DOSBox also 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...
You can re-live the good old days with the help of DOSBox, it can run plenty of the old classics that don't run on your new computer!
DOSBox is totally free of charge and OpenSource.