Great article. One potential improvement is not to call Two's complement MSB a 'sign bit'. It implies that it only stores a sign which is how 'Signed magnitude' works. With all its downsides like having two representations for 0 etc. The beauty of Two's complement is that everything works exactly like unsigned representation, with the exception of MSB. In Two's complement MSB contributes either 0 or negative 2^N-1. So for 8 bit signed numbers, most significant bit contributes either 0 or -128. Everything else, subtraction, hardware adders etc work the same. Signed numbers are basically numbers with a flexible number line, and the first bit represents where this number line starts. I personally remember MSB for signed integers as 'origin bit'.