• Network
• Commercial
• Enterprise
• Proprietary

(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

• Outsourcing is the practice of using third-party providers to perform services and/or create goods that would traditionally be done within the business.

• loss of jobs as some traditional shops/banks close
• lower profits for companies that do not get involved with e-commerce
• decline of leisure shopping as goods are bought on-line
• city centres becoming deserted as shops/banks close down
• gap between rich and poor widening as richer get savings from
• shopping on-line
• more people choosing to interact with computers rather than people
• increase in small businesses
• less pollution/travelling

 Control unit

• Single-mode fibre consists of a narrow core in which all light pulses travel at the same speed and arrive roughly at the same time at the destination.
• Supports higher bandwidth with less signal loss over a greater distance
• Multi-mode Multi-mode fibre consists of a larger core in which multiple light pulses can travel down the core.
• Supports a smaller bandwidth and signals attenuate at a shorter distance than single mode fibre.

• Repairing files
• Compression
• Defragmentation
• Back up
• Anti-virus / anti-spyware / anti-malware
• Firewall
• Managing application updates
• Format disks/drives
• System analysis tools

(a) Describe three effects this would have on the work force

• loss of jobs/unemployment
• deskilling
• need to re-train
• different jobs available/re-skilling
• no longer need to do hazardous/tedious jobs

(b) Give two advantages to the company of introducing robots

lower work force costs (no salaries to pay)

• lower environmental costs (less electricity for heating/lighting)
• higher throughput
• more consistent product
• robots don’t need breaks, holidays/work 24/7 etc.
• robots don’t take industrial action

(c) How could the robots be trained to assemble the televisions?

• tasks repeated by skilled worker and how each task is done is memorised
• tasks programmed directly into the computer/robot memor

(d) A whole batch of televisions was produced with some of the parts missing. How could this error have been avoided?

• if parts missing for a sequence, then a warning should be given and the assembly stopped
• several quality control stages to spot an error early on
• program in checks at each stage of assembly so robots can detect a fault immediately

• Security
• Installation cost
• bandwidth the medium can support
• Flexibility e.g wireless media
• Distance

• when designing a database a data dictionary provides the description and purpose of the fields/attributes of the database table(s). For example the field name (i.e. “phone number”), the data type (text); the size of the field (10) etc.

• Broadcast Radio
• Infrared
• Bluetooth
• Microwaves
• Satellite

 Data

Instructions

Optical Mark Recognition; Optical Character Recognition; Magnetic Ink Character Recognition ; Optical Bar Recognition

Giving answers as readers is also acceptable, that is, Optical Character Readers, Magnetic Ink Character Readers; Optical Mark Readers

• data shall only be used for the specific purpose for which it was collected
• data shall be adequate/relevant/not excessive
• data shall be accurate/up to date
• data shall not be kept any longer than necessary
• individuals have the right to see data about them (and have it changed if inaccurate)
• sufficient means taken for security/integrity of data
• data shall not be transferred to a country with lower protection laws
• data users must be registered

State the function of each of the following keys on the computer keyboard :  (2mks)

Backspace;

• Deletes characters to the left of the cursor

Insert

• Add characters at the cursor position
• Toggles between overtype and insert modes

An organization intends to replace an existing system by carrying out the process in stages .

Name the implementation strategy ;  (1mk)

• Phased change-over

Give two reasons why the  organization is opting to use the implementation strategy  in (a) above     (2mks)

• Gives employees time to learn
• Organizations can revert to the old system in case of failure
• Reduces resistance by the employees
• It is easier to find system errors as you are dealing with only one part at a time
• Accessing parts of the old system is still is possible in case of failure of the new system

A manager wishes to replace the current manual system with a computerized one. Describe three areas that must be evaluated to justify the replacement  (6 marks)

• Technical feasibility

• Does the current technology suffice

• Economic feasibility

• Benefits outweigh costs/ whether the project is cost effective

• Schedule feasibility

• Can it be done within the schedule

Headache, back and neck pain may result from the use of computers. State how each of them can be minimized                               (2mks)

• Proper lighting
• Regular breaks
• Use of antiglare
• Correct position of the screen
• Ergonomic furniture

Students of a school intended to elect their school Captain by secret ballot.  State three ways in which computers can be used to improve the election process                          (3mks)

• Registrations of voters
• Voter identification
• Actual voting
• Tallying

Explain why intranet is a more secure way to share files within an organization compared to internet (2mks)

