DOSEMU-1.1.5 vs. DPMI

["Peter B. Steiger" <wypbs_002@bornagain.com>]

1.1.5 compiles and runs fine, but I seem to be having some trouble with my 
DPMI-based programs.  Hardware is AMD Duron 850MHz with 512MB RAM.  
There's a 60-GB drive with a 10-GB fat32 partition on which I installed 
Windows 98 rev. A.  Linux is Linux From Scratch using kernel 2.4.20, gcc 3.2.2.  
Since I own Tool O' The Devil '98, I do not use freedos; my boot directory 
/usr/share/dosemu/bootdisk just contains links to /mnt/fat32 files and folders.

The program I'm most interested in running was written in Clipper, an old dBase-
type compiler that actually creates the EXE with a complete p-code parser built 
in so it can interpret your program on-the-fly.  The EXE is linked with Blinker, 
which allows you to link as a real mode or protected mode application.

In real mode my test program works fine... just a "Hello, world" display; I can 
also run an enormous memory hog test that creates a meg or two of string 
arrays in real mode (swapping to a disk file for VM).  But if I try to run either 
of those programs in protected mode, I get:

DPMI unhandled exception 06 - terminating client
it is likely that dosemu is unstable now and should be rebooted

... as soon as the program loads, before any output appears.  This happens 
regardless of whether I run as root (yeah, I know, danger Will Robinson...) or anyone 
else.  The same error occurs at the console and in an X window with xdosemu.  I 
tried building with and without mitshm; it makes no difference.

What's strange is, this used to work.  I'm using the same hardware and the same 
dosemu.conf files I had when I ran Red Hat 7.3 with kernel 2.4.20, gcc 2.96, dosemu 
1.0.something last year.

Relevant portions of dosemu.conf are:
$_xms = (16383)	
$_ems = (off)		
$_dpmi = (65535)	
$_dosmem = (639)	

I have experimented with various amounts of each type of memory, and I have made 
sure that /proc/sys/kernel/shmmax has a high enough limit to handle anything I throw 
at it.  The kernel is compiled with the SYSVIPC option enabled.

config.sys says:
device=C:\windows\himem.sys
device=C:\windows\emm386.exe noems
dos=high,umb
files=100

I can supply the complete dosemu.conf and/or the two EXE files (with and without 
DPMI support linked in) if anyone is bored enough or curious enough to explore this; 
I'm an applications developer so my knowledge of what's going on with the system's 
use of memory is just about nonexistent.

Any ideas, suggestions, or general ridicule gratefully accepted through the list or my 
own email.  Thanks!
pbs
--------
Peter B. Steiger
Cheyenne, WY