admin@kcseforecast.com

+2541026301456

Q&A-Computer Systems - Form 1 Revision Questions

What is a computer system ?

A computer system refers to computer components that collectively function as a single unit to achieve the desired goal. It can also be defined as a collection of hardware, software, and liveware that work together to receive, process, and manage data

The following are software classified according to the end user licence agreement. Briefly describe each of them:

open source software, freeware, shareware, and proprietary software

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.

 

Distinguish between an optical scanner and a magnetic ink scanner

  • 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

List four input devices used to capture data by way of scanning                 

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

 

Explain two computer hardware features that may be considered when selecting a laptop computer to be used in developing a KCSE computer studies project (4mks)

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.

 

A typical computer’s main memory consists of both volatile and non-volatile memory.

a)  i)  Explain what is meant by the term volatile memory                                                            (1mark)

  • Memory content is lost when the power is turned off

ii) What is normally stored in the non-volatile part of a computer’s main memory                       (1mark)

  • The Computer’s BIOS

b) Explain why having cache memory can improve the performance of the CPU                         (2mks)

  • Frequently used data/instructions are store in the cache; Meaning they don’t have to be fetched from the main memory;
  • Data/instructions stored in the cache memory can be accessed faster (than data/instructions stored in the main memory) MAX 2

State advantages and disadvantages of Solid State Drives and Hard Disk Drives

Advantages of  of Hard Disk Drive

  • Hard disk drives are cheaper per gigabyte than solid state drives.
  • Hard disks have a longer lifespan than solid state drives

Disadvantages of Hard Disk Drives

  • Consumes more power than SDD
  • They are noisy.
  • They are slower than solid state drives.
  • They are susceptible to wear and tear as they have movable parts.

Advantages of Solid State Drives

  • Are faster than HDDs
  • It is more durable as it does not have moving parts
  • Consumes less power
  • Are not noisy

Disadvantages of SDD

  • It costs more than a conventional hard disk
  • Have fewer write/erase cycles compared to a hard disk drive
  • Lost data cannot not be recovered

A company is developing a computer for use in schools.
(a) All computers have a CPU, memory and storage.
(i) Identify the type of physical storage that uses electronic circuits.

 

Solid state
 

(ii) State what ROM and RAM store.

 

ROM stores BIOS / bootstrap / start-up 

RAM stores currently executing programs and data

(iii) John von Neumann proposed the concept of a stored program.
   State the two items he proposed to store in main memory.

 Data

Instructions

(iv) Identify the part of the CPU that sends signals to the other components.

 

 Control unit

(a)State what is meant by the terms:

Parallel data transmission...................................................

Serial data transmission......................................................

(a)State what is meant by the terms:

Parallel data transmission

  • 8 bits/1 byte/multiple bits sent at a time  
  • using many/multiple/8 wires/lines

Serial data transmission

  • one bit sent at a time over a single wire

b) Give one benefit of each type of data transmission

Serial

  • -more accurate/fewer errors over a longer distance
  • -less expensive wiring  
  • less chance of data being skewed/out of synchronization/order

Give one application of each type of data transmission. Each application must be different

Parallel

  • sending data from a computer to a printer
  •  internal data transfer (buses)

Serial

  • connect a computer to a modem

Describe two benefits of using USB connections between a computer and a device.

  • devices are automatically detected and configured when initially attached
  • Impossible to connect device incorrectly/connector only fits one way
  • has become the industry standard
  • supports multiple data transmission speeds
  • lots of support base for USB software developers
  • supported by many operating systems
  • backward compatible
  • faster transmission compared to wireless

Describe each of the following storage devices

DVD - optical media which use one spiral track; red lasers are used to read and write data on the media surface; makes use of dual-layering technology to increase the storage capacity

ROM - non-volatile memory chip; contents of the chip cannot be altered; it is often used to store the start-up routines in a computer (e.g. the BIOS)

SSD/ Solid State Drive/memory (SSD)

non-volatile memory device that uses NAND flash memories (which consist of millions of transistors wired in series on single circuit boards)

Blue Ray -  optical media that uses blue laser technology to read and write data on the media surface; it uses a single 1.1 mm polycarbonate disc

Computer System Questions

  1. (a)State what is meant by the terms:

Parallel data transmission

 

  • 8 bits/1 byte/multiple bits sent at a time  
  1. using many/multiple/8 wires/lines

 

Serial data transmission

  • one bit sent at a time  
  • over a single wire

b) Give one benefit of each type of data transmission.

