DOSBox emulates CPU:286/386 realmode/protected mode, Directory FileSystem/XMS/EMS, Tandy/Hercules/CGA/EGA/VGA/VESA graphics, a SoundBlaster/Gravis Ultra Sound card for excellent sound compatibility with older games.

If you are like me and have a stack of old DOS games like Doom, Duke Nukem, and Heretic lying around this is a must have.