On Hein Veldhuis’s website (link) you can see a photo and read about the Turbo 16K prototype which was shown at the Nuremburg Toy Fair in February 1985. At the time it was assumed that this was a final product but as you will see the Turbo 16K changed quite dramatically between February and the end of 1985 when it was released. These rapid changes of product were a feature of the chess computer market of the mid-1980s.

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