Zaipul Anwar bin Zainudin Institute of Product Design & Manufacturing Universiti Kuala Lumpur Session 2

Objectives Describe the three fundamental characteristics of computers Describe at least four areas of society in which computers are used Identify the basic components of a computer system: input, processing, output, and storage List some common input, output, and storage media Distinguish data from information Describe the significance of networking Explain the significance of the Internet Explain the various classifications of computers

Computers are all around! Grocery store Schools Libraries Bank Mail Malls We interact with computers everyday! We interact with computers everyday!

What computers can’t do yet? Complex human activities What else? Can you think of others?

Computer System People Software Hardware

People Computer programmer – person who writes programs Users or End-users – make use of the computer’s capabilities

Software Programs Set of instructions that directs the hardware to do a required task and produce the desired results

Hardware: Basic Components of a Computer

Computer Components 1. Input Devices - examples: keyboard and the mouse - data entered on the keyboard and temporarily stored in the computer’s memory and displayed on the monitor 2. System Unit - contains the electronic circuits that cause the processing of data to occur - consists of central processing unit, memory, (RAM and ROM) and other electronic components - CPU has a control unit and arithmetic/logic unit - RAM temporarily stores data and program instructions when they are processed

4. Output Devices - most commonly used output devices are monitor and printer - Monitor :commonly as CRT or Flat Panel Display - Printer: Dot-Matrix, Ink-Jet etc. 5. Secondary Storage Devices - also known as auxiliary storage devices - stores instructions and data when they are not being used by the system unit - Examples : floppy disk and hard disk drive Computer Components – cont.

Input Process Output Data Information Storage How a Computer System Works

How a Computer System Works – cont. Software - The instructions needed to direct the computer to complete specific tasks. The CPU follows the step-by-step instructions in a program to complete the tasks from user. Operating system is the system software that controls the basic, low-level hardware operations and file management.

Microcomputers - Also known as personal computers - Physical sizes : palmtop, desktop and tower case - Cheaper and smaller in size Minicomputer - Also known as departmental computers - Physical sizes : small to large cabinets - Support business application Computer Configuration and Classification

Mainframe -Large computers with the capability to process data at millions of instructions per second. -Physical size : partial to full room of equipment Supercomputer -Most powerful and expensive computers -Vast quantities of data manipulation -Physical size : full room of equipment - No. of users : hundreds of users Computer Configuration and Classification – cont.

Central Processing Unit (CPU) -It is the heart of the computer, that is the microprocessor chip. -A highly complex, extensive set of electronic circuitry that executes stored program instructions. - CPU perform three main tasks :- Perform arithmetic operations Perform logic operations Retrieval and storage of data

- CPU consists of two main units :- 1. Arithmetic Logic Unit (ALU) - arithmetic operations e.g. +, -, x, / - logic operations e.g. >, >=, ==, <, <= CPU – cont. 2. Control unit - fetches instructions from memory - decode/translate instructions - executes the processing tasks - stores result in memory

CPU – cont. - CU fetches instructions from memory - CU decodes/translates instructions, directs necessary data to ALU - ALU executes arithmetic/logic instruction -ALU stores results into memory What happens in a CPU?

Memory - also known as primary storage, primary memory, main storage, internal storage, and main memory - Consists of RAM and ROM 1. RAM (Random Access Memory) - volatile; means the data exists only when power is ON - two types of RAM, dynamic and static 2. ROM (Read Only Memory) - non-volatile; means data permanently stored in and cannot be changed CPU – cont.

Function of Computer System Data handling IInput PProcess OOutput SStorage

Processing: Batch vs. Interactive 2 types of information processing –Batch processing –Interactive processing : Real time

Input devices Accept data or commands and convert them to electronic form Getting data into the computer –Typing on a keyboard –Pointing with a mouse –Scanning with a wand reader or bar-code reader –Terminal

Output devices Monitor or screen Text Numbers Symbols Art Photographs Video Printer Black and white Color Convert from electronic form to some other form May display the processed results Usable information

Input and Output Devices 1.Input devices - Common type of devices used are the keyboard and the mouse - Standard type of keyboard is the QWERTY which has 86 keys (basic) and keys (enhanced). - Mouse is a pointing device for effective use of computer interface. Trackball and touch pad are also considered as pointing devices.

