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| | Minus Zero |
 | | Consider: when the computer adds two numbers, with signed magnitude it first has to look at the signs of both numbers, then decide, based upon the signs, whether to add them or subtract one from the other, and what sign the result will bear. |
 | | The oddity of a negative number with no positive counterpart is also gone; the nine's complement of the largest positive number, 4999 is 5000, which represents -4999 just as you'd expect. |
 | | In summary, by admitting the added complexity of end-around carry, we have obtained a way of representing negative numbers which is symmetric, in which power-of-two division can be done by shifting for all numbers, and where negating a number and inverting all its bits are one and the same thing. |
| www.fourmilab.ch /documents/univac/minuszero.html (2935 words) |
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