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Paper 1: Testimonial

Hardware

The Von Neumann Architecture
In 1945, a Hungarian – American mathematician called
John Von Neumann, had a light bulp idea of computers storing data and program together. Back then computers were setted up, but Von Nuemann wondered how it would be good if computer worked even without a programm running, this would eliminate time on setting up machines and spent those hours on developing new programs  
Assembly Language 
All ‘Von Neumann’ CPUs contain an instruction set.
It has a list of instructions that it understands and knows what to do with.
Registers,memory locations during FDE cycle
The Accumulator (A)
• The Program Counter (C)
• The Memory Address Register (MAR)
• The Instruction Register (IR)
• The Memory Data Register (MDR)

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Fetch Decode Execute 

  1. PC contains the address of the next instruction to be fetched

  2. This address is copied to the MAR by the address bus

  3. The instruction of the address is copied into the MDR temporarily

  4. The instruction in the MDR is then placed in the IR

  5. The value in the PC is incremented by 1, pointing to the next instruction to be fetched

  6. The instruction is finally decoded and then executed

CPU ​

  • The central processing unit (CPU) (also known as a microprocessor or processor) is brain of computer which processes data 

Components of CPU​

Control unit - control unit controls the operation of the memory, processor and input/output devices

Immediate acess store-Stores the data which is to be immediately processed

Arithmetic Logic Unit-Carries out the logic system like calculations

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Cores, Cache and Internal Clock

Clock-Amount of F-D-E cycles that can be performed per second.

Overclocking-increasing clocks of CPU which can lead to overheating of CPU

Cache-small amount of memory that allows RAM faster access to the CPU ,stores frequently used instructions and data that need to be accessed faster, which improves CPU performance

Cores-The more cores in the CPU, the better and faster the performance

Input and output devices

Input device-supplying CPU with data, so data which goes into computers 
Two-Dimensional (2D) and Three-Dimensional (3D) Scanners: Devices used to create digital representations of physical objects.
2D Scanners: Capture flat, two-dimensional images or documents, like scanning a photograph or a page of text.
3D Scanners: Generate three-dimensional digital models of objects, capturing their shape, dimensions, and surface details.

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Barcode Scanner: A device used to quickly read the unique patterns of lines and spaces (barcodes) on products or items

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Digital Camera: An electronic device designed for taking pictures and recording videos. It stores these images as digital files that can be easily viewed, edited, and shared on a computer or other digital devices.

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Keyboard: An input device consisting of a set of keys, each representing a letter, number, or symbol. It allows users to enter text and commands into a computer or other digital equipment.

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Microphone: A piece of hardware that converts sound waves into electrical signals. It is commonly used for recording audio or speaking to voice-controlled devices.

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Optical Mouse: A type of computer mouse that uses a light-emitting diode (LED) or laser to detect movement on a surface. It moves the cursor on the computer screen in response to physical mouse movement.

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QR Code Scanner: A tool or application that captures and interprets Quick Response (QR) codes, which are two-dimensional barcodes

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Touch Screen (Resistive, Capacitive, and Infrared): A display interface that allows users to interact directly with a screen by touching it. Three common types include:

  • Resistive: Detects touch through pressure applied to the screen.

  • Capacitive: Recognizes touch based on the electrical properties of the user's finger.

  • Infrared: Uses infrared sensors to detect touch interactions.

Sensors 

  • Devices that read or measure physical properties

  • Data needs to be converted to digital

  • Analogue-to-digital converter (ADC) converts physical values into digital

  • Sensors are input devices 

Examples of sensor you need to know for IGCSE exam​

  • Acoustic - These sensors act like a microphone that converts sound to electric pulses.

  • Accelerometer - These sensors measure an object's acceleration or deceleration and motion.

  • Flow - This sensor measures the flow of liquid or gas.

  • Gas - These sensors measure the amount/level of any gas in the environment.

  • Humidity - This sensor measures the water vapour in the air or any sample.

  • Infra-red (active) - This IR sensor uses an invisible infrared beam. When the beam is broken/disturbed, it changes the amount of infrared light reaching the detector.

  • Infra-red (passive) - These sensors detect the heat emitted by any type of object.

  • Level - This sensor detects the solids, liquids, or gas level.

  • Light - These devices use light-sensitive cells that generate electric current based on light brightness.

  • Magnetic field - This sensor detects the change in magnetic field.

  • Moisture - This type of sensor detects the water content wherever this sensor has been installed.

  • pH - This measures the acidity or alkalinity.

  • Pressure - This sensor measures the pressure applied

  • Proximity - This sensor detects the nearby objects around the sensor

  • Temperature - These sensors measure the temperature of the environment.


