On 9/8/2010 11:18 PM, Fred van der Windt wrote:
close, but no cigar. Addres arithmetic wraps.
And if you wrap nearly all the way around, you effectively
end up with an address slightly lower than the starting point.
To my mind, this is *effectively* subtraction, even when
*technicall* the processor performed addition.
If you walk forward around the globe and stop 10 meters short
of your starting point, the net result is the same as going
back 10 meters. I'm sorry - it's as ugly (or beautiful) as it is.
But you can only walk 4095 meters, can't you? Way short of the circumference of
the globe.
Once my erroneous comma is removed, you can walk a lot further.
Read John Ehrman's article, as cited earlier by Michael Stack:
http://www.kcats.org/csci/464/ho/usingtechnique.shtml
-- gil
