After studying this chapter you will be able to understand: Input devices (contd.), interfacing with the computer using mouse & keyboard, output devices, storage devices, understanding of Central Processing Unit (CPU), How do computers work?
Learning About Parts of Computer ADE100- Computer Literacy Lecture 02 Knowledge test • What is computer? • Briefly explain role of Charles Babbage • What is the purpose of input devices? • What is the role of Joystick & OCR? Topics covered • • Input devices (contd.) Interfacing with the computer using mouse & keyboard • Output devices • Storage devices • Understanding of Central Processing Unit (CPU) • How computers work? What is input? • Any data or instructions used by a computer • Types of input: • Data- text form • Instructions- particular commands • Voice- audio signals through microphone • Image- inserting a picture The Keyboard • How keyboard works? • Keyboard controller (a tiny chip) detects a key pressed and places a code into its memory called buffer (a temporary memory area) • Controller sends a code to the CPU • Code represents the key pressed • Controller sends a signal to the operating system • Operating system responds • Controller repeats the letter if held The Mouse • Common mouse actions are: • Right click • Left click • Drag & drop • Move • Scroll • Double click The Mouse • Benefits • Pointer positioning is fast • Menu interaction is easy • Users can draw electronically The Mouse • Mouse button configuration • Configured for a righthanded user • • Can be reconfigured • Left mouse button is called a primary button • Extra buttons are configurable Procedure Ergonomics and Input Devices • Ergonomics • Study of human and tool interaction • Concerned with physical interaction • Attempts to improve safety and comfort Ergonomics and Input Devices • • Repetitive Strain/Stress Injury (RSI) • Caused by continuous misuse of the body • Many professionals suffer from RSI Carpal Tunnel Syndrome (CTS) • Carpal tunnel is a passage in the wrist • Holds nerves and tendons • Prolonged keyboarding swells tendons Computer RAM and - Right click My Computer CPU - Select properties • • from menu 26 Secondary storage devices • Stores data when computer is OFF • Three types • Magnetic storage devices • • Optical storage devices • • Hard disk drives, floppy disks, CD, DVD Mobile storage devices • Online storage • Flash memory • Memory cards Magnetic storage • Data organization • Disks must be formatted before use • Format draws tracks on the disk • Tracks is divided into sectors • Amount of data a drive can read Magnetic storage • Hard disk drive • Secondary storage device in a computer • or more aluminum platters • Each platter has sides • Spin between 5,400 to 15,000 RPM • Data found in 9.5ms or less • Drive capacity greater than 40 GB 30 Optical storage devices • CD-ROM (Compact Disk Read Only Memory) • • • • Read using a laser • Lands, binary 1, reflect data • Pits, binary 0, scatter data CD speed is based on the • Original CD read 150 Kbps • A 10 X will read 1,500 Kbps Standard CD holds 650 MB CD-R (Compact Disk Recordable) • Write data once Optical storage • • DVD- (Digital Versatile Disk) • Digital Video Disk • Use both sides of the disk • Capacities can reach 18 GB • DVD players can read CDs DVD-R • • DVD-R/W • • DVD recordable once DVD Rewriteable multi times Super drive- (CD R/W +DVD R/W) Mobile storage devices • Online storage • • • Dropbox, Google drive Flash memory • Found in cameras and USB drives • Combination of RAM and ROM • Long term updateable storage Smart cards • Credit cards with a chip • Chip stores data • Eventually may be used for cash CPU- Central Processing Unit • The CPU • • Brain of the computer Components of CPU • • Control unit • Controls resources in computer • Acts like Traffic Policeman Arithmetic logic unit • Simple math operations Working of CPU • Machine cycles • Steps by CPU to process data • Instruction cycle • • CPU gets the instruction Execution cycle • CPU performs the instruction • Billions of cycles per second • Multitasking allows multiple instructions Information Processing Cycle • Four steps followed to process data • Input • Processing • Output • Storage Activity-20 minutes • • • • Practice the use of mouse by selecting different icons on your desktop or in My computer Briefly talk about different parts of a real keyboard Detach and attach different input and output devices of your computer Install a typing tutor on your computer from a CD/DVD/internet • Practice first lesson for 15 minutes Further reading • “Introduction to Computers” by Peter Norton, 7th edition • 1B- Looking inside the computer system • 2A- using the keyboard & mouse • 3A- Video & sound • 3B- Printing • 4A- Transforming data into information • 5A- types of storage devices Thanks • End of Lecture 02 39 Allah Hafiz 40 ... the motherboard • More memory makes a computer faster • 512MB, 1GB up to 4GB ROM • Read Only Memory • ROM-BIOS Computer RAM and - Right click My Computer CPU - Select properties • • from menu 26... Types of monitors • Cathode-ray tube monitors or CRTs • Flat-panel • • Liquid crystal display (LCD) • Portable and thinner than CRTs Other monitors • E-books • Data projectors • High-definition... instructions used by a computer • Types of input: • Data- text form • Instructions- particular commands • Voice- audio signals through microphone • Image- inserting a picture The Keyboard • How