DOSEMU DPMI unhandled exception 0e (it's back!)

[David Griffith]

When I start DOSEMU and use any DOS program, I get "DPMI: Unhandled
Exception 0e - Terminating Client" and then I'm told that the emulator is
unstable and should be rebooted. Running any program after that causes
DOSEMU to crash.

Identical trouble was reported in https://bugs.debian.org/797378 and
attributed to a kernel bug that was fixed in 4.2.x. My Stretch machines
are now running 4.9.x. What's going on here?


--
David Griffith
da...@661.org

A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?

[bw]

>When I start DOSEMU and use any DOS program, I get "DPMI: Unhandled Exception 0e - Terminating Client"

That is really bad news, are you sure it's all programs, and not just programs that use DPMI ?
If the problem is only DPMI enabled programs, you can probably solve it with some persistent effort.

>and then I'm told that the emulator is unstable and should be rebooted. Running any program after that causes DOSEMU to crash.

I've used dosemu for a long time, but not on stretch, so I can't test it right now. It is tricky to setup, as most DOS environments always were.

>From what I recall, some programs will require vm.mmap_min_addr set to 0 in sysctl and
you should do your own research before using this, it seems to be a security risk on networked machines, or was at one point.
Not sure of the current state of things re: mmap_min_addr

Some older DOS programs have a plain 16 bit ver and a 32 bit DPMI ver, and some have a switch to turn off use of DPMI. Some also
used an environment variable to limit or control the use of DPMI. There's also a config option in dosemu.conf to set the base address.
# DPMI base address; default: auto
# If the default value fails, try 0x10000000

# $_dpmi_base = (auto)

>Identical trouble was reported in https://bugs.debian.org/797378

That bug showed pkzip as the culprit, not all dos programs?

If it's the same bug, maybe you should follow the links and file your bug against the kernel instead of dosemu?
https://ugs.debian.org/cgi-bin/bugreport.cgi?bug=866965

Good luck, and have fun. Thanks for the heads up I will follow along in case I run into the same issues.
bw

[David Griffith]

The trouble manifested when I tried using various components of an old release of Turbo C. Everything, 16 and 32 bit, tickles this bug.

--
David Griffith
da...@661.org

[bw]

>>The trouble manifested when I tried using various components of an old release of Turbo C.
>>Everything, 16 and 32 bit, tickles this bug.

Hey David, don't give up, i got Turbo C+ 3.0 working fine in dosbox by setting ver to 6.00 in the dosbox.conf and using a real
MS-DOS COMMAND.COM from msdos 6.

The only reason I ever use dosemu is for serial port, modems or old FOSSIL stuff. dosbox is a lot easier for games and programming.

I hope there's not some kernel issue with this, I really like my old stuff,
especially Vern Buerg's LIST.COM combined with semware Qedit Advanced. THE BEST two programs in history.

Let us know how it goes, try TC on dosbox with the right command.com

[David Griffith]

I'm using DOSEMU right now because I'm trying to get to the bottom of a bug in DOS Frotz. It crashes on real hardware and DOSEMU, but not DOSBOX.

--
David Griffith
da...@661.org