• Intranet involves the interconnection of computers  within  the organization hence it is easier to monitor the access and sharing of files since the users in an organization can be assigned accounts and passwords which will enable to access files they are authorized to access unlike the internet where many can access what is stored in the organization’s website

List two career opportunities directly associated with computer networking               (2mks)

• Network administrators
• Network engineers
• Network technicians

Distinguish between a formula and a function as used in spreadsheets

• A formula is a mathematical expression that returns a value
• A function is an excel inbuilt formula that returns a value given a range of values or arguments

 The C directory of a computer has folders named Form 1, Form 2, Form 3 and Form 4. Each class has students’ folder named according to their admission number.  The student created their own folder for subjects they are studying based on the table below:

• Financial accounting
• Prediction and forecasting
• Inventory keeping
• Budgeting
• Keeping records

Data and instructions are fetched from main memory, from addresses requested by the CPU on the address bus. (Data and instructions are sent) using the data bus. (Data and instructions are then) decoded and executed in the CPU.
Results of operations are sent back to the memory on the data bus

• By use of an ergonomic keyboard
• She should take regular breaks from her computer and stretch her joints
• She should use standard furniture with an upright backrest to reduce strain on the back

17. a) i) Explain the term search as used in the Internet.                                            [2]

A web based application that locates items or information from the World Wide Web

ii) Peter intends to download a movie from the Internet. State the three factors that may determine the total time taken to complete the download.                                           [3]

• Size of the video/format
• The bandwidth of the media/speed of network/network traffic
• Type of browser software
• Background activities running in the computer
• Restrictions enforced in the computer/firewall/antivirus
• Speed of the computer/CPU speed
• Size of RAM

b) Wakulima online is an organization that runs a web based system for assisting farmers to obtain market for their produce. State four technological reasons that may cause a farmer not to access the organization’s system.                                                                                  [4]

• Poor network/lack of connection
• Software failure in the system

• Hardware failure
• Lack of access rights
• System overload/hanging
• Lack of skills/disability/illiteracy
• Lack of power supply

c) Explain a situation when each of the following Desktop Publishing program features may be used when creating a publication:

i. Cropping                                                                                                               [2]

Applies to graphics – used to trim/remove/hide some portions in the graphics

ii. Transparency                                                                                                         [2]

Used to make background of a graphic to be clear/visible

d. List two areas where infrared waves are used in data communication.                             [2]

18. a) List four activities of the planning stage of systems development.                             Ignore this question, marks redistributed elsewhere

b) Explain a circumstance when each of the following feasibility studies are carried out during systems development.

i. Technical                                                                                                               [3]

Done to determine whether technology exists to support the proposed solution

ii. Economic                                                                                                              [3]

Done to determine whether the proposed solution is economically viable

iii. Schedule                                                                                                               [3]

Done to determine whether the proposed system can be done within an acceptable time.

c) Table 1 and Table 2 are related tables in a database. Use them to answer the questions that follow.

Table 1

Table 2

i. Identify the appropriate primary key for each table.                    [2]

Table 1 – Dept code, Student Registration No

ii. Explain two benefits of enforcing referential integrity in the database. [4]

• No record can be added in Table 2 if its corresponding record in Table 1 does not exist
• No record in Table 1 can be deleted without first deleting the corresponding record in Table 2
• Reduces data redundancies/ensures integrity
• Prevents deletion of related table

19. a) Describe each of the following validation checks as used in data processing.

i. Preserve check                                                                                                      [2]

Ignore this question, marks redistributed elsewhere

ii. Data type check                                                                                                    [2]

Ensure correct type of data is entered for the field

iii. Check digit                                                                                                           [2]

This is a number added/calculated by the computer to a binary number. The check digit ensures correct transmission of the binary number.

b. Write each of the following abbreviations in full:

i) BCD                                                                                                                                    [1½]

Binary Coded Decimal

ii) EBCD                                                                                                                                 [

This question was thrown out and marks redistributed elsewhere

iii) ASCII                                                                                                                    [1½]

American Standard Code for Information Interchange

c) Using 10-bits binary number system, perform the following decimal operation using two’s complement.                                                                                                                                   [6]

12910 - 12810

+129 = 00 1000 0001

128 = 00 1000 0000

-128 = 11 0111 1111 (ones complement)

                            +1

          11 1000 0000 (Twos complement)

129- 128

     00 1000 0001

+ 11 1000 0000

 100 0000 0001

Hence = 00 0000 00012 or 12 (the overflow bit is ignored)

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