• camera film speed, position (end of film), distance, light
• washing machine amount of water, speed of wash/temperature/time
• fridge temperature, display panel
• air conditioning temperature, timing, display pane

(a) Identifying technologies that may be used in a proposed system

• System Analysis/Information gathering/Problem recognition

(b) Identifying the shortcomings of the old system

• Problem definition

(c) Prepares the software migration plan

• Implementation stage

• Continual decrease in computer size
• Improved speed and power of processing
• Decrease in computer physical size and its related facilities cost

• devices are automatically detected and configured when initially attached
• Impossible to connect device incorrectly/connector only fits one way
• has become the industry standard
• supports multiple data transmission speeds
• lots of support base for USB software developers
• supported by many operating systems
• backward compatible
• faster transmission compared to wireless

(i) Referential integrity

• Two entities that are related require that a foreign key must have a matching primary key

(ii) Entity integrity

• Entity integrity specifies that the Primary Keys on every instance of an entity must be kept, must be unique and must have values other than NULL

(b) Describe how data integrity can improve the process of database management. (2 marks)

• Data integrity is the maintenance of, and the assurance of, data accuracy and consistency over its entire life-cycle and is a critical aspect to the design, implementation, and usage of any system that stores, processes, or retrieves data
• The overall intent of any data integrity technique is the same: ensure data is recorded exactly as intended (such as a database correctly rejecting mutually exclusive possibilities)

• it is easier / quicker to read/write/understand
• it is easier / quicker to debug
• code is portable.

(a)

• Hardware required by each computer to connect to a network is a Network Interface Card / NIC / network adapter

(b)

• Computer A adds computer D’s address to packet
• Computer A sends packet to switch
• Switch looks at address on packet  Switch compares to stored list of addresses on network
• Switch forwards packet to computer D’s address

• A physical file contains the original data whereas a logical file does not contain any data
• A physical file contains one record format while a logical file can contain up to 32 record formats
• A physical file can exist without a logical file while a logical file cannot exist without a physical file

• Artificial intelligence
• Parallel processing
• Natural language processing
• quantum computing

Syntax
• An error that occurs when a command does not follow the expected syntax of the language, e.g. when a keyword is incorrectly spelt
• Incorrect: IF A ADN B Then
• Correct: IF A AND B Then

Logical
• An error that causes a program to output an incorrect answer (that does not necessarily crash the program)
• An algorithm that calculates a person’s age from their date of birth, but ends up giving negative numbers

Manages memory (RAM) 

• Allocates memory to programs currently executing •

Ensures programs/data do not corrupt each other: Ensures all programs and data including itself is stored in correct memory locations

Manages processes: Ensures different processes can utilise the CPU and do not interfere with each other or crash •

Allows a user to run programs : On a multi-tasking O/S ensure that all tasks appear to run simultaneously

• Allocates time slices 
• Scheduling of programs
• Handles interrupt
• Allows a user to configure hardware

(i) State the name of this protocol.   HTTPS 

(ii) Identify how this protocol changes the data to transmit the data securely.

• It encrypts it
• It applies encryption algorithm
• It applies an encryption key

• System software that analyses, configures, optimises and maintains a computer system

• Encrypt network traffic
• Use of Firewall(s)
•  Anti-virus software
• Password protect the database

Manages memory (RAM)

•  Allocates memory to programs currently executing 

Ensures programs/data do not corrupt each other

• Ensures all programs and data including itself is stored in correct memory locations

Manages processes

• Ensures different processes can utilise the CPU and do not interfere with each other or crash  

Allows the user to run programs 

• On a multitasking operating system, it ensures that all tasks appear to run simultaneously 

Other roles

• Allocates time slices
• Scheduling of programs
• Handles interrupts
• Allows the user to configure hardware

Any two from:

• Registers
• Clock
• CU
• ALU

• Editor: this allows a programmer to enter and edit source code
• Automatic formatting:  Correctly indents code
• Automatic colour coding:  Changes key words, literals and annotation to different colours
• Linker: this is a program which allows previously compiled code, from software libraries, to be linked together
• Loader: this is a program which loads previously compiled code into memory.
• Debugger: this is a program which helps locate, identify and rectify errors in a program
• Syntax error detection:  Highlighting syntax errors before code is translated
• Trace: this is a facility which displays the order in which the lines of a program are executed, and possibly the values of variables as the program is being run
• Break point: this is a facility which interrupts a program on a specific line of code, allowing the programmer to compare the values of variables against expected values.  The program code can then usually be executed one line at a time.  This is called single-stepping
• Variable watch: this is a facility which displays the current value of any variable.  The value can be 'watched' as the program code is single-stepped to see the effects of the code on the variable.  Alternatively a variable watch may be set, which will interrupt the program flow if the watched variable reaches a specified value
• Memory inspector: this is a facility which will display the contents of a section of memory
• Error diagnostics: these are used when a program fails to compile or to run.  Error messages are displayed to help the programmer diagnose what has gone wrong
• Emulator: will provide and emulator to run the code/app so no physical device required
• Context sensitive menu:  SDE suggests available options
• Statement completion:  SDE will complete a statement such as adding an ‘end if’ to an ‘if’ statement GUI creation:  Allows programmer to create a GUI by dragging and dropping controls (buttons, etc...) onto a form.
• Publisher: facility to package up and deploy program as an easy to install package

– faster communications now widely available
– safety reasons, e.g. increase in terrorist attacks on international flights
– reduced transportation/accommodation/hardware costs
– environmental issues, e.g. reduced carbon footprint
– increase in multinational working

• Because data is recorded to the disks once but can be accessed many times without changing the content
• once data is written to the disk, it becomes read-only and cannot be altered or erased.