  • Parallel - faster rate of data transmission

Serial

  1. -more accurate/fewer errors over a longer distance
  2. -less expensive wiring  
  3. less chance of data being skewed/out of synchronization/order

Give one application of each type of data transmission. Each application must be different

Parallel

  • sending data from a computer to a printer
  •  internal data transfer (buses)

Serial

  • connect computer to a modem

State what is meant by the term USB

  • universal serial bus

Describe two benefits of using USB connections between a computer and a device.

  • -devices are automatically detected and configured when initially attached
    • Impossible to connect device incorrectly/connector only fits one way
    • has become the industry standard
    • supports multiple data transmission speeds
    • lots of support base for USB software developers
    • supported by many operating systems
    • backward compatible
    • faster transmission compared to wireless

 

 

 

DVD - optical media which use one spiral track; red lasers are used to read and write data on the media surface; makes use of dual-layering technology to increase the storage capacity

ROM - non-volatile memory chip; contents of the chip cannot be altered; it is often used to store the start-up routines in a computer (e.g. the BIOS)

SSD/ Solid State Drive/memory (SSD): a non-volatile memory device that uses NAND flash memories (which consist of millions of transistors wired in series on single circuit boards)

Blue Ray -  optical media that uses blue laser technology to read and write data on the media surface; it uses a single 1.1 mm polycarbonate disc

 

Viruses, pharming and phishing are all examples of potential Internet security issues.
Explain what is meant by each of these three terms
.

 

 

Virus

  • - program/software that replicates/copies itself
  • – can delete or alter files/data stored on a computer
  •  – can make the computer “crash”/run slow

Pharming - malicious code/software installed on a user’s hard drive/actual webserver

 – this code redirects users to a fake website (without their knowledge)

 – to obtain personal/financial information/data

Phishing - legitimate-looking emails sent to a user – as soon as the recipient opens/clicks on the link in the email/attachment,  the user is directed to a fake website (without their knowledge) – To obtain personal/financial information/data

 

control bus- this bus carries signals used to coordinate the computer’s activities

address bus - this uni-directional bus carries signals relating to memory addresses between processor and memory

data bus - this bi-directional bus is used to exchange data between processor, memory and input/output devices

 

The seven stages in a von Neumann fetch-execute cycle

  • the PC (program counter) contains the address of the next instruction to be fetched
  • the address contained in the PC (program counter) is copied to the MAR (memory address register) via the address bus
  • the instruction is then copied from the memory location contained in the MAR (memory address register) and is placed in the MDR (memory data register)
  • the entire instruction is then copied from the MDR (memory data register) and placed in the CIR (current instruction register)
  • the value in the PC (program counter) is then incremented so that it points to the next instruction to be fetched
  • the address part of the instruction is placed in the MAR (memory address register)
  • the instruction is finally decoded and is then executed

 

Modern LCD monitors and televisions use LED-backlit technology.
Give two advantages of using this new technology compared to the older cold cathode fluorescent lamp (CCFL) method

  • no need to warm up
  • – whiter tint/more vivid colours/brighter image
  • – higher resolution
  • – much thinner monitors possible/lighter weight
  • – more reliable technology/longer lasting
  • – uses much less power/more efficient

 

What is a utility software?

