Computer History Museum software curator Al Kossow has successfully retrieved the contents of the over-half-a-century old tape found at the University of Utah last month.

UNIX V4, the first ever version of the UNIX operating system in which the kernel was written in the then-new C programming language, has been successfully recovered from a 1970s nine-track tape drive. You can download it from the Internet Archive, and run it in SimH. On Mastodon, "Flexion" posted a screenshot of it running under SGI IRIX.

Last month, we wrote about the remarkable discovery of a forgotten tape with a lost early version of Unix, found by Professor Robert Ricci at the Kahlert School of Computing at the University of Utah. At the time, we quoted the redoubtable Kossow, who also runs Bitsavers, as saying that it "has a pretty good chance of being recoverable." Well, he was right, and at the end of last week, he did it. Ricci also shared a video clip on Mastodon.