2. Software and Hardware Components of an Information System

Hardware

• Is the physical components that make up a computer system
• Items that you can touch such as the mouse, keyboard and monitor 

Software:

• Is the programming code required to run programme on the computer 
• This includes operating system, application software and utilities

• Is enabling one piece of hardware to work with another and enabling data to be transferred from one package to another 

If you have two different systems there might be incompatibility in the hardware and software this can have the following negative impacts 

• No communication between system 
• Miscommunication between the systems leading to incorrect data being passed
• New equipment having to be purchased 
• The cost of training staff
• Lack of technical support on the system 

Specialist software devices are software that has been written to assist a physically disabled user

Screen Reader:

•  A programme that reads out a computer display 
• The screen reader maybe outputting information in Braille, using voice output or audio signals  

Auditory Feedback:

• Plays sounds in response to user activity, for example noises for key presses, opening windows and menus and deleting files, this is useful as it confirms the action 

Screen Magnifier:  

•  A utility that can zoom in on points of the screen to make it easier to view information on computer monitors

Predictive Text:

• This suggests the required words as the letters are typed so the user does not have to type the whole word

Sticky Keys : 

• Useful for those people that find it difficult to hold down more than one key at time. Skticky keys allow a key to be pressed once and the system to act as if it was being continually pressed. It allows combinations the CTRL, ALT or shift keys, by pressing ponly one key at a time.

Types of Software

• Application software 
• User interfaces 
• Operating systems 
• Utilities 

Operating System:

• Controls the allocation and usage of hardware, resources such as memory, central processing unit time, hard disk space and peripheral devices
• Performs basic data management tasks such as recognising I put from the keyboard, sending output to the display screen and keeping track of files and directories on the hard disk 
• Without the operating system the computer will not function 

User Interfaces: 

• The user interface means by which the users can interact with the application or operating system 
• There are different types of user interfaces 
• Menu - An on screen list of options 
• Form - an on screen spsvd for you to select 
• Command Line - A space to type instructions 
• Natural Language - A voice based interface 

Utilities:

• Are small programs that assist in the monitoring and maintaining of the computer system

Examples 

• Printed monitoring software
• Virus checkers 
• File compression software 
• Disk clean up

Application Software: 

• These are programs that allow the computer to be used to solve particular takes for the end user

Examples 

• Word processors 
• Spreadsheets 
• Databases
• Communications 

Input Devices: Piece of hardware that gets information to a computer 

Keyboard:

• Ideal for inputting data on a system 
• Concept keyboards have been programmed to only accept certain instructions 
• Often using symbols with no text on 
• Popular at tills in fast food restaurants and bars where quick service is needed 
• Reduces error and is easy to use, so there's no need for extensive staff training 

Mouse:

• Is used to select items on screen 
• Needs a flat surface to work 
• Has at least two buttons that allows the user to click the item that they wish to select 
• In laptops a touchpad is used instead 

Scanner:

• Converts information into something a computer can understand 

Barcode Scanner:

• Reads the barcode and converts bars into numbers 
• Can read and converyt data in less than seconds 
• Useful when at a supermarket til
• Allows 100 of items to be scanned in the space of few minutes 

OMR (Optical Mark Reader)

• When information has been coded onto a magnetic ***** in a card this scanner reads the data and converts into information 
• Very quick and reduces errors
• Holds secure and sensitive data 
• Therefore it is snesoble to code the data and only make it readable by a magnetic card reader 

Flatbread Scanner:

• This type of scanner digitises an image so that it can be entered into a computer to be edited or used electronically

Magnetic Ink Character Recognition (MICR)

• Detects magnetic ink marks and converts them into numbers
• This method is used on cheques. The numbers at the bottom can be read by a magnetic ink character recognition scanner
• Reduces error as the scanner reads the printed number

Graphics Tablet

• A flat electronic area like a pad or sheet of paper with a stylus
• Allows the user to draw free hand like they would with a pen and paper and convert the image digitally so it can be edited or used on the computer 

Output devices are used to display the results of processing information on a computer