SECTION A (40 MKS)

Answer all the questions in this section.

1. a) What is disk formatting?                                                        (1mk)

b) Indicate whether the following devices are used for input or output  (2mks)

i) Plotter

ii)Light pen

iii)Mouse

iv)Visual display unit

2.a)Explain why the following and give one reason why they are not allowed in a computer laboratory. (2mks)

b) For each of the following give one reason why they are not allowed in a computer laboratory.  (2mks)

i) Smoking

ii)Eating foods

3.Distinguish between Real, integer and Character data types as used in programming (3 mks)

4.The cells k3 to K10 of a worksheet contain remarks on student’s performance such as very good, good, fair and fail depending on the average mark.  Write a formula that can be used to count all students who have the remark “very good”      (3mks)

5.a) State the purpose of registers in a computer system               (1mk)

b)Name two multiprogramming operating systems                   (2 mks)

6.a) A series file comprises of records placed in positions 1 to 10.  State the position of the end of file marker.      (1mk)

  b)State the purpose of each of the following: (2mks)

 i)File server software

ii)Communication software

7.a) Name the control structure depicted by the flowchart below.                   (1 mk)

b)Explain the following terms as used in program implementation.      (2mks)

 i)Parallel running

 ii)Direct change over

8. Consider the linear arrays:

 i) AAA (5:50)

 ii)BBB (-5:10)

 iii)CC (18)

Find the number of elements in each array (3mks)

9.Define the term artificial intelligence  (2 mks)

10.Name two types of relationships that can be applied in database design  (2mks)

11.Explain binary Coded Decimal code of data representation (1 mk)

 a)Indenting

 b)Alignment

 c)Word wrap

12.Outline two ways in which a computer can be used in hotels               (2 Marks)

13.a)Explain Binary Coded Decimal code of data representation (1marks)

 b)Write the number 4110 in BCD notation (1 mk)

14.Arrange the following data units in ascending order of size.

   BYTE, FILE, BIT, NIBBlE     (2mks)

15.State two health issues that may result from prolonged use of computers     (2 mks)

SECTION B (60 MARKS)

16. a) State the stage of program development in which  (4 mk)

i) A flowchart would be drawn

 ii)The programmer would check whether the program does as required

 iii)The user guide would be written

iv)The requirements specifications would be written.

b)State the output of the following flow chart segment                  (1mk)

c) i)Draw a flowchart to compute the combined resistance ® of two resistors R1 and R2 in parallel using the formula;

                      (5mks)

ii)Write a program using Pascal or C languages for the flowchart in C (i) above. (5 ½ mks)

17. a)List three paragraph formatting activities in word processing  (3mks)

 b)Differentiate between bolding and highlighting text (2mks)

c) The following information shows the income and expenditure for “bebayote “ matatu for five days.  The income from Monday to Friday was Kshs. 4,000, 9,000, 10, 000, 15,000 and 12,000 respectively while the expenditure for the same period was Kshs.  2,000, 3,000, 7,000, 5,000 and 6,000 respectively

i)Draw a spreadsheet that would contain the information.  Indicate the rows as 1, 2, 3 …. And the columns as a, B, C    (4mks)

ii)State the expression that would be used to obtain:

 I Monday’s profit  (2mks)

 II Total income (2mks)

III)Highest expenditure (2mks)

18.a) Subtract 0112  from 10012 (1mk)

 b)Using two’s compliment, subtract 7 from 4 and give the answer in decimal notation (4mks)

c) Convert

i) 91B16  to octal    (3mks)

ii) 3768   to hexadecimal   (3mks)

iii) 9.62510 to binary  (4 mks)

19.a) Explain what the following DOS commands will do when executed.

    i)  A: \copy *.* B:    (2 mks)

   ii)   C: \> ERASE*. DOC   (2mks)

  iii)   b: \> Md EXAMS  (2mks)

 b)  i)  With the aid of a diagram, explain hierarchical (tree) network topology   (3mks)

  ii)List two advantages and two disadvantage of hierarchical network topology.  (4 mks)

   Advantages:-

   Disadvantages:

20. a)Name and explain the function of the keyboard keys represented by the following symbols.

  b) Simulation is one of the application areas of computers        

  i) What is meant by the term simulation      (1mk)

  ii)Name two application areas of simulation   (2 mks)

 iii) State three advantages of computer based simulation (3 mks)

 c) Explain three ways in which computers have impacted education (3mks)