Dr. Nim

Dr. Nim is a toy invented by John Thomas Godfrey and manufactured by E.S.R., Inc. in the mid-1960s. It consists of a marble-powered plastic computer capable of playing the game of Nim. The machine selects its moves through the action of the marbles falling through the levers of the machine.

Dr. Nim is an early computer game. The "game board" is a simple Digi-Comp digital computer with memory switches (the three-lobed levers) that "remember" earlier game actions. Their starting positions form the program that plays Nim.

Dr. NIM was based on a mathematical game called NIM, which similarly consisted of twelve marbles. The name NIM is actually WIN upside down, due to how a simple strategy will always win as long as the opponent goes first. This is the strategy for single-pile NIM: If the opponent takes 3 marbles, the first player should take 1. If the opponent takes 2 marbles, the first player should take 2. Finally, if the opponent takes 1 marble, the first player should take 3. The goal of the game is to get the last marble (the 12th marble).

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