You need:

0) NetBSD-1.2 source tree
1) replacement parts (see netbsd-1.2-diffs.gz)
2) dosemu with NetBSD patches: see dosemu-0.63.1.2.tar.gz
3) The S-Lang library.  See slang0.99-22.tar.gz (also on
	ftp://space.mit.edu/pub/davis/slang)
4) GNU make, bison
5) ld86 and as86.  See bcc.tar.gz here.  [Sources slightly modified, originally
   from ftp://ftp.freebsd.org/pub/FreeBSD/FreeBSD-current/ports/distfiles/bcc.tar.gz]
   Build ld and as, and install them in your path as ld86 and as86.

Build S-Lang with the termcap option (you'll need a minor edit to its
makefile).

Apply the patches into your source tree.  You need to patch the kernel.

Build a new kernel (use option VM86, plus all the SysV shared memory
options).  You must use the pcvt console driver.  (I use the config
found in PATTERN).  If you use 'options KOLVIR' then you can always hit
Alt-SysRq to turn off raw keyboard mode.  This is useful as a way to get
off the VC of a hung dosemu session.

Install the updated kernel include files by running 'make install' from
/usr/src/include.

Edit the dosemu Makefile.NetBSD for appropriate include paths, etc.
Replace lib/libarch_netbsd_slang.a with a symlink to the "right place";
also move include/slang.h aside and install a symlink to the "right
place".

Try building dosemu with "gmake most dosstatic".  I suggest you use
dosstatic--it has far fewer security concerns than 'dos' which
dynamically loads libdosemu0.XXplYY.

Once it's built, read the QuickStart DOSEmu documentation starting at
step 3.

Let me know how it goes,

==John Kohl <jtk@kolvir.Arlington.ma.us> and/or <jtk@atria.com>

NOTES:

Running in an X window doesn't work too well right now due to memory
mapping weirdness (you can't ever exit the process).  Running on the
console works fine.

I STRONGLY suggest you get a terminal on a serial port, or a network for
remote logins, while you are testing the console support.  You'll want
to be able to log in and tell whether things are hung really bad
or if just the console is screwed up.

If dosemu seems to hang, you may still be able to change virtual
consoles using CTRL-ALT-F<number>.

Using a builtin mouse is somewhat flaky--some programs work just fine
(e.g. dos EDIT), some don't (e.g. DOSSHELL).  Using an emulated serial
line to talk to the mouse seemed to work OK.

DPMI apps in particular are still a bit flaky--sometimes it just hangs
the virtual session (I've been able to kill off dosemu and recover,
though).

THANKS TO:

Charles Hannum <mycroft@netbsd.org> for much of the i386 specific changes
(particularly for stack mapping and TSS work)

The Dosemu folks <linux-msdos@vger.rutgers.edu> for the dosemu code itself
John Davis <davis@space.mit.edu> for S-Lang.