Computer Hardware

Computer Hardware

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Orasa T.

•
Identify the major types and uses of
microcomputer, midrange, and
mainframe computer systems.


•
Outline the major technologies and
uses of computer peripherals for
input, output, and storage.


13

Learning Objectives

•
Identify the components and
functions of a computer system.


•
Identify the computer system and
peripherals you would acquire or
recommend for a business of your
choice.


13

Learning Objectives (continued)

•
Computer Systems: End User and
Enterprise Computing

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Section I

•
All computers are systems of input,
processing, output, storage, and
control components.


•
Three basic categories

–
Mainframe

–
Midrange computers

–
Microcomputers

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Types of Computer Systems

•
Mainframe

–
Enterprise systems

–
Superservers

–
Transaction processors

–
Supercomputers


13

Types of Computer Systems (continued)

•
Midrange

–
Network servers

–
Minicomputers

–
Web servers

–
Multi
-
user systems


13

Types of Computer Systems (continued)

•
Microcomputers

–
Personal computers

–
Network computers

–
Technical workstations

–
PDAs

–
Information appliances

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Types of Computer Systems (continued)

•
The most important category of
computers

–
Desktop

–
Laptop


•
Workstation computers


•
Network servers

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Microcomputer Systems

•
Selection criteria

–
Solid performance at a reasonable price


–
Operating system ready


–
Connectivity

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Microcomputer Systems (continued)

•
Network computers

–
Designed primarily for use with the
Internet and corporate intranets

–
For specialized or limited computing
applications

–
Lower cost of purchase, upgrades,
maintenance, and support


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Microcomputer Systems (continued)

•
Network computers (continued)

–
Other benefits

•
Ease of software distribution and licensing

•
Computing platform standardization

•
Reduced end user requirements

•
Improved manageability


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Microcomputer Systems (continued)

•
Information appliances

–
PDAs


–
Set
-
top boxes and video
-
game
consoles


–
Wireless PDAs


–
Cellular and PCS phones

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Microcomputer Systems (continued)

•
Computer terminals

–
Dumb terminals


–
Intelligent terminals


–
Network terminals


–
Transaction terminals


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Microcomputer Systems (continued)

•
Multi
-
user systems that can manage
networks of PCs and terminals

•
Less costly to buy, operate, and
maintain than mainframes


•
Popular as network servers


•
Minicomputers

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Midrange Computer Systems

•
Large, fast, powerful


•
Handle high transaction processing volumes or
complex computational problems


•
Super servers for large client/server networks
and high
-
volume Internet websites


•
Popular for data mining and warehousing

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Mainframe Computer Systems

•
Supercomputers

–
Extremely powerful systems
specifically designed for scientific,
engineering, and business
applications requiring extremely high
speeds for massive numeric
computations

–
Use parallel processing architectures

–
Process at speeds measured in
gigaflops and teraflops


13

Mainframe Computer Systems (continued)

•
Computers are organized according
to the following system functions:

–
Input

•
Keyboards

•
Touch screens

•
Pens

•
Electronic mice

•
Optical scanners

•
Convert data into electronic form


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The Computer System Concept

–
Processing

•
Central Processing Unit (CPU)

–
Two subunits

»
Arithmetic
-
Logic Unit (ALU)

»
Control Unit


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The Computer System Concept (continued)

–
Output

•
Video display units

•
Printers

•
Audio response units


•
Convert electronic information into human
-
intelligible form


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The Computer System Concept (continued)

–
Storage

•
Store data and software instructions

•
May also include cache memory

•
Primary storage unit (hard drive)

•
Secondary storage

–
Magnetic disks

–
Optical disk drives


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The Computer System Concept (continued)

–
Control

•
The registers and other circuits of the
control unit interpret software instructions
and transmit directions to the other
components of the computer system


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The Computer System Concept (continued)

•
Computer processing speeds

–
Milliseconds (thousandths of a second)

–
Microseconds (millionths of a second)

–
Nanoseconds (billionths of a second)

–
Picoseconds (trillionths of a second)


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The Computer System Concept (continued)

–
Clock speeds

•
Megahertz (MHz)

–
Millions of cycles per second

•
Gigahertz (GHz)

–
Billions of cycles per second


13

The Computer System Concept (continued)

•
Computer Peripherals: Input, Output,
and Storage Technologies


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Section II

•
Generic name given to all input,
output, and secondary storage
devices

•
Depend on direct connections or
telecommunications links to the CPU

•
All peripherals are online devices


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Peripherals

•
Natural user interface

–
Enter data and commands directly into
a computer

•
Electronic mice and touch pads

•
Optical scanning, handwriting recognition,
voice recognition


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Input Technologies

•
Used for entering data and text

•
Work with your operating system’s
graphical user interface (GUI)

–
Electronic mouse

–
Trackball

–
Pointing stick

–
Touch pad

–
Touch screen

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Pointing Devices

•
Used in many hand
-
held computers
and PDAs

–
Digitizer pen

–
Graphics tablet


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Pen
-
Based Computing

•
Digitize, analyze, and classify your
speech and its sound patterns

•
Allow operators to perform data
entry without using their hands to
key in data or instructions

•
Speaker
-
independent

•
Voice
-
messaging computers


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Speech Recognition Systems

•
Read text or graphics and convert
them into digital input

•
Employ photoelectric devices to
scan the characters being read


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Optical Scanning

•
Optical character recognition (OCR)

–
Reads OCR characters & codes

•
Merchandise tags

•
Product labels

•
Sort mail, score tests

•
Hand
-
held optical scanning wands

–
Reads bar coding

–
Universal Product Code (UPC)


