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The Think-a-Dot was a mathematical toy invented by
Picture of a Think-a-Dot
3-D printable Think-a-Dot Replica
Mechanical puzzles
The Think-a-Dot was a mathematical toy invented by Joseph Weisbecker
Joseph A. Weisbecker (September 4, 1932 – November 15, 1990) was an early microprocessor and microcomputer researcher, as well as a gifted writer and designer of toys and games. He was a recipient of the David Sarnoff award for outstanding tech ...
and manufactured by E.S.R., Inc. E.S.R., Inc. was an American manufacturer of educational toys during the 1960s. The company’s founders included William H. Duerig and Irving J. Lieberman, both involved in missile research at Kearfott Guidance in New Jersey, and C. David Hogan, an ...
during the 1960s that demonstrated automata theory
Automata theory is the study of abstract machines and automata, as well as the computational problems that can be solved using them. It is a theory in theoretical computer science. The word ''automata'' comes from the Greek word αὐτόματο ...
. It had eight coloured disks on its front, and three holes on its top – left, right, and center – through which a ball bearing could be dropped. Each disk would display either a yellow or blue face, depending on whether the mechanism behind it was tipped to the right or the left. The Think-a-Dot thus had 28=256 internal states. When the ball fell to the bottom it would exit either to a hole on the left or the right of the device.
As the ball passed through the Think-a-Dot, it would flip the disk mechanisms that it passed, and they in turn would determine whether the ball would be deflected to the left or to the right. Various puzzles and games were possible with the Think-a-Dot, such as flipping the colours of all cells in the minimum number of moves, or reaching a given state from a monochrome state or vice versa.
See also
*Digi-Comp I
The Digi-Comp I was a functioning, mechanical digital computer sold in kit form. It was originally manufactured from polystyrene parts by E.S.R., Inc. starting in 1963 and sold as an educational toy for US$4.99.
A successor, the Digi-Comp II, ...
* Digi-Comp II
The Digi-Comp II was a toy computer invented by John "Jack" Thomas Godfrey (1924–2009) in 1965 and manufactured by E.S.R., Inc. in the late 1960s that used marbles rolling down a ramp to perform basic calculations. A two-level masonite platfor ...
* Dr. NIM
References
*. *. *{{citation , last = Gemignani , first = Michael , doi = 10.2307/2689850 , issue = 2 , journal = Mathematics Magazine , mr = 1572295 , pages = 110–112 , title = Think-a-Dot: a useful generalization , volume = 52 , year = 1979.External links
Picture of a Think-a-Dot
3-D printable Think-a-Dot Replica
Mechanical puzzles