Unitts

Unit 1 Hardware and software

Hardware

Hardware is the collection of physical components attaching to or forming part of the computer system

Software

Software is the collection of non-physical parts of the system

Operating System

collection of many programs that manage the hardware and allows the user to Rhymes of the applications applications, software carries out task for computer users,

Application Software

computer software created to allow the user to perform task

Standalone Application

stanalone or desktop application runs on a computer without any need for interaction with any other software network.

Network Application

Network applications is the designed to run on multiple computers that are connected via Network usually, the internet

synchronisation

a process where the data on your desktop and mobile device is consta

Control units

Controls the execution of each instruction icluding how it needs to be processed and what the processor does

Arithmetric Logic Unit

A logic unit calculations and logic comparisons take place in the Alu

register

registers is to store the current information and its data

Serial Processing

cpus could only process one instruction at a time.The process ahead is single core where the problem was broken down into a set of instructions that are executed sequentially One after the other and on a single processor parallel processing

Parralle processing

the concept of parole processing is a method of simultaneously breaking up and running program instructions on multiple microprocessors, thereby reducing process time

More processing

By duplicating the distance on the chip, it allowed the processor to appear to execute 2 sets of instructions at the same time, a hypotheright CPU appears like 2 logical cpus were in fact, there's only one physical CPU with 2 sets of registers. multiple processing is having multiple cpuce. Called cause on a single CPU chip.

Multiprocessing

Instead of duplicating only the registers, the entire coal was duplicated on the cpub. By having multiple cause, many processes can ran at the same time instead of appearing to run at the same time

level 3

there are 3 levels of crouch Ah as the numbers increase The space increases bought the excess time decreases crouch

cache

couch stores data so that future request for data can soot faster

Random Acees Memory

Ram is a volatile memory chip that can be used to temporary store data in computers.

DRAM

Dram stands for dynamic Ram, each d Ram chip contains A Capacitor , which loses is charged and must be refreshed many times per second

SDRAM

he s in sdrm stands for synchronist dram, the refreshing of the ramp chip is synchronised with the CPU so that the CPU does not have to wait while refreshing takes place

DRR

Double data Ram ddr means that data is transferred twice as fast as when data was transferred once a clock pulse

latency

latency is the time taken for a component to respond.

Motherboard

the Central printed circuit board that connects components and devices to each other

System clock

the microchip that maintains the timing and speed of all computer functions

Over Clock

Over clocking is the practice of making computer components run at faster speeds, then designed by manipulating the frequencies at which the component is set to run.

How to overclock

per component, its own clock manipulator factor Or the whole system, the system clock is increased,

Cooling overclocking

The methods of cooling over clocking fans, liquid cooling and heat sinks

Speed vs throughout

the actual speed bandwidth / theatrical speed of data. (swap)

Internal bus

was initially a parallel bus that connected all components on the motherboard.

Data Bus

Data bus is the transfer of the actual data bewteeen CPU and RAm

Address Bus

transfers to physical address of the data/instruction between CPU and Ram.

Control Bus

The control boss carries command beccq and Ram external buses

PCI express

Pci express peripheral component interconnect express slots. are used to connect graphic cards, read cards Wi-Fi cards to the murder board

peripherals

peripherals input/output and secondary devices that are peripheral rules which are connected to the Marlborough board, but are not directly placed on the motherboard

components of emotion

A component, anything place directly on the mother board is considered a component

SATA

serial advanced technology attachment is a computer bus interface used to connect mass storage devices

USB

universal serial boss technology was designed to standardise the connection of any Peripherals, to computers, both to communicate and supply electrical power

Secondary Storage

storage provides the permanent non-volatile storage,That keeps data after the device has been switched off for retrieval later.

ROM

a non-volatile memory chip that can be used to permanently store data on computers,

HDD (Hard Disk Drive)

HDDs are designed with mechanical parts that include a Reed and right head, that scans the disc. For data that is presented magnetically

SSD

a microchip that stores data permanently without read right heads and disc

SSD > HDD

faster access time, more reliable consumes less energy, consume, less CPU power consumption

HIgh defination Median Interface

HDMI posts provides a digital interface to receive and transmit video and audio signals.

Disk Cache

This cache is a hardware mechanism for improving the time it takes to read from or write to a hard disc

Broswer Cache

every time a website is accessed, a copy of the website is kept in the browser on your local disc

Web Cache /proxy server cache

stores the recently access web pages on a server in a network.

