TWO'S COMPLEMENT REPRESENTATIONS
One unnatural property of the offset binary code is that a signal amplitude of zero is represented by the nonzero bit pattern [1,0,...,0]. Why is this significant?

A solution is to use two's complement codes. A two's complement code can be constructed from the offset binary code by complementing the most significant bit:

Below is a summary of the common converter types and their I/O relationship:

Converter Type	I/O Relationship
natural binary
offset binary
two's complement