FreeDOS is a great drop in replacement for MS DOS when you need it.
However there is no download for a bootable USB stick so if you want one you have to make i yourself (or download at bottom).
There are a couple of steps involved, but nothing advanced.
First create and start a new virtual environment in qemu or what you like.
On my FreeBSD box:
character# qemu-img create freedos.img 100MB
Formatting 'freedos.img', fmt=raw size=104857600
character# kldload kqemu
character# qemu -boot d -cdrom media/FreeDOS-1.1.iso -hda freedos.img -vnc :3
Connect with vnc and run the install process and install to the VHD.
On my MBP(ymmv):
mbp:labb root# dd if=freedos.img of=/dev/disk1 bs=1m
After which you will see (at least in os X) a FREEDOS2012 volume mounted.
Add any utils you like to it and unmount the filesystem.
Boot your new FreeDOS USB drive!
(SHA256 (freedos.img.tar.bz) = 40db631d392b77cb8d9a71e04d14abf2982db67202db602113ade23f2d6a3a6d)
There are several guides about this on the internet, like this one which I found very good so I’m not claiming any credit for inventing the wheel in any way..