The DOSemu support for NetBSD has sat untouched for a while; the latest
stuff I have in good working shape (based on NetBSD/i386 1.1) is still
in the directory ftp://sipb.mit.edu/pub/netbsd/dosemu/

The latest -current NetBSD vm86 support has changed in ways that require
changes to DOSemu which I have not done yet, so it won't work as-is on
existing kernels.  The latest DOSemu in my private versions also
requires a gross hack in the kernel when using X mode so that it could
memory-map its own memory and successfully exit (it would hang inside
exit() due to some VM system interactions without the gross patch).

If you want to try your hand at this version of stuff, my most recent
attempt is at ftp://sipb.mit.edu/pub/jtkohl/dosemu-0.63.0.1.tar.gz

==John