Describe the key function of CPU
It controls all operations, executes instructions and processes data.
Describe the key function of a motherboard
The motherboard is a main circuit board, and it connects all hardware components such as CPU, RAM and I/O devices
Describe the key function of an Arithmetic Logic Unit
ALU performs arithmetic operations(add,subtract) and logical operations(AND, NOT)
Describe the key function of Random Access Memory(RAM)
RAM is used to store data and instruction that are actively processed by the CPU. It is fast and volatile(data is lost when power is turned off)
Describe the role of Moore’s Law in shaping the progress of computer technology
moore’s law states that the number of transistors double every 18-24 months
-faster and more powerful processors
-smaller and cheaper computers
-rapid improvement in storage, memory, and overall computer technology
Describe the function of general purpose registers in the CPU and provide a list of these registers.
general purpose registers temporarily hold data, addresses and results during execution
reduce the need to access slower main memory
speed up instruction processing
examples are AX,BX, CX,DX
SI,DI,BP,SP
Describe the function of cache memory in a computer system and its importance in improving CPU performance
Small, high-speed memory located closer to CPU than
main memory (RAM). It stores frequently accessed data
and instructions to speed up the processing time.
The CPU exchanges data with Memory and I/O devices. Explain and list the general-purpose registers used in the CPU for this purpose
General purpose registers temporarily hold data, addresses and results during execution. When exchanging data with memory or I/O devices.
-it holds data to be written to memory or I/O
-hold data read from memory or I/O
-store addresses used during memory access
-store intermediate results during arithmetic or logical operations
they make data transfer faster and more efficient by reducing memory access time.
List of General Purpose Registers:
AX(Accumulator Register) - holds data for arithmetic and I/O operations
BX(Base Register) - used for memory addressing
CX(Count Register) - used in loops, shifts and I/O operation
DX( Data Register) - used for multiplications, divisions
SI(Source Index) - used for data movement operations
DI(Destination Index) - used for string/data transfer operations
Describe the main function of each layer in the OSI model with an example
- Physical Layer
-transmits raw bits(0s and 1s) over physical media e.g ethernet cables, fibre optics - Data Link Layer
- creates frame, handles MAC addressing and detects errors e.g Ethernet(MAC), switches - Network Layer
- routing of packets between networks using logical addresses e.g IP(Internet Protocol), routers - Transport Layer
- end to end communication, flow control and error recovery. e.g TCP,UDP - Session Layer
-manages session and connections between devices e.g RPC(Remote Procedure Call) - Presentation Layer
- Data translation, encryption and compression e.g SSL.TLS encryption, JPEG format - Application Layer
-provide services to user application e.g HTTP,FTP, SMTP
mnemonics to remember
All People Seem To Need Data Processing
Compare CSMA/CD and CSMA/CA
CSMA/CD:
-used in wired Ethernet
- devices listen before sending
-if a collision happens, it is detected, and devices stop transmitting, wait a random time, then retry
-works because wired networks can detect voltage change
CSMA/CA:
-used in Wi-Fi (wireless)
-devices try to avoid collision using: RTS/CTS and random backoff timers
-collision cannot be detected in wireless because signals interfere silently
-CSMA/CA focuses on avoiding collisions before they happen
Function of modem
it converts digital signals to analog signals for transmission over ISP lines
Function of Repeater
regenrates weak signals
Function of Network Switch
it connects multiple devices into a LAN and forwards data frames using MAC addresses to ensure data goes to the correct device
Function of Wireless Router
provides WiFi access, assigns IP addresses and routes data between the local network and internet.
what is an operating system?
it is a system that manages computer hardware and software resources and provides services for running applications
Explain the role of device drivers in an operating system Input/Output management system.
they act as translators between os and hardware devices.
- allows the OS to communicate with hardware
- convert OS commands into device-specific instructions
- handle input and output operations so the OS does not need to know how each device works internally.
What happens if there is no kernel in an operating system?
The kernel is the core of the OS.
without it:
- The CPU,memory and hardware cannot be controlled
- No programs can run because there is no process management
- The computer will not boot and cannot function as an operating system
Identify the differences between machine code, assembly and high-level languages
Machine Code - Binary 0s and 1s executed by CPU e.g 10110001
Assembly Language - Human-readable mnemonics mapped to machine code e.g MOV AX, 09
High-level language - easy to read, closer to human language and needs compiler e.g Python, Java
What are the differences between two-address and three-address formats . Give some examples.
two-address:
- uses 2 operands
- one operand is often overwritten with the result
e.g ADD R1, R2 ; R1=R1 + R2
three address:
- uses 3 operand ( 2 source and 1 destination)
e.g ADD R3, R1, R2 ; R3= R1 + R2
Write an assembly language that multiplies 2 numbers, 9 and 14, then stores the result at memory location “0x0D”.
MOV AX, 9 ; Load value 9 into register AX
MOV BX, 14 ; Load value 14 into register BX
MUL AX, BX, CX ; CX=AX*BX
STORE CX, 0x0D ; Store the result (126) into memory address 0x0D
Write an assembly language(8086) to add the number “14” with the number read from the memory location “0x0A” and store the result in “0x0D”
MOV AL, 14
MOV BL, [0x0A]
ADD AL,BL
MOV [0x0D], AL
The CPU exchanges data with Memory and Input/Output Devices. Explain and list down the general purpose registers used in the CPU for this purpose.
AX(Accumulator Registers) - main register for arithmetic/logical operations
BX(Base Register) - used for addressing and calculations
CX(Count Register) - used for loops and shifting operations
DX(Data Register) - used in multiplication/division and I/O operations
Distinguish between ROM and RAM
ROM:
- non-volatine(keeps data even when power is off)
- stores permanent instructions like BIOS
- cannot be easily rewritten
RAM:
- volatile(loses data when power is off)
- stores data and programs currently being used
- can be read and written any time
Function of a firewall
-filters traffic
-prevents unauthorized access
-blocks harmful content
-monitors network activity
-protects sensitive data
basically a firewall protects a computer/network by checking all incoming and outgoing traffic and blocking anything unsafe of unauthorized
