Comp. hardware technologies

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Copyright © 2005 Prentice Hall, Inc.

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Information Systems TechnologyRoss Malaga

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"Part I Understanding Information Systems Technology"

COMPUTERHARDWARE

TECHNOLOGIES


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LEARNING GOALS

• Identify the major components of modern PCs.• Explain how the components of a computer work together;

– Explain the role of the CPU and how it operates.– Explain input devices and how they operate.– Describe output devices and how they operate.– Describe multimedia and alternative I/O devices.– Explain the role of primary storage.– Describe secondary storage devices and how they operate.

• Describe various types of computers.

2-3Copyright © 2005 Prentice Hall, Inc.

Bead Bar Wants Computers

• Hardware choices should be driven by the specific software the company needs to run

• Some of the requirements– Meredith – Computers for managers– Suzanne – Computer in each studio– Mitch – Notebook (laptop) needed for cruise ships– Julia – Keep the total hardware cost under $20,000– Miriam – Marketing can save money by using

computers to develop their own materials– Rachel – Mobile computing needed for traveling

purchasing rep– Jim – Must be ergonomically designed


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The Core Computer Components

• Input device(s)

• Output device(s)

• Primary storage

• Secondary storage

• Central processing unit (CPU)

• Busses


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The Historical Development of Computers

• Babbage’s Analytical Engine – 1820s – 1870s– Punched card program– Lady Ada Byron, the first programmer

• Herman Hollerith– Hollerith code– Punched card tabulating machines – 1890 census

• ENIAC during WWII used vacuum tubes• 1960s introduced transistor to replace tubes• 1970s – introduction of the microprocessor


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The Rise of the PC

• 1974 – Altair 8800 – the first PC• 1976 – Wosniak and Jobs – Apple I• 1977 – Apple II

– Plastic case– Keyboard– Capable of color graphics

• 1981 – IBM PC (introduction of MS-DOS)• 1984 – Apple Macintosh

– Graphical User interface (GUI) pioneered a Xerox PARC


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Input Devices

• Human input devices– Allow person to send data to the computer– Keyboard– Mouse (and other pointing devices)

• Machine-readable input devices– Send data directly to computer without human

involvement– No human involvement means no human error– Usually faster than human input


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Keyboard as Input Device

• Easy way to enter text, numbers, and simple commands

• Follows the layout of the typewriter• QWERTY keyboard leads to RSIs

– Repetitive Stress Injuries– Requires increased attention to ergonomics of

the work environment• Posture• Lighting• Working


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Machine-readable Input Devices• Bar code scanners

– Uses light to read series of coded stripes– Universal Product Code (UPC) – Adams.com– Package tracking at UPS

• Optical Character Recognition (OCR)– Software that works with scanner– Translates scanned digital image to character that user

can recognize and manipulate• Magnetic Ink Character Recognition (MICR)

– Character recognition technology used by banks to allow rapid routing of checks between banks

http://www.adams1.com/pub/russadam/upccode.html

http://www.ups.com/WebTracking/track?loc=en_US


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Output Devices

• Monitors– Cathode ray tube (CRTs)– Liquid crystal displays (LCDs)– Quality of display

• Resolution• Dot pitch

• Touch screens– Input and output via display device


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Printers

• Speed and resolution– Pages per minute– Dots per inch

• Number of ink dots to fill a square inch• Higher DPI the greater the page clarity

• Impact– Create image by striking paper and ribbon– Dot-matrix

• Non-impact– Create image by spraying or rolling ink on the page


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Non-impact Printers

• Ink-jet technology printers– Spray ink on the paper– Small– Quiet– Color is readily and cheaply available

• Laser printers– Laser heats drum which rolls ink (toner) on

paper– Can be faster than ink-jet– Color more expensive than ink-jet


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Multimedia I/O Devices

• Music, images, and video– Convert content to digital form– How MP3s work at HowStuffWorks.com– Digital cameras ; digital camera phones– Digital Video DVD recorders – Sony Handicam

• Game controllers• Virtual reality (VR) • Voice recognition• Text-to-speech• Brain wave input

http://entertainment.howstuffworks.com/mp3.htm

http://www.sonystyle.com/intershoproot/eCS/Store/en/documents/specifications/DCR-DVD300.pdf

http://www.sonystyle.com/intershoproot/eCS/Store/en/documents/specifications/DCR-DVD300.pdf


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Primary Storage

• Digital data stored in bits – BInary digiTs• Combination of 8 bits is called a byte• Different combinations of bits represent

different symbols– ACSII– EBCDIC

• All data and programs are represented in bits– Video– Pictures– Text


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Primary Storage (Continued)• The main memory of the computer• Stored on semiconductor chips

– RAM – random access memory• Volatile• Cache memory

– Internal – ultra high speed and VERY expensive– External – very high speed and less expensive than internal cache

– ROM – read only memory• Non-volatile

• Primary storage holds all programs that are running and the data those programs use


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Secondary Storage• Nonvolatile storage of digital data• Magnetic or optical• Magnetic media

– Sequential access (tape) or direct access (HDD)– Hard disk drives

• Metal disk with metallic coating• Disk spins at speeds of up to 7000 rpm• RAID – redundant array of inexpensive disks

– Floppy disks– Magnetic tape– Zip disks and other magnetic storage alternatives


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Hard Disk Drives and Direct Access


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Optical Secondary Storage

• Compact disks (CDs)– 600 MB capacity– CD-ROM– CD-R– CD-RW

• Digital versatile disks (DVDs)– 2 – 17 GD capacity– DVD– DVD+/-R– DVD+/-RW


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The Central Processing Unit

• Two main components– Arithmetic and logic unit (ALU)– Control unit (CU)– Registers are used as scrap paper – intermediate

results• Speed measured in hertz

– Megahertz – millions of instructions per second– Gigahertz – billions of instructions per second


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Moore’s Law on Processor Speed


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Computer Program Instruction Execution

• Connect all the pieces together– Bus – electrical pathway– All digital data moves from component to component on

the bus• Executing an instruction

– Control unit fetches next instruction from primary storage and stores it onboard the CPU

– The control unit decodes the instruction– The ALU executes the instruction possibly accessing other

data in primary storage• Cycle is repeated millions of times per second


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Types of Computers

• Supercomputers• Mainframes• Minicomputers• Workstations• Desktop computers• Notebook computers (laptops)• Handheld computers (PDAs)

2-28Copyright © 2005 Prentice Hall, Inc.

Bead Bar Consultant

• How Computer Hardware Issues Affect the Bead Bar– Meredith – Needs to understand the technology and terms– Suzanne – Computers in studios to improve studio operations– Leda – Use computers to improve franchise record keeping and

marketing– Mitch –Portable computer to allow working while traveling– Julia – Concerned about costs, including ROI– Miriam – Use multimedia to develop marketing materials– Rachel – Use bar codes and handhelds to reduce errors and

streamline operations– Jim – Upgrading skills of employees and finding new

employees to hire with the proper computer skills


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Learning Goals Summary

In this chapter you have learned: The major components of modern PCs How the components of a computer work together

The role of the CPU and its operation Input devices and how they operate Output devices and how they operate Multimedia and alternative I/O devices The role of primary storage Secondary storage devices and operation

The various types of computers

Comp. hardware technologies

Technology

prentice hall

secondary storage devices

primary storage digital

alternative io devices

inkjet color

role of primary storage

ink toner

multimedia io devices