• The user can access the source code  so, they can tailor the software to their needs and they can fix any bugs in it
• the source code could be studied for educational purposes
• The user can redistribute the software/program  but this must be done under the same terms as the original software

1. Virus scanning / Anti-virus. Used to locate and delete viruses / scans and compares files with databases of known viruses.
2. Firewall: checks data packets / examines source address / filters out unexpected packets.
3. Back up. Copies data onto a separate storage device for use if the original data is lost or corrupted.

(i) Crop - used when handling a graphic and there is a need to remove some of the portions in the graphic

(ii)Transparency - used when there is a need to make background of a graphic visible

• 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 

• Optical scanner is used read data by use a beam of light while a magnetic ink scanner is used to read data encoded/written using magnetic ink by magnetising the ink characters and translating them

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

• Thesaurus - Is a feature in a word processor that suggest words with the similar or opposite meaning to the one selected
• Comments: a feature in a word processor that allows a user to attach a remark about the selection

• Share peripherals/devices (e.g. printers, scanners)
• Communicate (e.g. email, instant messaging, play games)
• Share data (e.g. files/music/videos/backups on servers)
• Deploy/update applications
   
   

• Making prosthetic limbs for patients
• Making items which allow precise reconstructive surgery
• Making light-weight plane wings
• Making sculptures

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 employee
• 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

Domain integrity - ensures that all data in  a field contain valid values

• Real-time OS reads information from input devices and must respond within a short duration of time to ensure correct performance
• Distributed OS distributes computation among several physical processors which do not share memory or clock

give uninterrupted path through the system of linked traffic lights/
green link - wave
turn all lights to red
activate emergency generator
alarm

Any two from:

• Registers
• Clock
• CU
• ALU

Acme company needs to ensure that if they are reselling the drives they wipe the drive (this should be done regardless of the destruction of the drive) to the DoD standard.

• Disassemble the drive by pulling it apart the drive so that the data would not be accessed
• Destroy the metal disk either by drilling holes so it cannot be read
•  Encrypt drives with passwords that are not accessible
• Degaussing the hard drives
• Use specialized overwriting software

This would ensure that any software cannot be used to locate files.

• Standards specify a set of rules for hardware and/or software used in network communications. Because all manufacturers must adhere to the standards when manufacturing network hardware or software, it means that all devices should be able to communicate, regardless of manufacturer.

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

• 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

Trojan (horse); a program which misleads the user into thinking it is another
piece of software which, when run, executes another program;
Spyware; a program which records data such as usernames and passwords on
a host system and forwards the information to a third party;
Adware; code embedded or attached to program files which will persistently
show adverts (that attempt to generate revenue);
Worm; code which will run autonomously and replicates itself on a host system;
Ransomware; a program that encrypts a user’s data to make it unreadable until
they pay for the key;
Remote Access Tool (RAT); allows access to control and monitor a computer
from a remote network location;
Rootkit; malware that has managed to gain ‘root’ admin privileges;
Bots/Zombies; a program installed on a computer that performs a job for the
remote owner of the bot/zombie such as sending spam or sending web requests
to perform a DOS or attack a computer system;
Scareware; malware that tells you something is wrong with your system in an
attempt to get you to make a purchase;
Keylogger; a program that monitors/records a user’s keystrokes in order to steal
passwords/confidential details

Cloud computing refers to the delivery of on-demand computing resources over the internet. Instead of relying on a local server or personal computer, cloud computing allows users to access and utilize a wide range of computing services and resources hosted on remote servers.

• Sarah could keep all of her files in the cloud and easily access these with her devices. This way she does not have to keep different version on her desktop and laptop.
• Flexibility she could access the files from other devices such as the library etc.
• Disaster recovery if she accidently dropped or damaged a device – all files would be easy to access.