by Mark Kelly - VCE Applied Computing, VCE Data Analytics, VCE Software Development

Write to Mark Kelly

Hardware and software

Roles of hardware and software components in information systems

STILL BEING REVISED 2022-04-26 @ 12:20 PM


Information Systems

Information System components:

  • Hardware
  • Software
  • Procedures
  • People
  • Data
  • Usually, "systems" are computers but they may be specialised e.g. railway ticket machines, Alexa devices, smart fridges.

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, Chrome web browser, Twitter app.
  • Software controls hardware’s behaviour


  • Input
  • Output
  • Processing
  • Storage
  • Communication


Input Hardware

Let users enter data into an information system


Keyboard, keypad

  • QWERTY layout. The standard keyboard layout.
  • Dvorak layout – supposedly more efficient, but very rare.

Various key technologies (e.g. mechanical, membrane)

Mouse, trackball

  • Designed for GUI (Graphical User Interface - pronounced 'gooey') OS (WIMP = windows, icons, menus, pointer)
  • RSI (repetitive strain injury) concerns - prolonged use can cause muscle / tendon strain and pain.
  • Trackball = stationary upside-down mouse. Not seen often these days, but they still exist
    • .Trackball



  • Finger-operated
  • Used when mice are impractical
  • Found on laptops

Bar code reader

  • Reads bar codes – converts them to numbers
  • Common in supermarkets, libraries, warehouses etc
  • Much faster and more accurate than hand-typing product codes
  • QR codes encode web addresses to avoid the pain of typing in long URLs.
  • QR code for this page on

Touch screen

  • Touch sensitive to taps (clicks) and drags
  • Used on tablet computers, phones, railway ticket machines etc
  • Easy for public to use
  • Can mimic any sort of interface: buttons are only images
  • Delicate (and stealable) keyboards and mice are not needed

Data tablet

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

Scanner, digital camera

  • Digitises analogue documents, photos, pictures
  • Scans page like a photocopier
  • Can 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). The higher the resolution, the more detail can be stored in a given area.


  • Usually for gaming

Voice recognition

  • Modern form of dictation
  • Requires complex programming to recognise voices accurately
  • Users sometimes need to train software to learn their accent
  • Not useful in noisy environments, e.g. offices
  • 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
  • Voice recognition software is rapidly improving in accuracy - assistants like Alexa, Google have quite good comprehension in 2022.


Output hardware

Output hardware displays the results of processing.


LCD monitors

  • LCD = Liquid Crystal Display
  • Thin, saves desk space
  • 'Black' pixels are often just muddy grey - unless using oLED with truly black backgrounds.
  • Sizes are increasing. Some would be wider than your desk.

Data Projectors

  • Very portable
  • Very large display
  • Will struggle to be seen vividly in brightly-lit rooms
  • Excellent for group presentations

data projector


  • Laser
  • Inkjet
  • Thermal
  • Dot matrix

Laser Printers

  • Black and white or colour
  • More expensive to buy, but cheaper to run than inkjet
  • Fast printing
  • Prints whole page at a time, not line by line like inkjet
  • Very high resolution (dots per inch)
  • Print is waterproof (unlike inkjet)
  • Same mechanicals as a photocopier
  • Colour laser printers are expensive to buy and operate
  • Use toner

Inkjet Printers

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

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
  • Not good for archive documents – the paper blackens over time
  • Often used for bar coding boxes, Point Of Sale (POS) terminals
  • Silent in operation
  • Any 'slimy' receipt you are given (e.g. at a supermarket or most point-of-sale terminals) is from a thermal printer

Dot matrix printers

  • Alias impact printer
  • In the print head are pins arranged in a matrix which shoot out to hit an inked ribbon which is pushed against the paper leaving dots on it.
  • Noisy! Slow! Low resolution. Expensive ribbons.
  • BUT... they are only printer type that strikes the paper so only they can produce duplicates with pressure-sensitive paper
  • E.g. supermarket receipts - two or three copies (white customer copy, yellow shop copy) in only one print operation
  • If the printer screams like a scalded cat, it's dot matrix.

dot matrix output

Above: typical dot matrix output at different resolutions.


Other output devices


  • For audio soundtracks and music for video
  • Give system alerts & information (e.g. beeps to acknowledge keypresses, noises to signal errors)

Indicators, LEDs

  • LED lights to show hard disk activity, “power on” etc
  • Watches (are usually LCD, visible only in ambient light unless a backlight is turned on)
  • Alarm clocks
  • Car dashboard instrumentation

Haptic feedback

  • The tactile buzz of a phone, meant to be felt rather than heard.


  • For printing very large illustrations, e.g. maps, blueprints


Processing Hardware

Converts data to information


  • Central Processing Unit
  • Most are CISC (Complex Instruction Set Computer)
    • Lots of inbuilt commands
  • Some are RISC (Reduced Instruction Set Computer) - e.g. ARM CPUs
    • Fewer inbuilt commands, simpler design
    • Smaller size, less power, cheaper to make, generate less heat
  • Many now have multiple cores – equivalent of multiple CPUs in one package
  • Speed measured in hertz (cycles per second)
    • The more the hertz, the more work gets done in a fixed time
    • Usually measured in gigahertz
  • Speed also can be measured in FLOPS
    • Floating Point Operations per Second
  • Benchmarks – standardised tests to measure CPU and whole-system performance.


  • Graphics Processor Unit
  • A video card’s processor – much more powerful than a CPU (often used by Bitcoin miners seeking maximum processing power)
  • Needs lots of processing power to process and shift huge quantities of data to the monitor (especially for gaming)
  • Needs power to process complex video data (especially for gaming)
  • GPUs are used to help the CPU do heavy processing (e.g. video conversion)

Storage hardware

Stores & retrieves data and software.

