罗CAMBRIDGEUNIVERSITY PRESSComputer Sciencefor Cambridge IGCSETM &O LevelCOURSEBOOKSarah Lawrey Victoria EllisSecond editionDigital AccessCAMBRIDGEUNIVERSITY PRESSComputer Sciencefor Cambridge IGCSETM O LevelCOURSEBOOKSarah Lawrey Victoria EllisTable of ContentsTitle PageDedicationContentsHow to use this bookHow to use this seriesIntroduction1 Data representation1.1 Binary and hexadecimal1.2 Binary manipulation and negative numbers1.3 How do computers represent text.images and sound?1.4 Measuring data storage1.5 Data compression2 Data transmission2.1 The structure of a data packet2.2 Packet switching2.3 Methods of data transmission2.5 Detecting errors in data transmission2.6 Encryption3 Hardware3.1 The role of the CPU3.2 The fetch stage3.3 The decode stage3.4 The execute stage3.5 Factors that can affect the performance of a CPu3.6 Input and output devices3.7 Data storage3.8 Virtual memory3.9 Cloud storage3.10 Network hardware4 Software4.1 Types of software4.3 Interrupts4.4 Types of programming language4.5 Translators4.6 Integrated Development Environment (IDE)5.1 The internet and the world wide web5.3 The purpose of a weh browser5.4 Digital currency