COMPUTER HARDWARE

• Computer


  Programmable electronic device that can store, retrieve, and process data. Consists of input, output and processing devices.
• Computer


  • Stores data
  • Retrieves data
  • Processes data
• Output devices


  • Monitors
  • Printers
  • Speakers
• Computers have various communication devices that it uses to share information
• Central processing unit (CPU)


  The processing of information is done in the CPU

  
• Binary code


  The machine language of 1s and 0s
• Bit


  A single unit of data
• Byte


  Made up of 8 bits, the amount of memory needed to store one alphanumeric character
• Memory units


  Kilobytes (KB)<|>Megabytes (MB)<|>Gigabytes (GB)<|>Terabytes (TB)
• Computer classifications by processing power

  • Supercomputers
  • Mainframes
  • Midrange
  • Workstations
  • Microcomputers
  • Computing appliances
• Classification boundaries are blurred
• Input devices


  • Keyboard
  • Mice/trackball
  • Touch screens
  • Stylus
  • Joystick
  • Microphone
  • ATMs
  • POSs
  • Optical scanners
  • OMR
  • MICR
  • OCR
  • Voice recognition
  • Sensors
  • Cameras
• Output technologies


  • Monitors
  • Printers
  • Voice
  • Multimedia
• Computer hardware components


  • The case
  • The motherboard
  • Sound card
  • Network card
  • Hard drive
  • CD/DVD drive
  • Peripherals
• Computer encasement


  Holds components in a cool, clean, safe environment and shields from radio frequencies
• Computer encasement configurations


  • Desktop model
  • Tower model

  
• Desktop model


  • Horizontal encasement, takes up desk space, less room for expansion
• Tower model


  • Vertical encasement, easily placed off work surface, more room for expansion
• Motherboard components


  • CPU
  • BIOS
  • Bus
  • Memory
  • Ports
  • CMOS

  
• Central processing unit (CPU)

  Also known as microprocessor, the brain of the computer
• CPU


  • Manufactured by AMD and Intel
  • Reads data from storage, manipulates data, moves data to storage or external devices
• CPU component parts


  • Control unit
  • Arithmetic-logic unit
  • Registers
  • Primary storage

  
• Control unit


  Accesses program instructions, decodes instructions, controls data flow
• Arithmetic-logic unit


  Performs computations and comparisons on data
• Registers


  High speed storage areas that hold data and instructions
• Primary storage (main memory)

  Stores instructions from programs and data to be processed
• Machine instruction cycle


  1. Fetch instruction from primary storage

  2. Decode instruction

  3. ALU receives data and instruction, performs calculation or comparison

  4. Result stored in primary storage
• Computer performance


  • Measured by machine instruction cycles per second
  • Affected by clock speed, word length, bus width, line width
• Microprocessor evolution


  • Miniaturization of transistors
  • Decreasing distance between transistors (decreasing line width)
  • Improved conductivity
  • Improved instruction sets
• Basic input/output system (BIOS)


  Contains instructions for boot-up process, runs start-up diagnostics, oversees basic functions after boot-up, intermediary between OS and hardware
• Bus


  Series of connections, controllers, and chips that creates the information highway of the computer. Most modern PCs have a PCI bus.
• BIOS


  Basic Input/Output System - oversees the basic functions of receiving and interpreting signals from the keyboard and interchanging information with various ports. It is the intermediary between the operating system and the hardware.
• Bus


  A series of connections, controllers, and chips that creates the information highway of the computer. There are several buses throughout the computer that connect the microprocessor, the system memory, and various peripherals. Most modern PCs have a peripheral component interconnect (PCI) bus on the motherboard to serve as the connection of information to the various adapters. Other buses include SCSI, AGP, and USB.
• Types of Primary Storage

  • Registers
  • Random Access Memory (RAM)
  • Cache Memory
  • Read-only Memory (ROM)
• Primary Storage (Main Memory)

  Temporary storage area that holds information you are working with, the application software you are using, and the operating system software. Increasing memory capacity increases the performance of the system.
• Secondary Storage


  Non-volatile storage of data and instructions. Has huge storage capacity, is cheaper than Primary Storage, but is slower than Primary Storage. Includes magnetic and optical storage media.
• Secondary Storage Types


  • Magnetic tape
  • Magnetic Disk (Floppy, Hard disk, Zip drive)
  • Memory Cards and Cartridges
  • Optical (CD-ROM, CD-RW, DVD, FMD-ROM)
• Enterprise Storage Systems


  Provide coordinated, secure, managed storage for all enterprise data. Includes Redundant array of independent disks (RAID), Storage area network, Network-attached storage, and Storage Service Providers (third party storage utilities).
• Ports


  • Parallel port
  • Serial Port
  • USB port
  • IDE port
• Parallel port


  A 25-pin connector that was synonymous with a printer port prior to the use of USB connection.