Woohoo! Context: UNIX v4 was believed lost to history until a tape labeled “UNIX v4” was found in a cardboard box in a closet at the University of Utah. It was not clear whether or not there was anything on the tape still. It looks like the Voeks at the Computer History Museum were successfully able to recover the data.
This is significant because UNIX V4 was the first version to be written using this newfangled language called C. So exciting!