Dr. Nim

Dr. Nim is a toy invented by John Thomas Godfrey[1] 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 "game board" is based on the mechanical Digi-Comp II digital computer.

The fourth lever is the "equaliser" option; if set, the player can win if they play perfectly.

After the machine has played, the last released marble flips the switch back to end the turn.