DOSBOX allows you to run your old dos programs under Linux , DOSBOX provides a full featured dos environment inside your ubuntu box . DOSBOX allows running of DOS programs in Linux and Windows. To install DOSBOX type the following command in the Terminal window
sudo apt-get install dosbox
You can also use the Synaptic package manager located at System -> Administration -> Synaptic Package Manager for installing the DOSBOX emulator. Launch the synaptic package manager and click on Search button and type dosbox in the text field mark th checkbox of dosbox and click on install, for installation to start.
After completing installation, create a directory say (/home/user/games) where you would like to store your games,
now after copying your games to the directory launch dosbox by typing dosbox in terminal window.
In DOSBOX type the following command to make your games directory visible inside the dosbox emulator
mount d /home/user/games
Now go to d drive , then go to the directory of the game and launch the executable file of the game to start the game.
Source: http://linuxondesktop.blogspot.com/2007/03/playing-classic-games-under-ubuntu.html