10 ms·

Unix v4 Tape Found

• sema4hacker 11mo ago
  From 1973. See https://en.wikipedia.org/wiki/List_of_Unix_systems https://en.wikipedia.org/wiki/List_of_Unix_systems
• lproven 11mo ago
  Other posts on this subject, none with discussion: https://news.ycombinator.com/item?id=45846438 https://news.ycombinator.com/item?id=45846438 https://news.ycombinator.com/item?id=45844876 https://news.ycombinator.com/item?id=45844876 https://news.ycombinator.com/item?id=45842643 https://news.ycombinator.com/item?id=45842643
  • dang 11mo ago
    I've added https://oldbytes.space/@bitsavers/115505135441862982 https://oldbytes.space/@bitsavers/115505135441862982 and https://www.theregister.com/2025/11/07/unix_fourth_edition_tape_rediscovered/ https://www.theregister.com/2025/11/07/unix_fourth_edition_t... to the toptext as well. Thanks!
    • stinkbeetle 11mo ago
      Also this post from Rob Pike with interesting thread of a bit more information about tape recovery https://www.tuhs.org/pipermail/tuhs/2025-November/032758.html https://www.tuhs.org/pipermail/tuhs/2025-November/032758.htm...
      • dang 11mo ago
        Added up there too. Thanks!
  • ndiddy 11mo ago
    https://news.ycombinator.com/item?id=45857695 https://news.ycombinator.com/item?id=45857695 has discussion
    • lproven 11mo ago
      It does now. :-) It didn't when I posted earlier I wrote that article, but I no longer post my stories to HN because I am subject to a block and anything of my own I submit is flagged [dead]. I do not know why, and I have written to ask with no reply. I only write 5-10 articles a week so I don't exactly spam the site at high frequency, and if I don't feel I can add more context or insight to a story, I don't write it -- except at the very slowest times of the year, and I wouldn't post those stories here. Ah well.
• lproven 11mo ago
  Anyway, since nobody much seems to realise this is quite a big deal, I will share the explainer I wrote yesterday: https://www.theregister.com/2025/11/07/unix_fourth_edition_tape_rediscovered/ https://www.theregister.com/2025/11/07/unix_fourth_edition_t... Unix V4 is otherwise lost. It was the first version in C.
  • mongol 11mo ago
    Interesting article. I agree it is kind of a big deal. Certainly worth the effort to try to restore
  • nullhole 11mo ago
    The bit in the article about the recovery procedure, which involves dumping info from the tape into '100-ish GB of RAM' and then using software to analyze it stuck out to me. This video on the linked github page for the analysis software[1] is interesting: https://www.youtube.com/watch?v=7YoolSAHR5w&t=4200s https://www.youtube.com/watch?v=7YoolSAHR5w&t=4200s [1] https://github.com/LenShustek/readtape https://github.com/LenShustek/readtape
    • kragen 11mo ago
      Well, the tape may not survive its second pass across the read head, so it's good to capture the analog waveform in as much fidelity as possible.
      • hunter2_ 11mo ago
        I wonder if they'll find it suitable to bake [0] the tape first, which is quite popular in the audio restoration world but I'm not sure how much it applies to computer tape. [0] https://en.wikipedia.org/wiki/Sticky-shed_syndrome https://en.wikipedia.org/wiki/Sticky-shed_syndrome
        • debugnik 11mo ago
          I don't know much about tapes but it seems to apply, since the post mentions it: > I'm hoping I don't have to bake it, since that takes a day
• kazinator 11mo ago
  That is a big deal; I don't remember anything that old being available on tuhs.org.
  • larsbrinkhoff 11mo ago
    Check here https://www.tuhs.org/Archive/Distributions/Research/ https://www.tuhs.org/Archive/Distributions/Research/
• accrual 11mo ago
  > It is a '70s 1200ft 3M tape, likely 9 track, which has a pretty good chance of being recoverable. Not old enough to have this kind of knowledge or confidence. I wonder if instead one day I'll be helping some future generation read old floppies, CDs, and IDE/ATA disks *slaps top of AT tower*.
  • retrac 11mo ago
    You might be able to use that old floppy drive. But you won't be able to use that old Pentium machine the drive is in. Because you will need several hundred gigabytes of RAM and a very fast IO bus. The gold standard today for archiving magnetic media is to make a flux image. The media is treated as if it were an analog recording and sampled at such a high rate that the smallest details are captured. Interpretation is done later, in software. The only antique electronics involved are often the tape or drive head, directly connected to a high speed digitizer. And indeed that appears to be the plan Al Kossow has for the tape: https://www.tuhs.org/pipermail/tuhs/2025-November/032765.html https://www.tuhs.org/pipermail/tuhs/2025-November/032765.htm... As for CDs, I don't see the rush; the ones that were properly made will likely outlast human civilization.
