From: "Charles Sandmann" <sandmann AT clio DOT rice DOT edu>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: problem on a small pc card
Date: Tue,  5 Dec 2000 23:15:46
Organization: Aspen Technology, Inc.
Lines: 11
Message-ID: <3a2d7722.sandmann@clio.rice.edu>
References: <90fbqq$rds$2 AT antares DOT lu DOT erisoft DOT se>
NNTP-Posting-Host: dcloan.hou.aspentech.com
X-Trace: selma.aspentech.com 976080183 12841 10.32.115.107 (6 Dec 2000 05:23:03 GMT)
X-Complaints-To: postmaster AT aspentech DOT com
NNTP-Posting-Date: 6 Dec 2000 05:23:03 GMT
X-NewsEditor: ED-1.5.8
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Reply-To: djgpp AT delorie DOT com

> Anyone care to enlighten us what the bug/feature is?

If you run certain other software which goes into protected mode,
and it doesn't reset the proper values in FS/GS desciptors before returning
to real mode.  TC++ 3.0 was an example cited to me, if you don't have
HIMEM or an EMM loaded.  Some BIOSes Int 15 data move calls?  In 
that case, any code which tries to use FS/GS in real mode will hang.

CWSDPMI was using these "extended" segment registers before swapping
to protected mode.  This was fixed (to use DS/ES only) and it fixed
problems in some environments.