DOSEMU stands for DOS Emulation, and allows you to run DOS and many DOS programs, including many DPMI applications such as DOOM and Windows 3.1, under Linux.
 Choosing the right DOS emulator for your needs
DOSEMU is a virtualizer, similar to VMWARE. It runs DOS applications natively on your CPU, so it's very fast. On the other hand, DOSBOX is a full CPU emulator, which means it's more portable and correct, but a lot slower. DOSBox is useful for playing very old games, which are not compatible with DOSEMU. DOSEMU is more suited to newer 32bit DOS games, like Tomb Raider or Blood. Please note that DOSEMU will only work on x86 arch. Version 1.4.0 of DOSEMU also provides a native 64-bit port for x86_64.
 Installation of DOSEmu
First, you have to install DOSEmu which is fairly easy task on most distributions.
On Gentoo Linux:
Under X11 type:
Or, under the console type:
Then you can try to run DOS commands (cd, dir, mkdir, ...)
 Configuration files
 Fullscreen mode
In order to switch to fullscreen mode press Ctrl+Alt+F.
 Error Messages
If you get 'Please specify your keyboard map explicitly via the $_layout option or ERROR: Unable to open console to evaluate the keyboard map:
In order to prevent this error at startup, it may be necessary to configure the keyboard map, by adding an entry to the /etc/dosemu/dosemu.conf configuration file as follows:
$_layout = "uk"