In a signed binary in one's complement representation, the first bit (the leftmost) indicates the sign, 1 = negative, 0 = positive.
2. Get the binary representation of the positive (unsigned) number.
* Run this step only if the number is negative *
Flip all the bits of the signed binary in one's complement representation (reverse the digits) - replace the bits set on 1 with 0s and the bits on 0 with 1s:
!(1100 0101) = 0011 1010
3. Map the unsigned binary number's digits versus the corresponding powers of 2 that their place value represent:
27
0 26
0 25
1 24
1 23
1 22
0 21
1 20
0
The signed binary number in one's complement representation 1100 0101(2) converted and written as an integer in decimal system (base ten):
1100 0101(2) = -58(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.