Cardiff International School Dhaka (CISD)
Lost Class Make Up Assignment
Class: AS-6
Subject: Computing
th
Date: 8 (Sunday)-14th (Saturday) March 2015
Total Mark- 20
Instructions: All of your assignment must be done in A4 size paper. Mention your Name,
Class, Roll and Section clearly on the top sheet of your assignment.
Submission Deadline: Saturday 14th March 10.00 AM to the respective subject teacher. The
deadline is strict.
Name:.........................................................................................................................................................
Class: ................................Roll#........................Sec:..................Teacher: .............................................
Sunday-Saturday
8-14 March 2015
Lesson:
1.1 Components of a computer system and modes of use (Page 2-3)
1.2 1.2 System software (Page 4-13)
Task:
Read thoroughly the lessons mentioned above and then write down the answers of the
following questions on a separate sheet.
Worksheet/Exercise:
1.
2.
3.
4.
5.
State what is meant by the term hardware and software.
Describe the input, output and storage devices used in ATM.
Describe one batch processing and one real-time processing for banking system.
Write the differences between tailor made software and off the shelf software.
Explain the term integrated software, application package and generic software.
Text Book/Reference Book:
Cambridge International AS and A Level Computing Coursebook
Help Lines:
For any assistance, please contact
1. Coordinator:
Hafiz Mohammed Musa Khan, 01912334449, khanmusakhan@yahoo.com
2. Naznin Nahar Nishi, naznin_buet@yahoo.com, 04478882200
3. Principal Head of School: G.M.Nizam Uddin, +88-01622181818,
gmnu302@yahoo.com
Answer Keys:
Please do not see the answer keys before you do the work by yourself. Once you have done all
the work by yourself- you can match your answers with the answer options given below. In
some cases you answer might be different from what is given below but that might be correct
as well. The answer options given below for your understanding only. These answer keys are
the guidelines only, you may come out with different set of right answers in line with these
options
Hardware
Hardware is any part of the computer that you can physically touch, pick up, hold, move around the room
etc.
Examples of hardware include the monitor, mouse, hard disk, motherboard etc.
Software
Software are the applications and programming instructions needed to make the computer hardware do
useful work.
Some examples of systems software which tells the computer
what to do:
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Operating System
Utilities
User Interface
Some examples of application software which allow you to do your work:
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Word processors such as Microsoft Word
Spreadsheets such as Microsoft Excel
Databases such as Microsoft Access
Specialist applications.
Introduction to data processing
Most computer processing systems require some input from the user. The way this processing is to be
carried out is determined at the system design stage of the System Life Cycle.
This is called the 'processing mode'. The ones you need to understand are
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Batch mode
Interactive mode
Real Time mode
This mini-web will explain the differences between these modes and provide examples of their application.
Batch Processing
It is often not desirable to deal with a set of data inputs until a certain number have occurred or a set time
has passed. So they are stored until the system comes online to
process the data in one 'batch'.
For example
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A stock control programme may store records of every item sold in a shop that day. Then, at the end of each
day it calculates what needs to be ordered.
An online competition stores all the entries until it is time to find the winner.
Electricity, gas and telephone bills are usually calculated on a monthly basis.
Producing monthly bank statements to send out to customers
Payroll runs which may be weekly or monthly
After loading the data into the system, batch processing does not usually require any further interaction on
the part of the user. Therefore the user interface is often code-based. The user enters the parameters of the
batch run then leaves it to carry on.
Batch processing data sets
The advantage of batch processing is that it can be done during less-busy times on the computer or jobs can
be queued up in order to fairly share a computing resource such as a super-computer.
For example, a scientist may have data-logged a huge amount of data on an experiment - perhaps he is
working at the Large Hadron Collider in Switzerland and has Gigabytes of data to process. He submits the
data to the super-computer as a batch run. Once complete an output data set is available for further analysis
and visualization.
Batch processing print outs
This is probably the most common form of batch processing. Namely, an input data set results in a set of
printed documents.
For example, a payroll run results in a set of pay slips to be issued.
Disadvantage
The main disadvantage of batch processing is the time delay between collecting the input data and getting an
output. It can also be frustrating to find out only later that a batch run has failed due to a data input problem.
Interactive or Transactional processing
Inputs are noted by the computer, but it deals with them
after a short delay. It spends that delay handling other inputs
and managing data movements.
The delay may be so brief that it looks to you as if it has
happened straight away. But in terms of 'computer time',
where each computer cycle is far less than a millionth of a
second, it will have spent many cycles doing other things.
