1. Essential Computing Concepts

2. 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 Information System An Information System has the following parts:

3. What is a Computer? HardwareSoftware Equipment Programs

4. Any Computer System Memory Central processing unit (CPU) Input Hard Disk Output Secondary Storage Devices

5. The Main Parts of a PC include: The System Unit  CPU  Memory or RAM (Primary Storage) Input / Output Devices Secondary storage devices Communication Devices

6. The CPU Central Processing Unit (or processor) The brain of the computer Does all the calculation and processing

7. Input Devices Mouse Keyboard Scanner, video camera, etc.

8. Output Devices Monitor/Screen (VDU – Visual Display Unit) Printers  Laser printers  Inkjet printers Plotters, speakers etc.

9. 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)

10. CPU RAM HARDDISK CD

11. 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.

12. 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.

13. 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

14. 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 Digital Assistants) Types of Computers

15. 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

16. 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.

17. Hardware System Application S / W Back-end Front-end E.g. Operating system such as Windows XP E.g. End-user programs such as MS Word Types of Software

18. 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 exercises should 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