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, and finally if the opponent takes 1 marbles, the first player should take 3.
- "John Godfrey Obituary - Lansing, MI - Lansing State Journal". Lansing State Journal.
- Original manual (Pdf)
- Jim's Computer Museum (most links broken)
- BoardGameGeek entry for The Amazing Dr. Nim
- YouTube video of game play The Amazing Dr Nim game/puzzle
- The manual (PDF) with instructions on the basic game and on alternate ways to play the game.
- How to play Nim is explained & a script version to play can be found at Ancient Pond
- Yahoo Groups Friends of DigiComp - Owners and fans of Digi-Comp Toy Computers Special Interest Group for those who own or are interested in DigiComp computers & games.
- Dr. Nim Manual (PDF)
- The Alan Kaminsky Museum of Antique Computing Devices Dr. Nim
- The Unbeatable Game from the 60s: Dr NIM by Matt Parker