Introduction to Computer Systems

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

2. Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.McGraw-Hill Technology Education
Computers
Tools for an information Age

3. MIU
Question 1Question 1

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Index
• What is a computer?
• The beginning of Computer

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What is a computer?
• In a dictionary before 1940,
– Compute + er
– computer : a person who performs
calculations.
• The modern definition
– emerged in 1940s, when the first electronic
computing devices were developed

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The Computer Defined
• Electronic device
• Converts data into information
• Modern computers are digital
– Two digits combine to make data
• Older computers were analog
– A range of values made data

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The beginning of Computer
• ABC (Atanasoff-Berry Computer)
– 1942, John Atanasoff and Clifford Berry
- 1st Electronic digital computer
• MARK-1
– 1944, Howard Aiken
• ENIAC (Electronic Numerical Integrator and Calculator)
– 1946, John W. Mauchly and J.Presper Eckert, Jr.
- 1st
Large scale electronic digital computer
• EDSAC (Electronic Delay Storage Automatic Calculator)
– Maurice Wilkes
• UNIVAC-I (UNIVersal Automatic Computer)
– John W. Mauchly and J.Presper Eckert, Jr.
• EDVAC (Electronic Discrete Variable Automatic Computer)

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ABC(Atanasoff Berry Computer)ABC(Atanasoff Berry Computer)

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ENIAC computer

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EDVAC
• When : in 1952
• Where : in the United States
• Who : a team of engineers on a secret military project
• Why : as a response to World War II military needs. (to process
complex calculation automatically)
• How :
– 2000 multiplication in one second
– addition or subtraction 100,000 times in the same period
– Its memory : 1,024 numbers of 12 decimal places each

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Plans for EDVAC
• Described in a report by the
famous mathematician John
von Neumann.
• “The most influential paper
in the history of computer
science”

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What is a computer?
• Von Neumann’s report
– define the components of a computer and
describe their functions
– used the term “automatic computing
system”
• Today, just “computer”, or “computer system.

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A computer is…
• Based on the concepts presented in von Neumann’s paper
• Computer : a device that
1) accepts input,
2) processes data,
3) stores data,
4) and produces output.

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1) A computer accepts input
• Computer input : whatever is put into a
computer system.
• Examples
– words and symbols in a document
– numbers for a calculation,
– pictures, temperatures, audio signals
• Main input device : keyboard

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2) A computer processes data
• Data : symbols that represent facts and ideas.
– processing : data manipulation of computer
• Process : a systematic series of actions that a computer uses to
manipulate data
• Some of the ways :
– performing calculations,
– sorting lists of words or numbers,
– modifying documents and pictures
– drawing graphs.
• A device : central processing unit (CPU)

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3) A computer stores data
• A computer stores data for processing
• Places for storing data
– Memory : an area of a computer that holds data that is waiting to be
processed
Ex) RAM, ROM
– Storage : the area where data can be left on a permanent basis
while it is not needed for processing
ex) diskette, CD-ROM,HDD

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4) A computer produces output
• Computer output : the results produced by a
computer
ex) reports, documents, music, graphs, and pictures
• Output device : the device that displays, prints, or
transmits the results of processing.
ex) monitor, printer

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Example
• Fundamental computer function: 7+2=9
– Input : 7, +, 2
– Memory : 7, +, 2
– Processing : Add 2 to 7
– Memory : 9
– Output : 9
– Storage : 9

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Fundamental characteristics
• Speed
– Provide the processing speed essential to our fast-paced society for
quick service
• Reliability
– Extremely reliable, compute correctly
– Most computer error : by human errors
• Storage Capability
– Store tremendous amounts data, which can be located and retrieved
efficiently
• By-products characteristics by above three
– Productivity, decision making, cost reduction

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Classification of Computer
• By processing capabilities
–Microcomputers
–Minicomputers
–Mainframe computers
–Supercomputers

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Microcomputers
Using the Microprocessor. A small
computer that contains a
microprocessor as its central processor.
• Personal Computers (PC)
• In home and small businesses
– Desktop computer
– Portable Computer
• Palmtop, Notebook(Laptop)
• PDA (Personal Digital Assistant)

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PalmtopPalmtop

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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

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Minicomputer
• More powerful than microcomputer. A
computer of medium power, more than a
microcomputer but less than a mainframe.
• Stores data for all users in one centralized
location
• Used in school or small company
• Ex) VAX, MV 4000, MV 8000, SSM 032

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Computers For Organizations
• Mainframes
– Used in large
organizations
– Handle thousands
of users
– Users access
through a terminal

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Mainframes
• Large, fast and fairly expensive
computers
• Used by business or
government to provide
centralized storage
• EX) IBM 4381, 9300, 3090,
Cyber 180

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

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Supercomputers
• The fastest and most expensive type of
computer
• Used for code breaking, weather
prediction and molecular modeling
• The first : CRAY-1
• Intel’s ASCI Red, SGI’s ASCI Blue
Mountain, IBM’s ASCI Blue Pacific

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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

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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

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Computers For Individual Use
• 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
• Smart phones
– Hybrid of cell phone and PDA
– Web surfing, e-mail access
Computers For Individual Use

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

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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

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

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

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