Solid state
 

• They are accepted as exhibits in cases of litigation
• Can be used without a computer
• they are difficult to change without leaving any trace

The following are some of the possible definitions:

It is system software designed to help the users to analyse, configure, optimize, or maintain a computer

System software that helps maintain the proper and smooth functioning of a computer system

Examples include antivirus software, Disk clean-up tools, disk defragmenters, backup software, etc

Definition

• Disk formatting is the process of preparing a data storage media for initial use

Reasons:

• To make a disk blank for reuse
• To make it compatible with another operating system
• to create tracks and sectors for first time use

Refers to a small piece of software designed to update, fix, or improve a specific part of the operating system or an application.

NB: Patches are typically released by the software's developer or the operating system vendor to address security vulnerabilities, software bugs, or to add new features or enhancements

• Real time  E.g. turning the wheel must turn the car immediately
• On line - Otherwise system cannot be real time

• Sequential
• Random
• Serial
• Indexed-sequential

• Passive matrix create images by scanning the entire screen whereas active matrix displays are made using thin-film transistors technology(TFT)
• active matrix  display has a higher resolution compared to passive matrix
• Active matrix consume more energy than passive matrix

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)

Incremental:

• Only the changes need to be backed up
• The software/OS/settings are unlikely to have changed between backups
• Small number of files likely to be used/edited between backups
• Take less time to backup
• Each backup will take less memory space to store

Full:

• Backup all the data/files and software
• It might not take a significant time to back up entire system
• He might only have a small number of files to be backed up each time
• Safer as have more past versions to revert to
• User may have changed settings on computer
• Faster to restore the backup
• Needs to do a full before he can do an incremental

– multiple choice/yes-no answers
– easy to understand interface e.g. use of icons/drop down menus etc.
– output shown as % probabilities of fault

• Is where People are manipulated to divulge confidential information

– lightweight
– long battery life
– cool running processor
– touch pad
– internal webcam

• Data Integrity: they provide ways or mechanisms for enforcing data integrity constraints, such as referential integrity. If a record in the parent table is deleted, related records in the child table also get deleted. This ensures accurthe acy and consistency of data stored in the database
• Data Security
• Concurrency control
• Reduces data redundancy
• Data retrieval and querying
• Data indexing
• Data consistency and acid transaction
• Data backup and recovery
• Data sharing and collaboration
• Convenient data maintenance

• To get the latest features
• To update security features

Utility Software

(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

(a) Linear/Cascade/Waterfall

• a project is divided into stages or phases
• it is sequential, each stage needs to be completed before moving on
• clear goals are set for each stage

(b) Iterative Methodology

• effective in producing a working prototype in a short period of time
•  involves extensive user input and testing
• based on build – test – evaluate process, the philosophy is re-build until users are completely satisfied
• features user input throughout the process which enables ongoing, responsive changes to be made to the design.

(a) Cookies

• Information that a website stores about a user on their hard disk; this enables
  the website to remember details about the user when they next visit the website.

(b) Spyware

• Program installed on a PC to gather information about the user. It monitors
  every key press and relays the information back to the home base

(c) Phishing

• Sending an email that claims to be from a legitimate company; the recipient is then directed to a bogus website where their personal details will be collected

(d)Spam

• Junk/ (unsolicited) electronic mail advertising products and services sent to a general mailing list.

(e) Pharming

• Malicious code installed on a PC or on a server. This code directs users to a
  a fraudulent website without their knowledge.

Interviews

Advantages

• can gather specific information and additional information
• high response rate to questions
• The question can be rephrased to seek more clarification
• it is possible to win the confidence of the interviewee and get honest answers

Disadvantages

• time consuming
• responses to interview questions are subjective.
• the interviewee may not open up on some sensitive issues
•  

Questionnaire

Advantages

• easy to administer
• can be anonymous.

Disadvantages

• fixed (inflexible) design
• potential differences in understanding and interpretation.