For example:
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Booking pop concert tickets
Ordering books online
Handling bank accounts
Booking a holiday
Interactive processing takes place one transaction at a time.
Once the transaction is accepted, the database will be updated. For example, if you use an online system to
book a hotel room, you will fill in a web form, submit it and it will come back to inform you of the room
you have booked.
The user interface is very important with interactive processing. It must be clear, intuitive, easy to use and
responsive. Usually a fair bit of data validation also takes place to ensure the correct input data is present.
For instance the form may check that you have entered an address or telephone number.
A graphical user interface is the most common type of interface for transactional or interactive processing.
Real time processing
Real time processing is usually found in systems that use computer control.
This processing method is used when it is essential that the input request is dealt with quickly enough so as
to be able to control an output properly. The is called the 'latency'.
For example, the computer inside the Engine Control Unit in a car has to manage the engine at every
moment based on what the driver wants to do.
Real time processing has to be programmed very carefully to ensure that no input events are missed.
Note that real-time processing does not have to be 'fast'.
For example, a traffic light system is a real-time system but it only needs to process data relatively slowly.
On the other hand, controlling a car engine has to deal with input events happening every thousandth of a
second so a very fast computer is needed to do this -but both the traffic-light and the car engine computers
are carrying out 'real-time' processing.
Examples:
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Traffic lights
Heart rate monitoring
Aircraft control
Computer games
Controlling robots
The user interface of a real-time system may use specialist input devices to provide data input.. For example,
a car driver will be providing input data to the onboard computer with throttle and brake pedals. A gamer
may be using a joystick or hand held control to interact with the real-time game. A traffic light system may
sense the car at the lights using a buried inductive loop.
Operating Systems
The operating system is part of the system software. All computers have an operating system, they cannot
function without one.
The operating system is a program that allows applications software to communicate with the hardware.
Examples of operating systems are Windows Vista, Windows XP, Unix, Linux and MacOS.
An operating system has many tasks. Here are just a few of them:
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Sorting out where to store data on disk drives
Dealing with security - user names and passwords
Organising files and folders
Managing data transfer from the CPU to the peripherals e.g. printer, monitor
Deals with saving, deleting, opening, closing files
Software Categories
There are two main categories of computer software that you need to know about. They are:
1. System software – the Operating System, utility programs and drivers
2. Application software – the everyday programs that you use such as Microsoft Office, graphics packages
and web browsers.
We will look at each of these categories in a bit more detail over the next few pages.
Bespoke (Tailor Made) Software
Although most organisations use general purpose software, some organisations will find that it just doesn’t
do exactly what they want or it doesn’t work with their current systems.
In this case, they might decide to have the software system they need designed and developed specifically
for them. This is called ‘tailor-made’ or ‘bespoke’ software.
The main advantages are:
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the company will get the exact software/system that they need
the software will work exactly how they want it to work
the software will only have the features that they specifically need in their business.
The main disadvantages of this approach are:
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it takes a long time to develop such a system, between a few months to years
it costs a great deal of money to develop such a system.
the company may need to employ a team of people such as business analysts, programmers, testers
etc
there will be little in the way of user support and online help
General Purpose Applications Software
A general purpose application, sometimes known as ‘off-the-shelf’ is the sort of software that you use at
home and school. Examples include word processors, spreadsheets, databases, desktop publishing packages,
graphics packages etc.
This type of software tries to be a ‘jack-of-all-trades’. It provides many features that the majority of users
will want e.g. formatting text, creating charts, organising tables. But it does try to be’ all things to all
people’ and so there will be a vast number of features that you may never use e.g. statistical functions, mail
merge. This makes the storage size of these applications fairly large.
There are several good reasons for using general purpose software:
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It is relatively cheap
It is easily available from most computer shops
It will have been thoroughly tested so there won’t be any serious problems or bugs
There will be lots of user support i.e. books, user guides, online help and discussion forums on the Internet
Examples of use:
Word processing application - writing reports, memos, letters to customers
Spreadsheet application - keeping simple company accounts, calculating employee commission payments,
simple stock control system, modelling
Database application - keeping customer records, sales records, appointments system
Desktop publishing application - creating leaflets, posters, business cards
Presentation software - creating presentations to show to customers or staff
Graphics application - manipulating images that can be used at home, school or a business
Web design application - creating personal or business websites
Applications software
A software application carries out tasks that the user is interested in doing such as writing a letter, creating
graphs, sending an email or downloading a webpage.
Software applications work through the operating system to gain access to the hardware.
Application software can be classified under three main categories:
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General purpose software
Specialist software
Tailor made or bespoke software