Output device-Data that is being displayed on output device after processing it 

Actuator: A mechanism or device that responds to a control signal by moving or performing a specific action. It's commonly used in robotics and automation systems.

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Digital Light Processing (DLP) Projector: A projector that uses tiny mirrors to create images by reflecting light.

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Inkjet Printer: A printer that produces images or text by spraying tiny droplets of ink onto paper

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Laser Printer: A printer that uses a laser beam to create images on a photosensitive drum, transferring toner onto paper. It's known for its fast and high-quality printing

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3D Printer: A machine that creates physical objects layer by layer based on digital designs, commonly used in various industries for prototyping, manufacturing, and customized product creation

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Light Emitting Diode (LED) Screen: A display that employs an array of LED lights to create images and videos. It's energy-efficient and provides vibrant visuals, commonly found in TVs and digital signale

 

Liquid Crystal Display (LCD) Projector: A projector that uses liquid crystal panels to control light and produce images on a screen

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Liquid Crystal Display (LCD) Screen: A flat-panel display technology that relies on liquid crystals to control light and display images on a screen, commonly used in computer monitors and TVs.

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Speaker: A device that converts electrical signals into sound waves, allowing for audio output in devices such as headphones, loudspeakers, and multimedia systems.

Storage devices 

Primary storage
Storage that is directely acessed by CPU

RAM(Random Acess Memory)

  • RAM stores data of applications that are currentely used

  • RAM stores data as small charges of electricity in tiny transistors etched into a circuit in the device.

  • Volatile/temporary memory (contents lost if RAM is turned off)

  • The more GB your RAM has the more applications tyou can run and they will run faster

ROM(Read Only Memory) 

  • contains data to start computer

  • non-volitile 

  • data in the ROM is accessed by the CPU in order to start the computer and load the operating system successfully.

  • Without ROM computer won't start 

  • Cannot be changed by user

Virtual Memory ​

When RAM is overloaded virtual memory comes in,it can be either HDD or SSD

The main advantages of virtual memory are

  • They can be larger than the physical memory provided in the RAM.

  • Avoids the need to install/upgrade RAM, as it could be expensive

  • The system wastes no storage on unwanted/unused data.

Secondary storage 

Memory which is not directely acessed by CPU, but important for storing large files, there are 3 main types of secondary storage , Magnetic Optical and Solid state

 

Magnetic storage

  • uses platters which are divided into tracks and sectors

  • Data is read and written using electromagnets

Optical storage

  • consists of marks arranged in patterns

  • When writing to optical media the laser burns ‘pits’ into the shiny surface

  • When laser is shined on surface and getting reflects its 0 and if hits pits its 1

Solid State Storage (Flash)

  • has no moving parts

  • uses NOR and NAND system

  • transistors are used as control gates and floating gates

  • very fast 

  • expensive

Cloud Storage​

  • Cloud storage can be accessed remotely in comparison to storing data locally

  • Physical servers and storage are needed to store data in cloud storage

  • Unlimited storage 

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Network hardware

Network

Network is two or more computers connected together which can exchange data 

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Network Interface Card (NIC)
A network interface card (NIC) is needed to allow a device to connect to a network (such as the internet).

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Data Transfer Media

  •  Wires

  • Wireless Technology

Hub or Switch

  • A device that connects nodes together.

 Router

  • manage the data packets enabling them to be sent between networks – over the internet

  • They route data packets based on their address information

MAC adress ​

MAC stands for Media Access Control

  • Used to identify device or network

  • Six  pair of hexadical separated by colon

  • It is static 

IP adress ​

  • Each computer has an IP adress,

  • When you send a message you specify reciever's IP adress

  • Router can assign IP adress 

IPv4

  • each ipv4 adress is splited into 4 numbers ranging from 0 to 255

  • it consists of 32(4*8) bits which limits the number of users only to 4.3 billion unique adresses, 

  • separated by dot

  • IPv4 addresses are allocated using DHCP or manually

IPv6

  • Due to economical growth and internet development, 128 bits is now used

  • but they are using hexadecimal 

  • addresses are primarily assigned using stateless autoconfiguration.

Public and private ip adresses each computer have both public and private Ip adress

Public IP adress

Is used for internet, so each ip adress is unique, no 2 computers can have same ip adress.

Private IP adress

can create a network of computers for exchanging information, , private IP adress is used to communicate within the network 

Router

Device that enables to transfer information to different types of networks

used to create networks and connect to internet

Routers can send information to specific ip adress

Can assign Ip adress

can connect local network to internet  

by: Arnur Mussabekov

Topic 3 - Hardware

In this section you will find out how computer components are working together 

©2024 BY EDUCATION TOOLZ. 

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