[TUHS] Ideas for a Unix paper I'm writing

All, IEEE Spectrum have asked me to write a paper on Unix to celebrate the 40th anniversary of the release of 1st Edition in November 1971. I'm after ideas & suggestions! I think my general thrust is that Unix is an elegant design, and the design elements are still relevant today. The implementation is mostly irrelevant (consider how much the code has changed from assembly -> C, from the simple data structures in V7 through to current BSD), but the original API is classic. Note that about 28 of the 1st Ed syscalls are retained in current BSDs and Linux, and with the same syscall numbers. I'm having some trouble thinking of the right way to explain what is an elegant design at the OS/syscall level, so any inspirations/ideas would be most welcome. I might highlight a couple of syscall groups: open/close/read/write, and fork/exec/exit/wait. If you have any references/URLs you think I should look at, please pass them on to me. I'm also trying to chase down some quotes; my memory seems to be failing me but I'm sure I've seen these somewhere: - in a paper, I think by Thompson & Ritchie, where they assert that the kernel should provide no more than the most minimal services to the userland programs. I thought this was the CACM paper, but I can't spot this bit. Maybe it's in Thompson's preface to the Lions Commentary, of which my copy is elsewere at present. - I'm sure I remember someome (Kernighan?) say that Ritchie encouraged them to espouse the use of processes as context switching was cheap, but later measurements showed that in fact it wasn't that cheap in the early versions of Unix. Anyway, if you can think of good ideas/references about the elegance of Unix, especially from the design perspective, I would much appreciate them. Cheers, Warren