The Value of DOS

Many old DOS programs are still valuable. They were state-of-the-art at the time they appeared, and capable of very sophisticated operations. I have DOS on my Linux computer, and use it quite regularly. One simply enters cycles = max, and this speeds up DOS hundreds of times over. So one may achieve in a second what took several minutes in the past. Things which originally required a lot of "thought" on the computer's part -- say, board games, textual analysis, or compilers -- are now very quick. And now they are free, since the copyright has expired.