Monitors

• Used fpr displaying information on screen

Printer

Dot Matrix

• This type of printer is very old it can print a carbon copy of anything
• E.g. An invoice with copies on different coloured paper

Laser

• Uses toner to print the data onto paper and can produce high quality print outs very quickly
• Toner cartridges can be very expensive but usually last longer than inkjet cartridges

Inkjet

• This type of printer squirts ink onto the paper and is very cheap to run
• Mainly found in homes

Plotter

• Used tp [rint very large documents usually A1 or A2
• Used by architects or map makers

Several factors need to be considered when justifying the purchase and use of a printer

• Quantity - How much will be getting printed 
• Do you need a carbon copy
• where will the printer be installed

Storage Device - This is any device that stores data

Kilobyte (KB)

• 1024 bytes
• Floppy disk, memory pen

Megabyte (MB)

• 1024 KB
• Memory pen, CD, DVD

Gigabyte (GB)

• 1024 MB
• Memory pen
• CD
• DVD
• Hard Drive

Terabyte (TB)

• 1024 GB
• Memory Pen
• CD
• DVD
• Hard Drive
• Tape Drive

Floppy Disk

• Portable magnetic disk on which data and programs can be stored
• Storage capacity of 1.44 MB
• Used for transferring small files
• Less useful today because of their smaller storage capacities
• Many computers and laptops are now without any floppy drives

Hard Disks

• are the main storage devices for a computer and hold the data and programs
• Uses similar technology as floppy disks
• Has a far greater storage capacity 
• Comprises of a flat, circular, rigid plate with a flat surface that can be magnetised on one or both of thr sides and which data can be stored
• Disk is sealed in a case to prevent dirt entering and potentially crashing the drive read/write heads
• Can be internal or removable
• Portable hard drives are used for transferring large amounts of data between machines that are located further a part
• Used as external back up

Optical Disk

• CD-ROm (compact disk - read only memory)
• Similar to music CDs
• Storage capacity of about 700 MB
• CD-R are recordable
• CD-RW is rewritable
• CD-Rs are WORM (write once, read many) storage devices, once the data has been written on them it is fixed and cannot be removed
• CDS that you buy in shops have already been written
• You can buy blank CDRs and copy data
• CD-RWS can be written/erased/rewritten many times

DVD (Digital Versatile Disk)

• It has a storage capacity of 4.7GB 
• Come in recordable (DVD-R) and rewritalbe (DVD-RW) forms

Tape Drives

• Use cassettes to store data and have a high storage capacity
• Use for backing up large amounts of data

Memory Sticks

• Are a series of solid state drives
• Were originally developed for digital cameras but have found a market replacing the floppy disk
• Have a large storage capacity and come in a variety of different formats

Braille Keyboard

• A keyboard with braille dots on the keys

Microphone

• An input device for voice recognition

Loudspeaker

• An output device for hearing signals and text read out

Screen Magnifier

• A magnifying glass that fits on top of the screen and enlargens parts of it

Braille Printer

• A impact printer that can create braille on a page

Mouth Stick

• A stick for inputting controlled by the mouth

Puck **** Switch

• A tube placed in the mouth and blown/sucked through

Tongue Activated Joystick

• Placed in the mouth and manipulated with the tongue

Eye Typer

• A device that fits onto the muscles around the eye and when the eye is moved a pointer on the screen moves

Foot Mouse

• A mouse that is controlled by the foot

Command Based interface

• The user types instructions to control what the computer will do
• A good knowledge of the commands is needed and you can control the operating system directly
• MS-Docd is and example of command based interface

Forms

• Are limited areas on a screen that require data 
• Forms guide the user through typing in the required data
• Often look like paper based forms

Dialogue

• Makes use of forms and asks questions requiring a response before it will contine to the next part e.g. error messages

Menus

• Can be pop up or drop down
• Usually structured in a very logical way
• Often cascaded

Natural Language

• User communicates with the computer using their language
• E.g. Satellite navigation is a natural language because the user can say the destination and the machine will then locate and guide the user there using words not text

Natural Language

• User communicates with the computer using their language
• E.g. Satellite navigation is a natural language because the user can say the destination and the machine will then locate and guide the user there using words not text