Introduction to Computing Dr. Nadeem A Khan

Lecture 2

What is Computer?

A Computer: Device that accepts input, process and stores data, and gives output Device that can execute specific set of instructions in a well-defined manner

Computer System Basics Computer Hardware Electric, electronic, and mechanical devices Computer Software Programs and data in electronic form on a storage medium Program- Sequence of Instructions

Computer Hardware

Computer Hardware Input Processor & Memory Storage Output

Input Devices Mouse Keyboard Joystick Trackball Light pen Tablet Camera Microphone

Output Devices Printer - laser, inkjet, dotmatrix, thermal Plotter - flatbed, drum Speakers Monitor - CRT, LCD, projector

Modem?

(Secondary) Storage Punch cards Hard disk Floppy CD DVD

Peripheral Devices?

Processor/CPU Pentium 8086 Celeron SPARC Alpha etc What are Control Unit and ALU?

Memory (Primary Storage) RAM ROM EPROM etc. Virtual Memory?

Bits & Bytes Bit - a binary digit Byte - a binary word consisting of 8 bits kB - 1024 bytes MB - 1024 kB GB - 1024 MB TB - 1024 GB

Ports Parallell Serial etc.

Figure

The Bus?

Monitor System Bus HD Printer Integer Unit Control Unit CD Mouse Integer Unit Control Unit Keyboard CD Floating Point Unit System Bus Cache HD Processor Mem Bus RAM/ROM Printer Monitor

Computer Software Multiple user license Concurrent use license Licensed and Free Software Single user license  Multiple user license  Concurrent use license  Site license  Public domain software  Shareware

Computer Software: System Software: Application Software: Controls the computer Performs the basic operating tasks Application Software: Help user to accomplish a specific task

Application Software System Software Hardware

System Software Operating systems Works as coordinator between hardware and user software Example: Opening a word document, screen display, print, and save.  Allocates system resources (CPU, peripherals) Examples: use of key board, mouse, playing music, displaying on monitor  

System Software Contd. Utility Software   Utility Software Software that augment the system software Example: preparing disks to store data

System Software Contd. Device Drivers The system software that helps computer control a peripheral device. Usually supplied by the vendor of the computer device Example: DD for mouse, DD for Laser printer

System Software Contd. Programming Languages Tools to create the Application Software

Application Software Contd. Productivity software Software which enhance the productivity

Application Software Contd. Business software Help org. to efficiently do routine tasks Horizontal Market business software Vertical Market business software

Application Software Contd. Entertainment software Educational software

Computer Networks: A collection of computers and other devices that communicate with each other to share data, hardware and software

Computer Networks (contd.) Local Area Networks (LAN): Network that is located within a relatively limited area (a building or campus) Wide Area Networks (WAN): Network that covers a large geographical area

A Computer Network Workstation Network Server Network Printer Local workstation

Internet Is a collection of local, regional, and national computer networks that are linked together to exchange data and distribute computing tasks World Wide Web (WWW) and Electronic Mails (E-mail) are among the Internet Services

“Computer Concepts ” Second Edition Reading Assignment Chapter 1-4 of the book “Computer Concepts ” Second Edition by Parsons Oja You may be tested in Quizzes/Exams on this material

Program Planning Analyze Design Choose the Interface Code Test and Debug Complete the Documentation

The Problem-Solving Process Input Processing Output

Postage stamp problem: How many stamps to put on a envelop given one stamp is needed for every five sheets of paper or a fraction thereof