S4 Computer Systems

Question 1

What is a computer system?

Answer 1

A combination of hardware and software designed to input, process, store and output data.

Question 2

What is hardware?

Answer 2

The physical components of a computer system such as the CPU, memory, and peripherals.

Question 3

What is software?

Answer 3

The programmes and operating systems that run and hardware on perform tasks.

Question 4

How do hardware and software work together?

Answer 4

Hardware provides the physical platform, while software runs on it to perform tasks. Software depends on hardware to function, and hardware is useless without software.

Question 5

Draw the NOT gate

Answer 5

Question 6

Draw the AND gate

Answer 6

Question 7

Draw the OR gate

Answer 7

Question 8

Draw the XOR gate

Answer 8

Question 9

What does the NOT gate do?

Answer 9

It inverts the input:

If input = 1, output = 0
If input = 0, output = 1

Question 10

What does the AND gate do?

Answer 10

It outputs 1 only if both inputs are 1.

Question 11

What does the OR gate do?

Answer 11

It outputs 1 if at least one input is 1.

Question 12

What does the XOR gate do?

Answer 12

It outputs 1 if only one of the inputs is 1, but not both.

Question 13

Boolean algebra for a NOT gate?

Answer 13

A̅

Question 14

Boolean algebra for an AND gate?

Answer 14

A * B

Question 15

Boolean algebra for an OR gate?

Answer 15

A + B

Question 16

Boolean algebra for an XOR gate?

Answer 16

A ⊕ B

Question 17

What is system software?

Answer 17

Software that manages hardware and provides a platform for application software, e.g., operating systems and utility programs.

Question 18

Describe the term application software

Answer 18

software that performs end-user tasks

Question 19

Describe the term system software

Answer 19

• Manages computer hardware;
• Manages application software;
• Manages a computer (system);
• Manages the operation of the computer (system);

Question 20

What are the key functions of an operating system?

Answer 20

• Processor management (allocates CPU time)
• Memory management (manages RAM and virtual memory)
• Device management (controls input/output devices)
• Application management (runs software)
• Security management (user authentication, firewalls)

Question 21

What is an Operating System?

Answer 21

An operating system (OS) is software that manages computer hardware and software resources and provides services for computer programs.

Question 22

Examples of Operating Systems

Answer 22

Windows (Microsoft), macOS (Apple), Linux (Open-source), Android (Google – Mobile OS), iOS (Apple – Mobile OS).

Question 23

What is an operating system (OS)?

Answer 23

A set of programs that manage a computer’s hardware and software.

Question 24

What are the five key management functions of an OS?

Answer 24

Processor management, Memory management, I/O device management, Application management, Security management.

Question 25

How does an OS manage the processor?

Answer 25

It allocates CPU time to tasks, switching between them using time slices in a multitasking system.

Question 26

What happens when a computer has multiple processor cores?

Answer 26

The OS distributes tasks across cores to improve efficiency.

Question 27

How does an OS manage memory?

Answer 27

It allocates memory to programs and files, ensuring efficient use of RAM.

Question 28

What happens when a program is closed?

Answer 28

The OS frees up the allocated memory for other applications.

Question 29

What is an I/O device?

Answer 29

Any device that inputs or outputs data (e.g., keyboard, mouse, printer, monitor).

Question 30

How does the OS manage I/O devices?

Answer 30

It uses device drivers to translate data between the hardware and software.

Question 31

What is a device driver?

Answer 31

A small program that allows the OS to communicate with hardware devices.

Question 32

How does an OS manage applications?

Answer 32

It allocates memory & CPU time, allows applications to communicate, and provides a user interface.

Question 33

What is an API (Application Programming Interface)?

Answer 33

A system that allows applications to interact with the operating system.

Question 34

How does an OS handle security?

Answer 34

It controls access using passwords, user privileges, automatic updates, and encryption.

Question 35

How does an OS manage users on a network?

Answer 35

It tracks active users, logs user activity, and enforces access rights.

Question 36

What is an embedded system?

Answer 36

A computer system built into a device to perform a dedicated function.

Question 37

Give three examples of embedded systems.

Answer 37

Microwave ovens, traffic lights, smart meters.

Question 38

How do embedded systems differ from non-embedded systems?

Answer 38

Fixed purpose vs. general purpose, Stored in ROM and rarely updated, More reliable & efficient.

Question 39

What does encryption software do?

Answer 39

Converts data into ciphertext to prevent unauthorized access.

Question 40

Why are firewalls and antivirus software important?

Answer 40

They protect the system from viruses, malware, and hacking attempts.

Question 41

What is disk defragmentation?

Answer 41

A process that organizes fragmented files on a hard drive to improve speed.

Question 42

Why do SSDs not need defragmentation?

Answer 42

SSDs access data electronically, so fragmentation doesn’t slow them down.

Question 43

What does automatic updating do?

Answer 43

It downloads & installs security patches and software updates automatically.

Question 44

What does compression software do?

Answer 44

Reduces file size for storage or faster transmission.

Question 45

What are the two types of compression?

Answer 45

Lossy – Removes data permanently (e.g., JPEG). Lossless – Keeps all data (e.g., ZIP files).

Question 46

What are the two levels of programming languages?

Answer 46

High-level languages and low-level languages.

Question 47

What is the difference between high-level and low-level languages?

Answer 47

High-level: Easier for humans to read (e.g., Python). Low-level: Closer to machine code (e.g., Assembly).

Question 48

What are the two types of low-level languages?

Answer 48

Machine code and assembly language.

Question 49

Why are most programs written in high-level languages?

Answer 49

They are easier to write, debug, and maintain.

Question 50

What are the three types of program translators?

Answer 50

Compiler, interpreter, assembler.

Question 51

How does a compiler work?

Answer 51

Translates entire code at once, making execution faster.

Question 52

How does an interpreter work?

Answer 52

Translates line by line, allowing real-time debugging.

Question 53

What does an assembler do?

Answer 53

Converts assembly language into machine code (1:1 instruction mapping).

Question 54

What is the Von Neumann architecture?

Answer 54

A design model where a computer’s CPU fetches, decodes, and executes instructions stored in memory.

Question 55

What are the four major components of the CPU?

Answer 55

ALU, Control Unit, Registers, Bus.

Question 56

What is the function of the ALU (Arithmetic Logic Unit)?

Answer 56

Performs calculations and logical decisions.

Question 57

What is the function of the Control Unit (CU)?

Answer 57

Directs operations and controls the flow of data.

Question 58

What are the three steps of the Fetch-Execute cycle?

Answer 58

Fetch – Retrieves instruction from memory. Decode – Interprets the instruction. Execute – Carries out the operation.

Question 59

What are the four types of memory in a computer?

Answer 59

RAM, ROM, Cache, Registers.

Question 60

What’s the difference between RAM and ROM?

Answer 60

RAM: Volatile, temporary storage. ROM: Non-volatile, stores BIOS.

Question 61

What is the purpose of secondary storage?

Answer 61

Provides long-term data storage for programs and files.

Question 62

What are the three types of secondary storage?

Answer 62

Solid-state, optical, magnetic.

Question 63

How does cloud storage differ from local storage?

Answer 63

Data is stored remotely on servers instead of a physical device.