Control Unit; Decodes instruction; Controls the fetching and writing of data;

Arithmetic Logic Unit/ ALU; Executes mathematical instructions;  Executes logical instructions; Compares values held in registers;

 Clock; Controls the number of instructions carried out each second;   allows the CPU to synchronize operations;

• Continually monitoring, evaluating and updating the system once it is operational. Activities include rectifying bugs, requesting changes, updating aspects, finding errors, maintaining code etc.

(a)

– webcam
– speakers
– microphone
– broadband modem

(b)

– use of CODEC (converts/compresses analogue data into digital data)
– echo cancellation s/ware (allows talking in real time/keeps everything in sync)
– compression s/ware for video/audio
– s/ware to access broadband/networking

• Ease of installation and use
• Application software intended for use in the computer
• Processor type. Some processors do not support all operating systems

• a computer that responds to requests to provide information and services over the Internet - an Internet server
• defines how messages are transmitted and formatted over the Internet-HTTP
• software that enables users to access/view documents and other resources on the Internet - Browser     
• numerical ID for each device on the Internet-IP address
• unique ID for a network interface card  -MAC address

Physical topology - the physical arrangement of nodes of a computer network

Examples

• bus topology
• ring topology
• mesh topology
• star topology

Logical topology- the way data flows in a network

Examples

• Ethernet
• Ring

• Protection against Password-related Vulnerabilities: Traditional password-based authentication methods are vulnerable to various risks, such as weak passwords, password sharing, or password theft.
• Stronger Access Control: Biometric readers add an additional layer of access control to laptops. Even if someone gains physical possession of the laptop, they would still need the authorized user's biometric data to unlock it and access the data. This helps prevent unauthorized individuals from accessing sensitive information stored on the laptop,
• Audit Trail and Accountability: Biometric authentication systems often come with built-in logging and auditing capabilities. This means that each time someone accesses the laptop using their biometric data, it can be recorded and associated with a specific user. This creates an audit trail, allowing organizations to track and monitor access to laptops and establish accountability in case of any security incidents or breaches.

• it is a format style that shows the listed items of different levels rather than at one level. Each level has a different indentation and numbering style

1. Chapter 1

     1.1. Introduction

                 1.1.1.Definition of terms

Define the term internet      1mk

• The global interconnection of computer networks for purpose of communication and resource sharing

Explain the term web page    1mk

• A hypertext  page prepared to display the content on the web

Explain the following internet address http://www.google.co.us in reference to the structure of a URL    3mks

• HTTP- hypertext transfer protocol or simply protocol
• WWW – subdomain
• google – the name of the computer with the web content/domain name
• .co – top level domain for commercial organization
• .us- a TLD extension for the country US

What is the world wide web                                       1mk

•  A virtual space on the internet that allows web pages and sites to be accessed

Define the term browser                                    1mk

•  A software that used viewing of web content

Explain the meaning of the word hyperlink     1mk

• A text or picture that is a link to another webpage on the internet

What is a search engine?     1mk

• Is a special program that collects and stores links to information websites allowing users to search its database for them
• A specialized web-based application that help the user to search for specific information on the internet.

Explain the meaning of the term internet service provider            1mk

• A company that offers internet services to end-users

Identify three elements apart from a computer that is required for one to be connected to the internet    3mk

• Modem
• Internet software
• Internet service provider
• Telecommunication lines
• TCP/IP protocols

Define the term modem 1mk

• Stands for modulator-demodulator
• A device that enables telecommunication to use telephone lines

What is a protocol? Write the following in full: TCP/IP, HTML, HTTP and FTP           5mks

• Protocols – are special communication rules that govern sending and receiving of messages by computers on a network
• Html – hypertext markup language
• Hypertext transfer protocol
• Transmission Control Protocol
• Internet Protocol
• File Transfer Protocol

What would you do if a website refused to load on the browser within the first attempt?   1mk

• Click the refresh button on the toolbar

 State three internet services                         3mks

• Instant messaging
• E-mails
• E-commerce
• Social media and networks
• E-learning

Define the term internet telephony      1mk

• Transmission of voice data over the internet

State three benefits of the internet in our society

• Provides a platform for conducting business and marketing
• Provides many platforms such as social media through which people can contact each other
• Cost saving
• Efficient communication

• Physical topology deals with the placement of nodes
• Logical topology deals with the data flow  in the network

• It has electrical components.
• It is programmable.

