DOSBox is an x86 PC DOS-emulator for running old DOS games or programs.
No initial configuration is needed, however the official DOSBox Manual refers to a configuration file named "dosbox.conf". By default that file exists in your ~/.dosbox folder.
You can also make a new configuration file on a per-application basis by copying dosbox.conf from ~/.dosbox to the directory where your DOS app resides and modifying the settings accordingly. You can also create a a config file automatically as follows:
To create the file, simply run
dosbox without any parameters inside your desired application's folder:
Then at the DOS prompt, type:
Z:\> config -wc dosbox.conf
The configuration file "dosbox.conf" will then be saved in the current directory. Go in a change whatever settings you need.
The configuration options are described in the official DosBox wiki: http://www.dosbox.com/wiki/Dosbox.conf
A simple way to run dosbox is to place your DOS game (or its setup files) into a directory and then run dosbox with the directory path appended. For example:
$ dosbox ./game-folder/
You should now have a DOS prompt whose working directory is the one specified above. From there, you can execute the desired program(s):
If dosbox traps your focus, use CTRL-F10 to free it.
For more information visit the official DOSBox site: http://www.dosbox.com/