A tape-based piece of unique Unix history may have been lying quietly in storage at the University of Utah for 50+ years. The question is whether researchers will be able to take this piece of middle-aged media and rewind it back to the 1970s to get the data off.

The news was [1]posted to Mastodon by [2]Professor Robert Ricci of the University of Utah's [3]Kahlert School of Computing .

While cleaning a storage room, our staff found this tape containing #UNIX v4 from Bell Labs, circa 1973

Apparently no other complete copies are known to exist: [4]https://gunkies.org/wiki/UNIX_Fourth_Edition

We have arranged to deliver it to the Computer History Museum

The nine-track tape reel bears a handwritten label reading:

UNIX Original From Bell Labs V4 (See Manual for format)

Ricci says that the handwriting on the label is that of his former advisor [5]Jay Lepreau [PDF], who [6]died of multiple myeloma in 2008 .

[7]

If it's what it says on the label, this is a notable discovery because [8]little of UNIX V4 remains. That's unfortunate as this specific version is especially interesting: it's the first version of UNIX in which the kernel and some of the core utilities were rewritten in the new C programming language. Until now, the only surviving parts known were the [9]source code to a slightly older version of the kernel and a few [10]man pages – plus the [11]Programmer's Manual [PDF], from November 1973.

[12]

[13]

More was to follow – some hours later, [14]he continued :

We have some more information on this! One of [15]@regehr 's [16]grad students did some excellent sleuthing and figured out that this was received by Martin Newell: [17]https://archive.org/details/unix_news_july-30-1975/page/n9/mode/2up

If that name sounds familiar to you, it's probably because his teapot is ubiquitous in computer graphics: [18]https://graphics.cs.utah.edu/teapot/

So, this is the original copy of UNIX Fourth Edition received from AT&T by the inventor of the Utah Teapot – as seen in the [19]original Windows NT OpenGL screensaver .

[20]The elusive goal of Unix – or Linux – simplicity

[21]Forgetting the history of Unix is coding us into a corner

[22]Beta of Unix version 2 restored to life

[23]The Unix Epochalypse might be sooner than you think

Ricci [24]said :

The staff member who found it is planning to drive it to the CHM, rather than ship it.

That being the [25]Computer History Museum in Mountain View, California – which Google Maps tells us is a mere 771 miles away, a modest 12 hours' drive. The software librarian at the CHM is the redoubtable [26]Al Kossow of Bitsavers , who [27]commented in the thread that he is on the case. On the TUHS mailing list, he [28]explained how he plans to do it:

taping off the head read amplifier, using a multi-channel high speed analog to digital converter which dumps into 100-ish gigabytes of RAM, then an analysis program Len Shustek wrote: [29]https://github.com/LenShustek/readtape

It is a '70s 1200ft 3M tape, likely 9 track, which has a pretty good chance of being recoverable.

He also [30]noted :

This is rare enough that I'm pushing the recovery of it up near the top of my project queue.

The Reg FOSS desk has occasionally corresponded with Kossow, and we feel sure that this precious find could be in no better hands. ®

Get our [31]Tech Resources



[1] https://discuss.systems/@ricci/115504720054699983

[2] https://ricci.io/

[3] https://www.cs.utah.edu/

[4] https://gunkies.org/wiki/UNIX_Fourth_Edition

[5] http://ccr.sigcomm.org/online/files/p45-v39n1j-andersen.pdf

[6] https://web.archive.org/web/20151031110707/http://www.legacy.com/obituaries/saltlaketribune/obituary.aspx?page=lifestory&pid=117597321

[7] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/oses&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2aQ56BRC6JDRJmtF5MO8BmgAAAAA&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0

[8] https://minnie.tuhs.org/cgi-bin/utree.pl?file=V4

[9] https://minnie.tuhs.org/cgi-bin/utree.pl?file=V4/nsys

[10] https://minnie.tuhs.org/cgi-bin/utree.pl?file=V4/man

[11] https://dspinellis.github.io/unix-v4man/v4man.pdf

[12] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/oses&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44aQ56BRC6JDRJmtF5MO8BmgAAAAA&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0

[13] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/oses&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33aQ56BRC6JDRJmtF5MO8BmgAAAAA&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0

[14] https://discuss.systems/@ricci/115509057505895666

[15] https://mastodon.social/@regehr

[16] https://cv.thalia.dev/

[17] https://archive.org/details/unix_news_july-30-1975/page/n9/mode/2up

[18] https://graphics.cs.utah.edu/teapot/

[19] https://www.theregister.com/2024/06/13/windows_3d_pipes_screensaver/

[20] https://www.theregister.com/2025/05/27/elusive_goal_of_simplicity/

[21] https://www.theregister.com/2024/02/16/what_is_unix/

[22] https://www.theregister.com/2025/02/24/beta_unix_2_restored/

[23] https://www.theregister.com/2025/08/23/the_unix_epochalypse_might_be/

[24] https://discuss.systems/@ricci/115505025036183624

[25] https://computerhistory.org/

[26] https://terminals-wiki.org/wiki/index.php/BitSavers

[27] https://oldbytes.space/@bitsavers/115505135441862982

[28] https://www.tuhs.org/pipermail/tuhs/2025-November/032765.html

[29] https://github.com/LenShustek/readtape

[30] https://www.tuhs.org/pipermail/tuhs/2025-November/032764.html

[31] https://whitepapers.theregister.com/