Input and Output Devices – cont. Digitizer - A pad with a pen-like stylus. - The tablet sends electronic signals to the computer, displaying the image drawn.

Input and Output Devices – cont. the use of special equipment to collect data at the source and send it directly to the computer. Source data automation MICR Images OCR Bar code Hand Written Input devices– cont.

Input and Output Devices – cont. 2. Output devices - most common devices are monitor displays and printers - Two types of display; flat panel display and CRT display (Cathode Ray Tube) - Two categories of printers; impact and non-impact printers

Displays 1. Flat Panel - commonly used in laptop, notebook - examples of flat panel; LCD, Gas Plasma 2. CRT - produce best images for computers - two types of display; monochrome and color - monochrome; displays one color (green or amber) - color; four types: Input and Output Devices – cont.

Standard Graphic Add-on-Boards Resolution (by pixels) CGA (Color Graphic Adapter)640 x 200 EGA (Enhanced Graphic Adapter)640 x 350 VGA (Video Graphic Array)640 x 480 SVGA (Super Video Graphic Array)1024 x 768 Displays – cont. Input and Output Devices – cont.

Two types of printers (according to printing methods) Impact printers -use a physical contact with the paper to produce an image -e.g. dot matrix printer and line printer Non-impact printers -Place images on a paper without physically touching it -e.g. thermal, inkjet, laser printer Input and Output Devices – cont. Printers

Can you think of any other input/output devices?

The Processor Central Processing Unit (CPU) Converts data to useful information Interpret and execute instructions Communicate with input, output and storage

Two Types of Storage Secondary storage long-term storage Primary storage or memory temporary storage

Memory / Primary Storage Temporary storage Holds input to be processed Holds results of processing Contains the programs to control the computer and manipulate input into output Volatile

Secondary Storage Long-term storage Non-volatile

Secondary Storage Examples Magnetic disks – read and written by magnetic disk drive –Hard disk –Diskette Optical disks – read and written by optical disk drives –CD-ROM –DVD-ROM Magnetic tape – read and written by magnetic tape drives –Primarily used for back-up

Magnetic Disk

It is needed because –Main memory stores data temporarily –Main memory space is limited Secondary Storage Benefits of secondary storage Space Reliability Convenience Economic

Computer System Computer –CPU –Memory Peripheral equipment –Connected to the computer by a cable –Input, output, storage

Computer Network Definition –A system that uses communications equipment to connect computers and their resources. Types –Local area network (LAN) – connects computers in close proximity –Metropolitan are network (MAN) – connect computers between buildings in the same geographic area –Wide are network (WAN) – connects computers over great distances

Home Connectivity Connect home PC to other computers Use modem to convert signals between electronic (computer) and analog (voice) formats

Internet Collection of networks No ownership No central source for services available No comprehensive index of what information is available Individuals Businesses Organizations Libraries Research labs Government Connects Everyone!

Getting Connected User’s computer must connect to a server Server must communicate using TCP/IP The user can purchase access to a server from an ISP (Internet Service Provider)

Internet – What Can You Do? WWW – World Wide Web FTP – File Transfer Protocol UseNet IRC – Internet Relay Chat Bulletin Boards

World Wide Web Browser – program that allows the user to move around and explore the Internet Use the mouse to point and click on text and graphics Web page Web site Home page

Classifications of Computers Use the computer that fits your needs Based upon –Size –Speed –Cost –Portability –Number of simultaneous users supported –Available software –Typical use

Personal Computers Other names –PC –Microcomputer –Home computer Categories –Low-end functional –Fully powered –Workstations –Net computer or net box (Web TV) Desktop Models

Notebook Computers Portable –Lightweight –Fits in a briefcase –Battery operated Laptop –Larger –Heavier More expensive that desktop models

Handheld Computers Personal Digital Assistant (PDA) –Scheduling –Addresses –Handwritten input –May offer wireless and fax PDA Phone –More power than PDA –Cellphone, GPS, MP3/MP4, Camera, Video, TV, Radio etc. –Runs various type softwares, serving various applications

Other Types of Computers Mainframes –High speed –More expensive –Used to process large amounts of data quickly –Support multiple users –Does server tasks Supercomputers –Fastest speed –Most expensive

ANY QUESTIONS?