University of Utah team discovers rare computer relic

[Thomas Niccum]

https://www.youtube.com/watch?v=IR-f07LN0-Y 

Spoiler: It's a 9-track tape with an early version of Unix V4 from 1973...

[Thomas Niccum]

FEATURES the PiDP-11 running at the Computer History Museum! They're driving the tape there to see if they can read it.

[Thalia Archibald]

Hi Thomas,

I’m a PhD student at the U involved with the research into our tape. The PiDP-11 shown in the news report is actually Rob Ricci’s. My PiDP-11 was photographed for a recent article put out by the University[0] (guess what the switch setting means :) ). I’ll be part of the small group delivering it to the CHM in two weeks. Al Kossow will be doing a full-fidelity analog read of the tape and analyze the dump offline to get the digital data.

I found that it was delivered the Martin Newell[1], famously known for the Utah Teapot model, and a letter from Ken to Martin[2] was later found that places our delivery around June 1974. I’ve collected this and much more in a repo[3]. I’m still looking for our license agreement. If any of you know of good UNIX sources, particularly around 1973–1974, please let me know!

Thalia

[0]: https://attheu.utah.edu/science-technology/precious-computer-age-relic-turns-up-in-u-storage-room/

[1]: https://archive.org/details/unix_news_july-30-1975/page/n9/mode/1up

[2]: https://github.com/thaliaarchi/unix-history/blob/8f887ce324bc7dc7fc6de5eca09d4d028fe8f554/users/utah/1974-05-31_ken_letter.jpg

[3]: https://github.com/thaliaarchi/unix-history

On Dec 7, 2025, at 10:23, Thomas Niccum <tni...@gmail.com> wrote:

FEATURES the PiDP-11 running at the Computer History Museum! They're driving the tape there to see if they can read it.

<Screenshot 2025-12-07 at 9.22.38u202fAM.jpg>

On Sunday, December 7, 2025 at 9:20:42 AM UTC-8 Thomas Niccum wrote:

https://www.youtube.com/watch?v=IR-f07LN0-Y 

Spoiler: It's a 9-track tape with an early version of Unix V4 from 1973...

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[DR]

Very nice, I hope a followup will  be posted when it has been, or
attempted to have been, read.

I wonder if there are 'gentle' drives which would not stretch an aged
tape, or scrape the oxide off the backing.

My experience is that even LINC drives were a bit hasty with moving a
tape.  The old Univac 1108 beast drives would sure move the tape very
quickly and not, in my mind, be the right device to mount this on and
very slowly, carefully, see what happens.

[Thomas Niccum]

Thalia, that's awesome! Thanks for the additional context and "behind the scenes" look. 

Is that you in the group shot on the news report?  

Tom

[Thalia Archibald]

Yeah, I’m the one on the left in the group shot at 1:30. I was busy so I wasn’t in the interview.

Thalia

[Bert Driehuis]

Be careful about your selection of tape drives, as speed is not your only concern. The first computer repair I ever made was to a TU-56 which had developed a habit of banging real hard on the tape of our PDP8/e. As it turned out, one of the huge solder pads for the ground to one of the drive motors left the factory as a cold joint. After years of faithful service at a meat processing plant, and after retirement for another year under my care, it started to misbehave. It read and wrote the tape just fine, but it sounded awful, as every change in spool direction caused the tape to slap on the head. Fortunately, DECtape can take a beating, but I shut it off as soon as I could and analyzed its failure first...

The morale of the story? Even if you know the drive is good, before you try to read a priceless ancient tape, try reading a known good (and replaceable) tapre first...

--

Bert

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