• Commandline/ Character interface Operating systems
•  Menu Driven Operating Systems
•  Graphical User Interface Operating Systems

• RAID 10 is a combination of RAID 0 (zero) and RAID 1 (one)

Advantages

• Sharing of software and data files
• Sharing of hardware, e.g. printers
• Communication

Disadvantages

• Security of files is more of a problem

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

SECTION A (40 MKS)

Answer all the questions in this section in the spaces provided.

1.Describe the computer booting process.    (2 mks)

2. State the functions of the following keys on the computer keyboard   (2 mks)

  a) Backspace

  b)Insert (ins)

3. Jane has noticed the following problems with her computer keyboard    (2mks)

• It is taking a longer time to start-up;
• It is often hanging;
• Applications are taking longer to load.

 State three possible causes of these problems and how they can be solved (3mks)

4 a)Define authenticity as used in software selection  (1mk)

  b) List four ways of acquiring software in an organization     (2mks)

5 some of the storage disk available are:  zip disks, 3 ½ inch floppy disks, DVDs and 5 ¼ inch floppy disks. Arrange these devices in ascending order of storage capacity.    (2mks)

6.You have been asked to change your computer password. State a precaution you need to take in order to avoid each of the following:           

a) Forgetting the password     (1mk)

b) Hacking       (1mk)              

7.State four benefits of using a computer in a school library   (2 mks)

8. Using six bits, find the two’s complement of -2310.     (4 mks)

9. Explain data series, axis and legends as used in spreadsheet charts.  (3mks)

• Data

• Axis

• Legend                       

10. a) Describe the term data integrity.                                            (2 mks)

     b) State four situations in which data may lose integrity.           (2mks)

11.State the function of each of the following:

            a)Network interface card                                                           (1 mk)

            b)Network protocol                                                                    (1 mk)

           c)Hub                                                                                         (1mk)  

12. List four types of publications that can be designed by using desktop publishing software.   (2mks)

13. Differentiate between the following pair of terms as used in database design:

    a)  Input mask and design.                                                           (2 mks)

    b) Table and query                                                                      ( 2mks)

14. List four factors to be considered when purchasing an operating system.     (2mks)

15   Write an algorithm to compute the area of a triangle.   (2mks)

SECTION B (60 MARKS)

Answer question 16 and any other three questions from this section in the spaces provided

16. Study the flowchart below and answer the questions that follow

i) Name the control structures used in the flowchart                 (2mks)

ii) Determine the values of M, N, P and Q.                                ( 4 mks)

M………………………….. N………………………..

P ………………………….. Q ………………………

  iii) Write the pseudo code for the flowchart   (7mks)

 b)  List four functions of an assembler    (2 mks)

17. Define the following web related terms:       

 i)  Web browser   (1mk)

 ii)  Hyperlink      (1mk)

iii) Hypertext document                (1mk)

b)  List six activities performed on the web      (3mks)

c) An institution has ten stand alone computers

i)  Suggest with reasons the most appropriate topology required to inter-connect the computers.   (3mks)

ii) State the necessary steps required to connect the computers to the  internet.      (4mks)

d) Below is an email address:

Name the parts labeled:

                        i)

                        ii)

                        iii)

18.A computer C directory has folders for form 1, form 2, Form 3 and form 4.  Each class has student’s folders labeled according to their number.  The students create their own folder for the subject the are studying based on the table shown below

a)Assuming there is one student per class, draw the corresponding directory tree structure.  (6 mks)

b) i)  a form four student wants to create a folder to store her project. State the path for that project folder.(2 mks)

ii)Suggest how the student can ensure that:

                        1.         Work is not lost in case the hard disk fails.                (1mk)

                        2.         The project is not copied by other students.               (1mk)

c) i).  Other than I/O devices, list other three devices under the control of the operating system.                                                  (3mks)

 ii)Explain any one of the devices named in C (i) above            (1mk)

d)Define the term trouble shooting    (1mk)

19. A manager wishes to replace the current manual system with a computerized one

 a)Describe three main areas that must be evaluated to justify the  replacement   (6mks)

b) List the three areas that would be considered in the requirements specifications.      (3mks)

c)State and explain three ways that can be followed to replace the current system    (6mks)

20. a)  A head teacher keeps the following student details in a database:  Name, Address, Town, Date of Birth, Marks scored, Fees paid.

i)Name the most appropriate primary key. Give a reason      (2mks)

ii)For each item in the student’s details above, indicate its most appropriate data type as used in the database.           (3mks)

iii)Explain why input screens are better data entry designs than entering data directly to a table.        (2mks)

b)List two career opportunities associated with databases.       (2mks)

c)Distinguish between:

i) A table in a word-processing application and a table in a database application (2mks)

ii)Mouse pointer and insertion point.    (2mks)

d)Outline the steps to be followed in order to merge cells in a word processing table.    (2mks)

