The computer is perhaps the most important part of a robot, since it is the computer's "brain" that makes a robot different from other machines. Over the last several years, computers have become smaller and smaller. This is what has made possible the many recent advances in robotics, since robots can now carry their brains around with them. This was not possible when computers were the size of a large room only about 25 years ago. Computers can seem like very complicated machines, but they are actually based on simple ideas.
All computers today have the same basic part or hardware. The main part, where most of the actual computing is done, is the central processing unit (CPU). It caries out the instructons of the computer's program, or software, and directs the actins of all the other componetnts of the computer. The CPU is made up of one or more plastic boards holding lots of electrical connectors and sockets. Cables are attached to the connectors from other parts of the computer. Integrated circuits, or IC's, are plugged into the sockets. The IC's are tiny chips, so mall they could fit on the tip of your finger, housed in a protective plastic covering. Each chip is made mostly of silicon (a common element found in sand and rocks) and contains thousands of small switches.
A second important part of a computer is the memory. This is where the CPU stores the data that it needs or the answers to the problems it works on. Memory is also a small chip, usually made of silicon within a plastic covering. Computer memory is different from human memory in two main ways. A computer's memory can hold a definite limited amount of information and no more. To add new data means that some of the old data must be erased. Secondly, a computer's memory doesn't forget over time and only forgets when told to do so. Some types of memory, however, lose the information they are procssing when the power is turned off.
A computer needs a way to move information in and out of its brain. One familiar input device is the keyboard. It is used by humans to type information into the computer. Joysticks and paddles are other input devices. You've probably used them to play video games.
An output device is where the computer sends information out to the user or asks questions about what it should do next. It can be the computer's monitor (screen), a printer or a storage device like a disk drive.
