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The LEGO Turning Machine • Masterpiece 3 107

Bricks & Chips…

Additional Needs for the LEGO Turing Machine
This model doesn’t need many extra parts. You will need a LEGO RIS 2.0 kit,
which contains two motors, the light sensor, and the touch sensor, plus one addi-
tional motor. For the tape, though, you’ll need some additional pieces: the 6632
TECHNIC 1x3 Liftarm and the 3743 TECHNIC 1x4 Gear Rack. Quantities depend on
the length of the tape you want to build. In this project, we will build a tape
with 16 cells that is 32 wide, so we need 32 liftarms (plus four for the switch
mechanisms) and eight gear racks. For the base, we’ll also need eight 4162 1x8
tiles. If you’re missing some of the pieces, you can probably use something else
or try a different solution: for example, you can substitute the eight tiles with a
greater amount of shorter tiles, or leave a space between one tile and another.
In the LEGO Turing machine, we will use a combination of yellow bricks, gray
plates, and black parts. You can change nearly every color however you prefer,
but remember that you should use a light color for the liftarms and a dark color
for the bottom of the tape to ensure that the light sensor reads the symbol on
the cell correctly and that there is a significant difference in the light sensor’s
reading value.

Introduction

In Masterpiece 2,“The Learning Brick Sorter,” we entered the world of Artificial
Intelligence (AI), and saw how a robot can actually learn from its behavior. In this
chapter, we will see another notable example of this concept, going back to its very
beginning in the 1930s, with the birth of a very special device: the Turing Machine.
The Turing Machine was a very primitive sort of computer, the simplest possible
machine that could perform computation, and an ancestor of any modern computer that
we use everyday.Any digital computer or electronic device that is multi-purposed and
uses the concept of algorithm is, in fact, a reincarnation of such a device.You can even
consider the Turing Machine a grandparent of your RCX!
We will explain the concepts behind the invention, programming, and behavior of the
LEGO Turing Machine. By following the instructions and directions in the chapter, you’ll
soon be able to build your personal Turing Machine purely out of LEGO pieces. We’ll
see a couple of examples of how to program the LEGO Turing Machine using NQC,
and at the end of the chapter, we’ll see hints and tips on how to expand your creation.

The History of the Turing Machine

Let’s go back in time through some history of this fascinating device.The following his-
torical sections are not essential for building the model, but are still extremely useful to
explain the basic ideas that lead to the design and development of the Turing Machine,