IT Applications Theory Slideshows

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IT Applications Theory Slideshows
IT Applications Theory Slideshows
Roles of hardware and software components
Roles of hardware and software components

• By Mark Kelly
• McKinnon Secondary College
• Vceit.com

By Mark Kelly McKinnon Secondary College Vceit.com
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Information Systems

• Information System components
• Hardware
• Software
• Procedures
• People
• Data
• Usually systems are computers
• May be specialised e.g. railway ticket machines

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Hardware? Software?

• Hardware is physical
• E.g. a monitor
• Can be touched, seen, picked up, kicked
• Hardware needs software to operate
• Software is programming instructions
• E.g. Adobe Photoshop
• Recorded as electronic binary signals
• Controls hardwares behaviour

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• HARDWARE

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Unofficial ICT Hardware Categories

• Input
• Output
• Processing
• Storage
• Communication

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Input Devices

• Let users enter data into an information system.
• Keyboard, keypad
• Mouse, touchpad
• Bar code reader
• Touch screen
• Data tablet
• Scanner, camera
• Voice recognition

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Input Devices

• Keyboard, keypad
• QWERTY layout. Designed to be as inefficient as
  possible to stop fast typists jamming the early
  typewriters
• Dvorak more efficient key layout puts most
  commonly used keys on the home row. Rare!

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Input Devices

• Mouse, trackball
• Designed for GUI OS
• Ball mouse superseded by optical
• RSI concerns
• Trackball stationary upside-down mouse
• Touchpad
• When mice are impractical
• On laptops

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Input Devices

• Bar code reader
• Reads bar codes converts them to numbers
• Common in supermarkets, libraries, parts
  warehouses etc
• Much faster and more accurate than hand-typing
  product codes

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Input Devices

• Touch screen
• Touch sensitive
• Tablet computers
• iPhone
• Railway ticket machines
• Information kiosks
• Bank ATMs
• Easy for public to use
• Can mimic any sort of interface buttons are only
  images

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Input Devices

• Data tablet
• Far better than a mouse for art
• Works like a pen
• Pressure-sensitive

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Input Devices

• Scanner, digital camera
• Digitises analogue documents or pictures
• Scans page like a photocopier
• Use OCR (Optical Character Recognition) to
  interpret and digitise printed text
• Resolution determines how detailed the resulting
  digital image is.

• 1200 dpi resolution 1200 dots per inch
  (2.54cm)

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Voicerecognition1

• Modern form of dictation
• Requires complex programming to recognise voices
  accurately
• Users need to train software to get used to their
  accent
• Not useful in noisy environments, e.g. offices

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Voicerecognition2

• Not good for sensitive material would be
  overheard!
• May be useful if hands-free data entry needed
• May be quicker data entry for poor typists

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Output devices 1

• Display the results of processing.
• Monitor
• CRT
• LCD, TFT
• Plasma
• Data projector

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CRT monitor

• Cathode Ray Tube
• Heavy, bulky
• Chews up desk space especially with big screens
• Generates heat
• Cheap
• Fast image refresh
• Very good blacks
• Vivid colour
• Nearly extinct now

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LCD monitors

• LCD Liquid Crystal Display
• Thin, saves desk space
• Lighter than CRT
• Less power consumption than CRT
• Getting cheaper
• Refresh rates getting better
• Blacks often just grey
• Colour richness not as good as CRT

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Plasma

• Very power-hungry
• Cheap for very large displays (e.g. gt40 inches)
• Better blacks than LCD
• Faster refresh than LCD
• Good for public notice boards

150 (375cm) plasma display
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Data Projector

• Very portable
• Very large display
• Struggles in brightly lit rooms
• Colours are often dull
• Excellent for group presentations
• Lamps fail with age

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Output devices 2

• Printer
• Laser
• Inkjet
• Thermal
• Dot matrix, Impact
• Speakers
• Indicators, LEDs

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Laser Printers 1

• Black and white or colour
• Expensive to buy, cheaper to run than inkjet
• Fast printing
• Prints whole page at a time, not line by line
  like inkjet

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Laser Printers 2

• Very high resolution (dots per inch)
• Print is waterproof (unlike inkjet)
• Same mechanicals as a photocopier

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Inkjet Printers

• Cheap to buy, very expensive to replace ink
• Line-by-line printing

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Thermal Printers

• Low power requirements
• Low to medium resolution
• Can be battery powered - good for portable
  printing e.g. parking tickets
• Uses heat-sensitive paper, usually on a roll

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Thermal Printers

• Not good for archive documents paper blackens
  over time
• Often used for bar coding boxes,Point Of Sale
  (POS) terminals

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Dot matrix printers

• Sometimes called impact printer
• In the print head are pins arranged in a matrix
• They shoot out to hit an inked ribbon which is
  pushed against the paper leaving dots on it
• Noisy!
• Slow!
• Low resolution!
• Expensive to replace ribbons
• but