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

State advantages of hardcopy output

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

Differentiate between active matrix and passive matrix LCDs

 

  • 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

Explain how a magnetic hard disk drive (HDD) operates

  • A HDD can contain multiple platters (disks);
  • A disk/disks that move/spin
  • Each platter is divided into sectors;
  • The disks are spun at a very high speed (approximately 7,200 rpm to 10,000 + rpm);
  • Read\write heads (move across the disk to) read and write data;
  • There is one read\write head for each side of a platter ie two heads per platter;
  • Data is written to\read from the disk by magnetising\polarising\sensing microscopic regions on the disk;
  • Data is organised in concentric rings called tracks;
  • There is a small circuit board on the drive that controls the reading and writing of data;
  • Data is transferred from and to the disk via a cable/electrical current being passed;
  • The intersection of sectors and tracks are called blocks;
  • Data is read 1 block at a time

Describe one difference between system software and application software

  • System software manages the computer hardware/application software
  • application software is for end-user tasks

 Identify the type of software used to compress files.

Utility Software

Explain why solid state storage is the best choice for a fitness tracker.

  • Because it will be subject to movement  and it does not use mechanical/moving parts

          OR

  • Solid state storage is smaller/more compact so better suited for a wearable device

          OR

  • Doesn’t have moving parts  because they could be disrupted during use

Identify one component common to all computers.

  • Processor

 State two components of the CPU

Any two from:

  • Registers
  • Clock
  • CU
  • ALU

Describe how the CPU and main memory work together.

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

State two functions of utility software

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

Describe the function of the Cache memory

  • (Cache) Stores regularly accessed instructions/data
  • Reduces the need to access instructions/data from the main memory
  •  Makes up for the difference in speed of the CPU and main memory

Describe the principles of operation of  laser printers and describe how they are applied in real-life scenarios

  • A laser printer makes use of powdered ink and static electricity to print
  • Unlike inkjet printers which print line-by-line, laser printers print the whole page in one go

Steps

  • The data from the  file to be printed is sent to a printer driver
  • The printer driver checks that the data is in an understandable format
  • The printer driver checks if the printer is able to carry out the print job
  • The data is sent to the printer and is stored in a printer buffer
  • A printing drum in the printer is given a positve charge. A laser beam removes the positive charge in some areas. This leaves negatively charged areas which matches the characters/images to be printed
  •  

Explain the difference between the sequential and parallel computational models.

Any four of:
Sequential:
Individual instructions are executed one after another
Flow control is accomplished by jump/branch/goto instructions
Results are usually achieved less quickly than parallel processing (do
not award twice)
Parallel:
Individual instructions can be routed to different processors for
simultaneous execution
Results are usually achieved quicker than sequential instruction (do not
award twice)
Requires multi-core processors or multiple microprocessors
Tasks may be split into different parts with each part executed on a
different processor
Results need to be merged back together after completion

State the name of the storage space used by the operating system when there is insufficient RAM

  • virtual memory

Journalists are issued with laptops when they start working at a magazine publishing company. The company only uses free open-source software (FOSS).

  • 2.1.1 Explain the concept of open source in the context of FOSS. (2)
  • 2.1.2 Give ONE example of a free operating system the company could install on a laptop. (1)
  • 2.1.3 State TWO disadvantages of using free open-source software.

The laptops are equipped with either an HDD or an SSD.

  • 2.2.1 Users of laptops equipped with HDDs are advised to defragment the HDD regularly.
  • Briefly explain what defragmentation is. (2)
  • 2.2.2 Write out the abbreviation SSD in full. (1)
  • 2.2.3 Explain why an SSD accesses the data faster than an HDD.

The journalists can access their data remotely using virtualisation or Software
as a Service (SaaS).
2.3.1 Define the term virtualisation. (1)
2.3.2 Office365 is an example of SaaS.
(a) Except for remote data access, state TWO benefits of using
SaaS. (2)
(b) Describe how the license model of SaaS works. (2)

  • 2.4 The company takes precautionary measures to protect the magazine's data.
  • 2.4.1 An incremental backup strategy has been implemented to safeguard data. Explain how an incremental backup strategy works. (2)
  • 2.4.2 The company considers installing biometric readers on all the laptops. How would a biometric reader help safeguard the data on a laptop?

