2.4   SIGNED INTEGER REPRESENTATION

We have seen how to convert an unsigned integer from one base to another. Signed numbers require that additional issues be addressed. When an integer variable is declared in a program, many programming languages automatically allocate a storage area that includes a sign as the first bit of the storage location. By convention, a 1 in the high-order bit indicates a negative number. The storage location can be as small as an 8-bit byte or as large as several words, depending on the programming language and the computer system. The remaining bits (after the sign bit) are used to represent the number itself.

How this number is represented depends on the method used. There are three commonly used approaches. The ...

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