To add a little more detail to Tom Uban's reply, the version of Spacewar you get from the website url he listed is the *actual* *original* binary executable of the Spacewar program. It runs on an emulated PDP-1 that's written in Java and which gets downloaded to your PC or Mac when you go to the web page. So, the Spacewar *program* is as close to the original as possible, since it *is* the original. The real question to ask, is how close to a real PDP-1 does the emulator come? Regards, -doug q