We're continuing investigation to the performance issues, you can follow and react here: https://lemmy.world/c/friendicaworld

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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: gunkies.org/wiki/UNIX_Fourth_Eโ€ฆ

We have arranged to deliver it to the Computer History Museum

#retrocomputing

UNIX Fourth Edition - Computer History Wiki

gunkies.org
#unix #retrocomputing
in reply to Space Catitude ๐Ÿš€

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bitsavers.org

@TerryHancock
I have the equipment. It is a 3M tape so it will probably be fine.
It will be digitized on my analog recovery set up and I'll use Len Shustek's readtape program to recover the data.
The only issue right now is my workflow isn't a "while you wait" thing, so I need to pull all the pieces into one physical location and test everything before I tell Penny it's OK to come out.

The whole process is test the condition on a tape retensioner. I'm hoping I don't have to bake it, since that takes a day, then digititze it, shuttle the 10s of gigabytes of samples to another machine to decode it. I want to skip the shuttle step and get the analyzer running on the digitizer.

@Space Catitude ๐Ÿš€

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Ethan Blanton

This is freaking awesome. I took the liberty of posting it here: retrocomputingforum.com/t/unixโ€ฆ

Unix V4 tape found at The University of Utah

This toot on the Fediverse describes a fun and historically significant discovery: a magnetic tape containing what may be an installation image of Unix V4 has been found at the University of Utah.
Retro Computing

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Rob Ricci

@heretical_i The person who is going to attempt to read it is hopeful: oldbytes.space/@bitsavers/1155โ€ฆ

bitsavers.org

2025-11-06 22:34:57

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@TerryHancock
I have the equipment. It is a 3M tape so it will probably be fine.
It will be digitized on my analog recovery set up and I'll use Len Shustek's readtape program to recover the data.
The only issue right now is my workflow isn't a "while you wait" thing, so I need to pull all the pieces into one physical location and test everything before I tell Penny it's OK to come out.

The whole process is test the condition on a tape retensioner. I'm hoping I don't have to bake it, since that takes a day, then digititze it, shuttle the 10s of gigabytes of samples to another machine to decode it. I want to skip the shuttle step and get the analyzer running on the digitizer.

@Heretical_i
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Rob Ricci

@jbowen @heretical_i @robpike @bitsavers

Fun fact, some of the students in our department saw Rob's post there, posted about it on a Slack I'm on - without realizing that it was us that found it until I replied to them. Two minutes later there were in my office to have a look at it.

News spreads fast in 2025.

@Jason Bowen ๐Ÿ‡บ๐Ÿ‡ฆ @Heretical_i @rob pike @bitsavers.org

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JohnMashey

So cool, I hope itโ€™s readable!
I arrived at Bell Labs Piscataway, into Rudd Canadayโ€™s PWB/UNIX department October 1973, same week our PDP-11/45 got installed, 2nd one in BTL after ken+dmrโ€™s. We ran UNIX V4 of course, first one whose kernel was in C.
We even got documentation besides man pages: the CACM article & ~20-page C reference, which i still have.
My car celebrates UNIX every day:

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JohnMashey

@darkuncle
Yes, Peter Weiner (Interactive Systems) was first owner. He hired (one of my old bosses) Ted Dolotta away from BTL ~1981, who told me part of the inducement was transfer of the plate. In 1998, Ted was moving back to Princeton area (aging parents) and he put plate up for auction among small group of UNIXers, with deal that $ would go to USENIX as part if a memorial for John Lions (who I knew, and was very ill, not expected to live long.) Story:
en.wikipedia.org/wiki/John_Lioโ€ฆ

John Lions - Wikipedia

Contributors to Wikimedia projects (Wikimedia Foundation, Inc.)
@Scott Francis
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MarkD

@JohnMashey "I hope it's readable".

That's my question. Is a 50 year old magtape likely to be fully readable?

Sure, the recording density is extremely low by today's standards, but has anyone bothered to build a modern high-sensitivity magtape drive that can cope with degraded plastic?

On the other hand those early magnetic recording systems had to deal with significant technological limitations so they designed robust encoding systems which might survive the ages, such as NRZI.

