As a programmer and Unix historian, I can't help but find all this legal sparring a bit sad. From the very start, the authors and users of Unix worked as best they could to build and share, even if that meant defying authority. That outpouring of selflessness stands in sharp contrast to the greed that has driven subsequent legal battles over the ownership of Unix.

The world of computer hardware and software moves forward startlingly fast. For IT professionals, the rapid pace of change is typically a wonderful thing. But it makes us susceptible to the loss of our own history, including important lessons from the past. To address this issue in a small way, in 1995 I started a mailing list of old-time Unix ­aficionados. That effort morphed into the Unix Heritage Society. Our goal is not only to save the history of Unix but also to collect and curate these old systems and, where possible, bring them back to life. With help from many talented members of this society, I was able to restore much of the old Unix software to working order, including Ritchie's first C compiler from 1972 and the first Unix system to be written in C, dating from 1973.

One holy grail that eluded us for a long time was the first edition of Unix in any form, electronic or otherwise. Then, in 2006, Al Kossow from the Computer History Museum, in Mountain View, Calif., unearthed a printed study of Unix dated 1972, which not only covered the internal workings of Unix but also included a complete assembly listing of the kernel, the main component of this operating system. This was an amazing find—like discovering an old Ford Model T collecting dust in a corner of a barn. But we didn't just want to admire the chrome work from afar. We wanted to see the thing run again.

In 2008, Tim Newsham, an independent programmer in Hawaii, and I assembled a team of like-minded Unix enthusiasts and set out to bring this ancient system back from the dead. The work was technically arduous and often frustrating, but in the end, we had a copy of the first edition of Unix running on an emulated PDP-11/20. We sent out messages announcing our success to all those we thought would be interested. Thompson, always succinct, simply replied, "Amazing." Indeed, his brainchild was amazing, and I've been happy to do what I can to make it, and the story behind it, better known.

This article was corrected on 12 December 2011.

About the Author

Warren Toomey teaches at Bond University, in Australia. He was bitten by the Unix bug in 1982 while still in high school, when he spent two weeks at the University of Wollongong learning about computers. There he encountered "an amazing system called Unix." His later discovery of software for simulating the computers that ran the earliest versions of Unix got him collecting vintage copies of this operating system.