December 30, 2025
Ancient code, modern shade
An initial analysis of the discovered Unix V4 tape
Lost 1970s computer tape resurfaces — cue the comment chaos
TLDR: A long-lost 1970s Unix tape was restored and added to a public archive, spotlighting Unix’s leap into the C language. The top response was a curt “dupe” link, with familiar debates over whether it’s truly Version 4 and how to credit authors—an important, rare peek into computing’s roots.
A 1970s Unix treasure just popped out of a dusty drawer: a restored tape from Bell Labs’ Fourth Edition Unix, the early operating system that shaped modern computing. It’s a huge historical win — early Unix moved from hard-to-read machine code into a new high-level language (early C), and this tape shows that shift in the wild. But the first thing the internet did? Drop a brisk “[dupe]” and a link, of course — classic Hacker News energy, with the thread instantly redirected elsewhere (receipt).
From there, the drama writes itself. The article notes some argue the tape looks a lot like the next release (Version 5), which sparks the eternal purist fight: what “counts” as Version 4 versus “whatever was on the lab’s one development machine.” Meanwhile, the curator mapped unknown authors to legends Ken Thompson and Dennis Ritchie — historically honest about missing data, or a little too “blame Ken for everything”? You can practically hear the low-key memes forming. Even the cleanup commands — old-school “delete the binaries” lines — read like retro hacker poetry.
Love it or nitpick it, the mood is pure internet: a priceless time capsule lands, and the crowd immediately argues about labels and provenance while someone shouts “dupe!” in the doorway. Peak tech culture, starring a magnetic tape and a thousand opinions.
Key Points
- •A 1970s Fourth Edition Research Unix tape was discovered at the University of Utah and successfully restored.
- •The tape contained a complete system dump; binaries were removed before adding the source to the Unix History Repository on GitHub.
- •Commit timestamps were synthesized from file timestamps, and authors were mapped manually, defaulting to Ken Thompson and Dennis Ritchie where unknown.
- •Filename comparisons show only a few files unique to Fifth Edition (c13.c, c21.c, c2h.c, cmp.c, ldfps.s), indicating limited divergence.
- •Git blame with copy/move detection attributed 75,676 lines to Fourth Edition provenance; component authorship includes Ken Thompson (SNOBOL III) and Robert H. Morris (math library, emulator).