Since there are 256 possible bit patterns with 8 bits, there could be 128 positive and 128 negative integers.
You may have thought of the sign-magnitude method, discussed below.
There are many schemes for representing negative integers with patterns of bits. One scheme is sign-magnitude. It uses one bit (usually the leftmost) to indicate the sign. "0" indicates a positive integer, and "1" indicates a negative integer. The rest of the bits are used for the magnitude of the number. So -2410 is represented as:
1001 1000 The sign "1" means negative The magnitude is 24 (in 7-bit binary)
With 8-bit sign-magnitude representation, what positive integers can be represented and what negative integers can be represented?