 

2.1.1 Explain the concept of open source in the context of FOSS. (2)

  • Is a software whose source available and user can modify and redistribute

Give ONE example of a free operating system the company could install on a laptop. (1)

  • Linux
  • FreeBSD
  • ReactOS
  • Android
  • ChromeOS
  • OpenSolaris

2.1.3 State TWO disadvantages of using free open-source software.

  • Lack of support
  • Security risks
  • Compatibility issues
  • Hidden costs

Identify four events that take place during the fetch-execute cycle

  • An instruction is retrieved from the memory
  • The instruction is decoded
  • The instruction is executed
  • the program counter is incremented

What is secondary storage?

  • A non-volatile store of data

Describe the difference between a barcode and A quick Response code (QR code)

  • A barcode is one-dimensional while a QR code is two dimensional
  • Barcodes are a set of vertical lines and QR code contains squares
  • QR codes can be read from any angle . Barcode is only above or below and lined up horizontally

Explain how an SSD stores data

Uses transistors( resistors and capacitors) . It can be implemented by the use of NAND or NOR gates. Data is stored on the chip as a charge

State the uses of 3D printers

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

Describe the role of the registers and system clock within the fetch-execute cycle.

  • Registers are small amounts of memory available that hold data fetched from memory or data waiting to be stored in memory. A temporary holding place for the instruction that has been fetched.
  • The system clock purpose is to determine the pace of the cycle, each tick of the clock a part of the fetch-execute cycle occurs. Regulates the timing and speed of a computers systems functions.

Identify which processor in the PC systems below is likely to process instructions more efficiently. Justify your answer.

  • Processor X: Intel® Core™ i7 processor (3.8 - 5.0 GHz, quad core)
  • Processor Y: Intel® Core™ i5 (2.9 - 4.7GHz, dual core)

  • Processor X is likely to process instructions more efficiently as firstly it has the i7 CPU which is a faster processor as well as the quad core which processes quicker and the higher GHz versus Processor Y

What is a backup?

A backup is a copy of data that can be used if the original data is lost.


(i) Give three advantages and disadvantages of using a touch-sensitive interface.

Advantages

  •  A touch screen is very intuitive
  • Easy to use as the user simply touches what they see on the display
  • Save space as no keyboard or mouse is required.
  • Touch monitors can even be mounted on the wall.
  • Touching a visual display of choices requires little thinking and is a form of direct manipulation that is easy to learn.
  • Touch screens are the fastest pointing devices.
  • Touch screens have easier hand-eye coordination than mice or keyboards.
  • No extra workspace is required as with other pointing devices.
  • Touch screens are durable in public access and in high volume usage

Disadvantages

  • Difficult for people with accessibility issues, e.g no feedback, disability
  • Can be easily damaged/scratched
  • Damaged/scratched screen prevent the interface from functioning as it should
  • Dirty screens difficult to read
  • Users must be within arm’s reach of the display
  • It is difficult to select small items
  • User's hand may obscure the screen
  • Screens need to be installed at a lower position and tilted to reduce arm fatigue
  • Some reduction in image brightness may occur
  • They cost more than alternative devices

Explain the Fetch – Execute cycle and provide an example of a Central Processing Unit (CPU) component for each stage of the cycle

The Fetch – Execute cycle is a sequence of actions, performed by the processor as it fetches
a program instruction from its memory, determines what the instruction wants to do and
carries out those actions. The stages of the cycle are provided below.

  • Fetch the instruction – the processor fetches the instruction from a memory address stored in a program counter and transfers the instruction, via a data bus, to an instruction register. At the end of the fetch operation, the counter points to the next instruction that will be read in the next cycle.
  • Decode the instruction – the processor decodes the instruction stored in the instruction register, including getting any operands required to complete the instruction.
  • Execute the instruction – the decoded instruction is executed.
  • Store the result – the result generated by the execute phase is stored in the main memory, and/or sent to an output device. The program counter is updated with feedback from the arithmetic logic unit (ALU), to a different address from which the next instruction will be fetched.

Define an end user license agreement (EULA).

  • An end user license agreement (EULA) describes a contract (agreement) between a software developer and a user of that software.
     