1.State two reasons for the increased use of laptop computers in government offices. [2]

They are small and fit in a small storage space

They are light weight hence can be carried to areas where their services are required

The monitor, system unit, keyboard units are integrated together

Easy to share

Have rechargeable battery

Have low power consumption

2.Computer network technicians prefer to use command-line based operating systems when configuring networks. State three reasons for the preference. [3]

Do not take up a lot of memory

Have direct access to most hardware devices/provide complete control during configuration

Cheaper to acquire as some are freeware/shareware

Faster to execute commands

Difficult to hack/more secure

More stable

3.State three measures that should be put in place in a computer laboratory to safeguard users’ health. [3]

• All power cables must be insulated and hidden from users
• Furniture used must be of standard
• Room should have adequate lighting
• No overcrowding
• Monitor should be fitted with anti glare
• Avoid dust
• Avoid slippery floor
• Avoid bright coloured walls
• Promote use of ergonomic devices

4.State three ways in which barcode readers may be used in schools. [3]

Take inventory of items

Transactions in the school library

Keep track of movement of goods

Track students in and out of school

Used to register roll call

5.State three advantages of flat panel monitors over cathode ray tube monitors as used in computers.                                                                                                                     [3]

• Compact and light/portable/less bulky/occupy less space
• Consume less power
• Low angle distortion
• Improved color depth
• Higher resolution
• Have less radiation
• Produce less heat

6.State three possible reasons for the extinction of daisy wheel printers in the market. [3]

• Slow
• Noisy
• Lack of graphic support
• Monochrome printer
• Supported on font type and size

7.State three ways in which an operating system secures a computer system.             [3]

• User authentication
• Secure user accounts with privileges
• Encryption of data
• Keeping log files
• Auto backup and auto recovery features
• Inbuilt antivirus

8.A law firm prefers to use hard copy output when handling documents for legal matters. State two reasons for this preference.                                                            [2]

• Can be used without electricity
• Can serve as physical evidence/exhibit
• Not easy to change content without leaving evidence
• No need of computer knowledge

9.State the function of each of the following feature in a word processor

a. Thesaurus                                                                                                                    [1]

Feature that suggests words with similar or opposite meanings to the selected word

b. Comments                                                                                                                   [1]

Feature that allows a user to attach remarks

10. With the aid of an example, explain the term multi-level list as used in word processing.                                                                                                                [3]

1. Chapter 10
   1. Summary
      1. xxxxxxxx

Formatting style that shows listed items at different level instead of using one line

11. Distinguish between real-time operating system and distributed operating system. [3]

Accept answers based on data processing concept

12. Explain the function of protect sheet feature in a spreadsheet program.                   [2]

A tool/feature that prevents unwanted changes to the spreadsheet. Requires a user to key in a password inorder to make changes

13. State four computer based careers introduced as a result of computerized data processing method at the airport.                                                                                     [2]

• System analysts
• Web designers
• Network administrators
• Network technicians
• Programmers
• Database Administrators

NB/ Accept any computer based career

14. In a spreadsheet, the formula = If(A1>10,A1*77,A1*50) is entered in a cell. Interpret the results.                                                                                                                        [3]

Checks the value in cell A1if it is more than 10, if the comparison is true then the outcome of the value in cell multiplied by 77 is displayed, else if it is false the results of the value in cell A1 multiplied by 50 are displayed.

15. State a stage in systems development cycle where each of the following activities are carried out:

a. Identifying the technologies that may be used in a proposed system.                       [1]

Accept any sub stage within system analysis e.g. requirement specification, problem definition, information gathering, etc

b. Identifying shortcomings of a system.                                                                       [1]

All stages of system development

c. Preparing the system migration plan.                                                                          [1]

Implementation stage

(a) Buffer

• temporary storage or memory which compensates for the difference speed of peripherals and the CPU

(b)batch processing

• processing doesn’t start until all data is collected
• JCL (any reference to Job Control Language)
• no need for user interaction
• processed all in one go
• done at “quiet” times
• e.g. billing, payroll, cheque processing

(c) e-commerce

• electronic commerce
• buying and selling products/services using the internet/computer networks

(d) simulation

• studying the behaviour of a system by using a model/mathematical representation
• results can be predicted
• e.g. flight (or other) simulator, modelling hazardous chemical process

(e) Email

• sending messages from one device to another using computer networks/Internet

• It sends control signals that manage the transfer of data and instructions within the CPU
• It decodes an instruction using an instruction set

Blackout: This is unexpected discontinuation of power supply in the laboratory.

Power sag: Sudden drop of voltage levels that lasts less than a second.

Transients/ surge: High voltage flowing.

Brownout: Partial blackout where there's low voltage flow.

