Transcript **** 1

Management Information Systems
04
Chapter 4 (5th Week)
Business Hardware
by Prof. Park Kyung-Hye
Objectives
Business Hardware
List major hardware components of computers and explain
their functions
Classify computers into major categories, and identify their strengths
and weaknesses
Identify and evaluate key criteria for deciding what computers or
related devices to purchase
Discuss the possible health hazards of computer use
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Computer Hardware Components
Business Hardware
Hardware
: physical components of computers and related electronic devices
Consider software before hardware
Computer must handle four operations:
Accept data
Store data and
instructions
Process data
Output data
and/or
information
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Computer Hardware Components (continued)
Business Hardware
In general, every computer has the following components:
Input devices
Central processing unit (CPU)
Internal memory
Storage
Output devices
Input devices
receive signals from outside of computer and transfer them
into the computer
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Computer Hardware Components (continued)
Business Hardware
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Computer Hardware Components (continued)
Business Hardware
Central processing unit (CPU)
Accepts instructions and data
Decodes and executes instructions
Stores results (output) in memory
Internal (or primary) memory
stores data and instructions before and after CPU processes
them
RAM
random access
memory
ROM
read-only
memory
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Computer Hardware Components (continued)
Business Hardware
Motherboard
circuit board containing the CPU and primary memory
Storage
magnetic disks, magnetic tapes, optical discs, DVDs, and flash
memory
Allows permanent storage
Output devices
deliver information from the computer to the user
Monitors and printers are the most common output devices
Audio devices also deliver output
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Computer Hardware Components (continued)
Business Hardware
Bit
Binary digit
0 or 1
Byte
a standard group of eight bits
Most characters can be represented by a single byte
Computer memory and storage capacity are measured in megabytes
(MB), gigabytes (GB), and terabytes (TB)
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Computer Hardware Components (continued)
Business Hardware
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Classification of Computers
Business Hardware
Computers vary in size and power
Classified by power
Power is determined mainly by processing speed and memory
size
More powerful computers are more expensive
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Supercomputers
Business Hardware
Supercomputers: most powerful computers at any given time
Largest in physical size
and most expensive
Designed for complex arithmetic
calculations
Generally impractical for business
purposes
Parallel processing: multiple processors running simultaneously
Also known as multiprocessing
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Mainframe Computers
Business Hardware
Mainframe computers
: store large amounts of data and business transactions
Less expensive and less powerful than supercomputers
Often used by banks, universities, and insurance companies
as a central computer
40-50% of world’s business data resides on mainframes
Use multiple processors
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Midrange Computers
Business Hardware
Midrange computers
: often act as servers within organizations or through the Internet
Smaller and less powerful than mainframes
Serve hundreds of users that connect from personal computers
Use multiple processors
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Microcomputers
Business Hardware
Microcomputers
: personal computers,
notebook computers, and handhelds
Workstation
: more powerful microcomputer used for
CAD, CAM, and scientific applications
Power of microcomputers doubles about every two years
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Computers on the Go
: Notebook, Handheld, and Tablet Computers
Business Hardware
Notebook (or laptop) computer
: compact personal computer powered
by rechargeable battery
New models include wireless technology
Personal digital assistant (PDA)
: handheld computer
Stylus: pen-like device used to enter data
through a touch screen
Tablet computer
: PC in the form of a thick writing tablet that recognizes handwriting
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Business Hardware
Converging Technologies
Technology convergence
: building several technologies into a single piece of hardware
Prominent in handheld units
Commonly merged technologies include:
Digital
cameras
MP3
players
Cell
phones
Television
Digital
sound
recorder
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Converging Technologies (continued)
Business Hardware
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A Peek Inside the Computer
Business Hardware
Professionals must know about computer components to understand
their power and capabilities
They use this knowledge to make good decisions in purchasing
or recommending a computer
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The Central Processing Unit
Business Hardware
CPU has two units to store and process data
Control unit and arithmetic logic unit
CPU is a silicon chip with multiple circuits
Also known as microprocessor
Multicore processors
: processors that combine two or more CPUs or
“cores” on a single chip
Multithreading
: processing more than one program, or several
parts of a program, at the same time
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The Central Processing Unit (continued)
Business Hardware
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The Central Processing Unit (continued)
Business Hardware
Microprocessors are embedded with transistors
Transistor
: a semiconductor that can represent binary code’s two states
CPU machine cycle:
Time period during which the CPU fetches, decodes, and
executes each instruction
