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Bitwise math/Negatives/Sign and Magnitude
From NetSec
- back to Bitwise math
The first bit is considered the sign bit, which if set, translates the number to it's negative counterpart. While this is very straightforward, it requires a a new operation to be supported by the hardware (subtraction), and generates two representations for the 0 value (10000000 and 00000000). As a result, the sign bit is usually used on the largest endian number (called the two's compliment implementation), so that there can be a negative value one value higher or lower than the highest positive value, for example:
- 1000 = -8, while 0111 = 7
