Computer Hardware

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Computer Hardware
RAM
Computer Facts
Preview the exam questions.
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COMPUTER FACTS

• A computer is an electronic device which works
  within a binary digital system and has 4
  functions
• Accept input (data isolated facts)
• Process input (data)
• Produce output (information processed data)
• Storage

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Binary Digital System

• A system that works with two states. For the
  computer these two states are on/off or the
  digits of 1 and 0.

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Hard Drive
BUS
Tower
CPU
RAM
Floppy CD Drive Drive
Ports
Peripheral devices
keyboard
mouse
Monitor
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Some Hardware Definitions

• Tower box that holds CPU, RAM, etc.
• Peripheral Devices input/output devices such as
  the printer, monitor, etc.
• Bus electronic device that connects all the
  internal parts of the computer
• Port connectors for all peripheral devices

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CPU

• Central Processing Unit

F A C T S
How does this work?
Diagram of parts
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Control Unit
CPU Diagram
Registers
ALU
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CONTROL UNIT

• Fetches and Interprets
• Instructions
• From
• RAM

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ALU(arithmetic/logic unit)

• Executes instructions

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Register

• Fast accessing storage
• Inside the CPU

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CPU FACTS

• Megahertz unit of speed for the CPU
• CPU works with the machine cycle
• How are numbers, letters, graphics etc.
  represented in binary digits contained in
  registers?

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MACHINE CYCLE
1. Fetched
2. Interpreted
INSTRUCTION
3. Executed
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What part of the CPU fetches, interprets, and
executes?
CPU
Fetch
Interpret
Control Unit
ALU
Execute
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RAM

• Random Access Memory

Storage Units
F A C T S
How does this work?
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RAM FACTS
Click to view facts.

• Holds data and instructions waiting for
  processing by the CPU
• Temporary storage
• Contents are deleted when power source removed.
• What is CACHE?

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CACHE

• Cache is fast accessing intermediate memory that
  holds the most needed data and instructions.
• It is smaller than RAM.
• Because it is smaller than RAM a search of cache
  is faster memory access.
• Therefore it is always searched first when
  available.

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CPU
CACHE
RAM
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smallest unit of storage binary digit 1 or a 0
BIT
8 bits
1,000 bytes
1,000,000 bytes
1,000,000,000 bytes
1,000,000,000,000 bytes
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SECONDARY STORAGE
Basic Facts
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All secondary storage has 2 parts

• A disk a platter which stores the
  data/inforamtion
• A drive mechanism which reads the disk
• NOTE a read/write head is part of the drive
  which sits over the disk and read the data

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A CRASH is when the read/write head touches the
disk and destroys data.
CRASH
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All Disks have two parts
SECTORS
TRACKS
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All Disks have two parts
This makes an Addressable Space.
Therefore, Disks are Randomly Accessible.
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Hard Drives

• Composed of several disks.
• Large, permanent storage.
• Not portable storage.
• Disks are magnetic.

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Floppy Drives

• Composed of one disk.
• Large, permanent storage.
• Portable storage.
• Disks are magnetic.

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CD Drives

• Composed of one disk.
• Very large, permanent storage.
• Portable storage.
• Disks work with light waves.

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Graphic Resources

• www.bedford.lib.nh.us/ Basics.htm
• members.iweb.net.au/pstorr/ pcbook/book2/memchips
  .htm
• www.aiyamicro.com/htm-1/computer-parts/
  computer-parts-n...
• webhome.idirect.com/jadams/ electronics/identify2
  .htm
• www.csd.uwo.ca/bitbybit/