[Tutor] what is 'doubleword alignment'?

[Lisi]

On Saturday 16 July 2011 21:53:55 Albert-Jan Roskam wrote:
> I know that the buffer is comprised of variables of 8-bytes, or multiples
> thereof, each. Numeric variables are 8 bytes, char vars are at least 8
> bytes. For example, a 10-byte value is 'ceiled' to 18 bytes. This is done
> with padding (spaces, I think). But the aligment part...?
then wrote:
> Got it already, I think. The word boundary of one chunk of information (in
> my case 8 bytes) is aligned in the computer's memory such that the
> boundary's address is a power of two.

Sorry to be slow.  Blame virtually no sleep last night ;-(  But even were the 
power of two bit correct (and I see subsequently that it is not), how is 18 a 
power of two?

Lisi