sandmann" <sandmann AT clio DOT rice DOT edu>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: help! FPU emulation worries... (RHIDE?)
Date: Thu, 15 May 1997 22:18:37
Organization: Aspen Technology, Inc.
Lines: 7
Message-ID: <337b8bbd.sandmann@clio.rice.edu>
References: <337B82CA DOT 1A7 AT blackmagic DOT tait DOT co DOT nz>
Reply-To: sandmann AT clio DOT rice DOT edu
NNTP-Posting-Host: spica.dmccorp.com
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp

> I'm not certain, but I thing that setting the EM bit in cr0 has the same
> effect on a 486 as a 386, causeing fp code to generate exceptions.  The
> problem then becomes setting this bit when your code is in ring 3.

This is a DPMI 1.0 extension supported on almost all DPMI hosts (even most
MS Win stuff).  a "SET 387=N" should force this behavior.  See the source
for more details.

- Raw text -


  webmaster     delorie software   privacy  
  Copyright © 2019   by DJ Delorie     Updated Jul 2019