IT

• Hardware


  All the physical equipment and machinery associated with the computer system
• Regardless of size, modern digital computers are all conceptually similar
• Issues pertaining hardware is always a matter of consideration
• Categories of computer hardware


  • Input Hardware
  • Output Hardware
  • Processing and Memory
  • Secondary Storage Hardware
  • Communications Hardware
• Peripheral Device


  Any piece of hardware that is connected to a computer
• Keyboard


  • Originally used for all user control, they are now used mainly for text entry, menu accelerators, modifying mouse controls and visually impaired users
• Composition of Keyboard


  • Standard typewriter keys
  • Cursor movement keys
  • Numeric Keys
  • Function Keys
  • Special Purpose Keys
• QWERTY


  Refers to the order of alphabet keys in the top left row on a standard typewriter keyboard
• Delete


  To erase characters at the right of the insertion point
• Backspace


  To erase characters at the left of the insertion point
• Escape (ESC)


  To cancel a given command
• Pointing Devices


  • Mouse
  • Trackball
  • Joystick
  • Touchpad
  • Stylus and Touch Screen
  • Light pen
• Digital Cameras and Digital Video VCR


  Convert the captured photograph directly into a digital image and store it locally inside the camera for later download to a computer

  
• Scanning Devices


  • Image Scanners
  • Bar code readers
  • Magnetic Ink Character Recognition (MICR)
  • Optical-mark Recognition (OMR)
  • Optical-character Recognition (OCR)
  • Fax machines
• Bar Code

  Vertical zebra-striped marks you can see on most manufactured retail products
• Smart Cards

  Look like a credit card but contain a microprocessor and a memory chip
• Optical Card


  A plastic, laser-recordable card used with an optical card reader
• Voice-recognition Devices


  Convert a person's speech into digital code
• Audio-input Devices


  Record or play analog/digital sound and translate it for digital storage and processing
• Video-input Devices


  Videos are in analog forms, video card is used to convert it in digital form
• Sensors


  A type of input device that collects specific kinds of data directly from environment
• Human-biology Input Devices


  • Biometric Systems Or Biometric Security
  • Line-Of-Sight Systems
  • Cyber Gloves And Body Suits
• Central Processing Unit (CPU)


  It controls and manipulates data to produce information. In a microcomputer the CPU is usually contained on a single integrated circuit or chip, called a microprocessor
• Components of CPU


  • Arithmetic/Logic Unit (ALU)
  • Main Memory or Primary Storage Unit
  • Control Unit
• Memory


  The computer's "workspace", where data and programs for immediate processing are held. This is sometimes called primary storage
• Classification of Printer


  • Impact Printer
  • Non-Impact Printer
• Types of Impact Printer


  • Dot-matrix printers
  • Line printers
• Types of Non Impact Printer


  • Laser printers
  • Ink-jet printers
  • Thermal Printers
  • Plotters and Large Format Printers
• Hardcopy


  Refers to printed output
• Softcopy


  Refers to output that is in the form of sound or displayed on a computer screen
• Special-purpose printers


  • Snapshot printer
  • Label printer
• Display Screens


  • Cathode Ray Tube/Video Display Terminal
  • LCD display
  • Gas plasma
  • Data/Multimedia Projectors
• Audio Output Devices


  Many computers emit chirps and beeps. Some go beyond those noises and contain sound processors and speakers that can play digital music or human like speech
• Secondary Storage Hardware


  Consists of devices that store data and programs permanently on disk or tape
• Floppy Disk


  A removable round, flexible magnetic disk used for data storage
• Paper


  Transparencies usually supported
• Cathode Ray Tube/Video Display Terminal


  Display area of the computer that uses an electron gun to emit a beam of electrons that illuminate phosphors on-screen as the beam sweeps across the screen repeatedly
• LCD display


  A flat panel display which is used by handheld computers, digital watches and calculators
• Gas plasma


  Large displays of up to 42" of viewable area; Gas glows that produce pixels that form an image
• Data/Multimedia Projectors


  Allows an audience to view output