Lecture 1 Introduction to the Computers CSCS100 – Fall 2009 – Forman Christian College Asher Imtiaz *Several of these slides have been adapted and modified.

Lecture 1Introduction to the ComputersCSCS100 – Fall 2009 – Forman Christian CollegeAsher 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?

About Computers…

What is it, and what can it do?

What is a computer?

InputProcessing / Computation

Output

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

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

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

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/

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

Computers For Individual Use• Tablet computers

• Newest development in portable computers

• Input is through a pen

• Run specialized versions of office products

• 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

Computers For Individual Use

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

Computers For Organizations• 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

Computers For Organizations• 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?

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 Conferencinghttp://wearcam.org/wristcam/dusting/

www.gatech.edu/innovations/wearable/

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

Computers In Society• Computers at home

• Many homes have multiple computers• Most American homes have Internet• Computers are used for

• Business• Entertainment• Communication• Education

Computers In Society• 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

Computers In Society• Computers in government

• Necessary to track data for population• Police officers• Tax calculation and collection

• Governments were the first computer users

Computers In Society• Computers in health care

• Revolutionized health care• New treatments possible• Scheduling of patients has improved• Delivery of medicine is safer

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