List three other types of software license.

  • Network
  • Commercial
  • Enterprise
  • Proprietary

State one ethical responsibility of software users

  • Users need to ensure that their software is licensed

State advantages of solid state storage media

  • Portable
  • Light
  • Faster access speed
  • No moving parts
  • Efficient power consumption
  • Durable
  • Small physical size
  • Large storage capacity

Distinguish between Incremental and Full backup


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

Describe the purpose of two registers that are used by Von Neumann architecture.

MAR( memory address register)

  • Stores the address/location where data will be read/written/accessed/fetched
  • stores address/location of data/instruction being processed
  • stores address/location of data/instruction next to be processed

MDR or  memory data register

  • Stores the data/instruction that is fetched/read from memory
  • stores the data that is to be written to memory
  • stores the data/instruction from the address in the MAR
  • stores data/instruction next to be processed

 Program counter

  • Stores the address/location of the next instruction to be run
  • stores the address/location of the current instruction being run

Accumulator

  • Stores the result of manipulation/process/calculation

Explain why it is not always true that a computer which has  a quad-core processor runs twice as fast as a computer with a dual-core processor

 

  • Software may be designed to run on 1 core and not multiple cores
  • depends on the task(s)  i.e some tasks cannot be split across cores
  • Clock speed also affects speed i.e dual core may have a faster clock speed and quad-core may have slower clock speed so one task may be run faster/slower
  • RAM size also affects speed i.e Quad-core may have less RAM  amount of VM being used
  • Cache size also affects speed i.e Quad-core may have less cache

Describe what is meant by a clock speed of 3.8 GHz.

  • The number of FDE cycles run per given time/second
  • the frequency that the clock ‘ticks’
  • 3.8 billion cycles/instructions per second

Explain how virtual memory can compensate for the limited  RAM capacity in a computer.

  • VM is used when RAM is full  i.e part of the secondary storage used as (temporary) RAM/VM
  • Data from RAM is moved to the secondary storage/VM (to make space in RAM)
  • RAM can then be filled with new data
  • When data in VM is needed it is moved back to RAM

Explain why it is beneficial to get more RAM instead of relying on virtual memory.

  • 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

Describe the purpose of the control unit (CU) within this computer.

  • It sends control signals that manage the transfer of data and instructions within the CPU
  • It decodes an instruction using an instruction set

A computer is upgraded to a dual-core CPU.
Explain how the upgrade can affect the performance of the computer.

  • It can now process two instructions simultaneously (where suitable) increasing the performance.

 

Explain the following terms

(a) Disk mirroring

(b) Encryption

(c) Backup

(a) Disk mirroring- Data is written on two or more disks simultaneously.

(b) Encryption - Contents are scrambled so they cannot be understood without a decryption key

(c) Backup - A copy of the data is taken and stored in another location

State the functions of the following registers

Program counter // PC
Stores the address of the next instruction to be fetched
Memory address register // MAR
Stores the address where data/instruction is to be read from or saved to
Memory data register // MDR
Stores data that is about to be written to memory // Stores data that has just been read from memory
Current instruction register // CIR
Stores the instruction that is currently being decoded/executed

State the functions of the following utility programs

(a) Defragmentation software

(b) Disk contents analysis/repair software

(c) Disk formatter

(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

Distinguish between firmware and device drivers as used in computers.                  (2mrks)

  • 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. 
  • 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.

Mention at least two trends in the technological revolution of computers.

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

Explain one benefit to a user if the program is distributed as free software

  • 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

Describe what is meant by shareware.

 the trial version of software for a limited time/number of uses with limited features  free of charge

If a full version is required need to pay a fee/sign up

When the trial is over user is asked to pay/sign up

Protected by copyright

Type of software licence
 

Distinguish between operating system software and an application software

  • OS controls operation of system/hardware
  • Applications software allows the system to do something useful

State three utility programs associated with the use of a hard drive. Explain the purpose of each the program

  • File handling - Copy/move/delete
  • Anti-virus software - To protect files from attack by a virus
  • Defragmentation - To keep files sensibly arranged on the hard drive
  • Format - To divide the surface of a drive into smaller areas to aid storage

A computer game involves driving a racing car around a track. State which two modes of data processing  would be appropriate, justifying your answers

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

Describe two methods used to assist in finding program errors.