Advantages

• no wires
• fast/high-speed wireless Internet access
• WLAN is faster than a modem or mobile
• WLAN for working at home one day a week/teleworkers
• see internet content away on the move
• create and send multimedia messages to mobiles or e-mail
• picture messaging - send photos/pictures text/sound/recorded
• greetings from mobiles to mobiles/PCs
• instant transmission - no busy signals/no searching for phone jacks
• download e-mail and file attachments on mobile
• watch live webcast on mobile/hotspot
• listen to streaming video on mobile/hotspot
• news/weather/sport/games while on the move
• access information from mobile anytime
• send/receive/delete e-mail while on the move
• wireless Inbox on mobile - to contacts and calendar
• view business appointments while out of the office on mobile
• send corporate e-mail while out of the office - even behind a firewall on mobile
• wireless internet connection from chat rooms for discussions with colleagues while on the move
• give visual demonstrations from mobile and colleagues watch back at the office

 disadvantages e.g.

• WLAN speeds are slower than Net access at work/narrow band width
• any one within the WLAN nodes range with an appropriate device can use your WLAN and broad band link
• any one who walks past your house or WLAN linked into a corporate system can access sensitive information or credit card details
• 3G phones not compatible with 2G phones
• Blue tooth - has limited range
• blocked signal/distorted signal/weak signal/lag
• health problems from microwaves

(a) Pointer

•  A graphical object on a computer screen that responds to move movement and allows the computer user to select and execute commands in graphical user interface operating systems

(b) Desktop

• It Is a special folder in the file system that is displayed when no other windows are open

One to one  - Each record in the parent table has exactly one related record in the child table, and vice versa.

One to Many -  Each record in the parent table can have multiple related records in the child table, but each record in the child table is related to only one record in the parent table

Dual input of data

• Two inputs are compared by the system and any discrepancies are reported (and not stored.)
• Data input once, either printed out or checked on the screen and  errors corrected

 Rules are given to the processor

• Only accept A, B, C, D, E, F, G i.e Any other input rejected.

Drop-down list/radio buttons

• Provides only valid inputs, so no other validation is required

• the pain felt in muscles, nerves and tendons caused by repetitive movement and overuse.
• Injury as a result of repetitive use of parts of the body while performing work
• Strains and injuries due to prolonged typing and use of the mouse

Twisted pair cables

Coaxial cables

Fibre optic cables

• file deletion
• file copying
• file renaming
• file retrieval
• file closing
• file reading

(a) byte

• fixed number of bits, 8 bits
• represents a character

(b) compiler  program

• converts/changes/translates high-level language into machine code/machine language/low-level language/object code
• changes each high-level language instruction into machine code instructions
• produces an independent program capable of being executed by itself
• all (syntax errors) listed
• converts the whole program before execution/in one go
• converts source code to object code

(c) handshaking

• exchanging of signals to establish communication between two devices/computers e.g. printer and computer, modem and computer

(d) technical documentation

• documentation to ensure that the system can be maintained/updated/altered/developed/upgraded
• trouble shooting/correcting errors/correcting faults
• explanation of what the program does/how the system works
• contains file structures
• algorithms/flow charts/pseudo code
• program listings
• hierarchical chart

(e) simulation

• studying the behavior of a system by using a model/represents real-life/mathematical representation
  e.g. flight simulator (or others), hazardous applications results can be predicted

• The process of rewriting parts of a file to contiguous sectors on a disk

Direct Change-Over

• A date is chosen for the shutdown of the old system, then at that time, the old system
  is turned off and the new system is implemented

Phased

• Parts of the new system are implemented in stages or for a period of time, both the old and the new system are running together until all parts of the system are implemented.

• 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 

Modulation refers to the process of converting a digital signal to analog signal at the transmission end while demodulation is to converting analog signal to digital signal at the receiving end

• Any new or changed files since the last backup

Multimedia Capability - A laptop with strong multimedia capabilities is essential for a computer studies project submitted on CD-RW. This ensures that the laptop can efficiently handle multimedia content, providing a seamless experience in creating and presenting project materials.

Processor Speed - Opting for a laptop with a high processor speed is crucial. This feature enables the smooth execution of multiple applications simultaneously, enhancing overall project efficiency and reducing processing delays.

Hard Disk Capacity - Consider a laptop with ample hard disk capacity, as the Microsoft Office suite used in computer projects requires significant space for the installation and storage of project files. A spacious hard drive ensures that there is sufficient room for data and applications.

Main Memory Capacity - Given that students often work with multiple programs concurrently during a project, it's important to choose a laptop with an adequate main memory size. A smaller main memory may result in performance issues, hindering the seamless operation of various software applications during project development.

Explain the purpose of each of the following features of a spreadsheet chart (KCSE 2021, Q19 (a))

Legend

• Legends are a small visual representation of the chart's data series to understand each without confusion.

A data series

• is a row or column of numbers that are entered in a worksheet and plotted in your chart, such as a list of quarterly business profits
• A group of related data points or markers that are plotted in charts and graphs

Data Marker

• A symbol on the chart that represents a single value in the worksheet.
• A column, dot, pie slice, or another symbol in the chart representing a data value

https://www.lifewire.com/data-series-data-points-data-labels-3123411