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Essential Computing Concepts. Information System An Information System has the following parts:. People : the most important part Hardware : consists of the equipment: keyboard, monitor, etc…
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Information System An Information System has the following parts: • People: the most important part • Hardware: consists of the equipment: keyboard, monitor, etc… • Software: refers to the programs and its purpose is to convert data into information • Data: unprocessed facts, and once processed, it becomes information • Procedures: guidelines for people to follow when using software, hardware, and data
Hardware Software Programs Equipment What is a Computer?
Any Computer System Central processing unit (CPU) Output Input Memory Secondary Storage Devices Hard Disk
The Main Parts of a PC include: • The System Unit • CPU • Memory or RAM (Primary Storage) • Input / Output Devices • Secondary storage devices • Communication Devices
The CPU • Central Processing Unit (or processor) • The brain of the computer • Does all the calculation and processing
Input Devices • Mouse • Keyboard • Scanner, video camera, etc.
Output Devices • Monitor/Screen (VDU – Visual Display Unit) • Printers • Laser printers • Inkjet printers • Plotters, speakers etc.
Secondary Storage Devices • Provide Permanent Storage • Common Storage Devices: • Hard (Fixed) Disk :Consists of 1 or more rigid metal platters coated with a metal oxide material for recording. • Floppy disk :Consists of thin, circular, flexible plastic disk with magnetic coating. • CD (Compact Disk) :Flat, round, portable, metal storage. Uses laser technology. • DVD (Digital Versatile Disk)
RAM CPU HARDDISK CD
Storage Capacity • The amount of information that can be stored in a secondary storage device or in memory • A Bit (short for Binary digit) is the smallest unit of storage in the computer. It represents a pulse of electricity: Off = 0, On = 1 • All numbers in the computer must be represented by Bits (0 or 1). We cannot do this with decimal numbers, so instead we use binary numbers.
Bits & Bytes • Bit: • All computers work on a binary numbering system, i.e. they process data in one's or zero's. This 1 or 0 level of storage is called a bit. • Byte: • A byte consists of eight bits. A character needs one Byte of storage. • Kilobyte: • A kilobyte (KB) consists of 1024 bytes, approx 1,000 bytes. • Megabyte: • A megabyte (MB) consists of 1024 kilobytes approx 1,000,000 bytes. • Gigabyte: • A gigabyte (GB) consists of 1024 megabytes approx 1,000,000,000 bytes.
Storage Capacities Temporary Storage • Random Access Memory (RAM) 256MB Permanent Storage • Hard Disk 40 – 80 GB • CD (Compact Disk) about 700 MB • DVD (Digital Versatile Disk) 8.5 GB • Floppy Disk 1.44 MB
Types of Computers • Supercomputer: The fastest and most expensive high-capacity computers used by very large organizations • Mainframe: Large computers, capable of great processing speeds and data storage • Minicomputer: midrange computers used by medium-sized companies • Microcomputer: Least powerful, small computers, but most widely used (desktop, Notebook or laptop, and Personal DigitalAssistants)
Computer = Hardware + Software • Hardware : The Equipment • Software : The Programs. A program is a set of instructions which tell the computer how to do its work
Types of Software • System Software : Programs to control the operation of the computer. • e.g. Operating System (Windows, Unix, Linux etc), Utility Programs, Device Drivers • Application Software : Programs for various applications. • e.g. Programs for word processing, business, scientific and other applications such as Microsoft Office which consists of MS Word, MS Excel etc.
Types of Software E.g. Operating system such as Windows XP Hardware System S / W Back-end Application Front-end E.g. End-user programs such as MS Word
Occupational Health & Safety • Using the computer for long periods of time, may pose risk to health. • Check the following: • Position of the monitor – Frame above screen should be level with eyes, so • that you look slightly down. Distance should be less than an arm’s length. • Avoid screen reflection and flickering. • Posture of the user – Chair back upright, lower back supported, feet flat on • floor, Forearms should be horizontal, wrists straight and task materials • within comfortable reach of both hands. • Preventive exercisesshould be done before starting and during work. • Eyes: Take frequent short rests: Look away from screen towards objects • 20-30 ft away, or look outside the window far out, or close your eyes. • Muscles: Do neck exercises. After every hour walk around, stretch • all muscles and perform whatever relieves the feeling of muscle fatigue/strain • Suggested reading: www.healthycomputing.com/office