lecture 1 introduction to the computers

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Lecture 1

Introduction to the ComputersCSCS100 – Fall 2009 – Forman Christian College

Asher Imtiaz

*Several of these slides have been adapted and modified from LUMS CS101 course (Dr Sohaib Khan and Dr Arif Zaman), VU CS101 slides (Dr. Altaf A. Khan) and Peter Norton’s supplementary material.

Course Overview

What we’ll cover, and what we’ll not?

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About Computers…

What is it, and what can it do?

What is a computer?

InputProcessing / Computation

Output

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What is a Computer?

• [Norton] A Computer is an electronic device that processes data, converting it into

information that is useful to people.

• [Wikipedia] A Computer is a programmable device, usually electronic in nature, that can

store, retrieve and process data.

• [The American Heritage Dictionary]1. A device that computes… especially a programmable

electronic machine that performs high-speed mathematical or logical operations or that assembles, stores, correlates, or otherwise processes information

2. One who computes

What can computers do, or not do?

• A computer does what it is told to do…

• You tell a computer what to do by giving it a list of precise, unambiguous instructions, a computer program

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Calculator – A Simple Computer

Photographed by Adrian Pingstone in March 2004, and released to the public domain.

Thanks to Kodabar for removing the shadow.

Categorization of Computer Systems

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Computers Everywhere

• Not just Desktops, Workstations, Tablet PCs, Handheld PCs (PDAs), Servers, Mainframe computers, Minicomputers

• But also…

•Cell phones

• Alarm Clocks

•Microwave Ovens

• Lighting control in a building

•Washing Machines

Computer Types According to Capability

• Supercomputers

• Mainframes

• Servers

• Desktops

• Portables

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Computers For Individual Use• Desktop computers

• The most common type of computer

• Sits on the desk or floor

• Traditional design with monitor stacked on top of the system unit.

• Tower design.

• Performs a variety of tasks

Image credit: www.classiccmp.org/dunfield/pc/index.htm , www.comandati.ro

Computers For Individual Use

• Workstations• Specialized computers• Optimized for science or graphics

• Engineering design, modeling, animation, video editing.

• More powerful than a desktop• Often have high-resolution monitors, accelerated graphics

capabilities.• More expensive than the average desktop, typically by at

least more than double the price

Image from http://www.pcaccessoriesparts.com/

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Computers For Individual Use• Notebook computers

• Small portable computers• Weighs between 3 and 8 pounds• About 8 ½ by 11 inches• Typically as powerful as a desktop• Can include a docking station• Also called laptop computers• Power optimization (battery life: at least

2 hours)• About 1.5 times or higher than the cost

of desktops.

Image credits: images.businessweek.com

Image credits: http://gizmodo.com


• Tablet computers

• Newest development in portable computers

• Input is through a pen

• Run specialized versions of office products

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• Handheld computers• Very small computers• Personal Digital Assistants (PDA)• Note taking or contact management• Data can synchronize with a desktop• $200 onwards

• Smart phones• Hybrid of cell phone and PDA• Web surfing, e-mail access


Image credits: www.techpuddle.com

Computers For Organizations

• Network servers

• Centralized computer

• All other computers connect

• Provides access to network resources

• Multiple servers are called server farms

• Often simply a powerful desktop

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• Mainframes

• Used in large organizations, banks, e-commerce systems, military.

• Also called “Enterprise Servers”

• Handle thousands of users

• Users access through a terminal

• High reliability


• Supercomputers

• The most powerful computers made. IBM Deep Blue 1997.

• Handle large and complex calculations

• Process trillions of operations per second

• Cost tens of millions of dollars

• Found in research organizations

• Designed to focus on one task at a time

• In the past, single high end processor.

• Modern supercomputers, 1000s of processors working in parallel.

• Why would we want to do this?

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Wearable Computers

• A different interaction idea.

• Small in size, carried in a pocket, worn on the arm, waist, or head or elsewhere on the body

• Capability similar to PDA’s, but more expensive

• They are always ON, and always accessible.

• “A person's computer should be worn, much as eyeglasses or clothing are worn, and interact with the user based on the context of the situation” http://www.media.mit.edu/wearables/

• Example usage scenarios: military (e.g. land warrior) industry, health care

Wearable computers

Video Conferencing

http://wearcam.org/wristcam/dusting/

www.gatech.edu/innovations/wearable/

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Ranking w.r.t. installed number

• PC’s

• PDA’s

• Workstations

• Servers

• Wearables (will take the top spot in future)

• Mainframes

• Supercomputers

Computers In Society

• More impact than any other invention

•Changed work and leisure activities

• Used by all demographic groups

• Computers are important because:

• Provide information to users

• Information is critical to our society

•Managing information is difficult

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• Computers at home

•Many homes have multiple computers

•Most American homes have Internet

• Computers are used for

•Business

•Entertainment

•Communication

•Education


• Computers in education

•Computer literacy required at all levels

• Computers in small business

•Makes businesses more profitable

• Allows owners to manage

• Computers in industry

•Computers are used to design products

• Assembly lines are automated

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• Computers in government

• Necessary to track data for population

•Police officers

• Tax calculation and collection

•Governments were the first computer users


• Computers in health care

• Revolutionized health care

• New treatments possible

• Scheduling of patients has improved

•Delivery of medicine is safer

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Summary

• A computer is simply a device that computes, taking some input, processing it, and producing some output

• Computers can come in all sorts of forms, and not just the types you may be familiar with

lecture 1 introduction to the computers

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