Here's what I came up with for Dave's challenge. I did know of the underlying "unusual" characteristic of assembler arithmetic, as I used it once about 40 years ago. Still, it was interesting figuring out how to apply it to this problem. Without that hint from Dave I'm not sure I would have managed to work it all out. Also, my initial attempt neglected the case where A=B, which Dave kindly pointed out to me. This revised version handles that.
Base-64 encoded in case anyone is still working on the challenge :) TUFYICAgIEVRVSAgIEEqKChBL0IpLyhBL0IpKStCKigoQi9BKS8oQi9BKSkqKChBLUIpLyhBLUIp KQ== -- Walt
