• Realtime processing
• Batch processing
• Timesharing
• multiprogramming
• Online
• Batch
• Distributed

2.1.1 Explain the concept of open source in the context of FOSS. (2)

• Is a software whose source available and user can modify and redistribute

Give ONE example of a free operating system the company could install on a laptop. (1)

• Linux
• FreeBSD
• ReactOS
• Android
• ChromeOS
• OpenSolaris

2.1.3 State TWO disadvantages of using free open-source software.

• Lack of support
• Security risks
• Compatibility issues
• Hidden costs

• In a client-server network, every device is either a client or a server whereas in a peer-to-peer network each computer has equal responsibility and each has the ability to work as both a server and a client

20. a) The figure shows a network design. Use it to answer the questions that follow.

NB/ The diagram dor 20 (a)  is at the bottom

b. Explain the function of each of the following in the network

I     Router                                                                                                             [2]

- connects school LAN to the Internet/identifies the best route for data transmission/forwards data packets between a computer network and the Internet

II   Firewall                                                                                                                                  [2]

Hardware/software that filters unauthorized access to or from the school’s LAN

III  File Server                                                                                                                                [2]

Provides location for shared files/disk access/resources

c. State two categories of software that must be installed in a computer so that users can use it to access the Internet.                                                                                                                                  [2]

• Network operating system
• Browser e.g. I.E, Mozila, Google (accept examples)
• System drivers
• Protocol

d) State four ways in which computers may be used to manage data in a research environment.         [4]

The guiding principle is the candidate must mention the use and the technology to score

e.g.

1. Use of databases in data manipulation (Technology is database and the use is data manipulation)

2. Use of scanner to aid in data capturing

3. Use of Internet to communicate researched work

4. Use of printers to generate reports

5. Use of databases r hard disk to store data

etc etc

e) Some computer companies have opted to use the Internet to provide shared processing resources and online application services to users. State three advantages that this approach will have on their customers.                                                                                                                                 [3]

- The guiding principle is benefit/enhancement to the customer

• Customer will not be required to have powerful processing devices
• Customers can access services from anywhere
• There will be cost reduction for the customer
• Customers can collaborate with remote users
• Customers can access services at any time of the day
• Customers can upload/backup work in the cloud/Internet

(a) Defragmentation software   -   Reorganises files on a disk to improve efficiency

(b) Disk contents analysis/repair software - Scans a hard disk to identify bad sectors

(c) Disk formatter -  Prepares a hard disk for first use

• It is a feature used to prevent unwanted changes to be made on the data contained in a sheet by limiting the ability to make changes

Direct changeover – new system replaces existing system immediately/overnight

 Parallel running – new system runs alongside/together with existing system

Parallel running – there is always the old system to fall back on in the event of the new system failing/information is not lost/always a second copy

Direct changeover – if things go wrong lose all data/old system is not available

Direct changeover – training is more difficult to organise

Parallel running – training can be gradual Parallel running is more expensive to implement than direct changeover....

Direct changeover is a quicker method of implementation than parallel running

Direct Changeover: The old system is stopped completely, and the new system is started. All of the data that used to be input into the old system, now goes into the new one.

 Parallel Running: The new system is started, but the old system is kept running in parallel (side-by-side) for a while. All of the data that is input into the old system, is also input into the new one. Eventually, the old system will be stopped, but only when the new system has been proven to work.

• Radiowaves are omnidirectional while microwaves propagate in one direction at a time(unidirectional)
• Radiowaves can be propagated over long distances through sky mode while microwaves require a relay satellite to amplify and retransmit the microwaves signals to the receiver earth station

Number of cores
The number of cores a processor has directly affects the performance of the processor. Each core can perform its own fetch-execute cycle independently of others, so different applications can be allocated to different cores. Quad-core (four-core) and even octa-core (eight-core) processors are becoming common

Cache memory
A processor’s cache is a small portion of incredibly fast memory. It has read and write speeds far higher than hard disk drives and even SSDs. The cache is used to store frequently used information and reduces time wasted in fetching the same information from main memory time and time again

Clock speed
A processor’s clock speed relates to the frequency of the pulses generated by the system clock. The higher the frequency, the more cycles of the fetch-execute cycle can be completed in the same period of time.

Word length
A word is a group of bits that is treated as a single unit by a processor. Words can be used for representing both instructions and data. The length of a word is the number of bits that are assigned to it, with higher word lengths allowing for more bits to be transferred and manipulated as a single unit.

Address bus width
The width of a bus relates to the number wires that make up the bus. Increasing the width of the address bus increases the range of addresses that it can specify, hence increasing the computer’s amount of addressable memory. Adding a single wire doubles the number of addressable memory locations

Data bus width
Increasing the width of the data bus increases the volume of data that can be transferred over the bus at any one time. A wider data bus allows the processor to fetch more data from the main memory in one cycle of the fetch-execute cycle, reducing the number of cycles required to fetch large volumes of data.

• Implementation

c) Distinguish between a source program and a compiler as used in computer programming. [2]

Source program is the original program in a high level language as written by the programmer while a compiler is a program translator that converts source program to object code.

IMAP

• Retrieves/accesses/downloads (a copy of an) e-mail
• Allows synchronisation/management of account

SMTP:

• Sends/forwards/transmits e-mai

• Main memory is transitory/temporary/volatile, secondary storage is (semi-)permanent
• The processor can only use data/instructions that are in the main memory
• Main memory is directly accessible to the processor, secondary storage is not directly accessible to the processor 

Benefits

• The user is not restricted to the predetermined options//the GUI uses icons and set menus
• The user has more control over the computer settings//in GUI computer settings are protected from the user
• Uses less memory than GUI
• Requires less processing power for the interface
• More processing power is made available for the task

Drawbacks

• The commands used have to be learnt
• The commands used have to be remembered
• The commands used have to be typed in/entered exactly
• Have to remember the exact path/correct name of application
• More prone to errors on data entry Commands have to be typed in//in a GUI can use touchscreens/mice
• Tends to be used by specialist people//GUI is more user-friendly and can be used by non-experts

• The users may not have gained enough confidence to run the new system
• It may be very inconveniencing in case the new system fails or faces problems
• The weaknesses of the old system may not be corrected or may still be transferred to the new system

Prefixing an extra sign bit- A negative number is representes by prefixing a digit 1 to the number

Ones complement- This is flipping the binary equivalent of the number

Twos complement- this involves getting the ones complement and then adding a 1

(i) Incorrect use of language, e.g. PLINT instead of PRINT
(ii) A mistake in the structure of the solution, e.g. a jump goes to the wrong line
(iii) Inappropriate arithmetic is used, e.g. division by 0 is attempted

• Serial is the transmission of data one bit at a time/through one wire
• Parallel is the transmission of data more than one bit at a time/many wires
• Simplex is the transmission of data in one direction only
• Duplex is the transmission of data in both directions simultaneously

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)

a)  i)  Explain what is meant by the term volatile memory                                                            (1mark)

• Memory content is lost when the power is turned off

ii) What is normally stored in the non-volatile part of a computer’s main memory                       (1mark)

• The Computer’s BIOS

b) Explain why having cache memory can improve the performance of the CPU                         (2mks)

• Frequently used data/instructions are store in the cache; Meaning they don’t have to be fetched from the main memory;
• Data/instructions stored in the cache memory can be accessed faster (than data/instructions stored in the main memory) MAX 2