November 12, 2025
When C wore bell-bottoms
A Commentary on the Sixth Edition Unix Operating System
50-year-old UNIX guide ignites nostalgia—and a “weird C” meme war
TLDR: A classic 1977 guide to the early UNIX system is back in the spotlight, inspiring awe, laughs, and debates. Commenters celebrate vintage lessons, chuckle at quirky old C tricks, and argue whether today’s Linux still follows UNIX’s simple-do-one-thing-well ethos—proof that history still shapes how we build tech today.
A 1977 student booklet about early UNIX just crash-landed back into today’s feeds, and the comments are a full-on time capsule meets roast. Veterans are swooning over J. Lions’ classic Commentary on UNIX 6th Edition, calling it required reading, while others gawk at the vintage code’s extremely weird structs and tiny limits (think “max 50 processes”). One commenter breaks it down like a campfire horror story: old C let you poke the low byte of anything—cue the “undefined behavior speedrun” jokes. The nostalgia is strong: one fan says the book helped them evolve from their larval hacker phase and even drops a practical tip for tinkering with the xv6 teaching kernel—add a CPU sleep instruction to stop your laptop fans from screaming. Meanwhile, a side-quest erupts over the UNIX philosophy (“do one thing well”) versus modern Linux: one voice loves the old ideals but says today’s Linux isn’t a perfect match, which sparks the usual “purity vs practicality” debate. For vibes, the thread links to Brian Kernighan’s iconic pipes demo—watch it here. It’s half museum tour, half meme-fest, with grizzled pros reminiscing and newbies whispering: wait, people shipped code like this?
Key Points
- •The booklet by J. Lions is a 1977 companion commentary to the Sixth Edition UNIX source code for UNSW courses 6.602B and 6.657G.
- •UNIX was authored by K. Thompson and D. Ritchie at Bell Laboratories, and distribution was under Western Electric licensing.
- •The document’s circulation is restricted to holders of a Western Electric UNIX license; reproduction otherwise is prohibited.
- •Contents include technical topics such as assembler traps, software interrupts, the RK disk driver, buffer manipulation, directories, file systems, and character handling.
- •An excerpted code section defines kernel constants, signals, tunable parameters, and scheduler priorities (e.g., USIZE, ROOTINO, NSIG=20, NBUF, NPROC, HZ=60).