CPU clock
: special circuitry on the processor that synchronizes all tasks
Clock rate: number of pulses per second
A machine cycle takes several clock pulses
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The Central Processing Unit (continued)
Business Hardware
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The Central Processing Unit (continued)
Business Hardware
Data word
: maximum number of bits that the control unit can fetch from primary
memory in a single machine cycle
Current microcomputers have words of 32 or 64 bits
Arithmetic logic unit
: the part of the CPU that performs arithmetic and logical operations
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Computer Power
Business Hardware
Computer power depends on processing speed and memory capacity
Bus
: electronic lines or traces used for communication inside computer
Throughput
: number of bits per second that the bus can accommodate
MIPS
: millions of instructions per second, a common measure of computer
speed
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Business Hardware
Input Devices
Computers must receive input to produce output
Input devices include machines and devices used to enter
instructions and data into computer
Common input devices include:
Keyboard
Microphone
Trackball
Scanner
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Input Devices (continued)
Business Hardware
Keyboard
Keyboard: an input device that contains keys that users press to
enter data
Includes letters, numbers, punctuation,
and function keys
QWERTY: standard keyboard layout
Dvorak: keyboard layout that allows fast
er typing
Ergonomics: the study of the comfort and safety of humans in the
workplace
Ergonomic keyboard: fits the natural position of forearms and
prevents injury
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Input Devices (continued)
Business Hardware
Mouse, Trackball, and Trackpad
Mouse: input device that controls an on-screen pointer to facilitate
point-and-click approach
Has one to five buttons for clicking, lock
ing, dragging
Trackball
: similar to mouse, but user manipulates a ball
within the device to indicate movement on the
screen
Trackpad
: cursor movement is controlled by moving a finger over a
touch-sensitive pad
Mice and similar devices can be wireless units
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Input Devices (continued)
Business Hardware
Touch Screen
Touch screen: both an input and an output device
Often used for public applications,
such as kiosks
Prevalent in handheld devices,
GPS devices, and mobile phones
Allows the user to navigate
and select by touching the screen
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Input Devices (continued)
Business Hardware
Source Data Input Devices
Source data input devices: copy data directly from sources such
as bar codes, credit cards, and checks
Optical mark recognition devices detect positions of marks or
characters
Optical character recognition (OCR) devices try to interpret
handwritten and printed text
Magnetic-ink character recognition (MICR)
: detects magnetic ink on checks
Magnetic strips on credit cards store encoded data
Bar codes on products and packages store encoded information
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Input Devices (continued)
Business Hardware
Source Data Input Devices
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Imaging
Business Hardware
Imaging: converts documents into images
Saves paper
More efficient retrieval and filing
Scanned document images can be:
Indexed and linked to relevant records in databases
Easily retrieved
Original paper documents can be destroyed after scanning
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Speech Recognition
Business Hardware
Speech (or voice) recognition
: process of translating human speech into computer-readable data
and instructions
Receives input from microphone and processes it with software
Speech-operated computers may increase noise level in offices and
add distraction
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Output Devices
Business Hardware
Output device: a device that delivers results of computer processing
Popular output devices include:
Monitors
Printers
Speakers
In the future,
smell output is possible
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Output Devices (continued)
Business Hardware
Monitors
Pixel (picture element): small dots that make up the images on a
monitor
Cathode-ray tube: inner side of screen has layer of phosphoric
dots that make up the pixels
Electron gun receives instructions from computer and sweeps
the pixels
Flat-panel monitor: advantages include lower power use, sharper
images, and slim profile
Liquid crystal display (LCD) monitor: uses a liquid crystal filled
screen
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Output Devices (continued)
Business Hardware
Monitors (continued)
Monitor price depends on:
Size, measured as the diagonal length of the screen
Brightness
Contrast ratio (the higher the better)
Pixel pitch (closeness of the pixels)
Resolution: a measure of picture sharpness
Number of pixels in the width and height of the screen
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Output Devices (continued)
Business Hardware
Printers
Nonimpact printer: does not mechanically impact the paper
Laser printer is most common in business
Others include ink-jet and electrothermal printers
Speed is measured in pages per minute (ppm)
Density measured in dots per inch (DPI)
Impact printers: reproduce image by using mechanical impact
Dot-matrix printer: tiny pins strike ink ribbon against paper
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Business Hardware
Storage Media
Data must be stored on nonvolatile medium
Data is retained even when the storage device is not connected
to electrical power
Storage devices differ in the technology used to maintain data and
physical structure
Evaluate storage devices by comparing:
Cost
Capacity
Access speed
Access mode
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Modes of Access
Business Hardware
Sequential storage: data is organized one record after another
