Discovering things while researching Unix history

One of the nice things about researching things like the history of dump is that it teaches me things about Unix's history that I didn't know. For example, until I decided to write up dump's history, I had no idea that it had actually originated as far back as V6; for some reason I had it in my mind as a UCB invention.

(Perhaps because the idea of dump always struck me as the kind of baroque thing that UCB would come up with, instead of the sort of nice clean solution that I like to think of Bell Labs creating. Although, if we are being honest, V7 had its share of hacks too.)

Unix history is a bit arcane and I didn't start using Unix early enough to be fully familiar with all of it, so I can be fuzzy (or outright mistaken) about the exact details. Fortunately there are places like tuhs.org where I can actually check the primary sources. (Why I care about this stuff is another question entirely, one that I don't have a satisfactory answer to.)

On a side note, I put an unjustified slam on cpio into my original entry. According to Wikipedia, cpio seems to have been invented more or less at the same time as tar, just by a different group inside of AT&T (see the history of PWB/UNIX).