• Firmware is a software program permanently etched into a hardware device such as a keyboards, hard drive, BIOS, or video cards.
• Device drivers are operating system-specific and hardware-dependent. A device driver acts as a translator between the hardware device and the programs or operating systems that use it. 
• Firmware is a software that controls a system, and firmware's functionality ranges from performing basic tasks like minimal I/O controls to full-fledged software system running with simple or no OS, with scheduler, memory management, etc. 
• A driver, on the other hand, is usually part of the operating system that performs the specific task of controlling a hardware component like a display or USB controller, etc., and gives an interface to use the hardware by Operating system and applications.

(a) \(F C_{16}\)

(b) \(8 A_{16}\)

(c) \(93_{10}\)

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

• Real-time processing is where data is processed as it is received and the output is made available immediately to influence the ongoing activity
• Interactive processing is computer processing in which the user can modify the operations appropriately while observing results at critical steps

• more accurate/improved stock control/recording system/automatic
• reordering/automatic updating of stock file
• less staff/wages needed
• sales statistics now available
• faster throughput
• itemised receipt
• records every transaction
• records staff work rates
• less pilfering by staff/easier to identify pilfering
• less errors
• faster calculations
• links to EFTPOS

• More RAM will improve the performance of the computer 
• More RAM will speed up the access to data
• Excessive use of VM can cause disk thrashing which decreases performance
• VM is slower to access than RAM direct (because it has to go back to RAM first)
• Moving data between RAM and VM takes processor time

Open source : refers to software provided freely with its source code. The user can modify and redistribute the software.

Freeware: these are software that can be downloaded for free and distributed, buta  the source code is hidden and cannot be altered.

Shareware: is software that is available for free within a given trial period, after which it must be bought.

Proprietary: software made for commercial purposes. The source code is hidden, and it can only be used after paying for a licence.

• 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.

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

• Better/improved traffic flow control
• reduces accidents
• keeps delays to a minimum
• reduces pollution
• cars use less fuel

High level languages are used in situations when:

1. Speed of execution is not a critical factor, such as in office applications.
2. a programmer needs to use complex commands that perform complex tasks.
3. A programmer wants to make use of standardised library / sub routines.

Low level languages are used in situations when:

1. a program must execute quickly such as real time applications
2. a programmer needs to write code that interacts directly with the hardware, such as device drivers
3. a programmer needs to perform a specific command not available in a HL language.

Windows for example a word processing application and a spreadsheet
 
Menus, for example, allow the user to perform operations or run applications such as right-click to create a new folder  
 
Icons for example a picture of linked computers for networking
 
Pointers(mouse or touchscreen)  for example to select items/trigger events  
 
Shortcuts for example to frequently used applications for example having a shortcut to your mail client on your desktop
 
File navigation for example when searching the hard disc for a file/folder using a browser
 
copying / deleting / moving/sorting/naming/searching of files or folders for example copying of a file from the hard drive to a USB pen drive (File handling)
 
Desktop customisation for example changing the colours and background image
 
Copy and paste for example between applications e.g. copying a graph from a spreadsheet to a word processor
 
Error messages for example provide users with error/warning/help messages for example ‘printer out of paper’ 

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

16. a) With the aid of a flow chart, describe a loop control structure as used in programming. [4]  

A control structure that allows statement(s) to be repeatedly executed until a certain condition is met                                                                                                      2mks

NB. Accept any other looping construct

Network Failure - when the network becomes faulty or the network is down, users may not access network resources hence operations of an organization may be brought to a standstill

Security Issues:  A computer network can be accessed thus there is an increased chance of hacking

The rapid spread of viruses: Viruses can easily spread to terminals of a computer network which may be very expensive to clear

Cultural and moral effects: adult content may be shared in a networked environment which may be of negative impact on teenagers

• Allows creation and management of user accounts
• Helps in troubleshooting of the network
• controls access to network resources
• Provides communication services
• configures network resources
•  

• mirrored hard disk/hot standby/second computer
• re-run the old master file with the transaction file

A computer keyboard is an input device used to enter text, characters, and various commands into a computer or other digital devices.

• it generates and/or allocates an IP address

- (provides) user interface
– input/output control
– security
– handling interrupts
– spooling
– memory management
– processor management
– utilities (e.g. copy, save, delete, re-name, etc.)
– maintain user accounts
– load/run software
– error reporting/handling
– multiprogramming
– batch processing (JCL)/real time processing
– multitasking/multiuser/multi-access
– file management

• 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