bit-for-bit disk copy using dd?

Hi,

I'm trying to use "dd" to copy one HD to another.

The original is an old W95 disk, 1.7 GB and the destination is a blank 3 GB disk.  I do (booting from install disk floppies and dropping to a prompt):

$ dd if=/dev/rwd0d of=/dev/rwd1d  and wait 1,769 seconds and then it finishes.

But when I do this, the copy doesn't boot when I move it to the destination system; it's as if there's no OS.

The original disk boots just fine.

So, is there some extra-special secret sauce needed to make a "clone" of a disk with dd?

Thanks -Mike