Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill Technology Education Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.

McGraw-Hill Technology Education Chapter 1A Introducing Computer Systems

1A-3 The Computer Defined Electronic device Processes data and converts it into information Follows instructions Modern computers are digital –Represent data as having one distinct value or another Older computers were analog –Represent data as variable point along a continuous spectrum of values.

1A-4 Computers For Individual Use Desktop computers –The most common type of computer –Sits on the desk or floor –Performs a variety of tasks Workstations –Specialized computers –Optimized for science or graphics –More powerful than a desktop

Categories of Computers Designed to be used by single user, multiple users, and no user at all Also categorized by their power or speed and the type of tasks they handle Sub-catorized according to price, the type of hardware and software 1A-5

1A-6 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

How did computers come into existence? To automate the task of performing repetitive tasks To reduce number of mistake made by human while performing calculations To break the enigma code Abacus performed addition, subtraction division and multiplication operations. Digital computers had the economics, power and scalability 1A-7

Generation of Computers The Mechanical Era (1623 – 1900) First Generation Electronic Computers (1937 – 1953) Second Generation (1954 – 1962) Third Generation (1963 – 1972) Fourth Generation (1972 – 1984) Fifth Generation (1984 – 1990) Sixth Generation (1990 – till date) 1A-8

The Mechanical Era (1623 – 1900) Abacus (3000 BC) – one of the early inventions to perform mechanical calculations Napier’s bones (17 th century) – calculates products and quotients Pascaline (1642) – 1 st mechanical adding device Difference Engine (Charles Babbage, 1823) - automatic, mechanical calculator designed to tabulate polynomial functions. Analytical Engine (Charles Babbage, 1833) - proposed mechanical general-purpose computer Punched cards (Herman Hollerith, 1890) 1A-9

1A-10 Computers For Individual Use Tablet computers –Newest development in portable computers –Input is through a pen –Run specialized versions of office products

1A-11 Handheld computers –Very small computers –Personal Digital Assistants (PDA) –Note taking or contact management –Data can synchronize with a desktop Smart phones –Hybrid of cell phone and PDA –Web surfing, access Computers For Individual Use

1A-12 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

1A-13 Computers For Organizations Mainframes –Used in large organizations –Handle thousands of users –Users access through a terminal

1A-14 Computers For Organizations Minicomputers –Called midrange computers –Power between mainframe and desktop –Handle hundreds of users –Used in smaller organizations –Users access through a terminal

1A-15 Computers For Organizations Supercomputers –The most powerful computers made –Handle large and complex calculations –Process trillions of operations per second –Found in research organizations

1A-16 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

1A-17 Computers In Society Computers at home –Many homes have multiple computers –Most American homes have Internet –Computers are used for Business Entertainment Communication Education

1A-18 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

1A-19 Computers In Society Computers in government –Necessary to track data for population Police officers Tax calculation and collection –Governments were the first computer users

1A-20 Computers In Society Computers in health care –Revolutionized health care –New treatments possible –Scheduling of patients has improved –Delivery of medicine is safer

Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill Technology Education Chapter 1A End of Chapter