Write the 6-bit 2's complement representation of -32.
I think the answer is supposed to be something like "overflow" or some error. Because 32 in binary would be 10 0000, right? And $-32$ would be 110 0000 with 7 bits. How can I show this representation with it being signed? Then convert that to 2's complement?
Best Answer
Don't try to convert from signed-magnitude to two's complement. As you said, you can't express $32$ in $6$-bit signed magnitude. Just express it directly.
Your place values in unsigned $n$-bit binary are: $2^{n-1}, 2^{n-2}, \ldots, 2, 1$. But this only allows positive numbers. In two's complement, the sign of the leading bit is reversed. So your place values for 6-bit two's complement are: $-32, 16, 8, 4, 2, 1$. This allows you to express numbers from $-32$ to $31$, and lets you add and subtract numbers with different signs normally. In this case, $-32$ is really easy to express, it's just $100000$.
This also makes the whole $-x == \:\: \sim\! x + 1 == \:\: \sim\!(x - 1)$ trick make more sense.