Hard Disk Drive (HDD)

  • Magnetic storage
  • Multiple aluminium platters stacked on a spindle
  • Average HDD platters are 3½” (inches) diameter
  • Laptop platters are 2½”
  • Read/write heads move across top and bottom of each platter
  • Disks spin at 5,400, 7,000 or 10,000 rpm - the faster they spin, the quicker they can seek and read/write data
  • Head floats on a cushion of air a couple of molecules above the platter
  • Very fast storage & retrieval
  • Very large capacity, e.g. 16 Terabytes = 16,000 GB (gigabytes). In 2022, an average movie is about 1GB
  • Very cheap per megabyte
  • Must be handled gently
  • Draw quite a lot of current, reducing battery life

Solid State Disk (SSD)

  • Permanent storage in Flash RAM
  • Rugged: No moving parts, so SSD drives are very portable, unaffected by knocks and bumps.
  • Use less electricity than HDD = longer battery life for laptops & less heat.
  • Fast - read/write speed is far greater than HDD
  • Expensive ($AU)
    • 128G SSD = $650 (2010) $235 (2011)
    • 1000G HDD = $77 (2011)
  • Low capacity - SSDs are small capacity compared to HDD.
    • In 2022, a 'large' SSD drive is 2TB (about $140 per TB). The largest commercially available HDD is 20TB (about $50 per TB)
    • Data centres still use HDDs for archiving and bulk storage, with SSD drives for rapid-response needs (e.g. website storage)
  • Mortal - SSDs have limited read/write lives. Eventually (and probably without warning), they will fail. HDDs will also fail, but usually they give out warnings.
  • Bit Rot - data stored on SDD fades over time and eventually becomes unreadable. HDD magnetic data also fades, but seems to take longer than SSD to become unreadable.

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
  • 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
  • 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


  • 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.
  • Aluminium layer embedded in a 5¼” polycarbonate plastic disc
  • Laser burns data digitally as pits
  • Data also read by laser beam
  • Continuous, spiral data track extends from innermost to the outermost track, covering the entire disc surface
  • 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
  • DVD media come in 3 types:
    • DVD-R
    • DVD+R
    • DVD-RAM
  • Also come in single/double layer versions
  • Most burners can write all 3 formats
  • Most players can play all 3 formats


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

Tape & Floppy Disk

  • Tape storage is still used by corporations - it's cheap for high capacities.
  • It's 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
  • DAT (Digital Audio Tape) commonly used for backup in corporate networks
  • Floppy disks – slow, low capacity, unreliable, expensive. EXTINCT. Oh, the days I dreamt of being able to afford a floppy disk drive. I had to use an audio cassette drive to save data. Sob.

Communication hardware


Sends and receives data within and between systems

  • Modem
    • Dialup (analogue)
    • ADSL
    • Cable internet

  • Cabling
    • CAT6
    • Fibre optic
    • (Coaxial – extinct except for broadband)
    • USB, Firewire
  • Wireless
    • 802.11 wifi radio
    • Microwave (corporate level only)
    • Infrared (extinct in PCs)

Communication hardware

  • Switches, hubs
  • Repeaters, bridges
  • Routers
  • Wireless Access Points
  • File Servers
  • Network Interface Cards
  • More details in the Networks-Hardware PPT.

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


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


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

  • Computer’s startup data stored in BIOS (Basic Input Output System) Flash RAM chips
  • Hard disk type
  • Amount of RAM
  • Operating preferences
  • Security password
  • etc


  • 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
    • Dynamic memory contents continuously leaking, so must be refreshed many times per second
  • ROM – Read Only Memory
  • contains control software that is burnt in the factory and never changes (e.g. a hard disk’s controller software)
  • ROM variants
    • PROM (Programmable ROM)
    • EPROM (Erasable Programmable ROM)

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
  • Has a private data pipeline to the CPU for greater speed
  • Expensive, powerful
  • Outputs:
    • VGA (analogue)
    • DVI (digital)
    • HDMI
  • Some cards have 2 VGA or DVI sockets to run two monitors
  • The operating system splits the display across both monitors

Expansion Cards

  • Plug into the computer’s 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)



Oldest – ISA and EISA

Newer – PCI

Newest – PCI Express


Older – AGP

Ports – where things plug in

Also may find:

  • PC Card (PCMCIA)
  • SD card slot
  • ESATA (high speed hard disk port)
  • HDMI (digitial video + audio)
  • DVI video
  • Firewire
  • 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!


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


System Software

OS - Operating system (for a workstation, PC, phone etc)

  • Provides services to allow software to run
  • Allocates memory to programs
  • Controls multitasking
  • Controls hard disks and storage
  • Commands the graphics card
  • Manages printing
  • Enables security
  • Negotiates with external hardware
  • Supports network and internet connectivity


  • Microsoft Windows
  • Linux
  • Mac OS
  • Android

NOS (for a file server)

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)
  • Issues IP addresses for internet access
  • Caches downloads
  • Manages printers
  • Does backups


  • Microsoft Windows Server
  • Apache (web server)

Application Software (apps)

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


  • Specialised software that extends the functionality of a system
  • Usually are single-purpose tools, e.g.
    • Windows Defrag
    • Notepad
    • DivX, MP3 player
    • Calculator
    • Character map


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This page was created on 2022-04-26 @ 11:30 AM
Last modified on Tuesday 26 April, 2022 14:59