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Dot matrix printers

• The only printer type that strikes the paper
• Only they can produce duplicates with
  pressure-sensitive paper (modern equivalent of
  carbon paper)
• E.g. supermarket receipts - two or three copies
  (white customer copy, yellow shop copy) in only
  one print operation

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Other output devices

• Speakers
• Can use sound to give system alerts information
• Needed for playing audiovisual multimedia
• Screen-recorded tutorials use voice-overs
• Indicators, LEDs
• Caps Lock, NumLock, hard disk activity, power
  on light etc
• Watches, digital clocks
• Car instrumentation

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Processing Hardware

• Converts data to information
• CPU
• RISC, CISC
• Multicore
• GPU

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CPU

• Central Processing Unit
• Most are CISC (Complex Instruction Set Computer)
• Lots of inbuilt commands
• Some are RISC (Reduced Instruction Set Computer)
• Fewer inbuilt commands
• Simpler design
• Smaller size, less power used, less heat
• Can be faster, cheaper than CISC

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CPU

• Many now have 2 or more cores equivalent of
  multiple CPUs for extra processing power
• Speed measured in hertz (cycles per second)
• The more the hertz, the more work gets done in a
  fixed time
• Usually measured in gigahertz
• 2 to 4 GHz common nowadays

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CPU

• Speed also can be measured in FLOPS
• Floating Point Operations per Second
• Benchmarks standardised tests to measure CPU
  and whole-system performance.

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GPU

• Graphics Processor Unit
• A video cards processor much more powerful
  than a CPU (300)
• Needs power to shift huge quantities of data to
  the monitor

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GPU

• Needs power to process complex video data
  (especially for gaming)
• Now being used to help the CPU do processing
• See nVidias Tesla a GPU PC! 120 times more
  powerfulthan a normal PC.

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Storage hardware

• Stores retrieves data and software.
• Hard disk
• Solid state disk
• Flash RAM, RAM, ROM
• CD, DVD
• Tape, floppy disk

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Hard Disk Drive

• HDD
• Magnetic storage
• Multiple aluminium platters stacked on a spindle
• Average HDD platters 3½ (inches)
• Laptop platters 2½
• MP3 players 1

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Hard Disks

• Read/write heads move across top and bottom of
  each platter
• Spin at 5400, 7000 or 10000 rpm
• Head floats on a cushion of air a couple of
  molecules distance from the platter

A hard disk drive head resting on the disk
platter.
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HDD

• Very fast storage retrieval
• Very large capacity - 1.5 Terabytes
• 1,500 gigabytes
• Very cheap per megabyte
• Must be handled gently
• Draw quite a lot of current, reducing battery life

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SolidStateDisk

• SSD
• Permanent storage in Flash RAM
• No moving parts rugged portable
• Draw less current than HDD longer battery life
• Speed a little better than HDD
• Expensive
• 128G SSD 650
• 320G HDD 175
• Small capacity compared to HDD

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USB Flash Drives

• NAND memory
• Normal RAM (Random Access Memory) loses its
  memory contents when power is turned off
• Normal ROM (Read Only Memory) has its contents
  burnt at the factory and they cannot be changed
  later

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USB Flash Drives

• Flash RAM can be rewritten like RAM but its
  contents are retained when power is lost.
• Completely replaced floppy disks
• Limited life 1 million read/write cycles
• 10 year data retention

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USB Flash drives

• Small, light, rugged (sealed, no moving parts)
• Cheap ones can be rather slow
• Typical capacity from 64M to 64G.
• Easily lost or left behind - possible security
  issues
• Some USB Flash drives can be encrypted

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CD, DVD

• Compact Disk capacity about 700M
• Digital Versatile Disk about 4.7G (4700M)
• Come in writeable and rewriteable forms
• Writeable (CD-R, DVD-R) can be burnt (written to)
  once only contents become permanent
• Rewriteable (CD-RW, DVD-RW) can be erased and
  re-burnt several times.

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CD, DVD

• Aluminium layer embedded in a 5¼ polycarbonate
  plastic disc
• Laser burns data digitally as pits
• Data also read by laser beam
• Continuous, spiral datatrack extends from
  innermost to the outermost track, covering the
  entire disc surface

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CD, DVD

• Sensitive to scratches, heat
• Immune to magnetic effects
• Not perpetual storage as originally believed.
• Disks degrade over time, become unreadable
• Gold disks seem to last longer

The laser lens in a CD drive
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DVD

• DVD media come in 3 types
• DVD-R
• DVDR
• DVD-RAM
• Also come in single/double layer versions
• Most burners can write all 3 formats
• Most players can play all 3 formats

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Blu-ray

• Uses blue laser rather than red
• Smaller beam can write more data in the same
  space
• Compare writing with a thick red crayon and a
  sharp blue pencil

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CD vs DVD
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Tape Floppy Disk

