Input and Output

Posted in | at 2/23/2011 02:43:00 PM

Do you know what is Input?
•          Any data or instructions used by a computer
•          Input devices
–        Hardware
•          Keyboards
•          Pointing devices
•          Scanning devices
•          Other devices
–        Translates data into a form that the
system unit can process

Keyboard Entry
•          Keyboards
–        Traditional keyboards
–        Ergonomic keyboards
–        Wireless keyboards
–        PDA keyboards
–        Virtual keyboards
•          Features
–        Typewriter keyboard with numeric
keypad
–        Special purpose keys
•          Toggle and combination keys

   Pointing Devices


Scanning Devices
•          Optical scanners
–        Flatbed scanners
–        Document scanners
–        Portable scanners
•          Card Readers
–        Magnetic card readers
–        Radio Frequency card readers
•          Bar code readers
–        Handheld wand readers or platform scanners
–        Contain photoelectric cells that read bar codes
•          Character and mark recognition devices
–        Magnetic ink character recognition (MICR)
–        Optical-character recognition (OCR)
–        Optical-mark recognition (OMR)

Image Capturing Devices
•          Digital cameras
–        Images recorded digitally on a disk
–        Images can be downloaded to a computer
•          Digital video cameras
–        Records motion digitally
–        Can take still images as well
–        WebCams
•          Specialized digital video cameras
•          Broadcast
images over the
Internet


Audio-Input Devices

What is Output?
Monitors
•          Known as screens or display screens
•          Output referred to as soft copy
•          Features
–        Resolution/pixels
–        Dot pitch
–        Refresh rate
–        Size
•          Cathode-ray tube (CRT) monitors
•          Flat-panel monitors
–        Require less power to operate
–        Portable and thinner than CRTs
•          Other monitors
–        E-books readers
–        Data projectors
–        High-definition television (HDTV)

Printers
•          Translates information that has been processed by the system unit
•          Output referred to as hard copy
•          Features
–        Resolution
–        Color capability
–        Speed
–        Memory
•          Ink-jet printer
•          Laser printer
–        Personal laser printers
–        Shared laser printers
•          Thermal printer
•          Other printers
–        Dot-matrix printers
–        Plotters
–        Photo printers
–        Portable printers

Audio-Output Devices

Internet Telephone Approaches
•          Computer-to computer
–        Free long distance calls
–        Requires computers to be connected to the Internet
–        MSN is most widely used software
•          Computer-to traditional telephone
–        Place the call from a computer to a phone
–        Requires an Internet phone service provider
•          Software requirements
•          Small monthly and/or per-minute fee
•          Traditional telephone-to-traditional telephone
–        Does not require a computer
–        Subscription required to a special Internet phone service provider
•          Special hardware adapter
•          Cost is similar to the computer-to-traditional telephone approach

Careers In IT
•          Technical writers prepare instruction manuals,   technical reports, and other scientific or technical documents
•          Typically requires a college degree
–        Communications
–        Journalism
–        English
–        Specialization or familiarization with a technical field
•          Technical writers can expect to earn $46,500 to $76,500 annually.

A Look to the Future
Electronic Translators May Be in Your Future
•          Electronic Interpretation may soon exist to provide personal interpretation for foreign languages and images
•          Prototype portable handheld electronic interpreters are currently in a testing
phase at the U.S. Office of Naval
Research
•          Creating is labor intensive using
both linguists and programmers

 

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The System Unit

Posted in | at 2/22/2011 03:51:00 PM

Electronic Data and Instructions
•          Data and instructions are represented electronically
•          Two-state system or Binary System
–        Off/on electrical states
–        Characters represented by 0s (off) and 1s (on)
–        Bits
–        Bytes   

Character Coding Schemes
•          Three types of binary coding schemes
–        ASCII - American Standard Code for Information Exchange
–        EBCDIC - Extended Binary Coded Decimal Interchange Code
–        Unicode – handles languages with large numbers of characters