Boot sequence

The initial set of operations that the computer peforms when it is switched on

Boot loader

the program performs the boot sequence which ends withe operating system being loaded

BIOS (Basic Input Output System)

A software that resides on the ROM as firmware

BIOS Task

POST (Power On self test)

Inventory of connected hardware is checked through CMOS

Hardware is checked to determine if its running properly

Locates the MBR(master Boot Record), code usually stored on the hard drive disk. MBR loades and excutes the operating system kernel

Kernel

Remains on RAM and handels input/ouput request from software and translates it into instructions for the CPU and handles memory and peripherals

CMOS

a battery backed volatile memory that store:

hardware settings (type of hardware installed)

user settings (date and time)

BIOS sequence

BIOS - MBR - Boot loader - kernel - Operating System

UEFI sequence

UEFI - EFI Boot Loader- Kernal - Operating System

UEFI (Unified Extended firmware Interface)

More efficient system to start up

UEFI background

You can not switch from BIOS to UEFI on a existing PC

UEFI van provide BIOS emulation so you can install and use old BIOS operating system so they are backwards compatible

UEFI advantages over BIOS limitations

Could drives over 2.2 TB

can run 32 bit and 65 bit mode,the boot process faster

User friendly

Secure Boot

network features(makes network work in boot and offers remote troubleshooting and configuration)

Unit 3 network

Network

Network consist of 2 or more devices, cult nodes that are connected by some type of communication channel.

Nodes

Note any device connected to the network

UTP

which consists of several parts of twisted pairs of twisted wires in an outer protective plastic cover.The twisting of the wires helps to eliminate interfernce from signals or other wires from other electrical devices

STP

There is a more expesive bulkier type of cable called shileded twist pair which has twisted pairs enclosed in an protective foil.This type of cable is less affected than UTP by interference and crosstalk

problems with copper cables

Attenuation which is the loss of signal strength over a distance .

Electromagnetic Interference whereby signals from other sources such as Machinery corrupts traveling signals .

Eavesdropping where signals can be intercepted by outsiders .

Crosstalk where adjacent wires can interfere with each other

Advantages of utp

inexpensive, easy to install, widely used and tested

disadvantages utp

susceptible to interference from other devices crosstok

fibre optic cable

consist of Central glass or plastic core surrounded by several layers of protective materials.

cladding is used to surround the core and reflect light back into the centr

+Fibre Optic

Faster transmission rates. More secured in utp can transmit over much longer distances than utp lights signals are less susceptible to interference.

-Fibre Optic

expensive to install and purchase and complex to install

Fibre Optic cabling as a backbone

When several LAN cables hang off one fibre optic cable.

Bluetooth

Bluetooth is a wireless technology for sending data over short distances using wirlesss transmissions.

From 202400 to 2480 mag signals that ascent from fixed and mobile devices treating personal area networks and with high levels or security Bluetooth, one standard has a maximum speed of 1MB per second, Bluetooth can manage up to 3 made by for second. Bluetooth is backwards comparable with 1.0 devices. Bluetooth Rey can achieve up to 24MB per second Bluetooth point 4 and Bluetooth 5 introduce a new category called Bluetooth low and energy BLE and is designed for applications needing a lower power consumption such as wearable devices.

NFC

provides a wireless communication between 2 devices within close proximity.

Rdaio waves

Radio waves are a type of electromagnetic wave, which is known for their use in communication technologies and transfer data

Microwave Transmissions

Terrestrial or satellite

Terrestrial Microwave

Terrestrial microwave systems use line of sight metj=hod for transmitting data between antennas and can transmit over ranges of 50km provided there is no obstacle in the way

satellite Transmission

use satellites orbiting the earth to receive and pass on communication to the destination

Satellite height

Geo-sationary or Low orbit

Geo-satellite

which means they are in a fixed position above the earth's surface and they rotate at the same speed as the earth

Low orbit

mean they are much nearer to the earth's surface and rotate around the earth every few hours; and is has better communication because it's closer to the earth, geo-stationary has a little delay

point v point

A point-to-point. Communication directly connects 2 nodes of a network

broadcast

broadcast is a communication channel that is shared by all devices in network

Topology

The term topology refers to the physical set up of a network.

Star Topology

the cable that is connected to the NIc in each computer has its other end in the port on a switch

+ Star

easy to install and maintain, adding/removing z node does not upset the network,Easy to extend the netwrok

- Star

The switch adds to cost and if the switch fails the whole network fails

Bus topology

all nodes connect to a single which has a terminator at the end to stop the signal from bouncing out

+ Bus

Easy to extend and No switch needed which reduces cost

- Bus

A fault in the main cable can shut down the whole network. faults are hard to find because they all share a common cable

Ring Topology

all nodes are connected in a closed loop

+ Ring

Easy to make larger

very little signal degradation occurs

- Ring

Slower than Star topology

moves and removals can cause a disruption

One problem with a computer can cause crash

Hybrid Topology

A topology comprised of several topologies and combined into one network.

+ Hybrid

Reliable as error detecting, and troubleshooting is easy and flexible to suit the needs of an organization

- Hybrid

Complex in design and costly

Ethernet

technology that connects nodes in a local network and enables them to commmunicate with each other throught a common protocol

MAc

A media access control address is a hardware identification number that unity identifies each device on a network

IP

a numerical label assigned to eavh device connected to computer netweork so that the device can communicate on the internet

Internet protocol

protocol defined how data is transmitted between computering devices over networks.

Address Resolution Protocol (ARP)

Arp each device in the network has a unique MAC address which need to be linked to the computer's IP address in a table stored in the RAM of the Nic

DCHP (Dynamic Host Configuration Protocol)

Dynamic host configuration protocol DAC p takes all the manual work out of IP.