COMPUTER
HARDWARE
TECHNOLOGIES
(Week 2, Thursday 1/18/2007)
© Abdou Illia, Spring 2007
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LEARNING GOALS
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Identify the major components of modern PCs
Explain how the components of a computer work
together;
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Explain input devices and how they operate.
Describe output devices and how they operate.
Describe I/O (secondary storage) devices and how they
operate.
Explain the role of the CPU and the RAM.
Describe various types of computers.
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The Core Computer Components
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Three subsystems in a computer system:
1. Input subsystem
2. Processing subsystem
3. Output subsystem
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Input subsystem
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Main functions:
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Allowing the user to enter data
Transmitting data to the Processing subsystem
Includes keyboard, mouse, and other input
devices
Question: Name five other input devices
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____________________________
____________________________
____________________________
____________________________
____________________________
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Input Devices
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Human input devices
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Allow a person to send data to the computer
Examples: Keyboard, Mouse
Machine-readable input devices
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Send data directly to computer without human
involvement
No human involvement means no human error
Usually faster than human input
Examples: Bar codes reader, Optical Characters
Recognition (OCR) system
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Machine-readable Input Devices
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Bar code scanners
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Optical Character Recognition (OCR)
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Uses light to read series of coded stripes
Universal Product Code (UPC) – Adams.com
Includes OCR Software and scanner
Translates scanned digital image to character
that user can recognize and manipulate
Magnetic Ink Character Recognition
(MICR)
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Character recognition technology used by
banks to allow rapid routing of checks
between banks
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Output subsystem
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Main function: Show processing results
Includes monitor, printer, and other
output devices
Q: Name two other output devices
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____________________________
____________________________
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Output Devices
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Monitors
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Cathode ray tube (CRTs)
Liquid crystal displays (LCDs)
Quality of display
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Resolution in pixels (e.g. 640 x 480)
Dot pitch in millimeters (.26 to .28)
Active-Matrix vs. Passive-Matrix display
Touch screens
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Input and output via display device
Monitor size
Common resolution
15 inches
640 x 480
17 inches
800 x 600 or 1024 x 768
19 inches
1024 x 768 or 1280 x 1024
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Printers
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Speed and resolution
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Pages per minute (PPM)
Dots per inch (DPI)
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Impact printers
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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
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Create image by spraying or rolling ink on the page
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Non-impact Printers
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Ink-jet technology printers
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Spray ink on the paper
Quiet
Color is readily and cheaply available
Laser printers
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Laser heats drum which rolls ink (toner) on
paper
Can be faster than ink-jet
More expensive than ink-jet
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I/O devices or Secondary Storage
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Nonvolatile storage of digital data
Magnetic or optical
 Magnetic storage (Floppy disk, Magnetic
tape, Zip disk, Hard disk)
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Sequential access (tape) or direct access (HDD)
Hard disk drives
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Two main standards:
 IDE (Integrated Drive Electronics) aka ATA (AT Attachment)
 SCSI (Small Computer System Interface)
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SCSI allows disk fault-tolerance through RAID – Redundant
Array of Inexpensive Disks
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)
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Optical Secondary Storage
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Compact disks (CDs)
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600 MB capacity
CD-ROM
CD-R
CD-RW
Digital versatile disks (DVDs)
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2 – 17 GB capacity
DVD
DVD+/-R
DVD+/-RW
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Processing subsystem
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Two major components
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CPU (Central Processing Unit) or Processor(s)
Primary Storage:
 Random Access Memory (RAM)
 Read Only Memory (ROM)
CPU
Busses that
transfer data
Primary Storage
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Central Processing Unit
Processor
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Clock: generate time that
synchronize other components
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ICU: Fetches instructions from
RAM
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ALU: Execute instructions
(arithmetic & logic operations)
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Registers: Store control
information, data, intermediate
results
Clock
Instruction
Control Unit
Arithmetic
Logic Unit
Registers
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CPU speed
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Speed measured in hertz
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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
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RAM holds running programs
and the data they use
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ROM contains critical
programs such as those that
boot the computer
Data
ROM
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Moore’s Law on Processor Speed
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RAM capacity tends to double every 18-24 months
Processor speed tends to double every 18-24 months
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Types of Computers
Supercomputers
 Mainframes
 Minicomputers
 Servers
 Workstations
 Desktop computers
 Notebook computers (laptops)
 Handheld computers (PDAs)

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Bead Bar : Exercise 2
Visit Dell website at www.dell.com in order to
choose a computer system for Bead Bar. You
must select the components based on the
assessment of needs prepared by Stan after
interviewing the Bead Bar employees (See the
Assignment section’s of the course website for a
copy of Stan’s memo to you) . Your job consist
in filling out the Computer Hardware
specification form found in the Assignment
section of the course website with the
characteristics of the computer system you have
selected. Your assignment must include the
printout of the description of the computer
system from Dell website.
