I too found V5 to be the earliest currently-surviving source. Since the routine is documented in the V3 man pages (see http://minnie.tuhs.org/cgi-bin/utree.pl?file=V3/man/man3/sqrt.3 ) I suspect the code goes back at least to Feb 1973. Thanks for the link, my link was to a mirror of the same files. TUHS is "The Unix Heritage Society": http://www.tuhs.org/wiki/The_Unix_Heritage_Society On Tue, Apr 19, 2011 at 11:53, Tom Duff <td@pixar.com> wrote:
On Tue, 19 Apr 2011, Henry Baker wrote:
Very cool! Thx, Tom!
I searched for some of the strings in this code to see what I could find on Google, but could only find _later_ versions of the same code, so your reference is the best so far.
The same code was in 5th Edition UNIX, released in June 1974. I found that source code here:
http://minnie.tuhs.org/cgi-bin/utree.pl?file=V5/usr/source/s3/sqrt.s
tuhs.org ("The UNIX Historical Society", I think) is the best web-accessible source for early UNIX information. They only have fragmentary archives of UNIX editions earlier than the 5th -- not surprising, as those versions predate Ken & Dennis's CACM paper and weren't distributed widely.
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