  • Use of debugging utilities
  • Use of test data
  • Dry run / Desk checking

Explain the difference between main memory and secondary storage.

  • 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 

Name one item used in the home, other than a computer, that contains a microprocessor.

  • camera
  • microwave
  • washing machine
  • video recorder
  • fridge
  • sewing machine
  • air conditioning
  • games console
  • electronic game electronic toys
  • rice cooker
  • dish washer
  • TV
  • alarm clock
  • radio

For your item named in (a) describe two different tasks that the microprocessor performs.

  • camera film speed, position (end of film), distance, light
  • washing machine amount of water, speed of wash/temperature/time
  • fridge temperature, display panel
  • air conditioning temperature, timing, display pane

A family has purchased a computer system with the following specification:

Processor speed 2200 MHz
RAM 512 Megabyte
Hard disk drive 120 Gigabytes
CD ROM
DVD writer
Modem 56k
Monitor 17"

(a) The computer has been purchased for buying goods and services over the Internet. Explain how each of these items of hardware would be used for this purpose.

Hard disk drive

RAM

DVD writer
Modem

Hard disk drive

  • to hold the operating system/communication and applications software/ISP software
  • for storing files/information/cookies on backing store

RAM

  • for data, computer programs and operating instructions which are moved into it/downloaded for data currently in use

DVD writer

  • Films/videos/pictures/music/multimedia data downloaded/purchased

Modem

  • link/dial up/establish communication with the Internet
  • Convert digital signals to analogue/audio tones (and vice versa) Which can travel across the telephone system

Describe two desirable features to look for in a laptop rather than a desktop computer.

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

She lost all her photographs when her computer crashed.
(i) What is meant by the term crashed?
(ii) How could she have avoided losing all her photographs?

  • the computer appears to “freeze”/”hang”
  • computer won’t respond
  • failure of hardware (stops computer normal functioning)
  • failure of software (stops computer normal functioning)

State  the advantages and Disadvantages of GUI

Advantages

  • It is intuitive
  • Easy to navigate
  • Uses menus, pointers and icons thus easy to learn and use
  • It lets the user exchange data between different software applications
  • The user does not have to learn complicated commands

Disadvantages

  • Takes a lot of memory
  • A lot of processor power is needed
  • Takes up a larger amount of hard disk space than other interfaces
  • They need significantly more memory (RAM) to run than other interface types

 

State the advantages and disadvantages of the command-line interface

Advantages

  • It is quicker to type commands
  • Little memory needed
  • Little processing power needed

Disadvantages

  • Commands have to be typed precisely
  • There is a large number of commands to be learnt
  • It is not user friendly
  • The user has to remember commands
  • Users cannot transfer data between applications

Explain the functions of the following parts of the CPU

Control Unit; Decodes instruction; Controls the fetching and writing of data;

Arithmetic Logic Unit/ ALU; Executes mathematical instructions;  Executes logical instructions; Compares values held in registers;

 Clock; Controls the number of instructions carried out each second;   allows the CPU to synchronize operations;

List four ways of acquiring software in an organization

  1. Commercial off-the-shelf (COTS) software: Organizations can purchase pre-developed software solutions from commercial vendors. These software products are typically ready-made and designed to fulfill common business needs. Examples include productivity software, customer relationship management (CRM) systems, and accounting software. COTS software can be licensed based on a one-time purchase or a subscription model.

  2. Custom software development: Organizations may choose to develop custom software tailored to their specific requirements. This involves hiring software developers or outsourcing the development work to a third-party vendor. Custom software offers flexibility and can be designed to align with unique business processes and workflows. It allows organizations to have full control over the software's features and functionality.