System Board
•          Connects all components
•          Allows communication between devices
•          Main board or motherboard
•          Circuit board electronic components
–        Sockets
–        Slots
–        Bus lines

Microprocessor Chips
•          Central Processing Unit (CPU)
•          Two Basic Components
–        Control unit
–        Arithmetic-logic unit (ALU)
•          Chip capacities are expressed in word sizes
•          Two Recent Significant Developments
–        64-bit processors
•          Have become standard for most of  today’s desktop and laptop computers
–        Multi-Core Chips
•          Can provide two
separate and
independent CPUs
•          Parallel processing 

Specialty Processors
•          Coprocessors
–        Designed to improve specific computing operations
–        Graphics coprocessors
•          Smart cards
–        Credit card sized with an embedded chip
–        Used by many universities
•          Specialty processors in cars
–        As many as 70
–        Used to control features
•          RFID tags
–        Information chips
–        Used for tracking purposes
Memory
-          Holding area for data, instructions, and information
-          Memory is contained on chips connected to the system board
-          Types of memory chips
-          RAM
-          ROM
-          Flash
RAM
•          Random Access Memory (RAM) chips hold the program and data
–        Cache memory or RAM cache
–        Flash RAM or flash memory
•          Other types of RAM
–        DRAM
–        SDRAM
–        DDR
–        Direct RDRAM

ROM
•          Read-only memory (ROM) chips are not volatile and cannot be changed by the user
•          CPU can read, or retrieve data and programs but the computer cannot write
•          Contain special instructions
–        Needed to start a computer
–        Give keyboard keys their special capabilities
–        Put characters on screen

Flash
•          Flash memory offers a combination of the features of RAM and ROM. 
•          Flash memory is used for a wide  of range of applications.
•          If changes are made to the computer system, these changes are reflected in flash memory.

Expansion Slots and Cards
•          Allow for new devices to be added
–        Open architecture
–        Slots provide for expansion
•          Expansion cards are also called …
–        Plug-in boards
–        Controller cards
–        Adapter cards
–        Interface cards

Commonly Used Expansion Cards
TV Tuner Cards And Video Clips
•          Allows you to view your favorite TV shows while running other applications such as Excel
•          Video can be captured to a file, added to a Web page, attached to an email, or added to a class presentation
•          Relatively inexpensive
and easy to install

Plug and Play
•          Set of specific hardware and software standards developed by Intel, Microsoft, and others
•          Creating devices that are able to configure themselves when installed

Bus Lines
•          Connect parts of the CPU to each other
•          Data roadway for traveling bits
–        Measured as bus width
–        More lanes, faster traffic
•          Two basic categories
–        System buses
–        Expansion buses

Expansion Buses
•          Connects the CPU to other components on the system board, including expansion slots
Ports
•          Socket for connecting external devices
•          Ports can connect directly to the system board or they can connect to cards that are inserted into slots on the system board
•          Three Types
–        Standard Ports
–        Legacy Ports
–        Specialized Ports


Legacy Ports

Specialized Ports
•          Three specialized ports
–        Musical Instrument digital interface (MIDI)
–        Sony/Philips Digital Interconnect Format (S/PDIF)
–        High Definition Multimedia Interface (HDMI)

Power Supply
•          Computers require direct current (DC)
•          DC power provided by converting alternating current (AC) from wall outlets or batteries
•          Desktop computers use power supply units
•          Notebooks and handhelds use AC adapters



Careers In IT
•          Computer technicians repair and install computer components and systems
•          Employers look for
–        Certification in computer repair
–        Good communication skills
•          Continued education is
required
•          Computer technicians can
expect to earn an hourly
wage of $13.50 to $22.50

A Look to the Future
•          Wearable computers
•          Send and receive email while jogging
•          Maintain your personal schedule book
•          Remember the names of people at a party


Standard Ports

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