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190 Science and Technology

FIND OUT MORE. Electronics 188 • Robots 194

An electronic machine that uses binary code to store

and process data is a computer. Binary code can

represent numbers, text, sounds, pictures, and movies.

This data is stored in the computer’s memory and on

magnetic discs, CD-ROMs, and DVDs.

WHAT IS A MICROPROCESSOR?

A microprocessor is a computer’s brain. It is an

integrated circuit made of millions of transistors.

It carries out the instructions (the programs) that

make a computer operate. Everything the computer

does is broken down into simple steps. The power of

a microprocessor is measured by how fast it carries

out these instructions.

HOW IS VIRTUAL REALITY CREATED?

Virtual reality controls what you see, and responds to

your movements and actions. When you wear virtual

reality goggles, the scene you see changes as you

move. Sensors on special gloves, or a body suit,

allow you to interact with the scene by pointing or

touching. Sounds increase the experience of reality.

WHAT IS MEMORY?

Data is stored in binary code on microchips. They are

made up of millions of transistors that are on or off –

1 or 0 in binary code. The capacity (size) of a memory

chip is measured in megabytes (MB). One byte is an

eight-digit binary number. One megabyte is just over

one million bytes of information.

1 LAPTOP COMPUTER

All the components of a personal computer can be built into a

convenient folding package the size of a book. Some laptops use

wireless technology to interact with printers, scanners, and other devices

by radio waves. Through wireless telephone links, you can log onto the

Internet to send emails from your laptop.

1 HARD DISC DRIVE

The computer’s hard disc is the

main storage area for programs,

documents, images, and other

files. It can hold tens of gigabytes

of data (billions of binary

numbers). Information is written

(put on) and read (taken off) by

electromagnetic heads that swing

over the disc surfaces as they

spin at high speed.

Computers

1 VIRTUAL REALITY

Virtual reality goggles feed

slightly different images to the

right and left eyes to create a

realistic 3-D scene. These goggles

help architects visualize plans.

Motherboard holds

the microprocessor

and other

components that

operate the

computer

Screen

displays output

on a grid of

almost one

million coloured

dots (pixels)

Touchpad

moves the pointer

round the screen,

like a mouse

Keyboard

used to input

letters and

other characters

Read/write head

finds data stored

on disc

Arm moves to

retrieve data

Track

selector

mechanism

Magnetic disc

Disc drive

reads and

writes discs

Liquid crystal

monitor screen

computers