🚀 go-pugleaf

In article <303@gvlv2.GVL.Unisys.COM> kleonard@gvlv2.GVL.Unisys.COM (Ken Leonard) writes:
>There was at least one model/series/family of IBM machines that _DID_HAVE_
>hardware square root--the 70x0/STRETCH.
>In fact, it was _REAL_HARDWARE_ sqrt, not microcoded nor some funny use of
>the divider hardware.  The sqrt unit was implemented primarily with tunnel-
>diode gates and (at the time) a minimum amount of fastest available
>transistors.

Cray-2's, at least, have sqrt and 1/sqrt (no divide, of course; but they do
have reciporocal [sp?]), all in hardware.  God, aka Seymour Cray, doesn't
believe in microcode.  Then again, he also doesn't believe in virtual memory
(yes, it does slow things down; so does having to wait noticeably while one
extremely large application gets swapped out so that smaller ones can run).

Cray-1's and X-MP's don't have them, I believe; they seemed to be new with
the 2.  If memory serves me, the little instruction-set summary I got this
out of also showed a sqrt table in the functional-unit diagram...

-- 
Sean Eric Fagan  |    "[Space] is not for the timid."
seanf@sco.UUCP   |             -- Q (John deLancie), "Star Trek: TNG"
(408) 458-1422   | Any opinions expressed are my own, not my employers'.