SECTION A (40 MARKS)

ANSWER ALL THE QUESTIONS IN THIS SECTION

1.Compare the two types of diskettes used in microcomputers in terms of physical size and densities.    (2mks)

2.Why is it necessary to have a UPS in a computer laboratory?  (2mks)

3 a) Explain what is meant by batch processing   (1mk)

   b) Give one advantage and one disadvantage of batch processing ( 2mks)

4. List any four high level programming languages  (2mks)

5.A 3 by 4 matrix M is to be added to another 3 by 4 matrix array N so as to give a third 3 by 4 matrix array P.  Using a high level programming language, write a program segment that assigns the sum of M and N to P.(4mks)

6. The first column in the table below contains the formulae as stored into the cell F10 of a spreadsheet.  Enter the formulae, as they would appear when copied to the cell M20 of the same spreadsheet.  (3mks)

7.  Give three advantages of separating data from the applications that use the data in database design. (3mks)

8.  Explain the impact of information on organizations in each of the following areas:  (2mks)

   a) Competition

   b) Pace of growth

9. a) List any four tasks that an electronic spreadsheet should be able to perform other than calculations  (2mks)

    b) Explain what is meant by automatic recalculation as used in a spreadsheet.(1 mk)

10. Describe the functions of the following computer hardware components:

   a)Mouse                     (2 ½  mks)

   b)Scanner.                   (1 ½ mks)

11. a)State two differences between Disk Operating System (DOS) and WINDOWS operating system.

 b. i) Define the term application software  (1mk)

     ii) Give one example of application software (1mk)

12. a)  Give one difference between internal and external commands in Disk Operating System.   (2mks)

      b)  Name two DOS commands that may be used for checking disk errors.  (2mks)

13. Explain how a paragraph can be moved from one place to another in word-processing. 2mks)

14.  Define the term structured programming. (2mks)

SECTION B (60MKS)

Answer question 15 and any other three questions from this section.

15.a)  What is meant by each of the following terms:

 i)   pseudocode        (1 ½ mks)

  ii)  Flowchart           (1 ½ mks)

b) a program is required to list the first 1000 numbers in the series:  2, 4, 6, 8,

10. Draw a flowchart and write a program that can be carried out this task.   (12 mks)

16. The following car details are to be entered in a database; make, date-of-manufacture, colour and cost.

 a) Prepare a suitable database structure showing field names and their field types   (5mks)

 b) Explain how you index the data such that cars of the same make and colours are together   (2mks)

 c)  Write a statement that can be used to select cars of the colour green        (2 mks)

 d) Give an instruction that would;

  i)select cars whose cost lie between 500,000/= and 1,000,000/=  (3 mks)

 ii)Determine the average cost of all cars         (3mks)

17.  a)The diagram below represents the essential features o a computer system. Study the diagram and answer the questions that follow:

i)Name the components (4mks)

            A

            B

            C

            D

ii) On the diagram above, indicate the direction of data flow using arrows.  (3mks)

b) Name the three types of buses in a computer system (3mks)

c) Explain how CPU registers may be used to carry out a basic calculation such as:2 + 7 = 9

d) Name two computers output devices. (1 Mark)

18. a)State three ways in which computer technology may affect employment patterns in organizations   (3mks)

b) State three ways in which computer technology may affect employment patterns in organizations (3mks)

c)Suggest three strategies that can be employed to manage resistance to change  (3mks)

d) Give three advantages of computerization in an organization.  (3mks)

19. a)In a computer based information system, state the purpose of the following files and give one example where such a file may be required in a school.                (8mks)

i) report file

ii)Back-up file

iii)Reference file

iv) Sort file

b) State three precautions that should be taken to ensure that diskettes are well stored.  (3 mks)

c)  Distinguish between “serial” and Indexed sequential” file organization methods.  (2mks)

d)  Distinguish between binary and octal number systems and give an example of each  (2mks)

1. Enable resource sharing
2. Facilitate remote communication
3. Enable distributed processing
4. Provide better data security and management

1. Availability in the market
2. Initial and maintenance cost
3. User friendliness
4. Compatibility
5. User needs

• A compiler translates the whole program in one go whereas An interpreter translates each line of code (often an intermediate code) at run time
• A compiler produces an executable file that will run on the target hardware machine without the compiler being installed  A run time interpreter will be required at run time
• Compilers tend to be large complex programs Interpreters are smaller simpler programs
• Interpreted programs can be amended and run without translating whole program Compiled programs have to be re-compiled after a change
• Compilers compile programs that will usually only run on the target platform (hardware/operating system)  Interpreters will interpret same program (or intermediate code) on different (some virtual) platforms