    • fsckboy 11mo ago
      >As for CDs, I don't see the rush; the ones that were properly made will likely outlast human civilization. recordable CD-Rs or DVD-Rs do not last close to that long, and those are the ones that hold the only copies of certain bits (original versions of software, etc) that people are most interested in not losing. manufactured CDs and DVDs hold commericial music and films that are for the most part not rare at all.
      • accrual 11mo ago
        Yes, good distinction. Recordable media will most likely contain data an individual intended to save. But because it's recordable, the dyes and structures on the disc aren't as stable. Long-lasting, good quality mastered optical media is probably mass produced and has many copies, including a distinct and potentially well-preserved source. It's probably fair to say that a lot of mixtapes (mix CDs?) from the early 2000s are lost to dye issues...
• reactordev 11mo ago
  Please let there be an ultimate force in the universe that spared this tape from tape degradation and/or magnetization that it can be read and extracted into a raw dump fs that we can preserve for all time. (fingers crossed) Tapes from back then haven’t held up over the years. It all depends on the environment it was stored in.
  • dmix 11mo ago
    I remember reading we're nearing a timeframe where VHS and cassette tapes made in the <=1980s will start degrading pretty seriously. So if you own lots of VHS or camcorder tapes you have a relatively short window to save old family videos... or just deal with fuzzy images and bad audio.
    • superxpro12 11mo ago
      I recently went through this. The problem is finding VCR's... there arent any. And then the ones with manual tracking are even more rare, or out of the price range, which you likely need as the tracks degrade.
    • bigiain 11mo ago
      Somewhat related, there are people doing amazing things by modifying VHS players and tapping into the raw output from the tape heads (bypassing all of the player's other electronics), and then using modern signal processing techniques to extract unbelievable great footage from old tapes. Check out this extraction/decoding of a 1987 VHS recording of The Cure: https://www.youtube.com/watch?v=ks1wE_NXWv8 https://www.youtube.com/watch?v=ks1wE_NXWv8 Play if full screen at whatever the highest resolution your screen can take advantage of, It's amazing! Check out the quality of the big headshots of Robert Smith, the resolution of stuff like his hair is way beyond what I believed VHS to be capable of - based on growing up recording similar music acts in the 70s and 80s. Here's the software (and descriptions of the hardware and VHS player mods) they use: https://github.com/oyvindln/vhs-decode https://github.com/oyvindln/vhs-decode I suspect the recording technique/format on those is a similar analog signal on the tape - and from The Reg's article (quoting various sources) it sounds like they're already planning on similar approach: "The software librarian at the CHM is the redoubtable Al Kossow of Bitsavers, who commented in the thread that he is on the case. On the TUHS mailing list, he 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: https://github.com/LenShustek/readtape https://github.com/LenShustek/readtape It is a '70s 1200ft 3M tape, likely 9 track, which has a pretty good chance of being recoverable."
• ekjhgkejhgk 11mo ago
  OT - Mastodon is seriously cool. If you haven't yet bothered, I suggest to everyone that you spend a bit of time exploring.
  • fishgoesblub 11mo ago
    Mastodon is just a part of the larger Fediverse.
    • ekjhgkejhgk 11mo ago
      Yeah I guess I still haven't wrapped my mind around that other part.
  • mmooss 11mo ago
    What makes it cool?
    • CamperBob2 11mo ago
      It shoves dark mode down your throat whether you want it or not. What could be cooler than that?
      • pavo-etc 11mo ago
        There's an option
        • CamperBob2 11mo ago
          Really. Where? Unhelpful answers of the form "Just install extension X for browser Y and use it to run script Z" are all anyone has ever been able to suggest when I've asked this question elsewhere.
          • glenstein 11mo ago
            If you click on Preferences, it's under Appearance which is the first section you see. You can change the site theme to a light option. At least on Mastodon.social.
• olivia-banks 11mo ago
  I really, really hope data can be recovered from this. I’ve read a bunch of the original sources, and such an ancient C would be especially interesting to study. Very proud to have had this found at my University :-)
• don-code 11mo ago
  This seems to be how a lot of modern history is found. I recently got to talk to a big-ish name in the Boston music scene, who republished one of his band's original 1985 demos after cleaning the signal up with AI. He told me that he found that tape in a bedroom drawer.
• CobrastanJorji 11mo ago
  What are the odds that a medium like that has successfully stored the full data without error?
  • shanoaice 11mo ago
    From the information I've read, quite likely, given that Utah is pretty dry. Also the original data might be stored in its uncompressed form, so even if there were some non-extensive damage it might still be possible to recover some data based upon guessing with context (if it contains text source code, otherwise if it is just the binaries then not that easy).
• nineteen999 11mo ago
  This is amazing news for UNIX fans. Really hope the source can be recovered and put alongside the other historical UNIX source that's out there.
