[TUHS] reviving a bit of WWB

[Doug McIlroy]

> Turing save us from 1-complement machines!

Users of Whirlwind II were warned about the quirks of -0.
We were not warned, though, about integer divide with remainder 0.
The result of dividing 6 by 3, for example, was binary 1.111111... -
a valid answer when carried to infinity. Unfortunately, the
"fractional" part was dropped.

Most people used Whirlwind for floating-point computation, and
blithely dismissed printed answers like 1.999999 as "roundoff
errors".

Doug