(Update: It’s gone again.)
For a few glorious hours last October, iPhone and iPad owners could turn their devices into fully-functioning DOS emulators with iDOS, a $1 app. It was, of course, too good to be true, and Apple quickly removed the program.
Surprisingly, iDOS is back in the App Store, possibly for good, and now it’s free. The only major concession is the removal of file transfers through iTunes, which allowed users to load and install pretty much anything — even Windows 3.0.
But as TouchArcade points out, you can work around this roadblock by downloading iPhone Explorer on your PC and dropping files into the “/Apps/iDOS/documents” directory, which becomes the C: drive in iDOS. Hooray nostalgia!