• lexurco 11mo ago
  I remember at one point I browsed tuhs.org in an attempt to find the source code for the original B (the language predating C) compiler. I don't think it should be in the 4th edition. I still wonder if there's a copy somewhere. I know there are a few modern implementations, but it would be interesting to look at the original.
  • ForOldHack 11mo ago
    The 'B' compiler was written in TMG-Compiler-Compiler. TMG (Transmogrifier) https://github.com/amakukha/tmg https://github.com/amakukha/tmg https://news.ycombinator.com/item?id=26722097 https://news.ycombinator.com/item?id=26722097 ""Douglas McIlroy ported TMG to an early version of Unix. According to Ken Thompson, McIlroy wrote TMG in TMG on a piece of paper and "decided to give his piece of paper his piece of paper," hand-compiling assembly language that he entered and assembled on Thompson's Unix system running on PDP-7." We are not worthy, friends. We are not worthy." Tons of info, but not much source: "The first B compiler was written by Ken Thompson in the TMG language around 1969. Thompson initially used the TMG compiler to create a version of B for the PDP-7 minicomputer, which generated threaded code. The B compiler was later rewritten in BCPL and cross-compiled on a GE 635 mainframe to produce object code, which was then re-written in B itself to create a self-hosting compiler. " So... a B compiler would use GE 635/Multics as a OS.
    • ForOldHack 11mo ago
      Of course I found it, AFTER I hit post... https://retrocomputingforum.com/t/b-a-simple-interpreter-compiler/489 https://retrocomputingforum.com/t/b-a-simple-interpreter-com...
• shevy-java 11mo ago
  Finally we can see the naughty stuff they recorded!
• rurban 11mo ago
  Will not be much different to the existing v5 source code, we can assume. https://minnie.tuhs.org/cgi-bin/utree.pl?file=V5/usr/source/s1 https://minnie.tuhs.org/cgi-bin/utree.pl?file=V5/usr/source/...
• whizzter 11mo ago
  Someone in the Mastodon thread mentioned the Andrew Tannenbaum "Never underestimate the bandwidth of a station wagon full of tapes hurtling down the highway." So I wondered about a modern day equivalent, looked up 1tb micro-sd cards (sold locally for Nintendo Switch) and calculated that there'd be roughly space for 400 exabytes of data in a shipping container filled to the brim with SD-cards. (SDcard being 1tb for 1.092 x 1,499 x 0,102 CM's and a shipping container being 1203 x 235 x 239 CM's inside so holding 400 million SD cards)
  • avar 11mo ago
    Actually a shipping container full of micro-SD cards hurtling down the highway has lower overall bandwidth than a 56k modem. That's because whoever's attempting to load an ideal 400 million micro-SD cards into one will take approximately forever carefully trying to line up even one row of them on the floor of a shipping container, before having the whole thing fall over like dominoes. And even if they manage that, the whole thing will tumble over once they need to deal with the first row of the container's side corrugation. Nobody at the department of Spherical Cows in Vacuums thought to account for those dimensions[1] not lining up with the size of micro-SD cards. If they do manage some approximation of this it'll take forever just to drive this down the road, let alone get the necessary permits to take the thing on the highway. Turns out not a lot of semi truck trailers or roads are prepared to deal with a 40 ft container weighing around 100 metric tons (the weight of one packed to the brim with sand, a close approximation). The good news is that such transportation gets more fuel efficient the longer the trip is. The bad news is that the container will arrive mostly empty, as it's discovered that shipping container door panel gaps and road vibrations conspire to spread a steady stream of micro-SD cards behind you the entire way there. Commuters in snowy areas held up behind the slowly moving "OVERSIZED LOAD!" with a mandatory police escort wonder if it's a trial for a new type of road salt that makes a pleasant crunchy sound as you drive over it. Finally, an attempt to recover the remaining data fails. The sharding strategy chosen didn't account for failure due to road salt ingression into the container, cards at the bottom of the container being crushed to dust by the weight of those above, or that the leased container hadn't been thoroughly cleaned since last transporting, wait, what is that smell? 1. https://www.discovercontainers.com/wp-content/uploads/container-end-corrugation-filleted.png https://www.discovercontainers.com/wp-content/uploads/contai...
• tgtweak 11mo ago
  Very interesting storage format too - Those tapes actually held quite a bit of data (comparatively) - around 45MB (Although this one is shorter ~1000ft and probably carries about 10-15MB which is close to V4's source code, binary and documentation size).
• jonathaneunice 11mo ago
  For context, I'm a geezer who got early access reading Lions' Commentary (6th Edition) and comparing it with 7th Edition source (running on a PDP-/something with no more than 128 KiB RAM). That was 1985, as Unix was spreading its way through universities. SIGSEGV haunts me to this day. That was a full 40 years ago. And yet, 4th Edition is ancient history even to me.
• pabs3 11mo ago
  Hope they will upload it to archive.org and Software Heritage.