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Optical Scanning (continued)

•
Magnetic stripe technology

–
Credit cards


•
Smart cards

–
Embedded microprocessor chip

•
Debit, credit, and other cards


•
Digital cameras

–
Still cameras

–
Digital camcorders


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Other Input Technologies

•
Magnetic ink character recognition
(MICR) technology

–
Used by banks to sort and post checks
and deposit slips

–
14 characters of a standardized design

–
Reader
-
sorters

•
Video

•
Print

•
Storage


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Other Input Technologies (continued)

•
Video monitors

–
Cathode ray tube (CRT)

–
Liquid crystal displays (LCDs)


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Video Output

•
Inkjet

–
Spray ink onto the page one line at a
time


•
Laser

–
Use an electrostatic process similar to
a copier


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Printed Output

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Storage Trade
-
Offs

•
Computer storage fundamentals

–
Information is stored through the
presence or absence of electronic or
magnetic signals

•
Binary representation

–
1 = ON

–
0 = OFF


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Storage Trade
-
Offs (continued)

•
Computer storage fundamentals
(continued)

–
Bit

•
The smallest element of data

•
May have a value of either one or zero

–
Byte

•
Basic grouping of bits

•
Typically, a byte consists of 8 bits and
represents one character of data

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Storage Trade
-
Offs (continued)

•
Computer storage fundamentals
(continued)

–
Storage capacities

•
Kilobytes (KB)

–
1,000 bytes

•
Megabytes (MB)

–
1 million bytes


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Storage Trade
-
Offs (continued)

•
Computer storage fundamentals
(continued)

•
Gigabytes (GB)

–
1 billion bytes

•
Terabytes (TB)

–
1 trillion bytes

•
Petabyte (PB)

–
1 quadrillion bytes


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Storage Trade
-
Offs (continued)

•
Direct and sequential access

–
Terms direct access and random
access describe the same concept

–
An element of data or instructions can
be directly stored and retrieved by
selecting and using any of the locations
on the storage media

•
Each storage position

–
Has a unique address

–
Can be individually accessed in approximately
the same time


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Storage Trade
-
Offs (continued)

•
Direct and sequential access
(continued)

–
Sequential access

•
Does not have unique storage addresses

•
Serial process

•
Data are recorded one after another in a
predetermined sequence.

•
Locating an individual item requires
searching all of the data until the desired
item is located


13

Storage Trade
-
Offs (continued)

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Storage Trade
-
Offs (continued)

•
Primary storage of your computer

•
Advantages

–
Small size

–
Great speed

–
Shock and temperature resistant

•
Disadvantage

–
Volatility

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Semiconductor Memory

•
Two basic types of semiconductor
memory


–
RAM
–

random access memory

•
Volatile memory

•
Read/write memory

•
“working” memory


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Semiconductor Memory (continued)

–
ROM
–

read only memory

•
Nonvolatile

•
Used for permanent storage

•
Can be read but not erased or overwritten


–
Variations of ROM

•
PROM

–
Programmable read only memory

•
EPROM

–
Erasable programmable read only memory

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Semiconductor Memory (continued)

•
Most common form of secondary
storage

•
Data is recorded on tracks in the
form of tiny magnetized spots

•
Thousands of bytes recorded on
each track


13

Magnetic Disk Storage

•
Types of Magnetic Disks

–
Floppy disks


–
Zip disks


–
Hard disk drives


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Magnetic Disk Storage (continued)

•
Redundant arrays of
independent disks (RAID)

–
Provides large capacities with high
access speeds

–
Data are accessed in parallel over
multiple paths from many disks

–
Fault tolerant

–
Storage area networks (SANs)

•
Fiber channel LANs that connect many
RAID units


13

Magnetic Disk Storage (continued)

•
Used as secondary storage

•
Also used in robotic automated drive
assemblies

•
Lower
-
cost storage

•
Archival storage


13

Magnetic Tape Storage

•
CD
-
ROM

•
CD
-
R

•
CD
-
RW


•
DVD

•
DVD
-
ROM

•
DVD
-
RAM


13

Optical Disk Storage

•
Business applications

–
Image processing

–
Provide access to reference materials
in a convenient, compact form

–
videos


13

Optical Disk Storage (continued)

•
Do you agree with the statement:
“The network is the computer”?


•
What trends are occurring in the
development and use of the major
types of computer systems?

13

Discussion Questions

•
Do you think that network computers
(NCs) will replace personal
computers (PCs) in business
applications?


•
Are networks of PCs and servers
making mainframe computers
obsolete?

13

Discussion Questions (continued)

•
What trends are occurring in the
development and use of peripheral
devices? Why are those trends
occurring?

•
When would you recommend the use of
each of the following:

–
Network computers

–
NetPCs

–
Network terminals

–
Information appliances in business applications


13

Discussion Questions (continued)

•
What processor, memory, magnetic
disk storage, and video display
capabilities would you require for a
personal computer that you would
use for business purposes?


•
What other peripheral devices and
capabilities would you want to have
for your business PC?


13

Discussion Questions (continued)

•
The Business Value of PDAs


•
What are the business benefits of
PDAs for business applications?


•
What are the limitations of PDAs for
business use?


13

Real World Case 1
–

City of Richmond

& Tim Beaty Builders

References

•
James A. O'Brien; George M. Marakas.
Management

Information Systems:
Managing Information Technology in the
Business Enterprise 6th Ed., Boston:
McGraw
-
Hill/ Irwin
,2004


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