Computing All Around Us Computers were once used only in huge science and military labs Today computing which means work done by computers is a part of so many things in our daily lives Inside guide Inside your home dozens of devices and household appliances feature computer technology They run the microwave oven and fridge in your kitchen and the Bluetooth speaker and smart TV in your living room All smartphones tablets game consoles and many other digital devices rely on computer technology Much of the music and many of the TV shows you enjoy have also been created using computers 4 The Internet The Internet is a medium or a place for communication that links groups of computer networks Hundreds of millions of computers around the world and other digital devices such as tablets and smartphones communicate with each other through the Internet Whenever you send an email use social media to share a photo or message or surf websites on the World Wide Web you are using the Internet
Out in the open Computing is everywhere outside the home too from barcode scanners to store checkouts to digital signs and cash-dispensing bank machines Computers manage traffic lights and other signals to keep vehicles moving smoothly and in-car computers help guide cars to their destinations TRUE STORY Poor Predictions In 1943 the IBM Thomas Watson said for maybe five computers president of the computer company I think there is a world market In 1977 Ken Olsen who founded the computer company DEC said individual to have a computer in his home Today there are over two billion personal computers worldwide and twice as many There is no reason for any smartphones UP IN THE AIR More than 70,000 aircraft fly through the skies above the United States every day Each plane needs to be guided through its journey at the correct altitude or height to avoid colliding with other aircraft Planes are guided by computer controls inside the aircraft as well as by human air traffic controllers in the airport's control tower Customers and computing Many of the items you buy are designed on a computer and then manufactured using computer-controlled machines Some items are built by robots which are controlled by computers Computers are even involved in testing products as well as delivering products sold 5
input and Output Computers need a way to interact with the real world They have to be able to receive information and output the results in a way that can be used by people Processing and programs The work is usually performed by the computer’s central processing unit CPU This is a microprocessor often referred to as a chip It can perform thousands or even millions of operations every second The CPU runs a set of instructions called a program stored in the chip The instructions are made up of lines of code These are commands or instructions to the computer INPUT PROCESSING OUTPUT STORAGE FEEDBACK Information flow When data is put into a computer it is called input The computer works on the data in the next stage called processing The results may be stored and can be displayed now or later in a useful form called output Sometimes the output becomes new data for input This information is called feedback 6 T RU E S T O R Y Lightning Lines of Code Some machines need vast amounts of code to run The F-35 Lightning II aircraft features more than eight million lines of code in its programs to fly and navigate this military jet
Input devices A home or office computer uses input devices such as keyboards a mouse document scanners and webcams Common input devices on a smartphone or a tablet include touchscreens microphones and cameras These devices gather information and send it for processing Devices called sensors see pages 12 13 also provide input in some computer systems Output from this iPad tablet are signals sent to the educational robot s motors instructing them to move the robot s parts Output devices Common output devices include speakers for sound and monitor screens which can display text photos and graphics A printer provides people with a physical copy of the information worked on by the computer Sometimes a computer’s output sends a series of signals to control electric motors or pumps to move parts of other machines A Virtual Reality headset game surrounds the player with a realistic three-dimensional or 3-D view The game s graphics and action are projected onto screens inside the headset Computer Languages Computers don’t read code written in English They read code written in computer language and there are hundreds of computer languages Some languages such as Scratch Kodu and Tynker are for beginners just learning to program or create code Others such as C Python and C are power ful languages that can be used to control major systems and machinery from traffic light systems to automated factories 7