• Magnetic storage data can be damaged by
  magnetic fields data can fade over time until it
  becomes unreadable
• Read/write head rubs on the media surface
  eventually wear off the magnetic coating

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Tape Floppy Disk

• DAT (Digital Audio Tape) commonly used for backup
  in corporate networks
• Floppy disks slow, low capacity, unreliable,
  expensive. Never recommend them for anything but
  target practice

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Communication hardware

• Sends and receives data within and between
  systems
• Modem
• Dialup (analogue)
• ADSL
• Cable internet

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Communication hardware

• Cabling
• CAT6
• Fibre optic
• Coaxial
• USB, Firewire
• Wireless
• 802.11 wifi radio
• Microwave
• Infrared

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Communication hardware

• Switches, hubs
• Repeaters, bridges
• Routers
• Wireless Access Points
• File Servers
• Network Interface Cards

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Stuff in the box

• Case protects internal components. Needs good
  ventilation to prevent overheating
• Tower
• Desktop
• Laptop, notebook
• Power supply unit (PSU)
• Supplies voltage to the devices inside the case
• Fan to cool the case

PSU
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Stuff in the box

• The case (chassis)
• Motherboard
• Power supply
• Memory
• Graphics card
• Expansion slots
• Ports

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Motherboard

• Motherboard the main circuit board to which all
  the system components connect
• Slots for
• Memory
• CPU
• Expansion cards

Motherboard
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• Computers startup data stored in BIOS (Basic
  Input Output System) Flash RAM chips

• Hard disk type
• Amount of RAM
• Operating preferences
• Security password
• etc

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Memory

• RAM Random Access Memory
• holds running programs, current calculations,
  user preferences etc
• Average RAM now 1 to 4 gigabytes
• Comes in chips on a little circuit board
• Memory contents continuously leaking, so must be
  refreshed many times per second

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Memory

• ROM Read Only Memory
• contains control software that is burnt in the
  factory and never changes (e.g. a hard disks
  controller software)
• ROM variants
• PROM (Programmable ROM)
• EPROM (Erasable Programmable ROM)

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Graphics Card

• A.K.A. video card
• Sometimes built into motherboard
• Creates screen image data
• Has its own processor GPU more powerful than
  the main CPU

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Graphics Card

• Has a private data pipeline to the CPU for
  greater speed
• Expensive, powerful
• Outputs
• VGA (analogue)
• DVI (digital)
• HDMI

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Graphics card

• Some cards have 2 VGA or DVI sockets to run two
  monitors
• The operating system splits the display across
  both monitors!

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Expansion Cards

• Plug into the computers bus (data highway) and
  become part of the system
• Allow new or better components to be added
• Graphics
• Sound card
• Network card
• Specialist circuitry to control exotic
  peripherals (external equipment plugged into the
  system)

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Slots
GENERAL PURPOSE Oldest ISA and EISA Newer
PCI Newest PCI Express
VIDEO CARDS Older AGP
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Ports where things plug in

• Also may find
• PC Card
• SD Card
• ESATA (high speed hard disk port)
• HDMI
• DVI video
• Firewire
• Phone jack

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Ports

• USB (Universal Serial Bus) ports now replace many
  older single-purpose ports such as
• Keyboard
• Mouse
• Modem (serial port)
• Printer
• Especially on notebooks/netbooks where space for
  ports is very limited
• Low-powered USB devices can be powered by the
  port no power adaptor needed!

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• SOFTWARE

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Software categories

• System software
• Operating system
• Network operating system
• Application software
• Utilities

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System Software

• Operating system (OS)
• Provides services to allow software to run
• Allocates memory to programs
• Controls multitasking
• Controls hard disks and storage

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OS

• Commands the graphics card
• Manages printing
• Enables security
• Negotiates with external hardware
• Supports network and internet connectivity
• Microsoft Windows
• Linux
• Mac OS

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System Software

• Network Operating system (NOS)
• Runs on a file server
• Controls a network just as an OS controls a
  computer
• Manages logins and security
• Issues privileges to users (e.g. home directory,
  printer access)

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NOS

• Issues IP addresses for internet access
• Caches downloads
• Manages printers
• Does backups
• Microsoft Windows Server 2008
• Novell Netware

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Application Software

• Lets users get work done
• Designed to run on a particular OS
• Needs to be ported if its to run on other OSs.
• Examples
• Microsoft Office Word, Excel, Powerpoint etc
• Filemaker Pro database
• Adobe Photoshop

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Utilities

• Specialised software that extends the
  functionality of a system
• Usually are single-purpose tools, e.g.
• Windows Defrag
• Notepad
• Nero DVD burner
• DivX, MP3 player
• Calculator
• Character map
• XN View picture viewer and processor

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IT APPLICATIONS SLIDESHOWS

• By Mark Kelly
• McKinnon Secondary College
• vceit.com

These slideshows may be freely used, modified or
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