Computing and the Web

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Computing and the Web

• Computer Hardware Components

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Overview

• Basic Concepts of Computer Hardware
• Input Devices
• Output Devices
• Connecting Devices
• Primary memory
• The Central Processing Unit
• Moving information within the computer
• Categories of computers
• Software applications Tools for maintaining your
  PC

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Basic Concepts of Computer Hardware

• The need to compute

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Basic Concepts of Computer Hardware

• The need to order information

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Basic Concepts of Computer Hardware

• The ability to store information

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Basic Concepts of Computer Hardware

• . . . And interface with humanity

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Basic Concepts of Computer Hardware

• Analog Computers . . . .

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Basic Concepts of Computer Hardware

• Digital Computers . . .

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Basic Concepts of Computer Hardware

• Super Computers . . .

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Basic Concepts of Computer Hardware

• von Neumann Computer
• Program data are stored in the same memory
• Single program counter one instruction at a time

• Input devices accept data and programs from the
  outside world
• Output devices provide results to the user
• Some devices are both input and output

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Basic Concepts of Computer Hardware

• Input devices
• Keyboard
• Mouse
• Touch pad
• Touch screen
• Light pen
• Microphone
• Scanner
• Digital camera

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Basic Concepts of Computer Hardware

• Output devices
• Display Monitor
• Hard drive
• Speakers
• Optical Disk
• Printers

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Basic Concepts of Computer Hardware

• Dual Mode (input output)
• Touch screen display
• Hard drive
• Optical Disk
• Network card
• Modem
• Zip / Jazz drive

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Connecting Devices

• Direct interface to motherboard
• Usually a card (NIC, Modem, Special Function)
• Usually require special software (driver)
• Connect via a port
• Port is a pathway for data to go in out of the
  computer from external devices
• External devices are usually referred to as a
  peripheral
• Different types of ports have different
  characteristics

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Connecting Devices

• Some of the ports
• Parallel
• Serial
• Video
• USB
• RJ-11
• RJ-45

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Connecting Devices

• Properties of ports
• Serial vs Parallel
• Daisy chain devices (USB or SCSI)
• Speed (10M / 100M / 1G)
• Buffer requirements / capacity

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Storing Data Information

• Three different types of storage
• Primary memory (RAM)
• Secondary storage (Hard drive)
• Tertiary storage (removable material ie CD)
• All storage has characteristics (properties)
• Size
• Speed
• Access method
• Volatility

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Storing Data Information

• Primary Storage usually called RAM
• Random access memory
• Electronic (no moving parts)
• Fastest type of storage
• Access time in the nanosecond range
• Direct access (can go directly to any location)
• Volatile form of storage
• Most expensive of the three types
• Special types of memory
• ROM (read only memory)
• Cache (high speed memory)
• PROM (programmable read only memory)

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Storing Data Information

• Secondary Storage usually hard drive
• Supports direct access at block / file level
• Electronic mechanical ( moving parts)
• Slower than RAM due to mechanical aspects
• Access time in the millisecond range
• Nonvolatile form of storage
• Much less expensive than RAM
• Usually significantly larger than RAM

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Storing Data Information

• Tertiary Storage usually removable
• More often than not it is sequential
• Electronic mechanical ( moving parts)
• Slower than hard drive due to mechanical aspects
  and removable media
• Nonvolatile form of storage
• Cheapest form of storage
• Used for archival storage, not frequently
  referenced, or extremely large data sets
• Good for backup purposes

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Storing Data Information

• Capacity
• 1 byte 8 bits
• 1K 1024 bytes
• 1M 1024 K 1,048,576 bytes
• 1G 1024 M 1,073,741,824 bytes
• 1T 1024 G 1,099,511,627,776 bytes
• Speed
• Millisecond one thousandth of a second
• Microsecond one millionth of a second one
  thousandth of a millisecond
• Nanosecond one billionth of a second one
  thousandth of a microsecond

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Storing Data Information

• Information Retrieval
• Random Access (direct) allows immediate access
  to stored data
• RAM / ROM (each location is directly accessible)
• Sequential Access requires accessing everything
  from the beginning of the file up to the item you
  want
• VHS video tape
• Pseudo-direct access can jump to designated
  starting points
• Audio CD can directly access starting point of
  each song, but must search within the song
  sequentially
• Type of retrieval and frequency of use will
  determine how the data should be stored

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Storing Data Information

• Characteristics of different types of storage
• RAM
• Access time access times ranging from 80ns to
  50ns
• Size PCs today can range from 256M to 1G
• Cost depends on density 256M 110 / 1G 375
• Hard drive
• Access time depends on speed 7200rpm -- 8.9ms
• Size 160 G
• Cost 110
• Removable Storage (Zip / Jazz) 250 M Zip
• Access time depends on interface 40ms seek /
  1.4Mbps xfer
• Size Unlimited
• Cost 130 cost of media (8 pack - 85)

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The Central Processing Unit

• Multiple components within the CPU
• ALU does arithmetic and logic
• Control manages all components
• Registers used to manipulate data
• Instruction Decode figures out what the
  instruction does
• Program Counter keeps track of next instruction
• Accumulator special register for arithmetic
• Buses interconnect components

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Moving information within the computer

• Data bus used to move data between components
• Address Bus used to specify memory location
• Control Bus used to synchronize / regulate
  components
• Data is moved around in bytes
• Data moves either serially or in parallel
• Serial data is sent one bit at a time ins
  sequence
• Parallel data is sent eight or more bits at a
  time
• Maximum size depends on width of the bus
• Pentium has a 32bit data bus
• The type of component determines the need for
  serial or parallel
• Keyboard mouse are serial
• Hard drive, CDrom, Printer are parallel
• Everything in CPU is parallel

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The CPU Cycle
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The CPU Cycle

• Fetch instructions from memory
• Decode instructions and fetch operands
• Execute the decoded instruction
• Service device interrupts
• Repeat cycle
• Cycle runs at the approximate clock speed of the
  CPU (more or less)

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Categories of computers

• Supercomputers ultimate in speed due to
  multiple instruction execution
• Mainframe business class computing
• Minicomputers multi-user system
• Workstations single user system
• Microcomputers contains microprocessor
• Palmtop Computers between palm micro
• Calculators limited functionality

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Tools for maintaining your PC

• Standard Windows tools
• Defragmentation tool
• Scan disk for error checking
• System Info
• 3rd party tools
• Norton disk doctor
• System Mechanic

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Relationship between Components

• Run Task Manager
• Examine I/O Memory parameters
• Run msinfo
• See what is taking up memory
• Run Defrag
• See what disk utilization looks like
• Performance Tuning aspects of Computers