Download INTRODUCTION TO INFORMATION SYSTEMS TECHNOLOGY

Review For Final
(Fall 2009)
© Abdou Illia
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Computer Hardware
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The Core Computer Components

Four subsystems in a computer system:
1. Input subsystem
2. Processing subsystem
3. Output subsystem
4. I/O (Storage) subsystem
Input/Output (storage)
Input
Process
Output
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Output Devices

Monitors



Cathode ray tube (CRTs)
Liquid crystal displays (LCDs)
Quality of display



Resolution in pixels (e.g. 640 x 480)
Dot pitch in millimeters (.26 to .28)
Active-Matrix vs. Passive-Matrix display
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Printers

Speed and resolution


Pages per minute (PPM)
Inkjet: Dots per inch (DPI)



Impact printers



Number of ink dots to fill a square inch
Higher DPI = greater page clarity
Create image by striking paper and ribbon
Dot-matrix printers = most common impact printers
Non-impact printers

Create image by spraying or rolling ink on the page
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I/O or Secondary Storage devices

Secondary compared to the main primary memory called RAM
Nonvolatile1 storage of digital data
Could be Magnetic or Optical

Magnetic storage (i.e. data stored on magnetically coated


surface)



Examples: Magnetic tape, Hard disk, floppy disk
Sequential access (e.g. tape) or direct access (e.g. HDD)
Hard disk disks

many standards:
 Parallel ATA (PATA) or IDE (Integrated Drive Electronics)
 Serial ATA (SATA)2
 SCSI (Small Computer System Interface)


SCSI provides disk fault-tolerance by using RAID – Redundant Array of
Inexpensive Disks; that is multiple disks set together to provide
continued service in case one disk fails.
Disk speed:
 Transfer rate in MBps (Megabytes per second)
 Average Read Time (in milliseconds or ms)
 Platter rotation speed in RPM (5400/7200/10,000/15,000)
1. Means that the stored data wouldn’t disappear (or be deleted) in case of power shortage
2. In SATA and PATA, ATA stands for Advanced Technology Attachment
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Measuring Storage Capacity
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Processing subsystem
Motherboard: chipset that all components connect to
 Two major components in processing subsys.



CPU (Central Processing Unit) or Processor(s)
Primary Storage:
 Random Access Memory (RAM)
 Read Only Memory (ROM)
Other
components
on the
Motherboard
CPU
Busses that
transfer data
Primary Storage
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Central Processing Unit
Processor

Clock: generate time that
synchronize other components

ICU: Fetches instructions from
RAM

ALU: Execute instructions
(arithmetic & logic operations)

Registers: Store control
information, data, intermediate
results
Clock
Instruction
Control Unit
Arithmetic
Logic Unit
Registers
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CPU speed

Speed measured in hertz



Hertz = # of instructions executed per second
Megahertz = 1 million of instructions per second
Gigahertz = 1 billion of instructions per second
Major Processor manufacturers
Intel
-
Celeron
- Pentium 3, Pentium 4, Pentium 4 Xeon, Dual Core
Advanced Micro Devices (AMD)
- K6 series processors (which compete with Intel Pentium 3)
- Athlon series (which compete with Intel Pentium 4)
IBM
- PowerPC 740, 750, 750FX, 750GL, 750GX
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Primary Storage
 Computer’s memory stored on semiconductor chips
 Two categories:
 RAM (Random Access Memory) which is volatile
 Synchronous Dynamic RAM (SDRAM)
 Double Data Rate SDRAM or DDR SDRAM
 ROM (Read-Only Memory) which is non-volatile
 Capacity in Megabytes (MB) or Gigabytes (GB)
Primary Storage
RAM
Program

RAM holds running programs
and the data they use

ROM contains critical
programs such as those that
boot the computer
Data
ROM
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Summary Questions
Book
Notes
1) Name two devices that could be used for both input
and output.
2) What is the difference between: (a) a Kilobyte and a
Gigabyte? (b) a Megabyte and a byte?
3) What is the function of the Instruction Control Unit
or ICU found in the processing subsystem?
4) Explain the difference between RAM and ROM.
5) What is pixel? What is dot pitch
6) What is a byte?
7) What is a Hertz?
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Network Technology
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Computer Network

Once connected to the network,
the computer (or another device)
becomes a network node
An interconnection of computers and
computing equipment using either wires
or radio waves over small or large
geographic distances
GHI
DEF
ABC
MNO
“Connect to GHI”
JKL
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Physical
Transmission Media

Physical media



Wireless
Transmission media used to physically connect
nodes in to the network
Transmits electrical or optical signals
Could be cooper wire or fiber optic cable
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Transmission Media (Continued)

Twisted Pair
Category
Use
Signal
Data rate
Distance
Problem
Category 1
Telephone
Analog/Digital
<100Kbps
3-4 miles
Security, noise
Category 2
T1, ISDN
Digital
<2 Mbps
3-4 miles
Security, noise
Category 3
LANs
Digital
10 Mbps
100 m
Security, noise
Category 4
LANs
Digital
20 Mbps
100 m
Security, noise
Category 5
LANs
Digital
100 Mhz
100 m
Security, noise
Category 6
LANs
Digital
250 Mhz
100 m
Security, noise
Category 7
LANs
Digital
600 Mhz
100 m
Security, noise
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Wireless Media



Uses electromagnetic waves or electromagnetic radiation
for data transmission
Propagation through space, and indirectly, through solid
objects
Two kinds of wireless media used

Radio waves (radio Frequency)

Infrared light




Affected by Multipath interference
Highly vulnerable to snooping
Limited distance
Blocked by thick objects

Close proximity and “line of sight” location required
Laptop
Comm.
Tower
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Network Topologies

The configurations of network components



How physically the network looks like
How logically data is transferred on the network
Widely used network topologies:




Bus
Star
Ring
(Mesh, not common in business setting)
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Bus Network Topology
Most simple network topology
 All devices connected to a common central
cable called a “bus”
 Inexpensive
 If cable fails, the entire network will shut
down

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Star Network Topology
Centered around
central device called
a hub or a switch
 All network nodes
connect to the
hub/switch
 Easy to install and
update
 If hub fails, network
fails

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Ring Topology

Node connected to a
logical ring in a central
device called MAU

More reliable than bus or
star


Only one node sends at a
time (no collisions)
Expensive and limited
speed
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Network Architecture

Defines how the
processing takes
place on the network

Two primary types


Client-server
Peer-to-peer (P2P)
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Summary Questions
Malaga
Notes
1) What is a node?
2) Name physical and wireless media used in networking
3) What transmission media is used for the telephone?
4) What are the main network topology? What are the
differences between them?
5) Distinguish between Client-server and P2P networks
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The Internet and
eBusiness
See Exam 3 Review (Part 2)
PowerPoint notes in Final Review
Section of course web site
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Managing Security
See Exam 3 Review (Part 2)
PowerPoint notes in Final Review
Section of course web site
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Managing the Development
and Purchase of IS
See Exam 3 Review (Part 1)
PowerPoint notes in Final Review
Section of course web site
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