Thread: Unsigned intger, sign magnitude notation (Binary)

Hey guys, I've searched and searched but I can't seem to find any help on this question I have.

Express the following bit pattern 10011001 in:

a) Unsigned integer
b) Signed integer in sign-magnitude notation
c) Signed integer in Twos-compliment

I don't understand what these means and I've looked online but I can only find converters etc but I need to learn how do do this with pen and pad for my exams. Please try to explain the best you can if you can. Thanks.

OK I can do a and b. In binary there is no + or - so all numbers are unsigned integers unless otherwise specified, therefore converting the binary no to a decimal will give a). We know computers deal with signed integers too, in this case the first digit in binary assigns + or - to the figure (not sure which is which), so the signed int will be -/+ from the first digit and the decimal will be the representation of the rest of the digits.. not sure about c.

I suggest googling for how computers use numbers for this rather than just binary

Can anyone else shed some light?

"twos complement" has negative numbers with "1" as first bit and the magnitude given as the complement of each bit:
the number +1011011 would be stored as 01011011 while -1011011 would be stored as 10100100.