Instructions
Download, install and launch the DOSbox application. In Ubuntu, open "Terminal" and type:
sudo apt-get install dosbox
dosbox
This downloads, installs and launches DOSbox.
Locate an older game from an abandonware or reputable old computer games site, such as GOG.com. In Terminal, navigate to "~\games$" then type "unzip game.zip," where "game.zip" is the name of the game archive file.
Open the DOSbox window again. Type "mount c /home/username/games." Hit enter. This mounts your games folder as "C:" driver in DOSbox. Type "C:," "dir" to see the contents of this mounted directory. Open the folder your game is in. Run the game executable to begin playing.