QZ qz thoughts
a blog from Eli the Bearded

LEGO Difference Engine

Andrew Carol's Lego Difference Engine is a low tech computer after Babbage's nineteenth century mechanical computer designs. This can evaluate any polynomial of the form ax^2 + bx + c, to three digits of precision, with an effort of a hundred or so turns of the crank.

dead link: http://acarol.woz.org/