DOSBox is a free, open-source DOS emulator for Windows, Mac, Linux, and other platforms.
It 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. So if you want to go Old-School, and play over 3,000 supported classic Dos games, grab yourself a free copy of DosBox and live the nostalgia.