Computer Hardware

1
Introduction

• Computer Hardware

2
Hardware

• Hardware the physical devices that make up a
  computer (often referred to as the computer
  system)

3
Computer Hardware

• Computer Systems are made up of the following
  components
• Processing units
• CPU
• GPU (graphics card)
• Disk controller
• Storage Devices
• Main memory
• Cache memory
• Disk

4
Computer Hardware

• Input/Output (I/O) Devices
• Keyboard, mouse, scanner, stylus, joy stick,
  trackball, game controllers, digital cameras, web
  cams, monitors, printers
• Communication Devices
• Internal Processor bus
• PCI Bus
• SCSI Bus
• Ethernet link

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Computer Hardware
6
CPU
7
Hardware

• Central processing unit (CPU) the hardware
  that interprets and executes software and
  coordinates all hardware
• Random access memory (RAM) temporary
  holding area for information, as well as system
  and application software instructions

8
Hardware

• CPU components
• Control unit directs what happens in the CPU
  and the rest of your computer
• Arithmetic logic unit (ALU) performs
  arithmetic, comparison, and logic operations
• CPU cache CPU memory where instructions wait
  until theyre needed
• CPU clock beats to keep instructions and
  information moving in synchronized fashion

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Hardware

• CPU and RAM work together to form the brain of
  your computer
• CPU speed measured in gigahertz (GHz)
• GHz number of billions of CPU cycles per second
• CPU (machine) cycle retrieve, decode, and
  execute instruction, then return result to RAM if
  necessary

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CPU (Machine) Cycle

• Retrieve The control unit sends to RAM for the
  instructions and information it needs
• Decode CPU gets the instruction out of cache and
  examines it to see what to do
• Execute Does what the instruction says to do
• Store Sends the result of processing to be
  stored in RAM if necessary

11
Programming a computer

• Consider a simple hypothetical "human powered"
  computer with a CPU (the human) and a main memory
  consisting of a wall of "post office" type boxes.
• Each box has a unique address or "box number"
• Addresses range from 0, 1, 2, , n 1, where n
  is the number of different boxes.
• Each box can hold either
• An instruction to the human
• A real number
• The human computer is limited in her capacity to
  understand instructions, but performs the
  instructions she can understand with 100
  reliability.

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Programming a computer

• The human computer instruction set consists of
  the following
• store value,box
• store 20,100 // stores the value 20 in box
  100
• add box,box,box
• add 100,101,120 // Adds the values stored in
  box 100 and 101
• and puts the answer
  in box 120
• sub box,box,box
• sub 50,60,70 // subtracts the value stored
  in box 60 from
• the value stored in
  box 50 and stores the result
• in box 70
• halt // terminates execution

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Programming a Computer

• Give the instructions to have the human computer
  add 10 and 15 and leave the sum in box 200.

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Hardware

• Input device tool that you use to enter
  information and commands
• Output device tool you use to hear, see,
  hear, or otherwise recognize the results of your
  information-processing requests
• Storage device tool you use to store
  information for use at a later date

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Hardware

• Telecommunications device tool you use to
  send information to and receive it from another
  person or computer in a network
• Connecting hardware any hardware that lets
  you connect peripherals to your computer, such as
  cables, ports, expansion boards, etc.

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Capacity of Storage Devices

• Megabyte (MB or M or Meg) about 1 million bytes
• Gigabyte (GB or Gig) about 1 billion bytes
• Terabyte (TB) about 1 trillion bytes

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Common Ports and Connectors
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Wireless Connections

• Infrared IR or IrDA (infrared data association)
  uses red light to send and receive information
• Bluetooth transmits information as radio waves
  for a distance of 30 feet
• WiFi (wireless fidelity) or IEEE 802.11a, b, or g
  transmits information as radio waves for a
  distance of up to 300 feet

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Expansion Cards and Slots

• Expansion card (board) circuit board that you
  insert into the expansion slot and connect to a
  peripheral device
• Expansion slot long skinny socket on the
  motherboard for expansion card
• Expansion bus pathways along which information
  moves between devices (outside the motherboard)
  and the CPU