19 Nov
2003
19 Nov
'03
2:23 p.m.
On Wed, 19 Nov 2003, William R. Buckley wrote:
William, you are completely contradicting yourself at this point. You
started out asserting that all computers are Turning machines, then you
quoted the source above which is saying that they really aren't, and
implying exactly what Tony Duell said a few messages ago, which is that
they aren't because they don't have infinite memory.
Thanks, but I'll pass on the salad bar of verbage that you are offering up
here.
--
Sellam Ismail Vintage Computer Festival
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From Daniel I.
A. Cohen's book, Introduction To Compuer Theory,
pp 788
>Definition. If a Turning Machine (TM) has the
property that for every
word
>it accepts, at the time it halts, it leaves
one solid string of a's and
b's on
>its Tape starting in cell i, we call it a
computer. The input string we
call
>the input (or, string of input numbers), and
we identify it as a sequence
>of nonnegative integers. The string left on the Tape we call the output
>and identify it also as a sequence of nonnegative integers.
The discussion continues,
"Now we finally know what a computer is. Those expensive boxes of
electronics sold as computers are only approximations to the real McCoy.
For one thing, they almost never come with an infinite memory like a true
TM."