This was way to cool to pass up.

"Napier's Chessboard Calculator

It is a long read but well worth it.

By kbs
Mon Dec 13th, 2004 at 06:39:30 PM EST

Isn't Napier the logarithm guy? Yes indeed. A man of varied talents, he popularized the modern decimal point notation and argued that the Pope of 1593 was the Antichrist.
And created one of the first devices to automate binary arithmetic. Using nothing more than a chessboard and some counters, he developed ways to multiply, divide and even find the square roots of binary numbers.
Full Story"