@JohnMashey
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JohnMashey

@markd
I think it is unlikely, but still hope, as there seems to be wide variation in the longevity of such tapes.
This says claimsof 30, but typically 10-20 years.
mediaduplicationsystems.com/blโ€ฆ
This says 10-30:
cool.culturalheritage.org/bytoโ€ฆ
BUt I've been sometimes surprised by Al Kossow's ability to recover old info.
(I'm a Foundign Memberr of Computer Hsitory Museum, was a Trustee 2000-2023.)

Understanding the Lifespan of Magnetic Tape and When to Migrate Data

Magnetic tapes have long been a preferred storage medium for archival and backup purposes. Despite the rapid advancement of data storage technologies introducing alternatives like solid-state drives and cloud-based solutions, magnetic tape storage coโ€ฆ
Media Duplication Systems
@MarkD
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F4GRX Sรƒยฉbastien

@markd @JohnMashey It looks like a 9-track tape. If thats the case the last of these readers was made around 2002 according to wikipedia so hardware should be around. the real issue is the condition of the plastic tape itself, which can become contaminated with mold and become sticky, which strips the magnetic layer. Such old tapes, if not preserved properly, need conditioning in very low heat dessicators and extreme care when reading them.
@MarkD @JohnMashey
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bitsavers.org

@f4grx @markd @JohnMashey
I have started a discussion internally about making a video about how the sausage is made. This would be one of the few times I appear in a CHM video.

I think it's necessary to start preserving my knowledge and bringing in the next generation of people able to do this.

@F4GRX Sรƒยฉbastien @MarkD @JohnMashey

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Rob Ricci

@greatquux It probably spent most of its life sitting in my former advisor Jay Lepreau's office, whose handwriting is on the label. We've only had this specific storage space for like a decade.

The staff member who found it is planning to drive it to the CHM, rather than ship it, so maybe the story will get more interesting after that - other than, we we cleaning out some stuff and this was in a box ๐Ÿ˜€

@greatquux
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F4GRX Sรƒยฉbastien

I hope the tape media is still in a good enough condition not to be destroyed once just installed in a deck. What kind of tape is that btw? 9-track?

edit: according to wikipedia, the value 3200 hints at a "ISO/IEC 3788:1990 9-track, 12.7 mm (1โ„2 in) wide magnetic tape for information interchange using phase encoding at 126 ftpmm (3,200 ftpi),"

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๐Ÿ‡บ๐Ÿ‡ฆ haxadecimal

@f4grx @larsbrinkhoff
Almost guaranteed 9-track. On a PDP-11, 7-track would only have been used for interchange with older architectures that didn't use 8-bit bytes.
The tape will be very carefully handled by one of the leading authorities on data recovery from old 1/2" tape, and knows about all of the failure modes thereof (e.g. sticky-shed), and how to handle the tapes without stripping the oxide or otherwise ruining the tape.
@F4GRX Sรƒยฉbastien @Lars Brinkhoff
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zl2tod

@f4grx

Yep, 1600 characters per inch. The ninth track was usually parity. These tapes could often run at 6250 cpi on capable drives. There's a groove around the bottom of the spool close to the inside to take a write protect ring.

@brouhaha @larsbrinkhoff @ricci

@๐Ÿ‡บ๐Ÿ‡ฆ haxadecimal @F4GRX Sรƒยฉbastien @Rob Ricci @Lars Brinkhoff
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Poul-Henning Kamp

@brouhaha @larsbrinkhoff
I have the same good impression, but it's not clear to me if they are taking a "risk-of-loss" based approach to resourcing.

The highest failure-to-recover ratio for us in datamuseum.dk is (non-CDC-origin) hard-disks from the 1990ies, about one in ten hard-disks are not recoverable.

@๐Ÿ‡บ๐Ÿ‡ฆ haxadecimal @Lars Brinkhoff
in reply to Poul-Henning Kamp

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๐Ÿ‡บ๐Ÿ‡ฆ haxadecimal

@phloggen @larsbrinkhoff
Their Software Curator is one of the leading experts on 9-track data recovery, has designed and built custom apparatus for that, and is well aware of the various issues that require special attention to avoid destroying the data, as can happen if one just tries to read a tape by entirely normal means, e.g., destroying the oxide layer.
@Poul-Henning Kamp @Lars Brinkhoff
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bitsavers.org

@phloggen @brouhaha @larsbrinkhoff
I have about 100 Apollo ESDI disks that have been waiting for me to have time to look at them since the 00s. I'm not expecting a high recovery rate.

