Comment by lproven
2 months 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_t...
Unix V4 is otherwise lost. It was the first version in C.
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
[1] https://github.com/LenShustek/readtape
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.
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
1 reply →
What a fantastic talk! Thanks for sharing.
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?
Perhaps a prior promise to someone else?
Or you know... just the definition of a FIFO Queue. I mean, using a FILO Stack to organize your work would certainly be a choice...
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Interesting article. I agree it is kind of a big deal. Certainly worth the effort to try to restore