[rgj]

The Dutch childrens magazine Donald Duck included a DIY cardboard 3 bit computer in four editions in 1980. It was powered by a marble and gravity and it included QA cards, like “What shall we eat? followed by three questions (hungry? Want sweet? etc) and then on the back of the cards there were eight answers. You set the switches to left or right, put in the marble at the top and looked up the answer corresponding to the place where the marble appeared.

I was seven years old and at that moment I decided I wanted to become a computer scientist. It determined my life.

http://rene.steetskamp.nl/2015/04/

[scrozier]

The DigiComp I did it for me: https://en.wikipedia.org/wiki/Digi-Comp_I

[andrehacker]

That is very cool, a bit of Google Foo then gave me this:

https://drive.google.com/folderview?id=0B-V14n0_048hOUR1Ymdv...

That and Google Translate will allow you to build your own.