Must read through all records that are stored prior to the desired
record
Direct access: records are organized by physical address on the
device
A record can be accessed directly (randomly)
Flash drives: small storage devices that connect via universal serial
bus (USB)
Direct access storage media is the only practical way to organize and
query databases
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Modes of Access (continued)
Business Hardware
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Magnetic Tapes
Business Hardware
Magnetic tapes: similar to tapes used in tape recorders and VCRs,
usually as cartridges
Provide lowest cost (bytes per dollar)
Can back up all data
Takes a long time to copy from tape
Tapes are unreliable after long periods of time or usage
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Magnetic Tapes (continued)
Business Hardware
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Magnetic Disks
Business Hardware
Magnetic disk: most widely used storage medium
Includes hard disks and floppy disks
Hard disk: stack of several rigid platters
installed in the same box that holds the CPU
Stores up to one TB of data
External hard disks connect to computer
through USB port
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Optical Discs
Business Hardware
Optical disc: recorded by treating the disc surface to reflect light in
different ways
Two basic categories of optical disk:
Compact discs (CDs)
Digital video discs (DVDs)
Compact discs: available as read-only,
recordable, and rewritable
DVDs: store 4.7 GB per side
Optical discs are slower than hard disks
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Optical Tape
Business Hardware
Optical tape: uses same technology as optical discs to store and
retrieve data
Bits are organized sequentially, similar to magnetic tape
Mainly used in digital video camcorders
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Flash Memory
Business Hardware
Flash memory
: rewritable memory chip that holds content without power
Consumes very little power
Does not need a constant power supply
Fast access times
Relatively immune to shock or vibration
Available as memory card and USB drive
Solid state disk: storage media that does not have latency time
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Flash Memory (continued)
Business Hardware
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DAS, NAS, and SAN
Business Hardware
Direct access storage (DAS)
: disk or array of disks or tapes directly connected to server
Easy to deploy and manage
Does not relieve any of server’s workload
Network-attached storage (NAS)
: device designed for networked storage
Includes both the storage media and the software to manage it
Offloads processing from the server
Highly scalable
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DAS, NAS, and SAN (continued)
Business Hardware
Storage area network (SAN)
: a network fully devoted to storage and transfer of data
Managed separately from the rest of the LAN
May combine DAS and NAS devices
Can transfer larger blocks of data at higher speeds
Expensive and complex to manage
RAID: redundant array of independent disks
Used by DAS, NAS, and SAN
Fault-tolerant: can continue even through disk failures due to
redundancy
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Business Considerations
in Evaluating Storage Media
Business Hardware
When purchasing storage devices, managers must consider:
Purpose of data storage
Amount of data to be stored
Required speed of data storage and retrieval
Unit space and portability of the device
Cost
Reliability and life expectancy
Trade-offs
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Business Considerations
in Evaluating Storage Media (continued)
Business Hardware
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Considerations in Purchasing Hardware
Business Hardware
Companies must consider the following when selecting equipment to
purchase:
Power of the equipment (memory size, capacity, speed)
Expansion slots and ports (sockets used to connect computer to
external devices)
Monitor type and resolution
Ergonomics
Compatibility with existing hardware, software, and networks
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Business Hardware
Considerations in Purchasing Hardware (continued)
Considerations (continued):
Hardware footprint (physical size of equipment)
Reliability of vendor
Warranty policy and post-warranty support
Power consumption and noise
Cost
Backward compatibility
: the capability to work with older hardware or software
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Business Hardware
Considerations in Purchasing Hardware (continued)
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Scalability and Updating Hardware
Business Hardware
Scalability: resources can be expanded or upgraded to provide
increased power
Not all hardware is scalable
Leasing hardware is a valid option to avoid short useful lifetime of
hardware
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Summary
Business Hardware
Understanding hardware is important for purchasing decisions
Computers are classified according to power
All computers have a CPU to process instructions
Clock rate measures the speed of a CPU
Data word: the number of bits the computer can process in a single
cycle
Computer power: measured by its speed, memory size, and number of
processor cores
RAM: volatile memory that forms the largest part of computer’s memory
ROM is nonvolatile; it does not require power
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Summary (continued)
Business Hardware
Imaging devices help process text and graphics
When evaluating external storage, consider transfer rate, capacity,
portability, and form of data organization supported
Data is organized sequentially on tapes
Direct access storage devices such as RAM, magnetic disks, and
optical discs allow random access
Databases require direct access storage devices
When purchasing hardware, professionals should consider cost, power,
scalability, and compatibility
Information technology may pose health risks such as carpal tunnel
syndrome
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