DOSBox

DOSBox is a free x86 emulator written in C++ and primarily used to run old DOS games.

Emulated hardware

 * CPU: 286/386 realmode/protected mode
 * Directory File System
 * XMS/EMS
 * Tandy/Hercules/CGA/EGA/VGA/VESA graphics
 * Adlib/PC Speaker/SoundBlaster/Gravis Ultra Sound
 * IBM Joystick
 * IPX/Serial/Modem

Resources

 * Website
 * DOSBox wiki