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:
> This is rare enough that I'm pushing the recovery
> of it up near the top of my project queue.
The reader is left to wonder what the software librarian at the Computer History Museum could have possibly found recently that warrants a placement ahead of Unix v4 in their project queue. A copy of Atlantian Unix from the ancient Library of Alexandria?
> 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*.
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.
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 :-)
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.
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.
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)
I used to be a digitial hoarder (now less so, but I still have what I hoarded, built over a 15 year period). When I moved overseas, I shipped my 120HDs (~600TB) in a container (120 HDs don't take up "that" much space (they all arrived in one piece, though 5 have died, though only 3 non recoverable, after the first one died, I made sure to image each one first and then writing it back (bitrot was a problem)).
anyways, in took 2-3 months for it to arrive (and most of that time it was waiting in either port), but by my calculation, I have needed to transfer it at a consistent 80MB/s or so (close to gigabit) to be able to net the equivalent transfer rate.
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).
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.
25 comments
[ 2.8 ms ] story [ 40.8 ms ] threadhttps://news.ycombinator.com/item?id=45846438
https://news.ycombinator.com/item?id=45844876
https://news.ycombinator.com/item?id=45842643
https://www.theregister.com/2025/11/07/unix_fourth_edition_t...
Unix V4 is otherwise lost. It was the first version in C.
This video on the linked github page for the analysis software[1] is interesting:
https://www.youtube.com/watch?v=7YoolSAHR5w&t=4200s
[1] https://github.com/LenShustek/readtape
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*.
Tapes from back then haven’t held up over the years. It all depends on the environment it was stored in.
Very proud to have had this found at my University :-)
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.
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)
anyways, in took 2-3 months for it to arrive (and most of that time it was waiting in either port), but by my calculation, I have needed to transfer it at a consistent 80MB/s or so (close to gigabit) to be able to net the equivalent transfer rate.
https://what-if.xkcd.com/31/
That was a full 40 years ago. And yet, 4th Edition is ancient history even to me.