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Summary Questions
Malaga
Notes
1) Name five (3) computer input devices
2) Name three (3) computer output devices
3) What computer devices can be used for both input
and output?
4) What is the difference between: (a) a Kilobyte and a
Gigabyte? (b) a Megabyte and a Terabyte?
5) Name the two main types of monitors used in
today’s computer systems.
6) (a) Name main components of the Processing
subsystem. (b) What is the function of the ALU?
7) Explain the difference between RAM and ROM.
8) Describe the various types of computers.
9) What is meant by Moore’s law?
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File
RAID
RAID 0
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Strips data across multiple disk
No redundancy
Advantage: Fast data access through multiple reads
Disadvantage: Loosing one disk results in loosing data on all disks
File
RAID 1
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Doesn’t strip data across many disk
Mirrors data between two disks
Data kept synchronized between two disks
Advantage: Fault-tolerance, i.e. If one disk fails, the other continue working until failed disk can be replaced
Disadvantage: Only half of available storage space is used.
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RAID
Data spread across these disks
Last disk contains
ECC* data for
disks 1-4
RAID 3
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Spreads data across multiple disks and uses ECC bits for recovery purpose in case of problem
ECC bits determined based on data stored on data disks
If one data disk fails, disk controller automatically regenerates missing data
* Error Checking and Correcting
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Dell XPS 700 Desktop computer
Intel D955XBKLKR motherboard
Pentium® 4 Processor with Dual Core Technology (3.00GHz, 800FSB)
Windows® XP Professional Edition with re-installation CD
1GB Dual Channel SDRAM at 667MHz (2 DIMMs)
250GB Serial ATA 3Gb/s Hard Drive (7200RPM and 10 ms ART)
3.5 in Floppy Drive
17 inch UltraSharp LCD Active Matrix screen, 1280x1024 Resolution, 0.26 dot pitch.
16x CD-ROM Drive
16x DVD+/-RW Drive
$1,640.00
nVidia GeForce 7900 GS Video card
Sound Blaster® X-Fi™ XtremeMusic (D) Sound Card w/Dolby
Dell A525 30 Watt 2.1 Stereo Speakers with Subwoofer
Dell USB Enhanced Multimedia Keyboard
Logitec Optical USB Mouse
56K PCI Telephony Modem
10/100/1000 NIC PCI
Dell Inkjet Printer 924, Up to 17 PPM Black/White, 600 x 600 dpi
1Yr Ltd Warranty, 1Yr At-Home Service
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PowerEdge SC1420 server computer
Intel D955XBKLKR motherboard
Dual Pentium® Xeon Processor with Dual Core Technology (3.00GHz, 800FSB)
Windows® XP Professional Edition with re-installation CD
2.0GB DDR2 400MHz, 4X512MB SDRAM
Two 73 GB 10K RPM SCSI Hard Drives Ultra 320
PERC Ultra 320 2-Channel SCSI RAID Controller Card
3.5 in Floppy Drive
48X IDE Internal CD-RW/DVD ROM Drive
nVidia GeForce 7900 GS Video card
$3,040.00
Sound Blaster® X-Fi™ XtremeMusic (D) Sound Card w/Dolby
Dell A525 30 Watt 2.1 Stereo Speakers with Subwoofer
Dell USB Enhanced Multimedia Keyboard
Logitec Optical USB Mouse
10/100/1000 NIC PCI
Dell Inkjet Printer 924, Up to 17 PPM Black/White, 600 x 600 dpi
1Yr Ltd Warranty, 1Yr At-Home Service
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