This is the first Lego robot. You will not find it as an individual set on Bricklink — it’s described on pages 78-93 of the Expert Builder Idea Book which is set #8888 though it contains only reading material, not any parts. (Younger readers: “Expert Builder” is what Lego called its movement sets before the name Technic). This robot runs analog software and mechanical hardware, not a digital electronic system. Analog and mechanical methods were important concepts in calculating and computing from several hundred years ago until about the 1970s.
To understand the 8888 robot, first you must understand digital vs. analog computing.
Digital logic powers virtually all modern computing systems. In a digital system, a programmer’s code is translated into a series of 0s and 1s. The process is complicated but in simple terms each 0 turns a circuit off and each 1 turns a circuit on. Combinations of the circuits inside a microprocessor being off and on correspond to different functions such as changing the color of a single pixel or making a sound. But we use 0 and 1 because these numbers are convenient for mathematical purposes, not because there’s anything inherently analogous between off/on and 0 and 1 — the decision is arbitrary. The numbers 0 and 1 are abstract representations of the off/on choice in a chip’s circuits.
Analog computing does not use 0s and 1s. “Analog” is the root word of analogy; analog computing uses various methods (usually electrical measurements such as voltage and current) to compute in analogies of your data. A pocket calculator is a digital system, but a slide rule based on logarithms is analog. However, there is a misconception that digital systems are electronic and analog systems are mechanical — not so! An abacus is a digital mechanical system invented several millennia ago, while most analog computers of the 1960s and 1970s are electronic.
Now let’s see how the 8888 robot works. There are no motors, batteries, or digital computers involved. It is all mechanical. The robot has gears inside which make it move in different ways. There is a slot at the end of the robot’s base. You place rack parts in various locations on a plate, and you slide that plate into the slot. The decision about where you place the racks determines which of the robot’s internal gears are activated (in theory you could make a programming language to indicate how the size of the plate and the location of the racks lead to the robot movements). But the final decision about how long to activate those gears is based on how far and how fast you slide the plate. The movement of the gears is in direct proportion to that speed and distance. The robot will move faster, slower, farther, or shorter analogous to the plate movement controlled by nothing more than your hand.
This is the first Lego robot. You will not find it as an individual set on Bricklink — it’s described on pages 78-93 of the Expert Builder Idea Book which is set #8888 though it contains only reading material, not any parts. (Younger readers: “Expert Builder” is what Lego called its movement sets before the name Technic). This robot runs analog software and mechanical hardware, not a digital electronic system. Analog and mechanical methods were important concepts in calculating and computing from several hundred years ago until about the 1970s.