  3. Open-source software: Open-source software is developed collaboratively and made freely available to the public. Organizations can acquire open-source software without incurring licensing costs. They have the right to use, modify, and distribute the software as per the terms of the open-source license. Open-source software can be an economical option, and it allows organizations to benefit from community-driven development and ongoing improvements.

  4. Software as a Service (SaaS): SaaS refers to software applications that are accessed and used over the internet. Organizations can acquire software on a subscription basis, where the software is hosted and maintained by the vendor. Users access the software through web browsers or dedicated client applications. SaaS eliminates the need for local software installation and offers scalability and accessibility from any location with an internet connection.

What are the functions of the system clock in the CPU?

  • It dictates the speed at which data is transferred between these components and enables the sequential execution of instructions in the correct order.
  • generates a timing signal that is used to synchronize communication between CPU components and the rest  of the computer system

State the factors that affect the performance of the CPU

Number of cores
The number of cores a processor has directly affects the performance of the processor. Each core can perform its own fetch-execute cycle independently of others, so different applications can be allocated to different cores. Quad-core (four-core) and even octa-core (eight-core) processors are becoming common

Cache memory
A processor’s cache is a small portion of incredibly fast memory. It has read and write speeds far higher than hard disk drives and even SSDs. The cache is used to store frequently used information and reduces time wasted in fetching the same information from main memory time and time again

Clock speed
A processor’s clock speed relates to the frequency of the pulses generated by the system clock. The higher the frequency, the more cycles of the fetch-execute cycle can be completed in the same period of time.

Word length
A word is a group of bits that is treated as a single unit by a processor. Words can be used for representing both instructions and data. The length of a word is the number of bits that are assigned to it, with higher word lengths allowing for more bits to be transferred and manipulated as a single unit.

Address bus width
The width of a bus relates to the number wires that make up the bus. Increasing the width of the address bus increases the range of addresses that it can specify, hence increasing the computer’s amount of addressable memory. Adding a single wire doubles the number of addressable memory locations

Data bus width
Increasing the width of the data bus increases the volume of data that can be transferred over the bus at any one time. A wider data bus allows the processor to fetch more data from the main memory in one cycle of the fetch-execute cycle, reducing the number of cycles required to fetch large volumes of data.

Why are CD-Rs and CD_ROMs referred to as WORM?

  • Because data is recorded to the disks once but can be accessed many times without changing the content
  • once data is written to the disk, it becomes read-only and cannot be altered or erased.

Define the term multimedia

  • Is an integration of sound, text, graphics, and video to convey information

State the types of storage devices used in a computer

  1. Primary Storage (Memory):

    • Random Access Memory (RAM): This is a volatile memory used to store data and instructions that the CPU (Central Processing Unit) can access quickly. RAM is essential for running applications and the operating system. However, its contents are lost when the computer is powered off.
    • Read-Only Memory (ROM): ROM is a non-volatile memory that stores essential firmware and instructions necessary for the computer's boot-up process. It retains its contents even when the power is turned off.
    • Cache Memory: Cache is a small and fast memory located closer to the CPU. It stores frequently accessed data to speed up the processing.
  2. Secondary Storage (Mass Storage):

    • Hard Disk Drive (HDD): HDDs use magnetic storage to store data on rotating platters. They provide relatively large storage capacities and are commonly used in computers and laptops for long-term data storage.
    • Solid-State Drive (SSD): SSDs use NAND flash memory to store data, offering faster read and write speeds than HDDs. They are more durable and consume less power, making them increasingly popular in modern computers.
    • Optical Discs: CDs, DVDs, and Blu-ray discs are examples of optical storage media. They are mainly used for distribution of software, music, movies, and archival purposes.
    • USB Flash Drives: Also known as thumb drives or pen drives, these portable storage devices use flash memory to store data and can be easily connected to a computer's USB port.
    • Memory Cards: Memory cards, such as SD cards and microSD cards, are used in various devices like cameras, smartphones, and tablets to store data, photos, videos, etc.
    • External Hard Drives: These are HDDs or SSDs contained within an external enclosure, allowing users to expand their computer's storage capacity or create backups.