Disk recovery, especially removable cake-platters, are a huge problem, so much so that we decided to send all of our DEC 10 packs to LCM. Fortunately SDF has them now.

Magnetic tape is the highest risk format we have of high historical value that I can deal with right now.

@๐Ÿ‡บ๐Ÿ‡ฆ haxadecimal @Poul-Henning Kamp @Lars Brinkhoff
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Poul-Henning Kamp

@bitsavers @brouhaha @larsbrinkhoff
I've had good luck with ST506 and ESDI until now, they generally have huge engineering margins.

CDC 5ยผ" designs, whatever their names: No problems.

We even have a father&son team who has managed to read a handful of CDC 762 disc-packs, using a RpiPico to implement the SMD interface.

But once IDE/ATA/SCSI disks ecame comodity ? Get your bits while they last!

Agree on magtapes: Currently trying to get a drive going for a dozen 3480 cartridges.

We are lucky we got a box of german ยผ" QIC cartridge tapes with good tension bands, but transplanting them ? Ugh.

Paper Tape and punched cards read nearly perfect, and you can spot the problems with the naked eye.

@๐Ÿ‡บ๐Ÿ‡ฆ haxadecimal @bitsavers.org @Lars Brinkhoff
in reply to Poul-Henning Kamp

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Poul-Henning Kamp

@bitsavers @brouhaha @larsbrinkhoff
Also: If you run into weird 8" formats, we've written some software which can decode some of them from flux files:

github.com/Datamuseum-DK/Floppโ€ฆ

GitHub - Datamuseum-DK/FloppyTools: Tools for preservation of floppy disks

Tools for preservation of floppy disks. Contribute to Datamuseum-DK/FloppyTools development by creating an account on GitHub.
GitHub
@๐Ÿ‡บ๐Ÿ‡ฆ haxadecimal @bitsavers.org @Lars Brinkhoff

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Rob Ricci

We have some more information on this! One of @regehr's grad students

did some excellent sleuthing and figured out that this was received by Martin Newell : archive.org/details/unix_news_โ€ฆ

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

cv.thalia.dev/

UNIX News July 30 1975 : USENIX Association : Free Download, Borrow, and Streaming : Internet Archive

UNIX NewsVolume 1 Number 1, July 30, 1975
Internet Archive
@John Regehr
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Rob Ricci

Great talk on how recovering an old tape like this is done:

youtube.com/watch?v=7YoolSAHR5โ€ฆ

Virtual Vintage Computer West 2020

Auf YouTube findest du die angesagtesten Videos und Tracks. AuรŸerdem kannst du eigene Inhalte hochladen und mit Freunden oder gleich der ganzen Welt teilen.
Vintage Computer Federation (YouTube)

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Rob Ricci

Thalia Archibald has been transcribing old issues of #UNIX News from @internetarchive and John Gilmore's scans, and has the text up on github:

github.com/thaliaarchi/unix-neโ€ฆ

#retrocomputing

GitHub - thaliaarchi/unix-news: Transcriptions of UNIX News, the first UNIX newsletter, from 1975 to 1977

Transcriptions of UNIX News, the first UNIX newsletter, from 1975 to 1977 - thaliaarchi/unix-news
GitHub
#unix #retrocomputing @internetarchive
This entry was edited (3 weeks ago)
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Sean Riley

If I remember correctly there's a tape copy over the shoulder of Prof Brailaford in this Computerphile we made a few years back, whether it's still at University of Nottingham I don't know...

youtu.be/-rPPqm44xLs?si=cTobzcโ€ฆ

Mainframes and the Unix Revolution - Computerphile

Auf YouTube findest du die angesagtesten Videos und Tracks. AuรŸerdem kannst du eigene Inhalte hochladen und mit Freunden oder gleich der ganzen Welt teilen.
Computerphile (YouTube)

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โ‡ง