CSC1402 Foundation Computing

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CSC1402Foundation Computing

• Lecture 4
• Computer Hardware

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Why do you need to know this?

• Perhaps you can drive a car without knowing how
  big its engine is, how many gears it has or how
  the differential works!
• So too you can use a computer without knowing
  anything about its "insides".
• But as a PROFESSIONAL you are expected to be
  computer literate and to have a basic
  understanding of how a computer works.

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An Ideal World?

• There is an old story that when the PC user asked
  the Macintosh user how much memory his machine
  had, he replied "Enough".
• Ideally you do not have to be concerned with what
  is inside your computer it just works!
• Unfortunately the world is far from ideal. Such
  knowledge turns out to be very useful.

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Input Devices

• Qwerty Keyboard (from early typewriters)
• Dvorak Keyboard (Dr. August Dvorak)

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Input Devices

• Mouse (Douglas Engelhart, 1963?)
• Nowadays more buttons, scroll wheel, balls or
  optical sensors, wireless, recharge cradle.

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Input Devices

• Scanner
• Digital Camera
• PC Camera (webcam)
• Sound card (input and output of sound)

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Output Devices

• Monitors
• Cathode Ray Tube (CRT)
• Liquid Crystal Display (LCD)
• LCD Digital Light projectors
• Speakers headphones
• Printers Plotters
• Impact
• Ink Jet
• Laser

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Resolution

• For both monitors and printers we are interested
  in the resolution how small are the pixels
  (tiny dots)?
• Monitors have 640 ? 480 up to 1280 ? 1024 with a
  screen size of 15-19 inches (or bigger) measured
  diagonally.
• For printers the resolution is in pixels or dots
  per inch, typically 600 dpi for a laser printer.

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Storage

• Primary Storage (Memory)
• Semiconductor integrated circuit (chip).
• Random Access Memory (RAM) where your program and
  data are stored while the program is running.
  Typically 64Mb to 256Mb in a PC.
• Read Only Memory (ROM) where the bootstrap
  program is stored so that it is available when
  you first turn on the power.
• FAST, less than a microsecond.

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Storage

• Secondary Storage
• Hard Disk
• Rotating platter covered in magnetic material
• Typically 40 to 400 Gb on a PC.
• SLOWISH because of seek rotational latency
  (7200 rpm 8.4 millisecond).
• Other storage devices
• Floppy Disk, Zip Disk (also magnetic)
• CD, DVD (optical)
• Tapes
• Flash Memory, eg. USB memory sticks

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Bytes, Megabytes, Gigabytes?

• All computer data stored in the binary numbers.
• One bit is either 0 or 1.
• One byte is 8 bits (28 2?2?2?2?2?2?2?2 256
  possible values).
• Memory and storage size are in bytes.
• 1024 (210) is used as the major scaling factor.
• 1KB 1024 bytes
• 1MB 1024 1024 1,048,576 bytes
• 1GB 1024 1024 1024 1,073,741,824 bytes

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Basic Computer Architecture
Read Only Memory(ROM)
Microprocessor(CPU) 1) Control Unit 2)
Arithmetic Logic Unit 3) Registers
Printer
Main Bus(Address Bus Data Bus)
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The CPU or "Processor"

• This is the "brain" of thecomputer.
• It controls all activities.
• Runs software made up of simple machine
  instructions like "fetch this value from memory"
  or "add these two numbers".
• Must current PCs have a Pentium or Celeron
  CPUdesigned and manufactured by Intel.

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Bus Operation Clocking

• A Bus is a collection of wires that link together
  everything inside the computer.
• The CPU "sends" an address down the bus and
  something (memory or a device) responds.
• Everything happens synchronised by a regular
  clock "tick", typically 1 to 3 GHz (billions of
  cycles per second)

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Primary Memory

• Usually comes as a set of RAM "sticks"
• RAM Random Access Memory
• Also cache memory - inside the processor.

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Motherboard

• The CPU, part of the BUS, and many other
  essential components, eg. device controllers,
  modem, video card, USB (universal serial bus)
  port, will be combined on a single printed
  circuit board called the motherboard. Slots for
  RAM sticks and other devices.

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Power Supply

• The insides of a computer generally use 5 volts
  or 12 volts (or both) DC (direct current).
• Power supply is a transformer that takes 110-250
  volts AC (alternating current) and produces the
  5-12V DC.

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Fans

• Computer components gets HOT!!!
• Essential to dissipate the heat.
• Sometimes processor has its own fan.
• Keep fans clean!

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Buying a Personal Computer

• Understand your requirements
• Capacity
• Speed
• Software and its requirements for memory or
  special hardware, eg. graphics.
• Packing with software
• Warranty support
• Ability to upgrade
• Price versus budget!

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Buying a Personal Computer

• How to buy?
• New pre-configured "off the shelf"
• Second hand
• Assemble from components
• Require research
• Careful assembling or use an expert
• Can save

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Caring for Computers

• Physical care temperature, dust, fluids.
• Electrical care power surge protection,
  Uninterrupted Power Supply (UPS).
• Appropriate security protection password
  access, antivirus software, firewalls.
• Appropriate data backups and physical security of
  backup media.
• Appropriate system maintenance disk
  fragmentation etc.

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Ergonomics

• Old monitors glare, radiation.
• Interlaced monitors and high quality graphics.
• Proper seating, keyboard, monitor positions.
• Appropriate lighting.
• Avoid long periods of continuous use eye strain
  and/or repetitive strain injury.

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Environmental Awareness

• Where do all the old computers go?
• The myth of the paperless office.
• Careful on screen checking before printing.
• Double sided printing.
• Recycle paper, toner cartridges etc.

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Reading Reading Reading

• Study Book Module 4
• Computing Concepts Chapters 5 6i.e. Composite
  text pages 201 - 267
• Also try to read Module 5 on spreadsheets in
  preparation for Lecture 5.