UNIX V4 tape successfully recovered
Posted by jpluimers on 2026/08/04
I forgot to schedule this post, but it was great news: a 50+ year old Unix V4 tape that was discovered in November 25 and digitally restored in December 25.
This was a big step forward in restoring the History of Unix.
There was a lot of coverage, but I think this thread was was the coolest part. It starts at [Wayback/Archive] Rob Ricci: “While cleaning a storage room,…” – discuss.systems.
An archive of the tape is now at for instance UNIX V4 tape from University of Utah (raw) : Computer History Museum : Free Download, Borrow, and Streaming : Internet Archive.
Not just the tape was found back, also the 1974 letter accompanying it: Letter to Martin Newell on UNIX delivery to University of Utah : Ken Thompson : Free Download, Borrow, and Streaming : Internet Archive.
If you want to play around with it yourself, then try [Wayback/Archive] UNIX v4 (1973) – Vintage Terminals (which I found through the thread I mentioned above).
Two of the many articles that covered the recovery (pun intended):
- [Wayback/Archive] 52 year old data tape could contain Unix history • The Register
- [Wayback/Archive] UNIX V4 tape successfully recovered • The Register
The second article links to the video [Wayback/Archive] Unix V4 Tape Reading – Exquisite.tube showing how the tape got restored into about 1.6 gigabyte of raw tape data which then was post-processed into the actual much shorter data that is available from [Wayback/Archive] minnie.tuhs.org/cgi-bin/utree.pl?file=V4 which is part of a larger project [Wayback/Archive] The Unix Tree
Welcome to the Unix Tree. Here you can browse the source code and manuals of various old versions of Unix. For every file, you can also find related files from other versions: this can help show how the different versions of Unix are related.
…
The software used to postprocess the raw data is [Wayback/Archive] GitHub – LenShustek/readtape: Decode the analog waveform extracted from old computer mag tapes.
A short history used to be at [Wayback/Archive] Early Unix history and evolution but since the end of 2024 it is now only in the archives.
This blog post is kept short as it is mainly for my own link archive in order to find back when I want to look deeper into it.
Reference: [Wayback/Archive] danielcowen: “@ricci if anybody is keen to p…” – discuss.systems
@ricci if anybody is keen to play around with this newly discovered system I’ve created a site where you can get a live (emulated) terminal of it in your browser – https://unixv4.devCheck out all the history (including the janky lack of backspace and cd command), have a go at some of the demo programs I’ve uploaded to it (otherwise the disk is stock), see if you can port Doom over to it. Let me know of any feedback.
Query: [Wayback/Archive] github lenshustek readtape at DuckDuckGo
--jeroen
The Wiert Corner - irregular stream of stuff 
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