OCR ICT UNIT 1 FUNDAMENTALS OF IT REVISION NOTES LO1

LO1 Understand computer hardware

Input devices: Learn characteristics, advantages and disadvantages

-Keyboard

-Mouse

-Scanner

-Sensors

-Microphone

-Graphics Tablet

-VDU

-Barcode reader

Input & Output devices:

-Touch screen

Output devices

-Printers

-Plotters

-Braille terminal

Communication devices:

A device capable of transmitting an analog or digital signal over telephone or other communication wire or wirelessly.

Modem- Converts digital sgnals produced by the computer intot an analog signal required by telephone line. Another modem converts the signal back into digital format so the recieving computer can understand the message.

+More useful in connecting LAN with the internet

+Speed depends on the cost 

-Very slow speed in camparison to a HUB 

-Does not know about the own destination path

Network Interface Card- Enables computers to communicate with other computers in a network.It is the hardware connection

+Inexpensive 

+Makes it easy for computer owners and IT technicians to troubleshoot problems.

-They need to be configured properly

-Require a hard wired connection

Terminal adapter-A coputer component which connects the computer to the integrated services digital network.

Wireless router-Converts internet signals into a wireless signal, which computers and other devices use to communicate with eachother and the router.

+Easily shared internet

+Security and adaptibility

-Complicated to set up

-Data overhead 

Wireless network card-Computers and other devices are able to recieve and send wireless communication

+Cheaper

+More mobile and versatile

-Extra costs and equipment to set up

-Slower speed

HUB-Allows multiple computers to communicate over a network and multiple peripherals to connect through a singal USB port.

+Costs less

+Easy to utilise

+Can communicate much quicker

-Slow speed

-HUBS broadcast all the ports

Used to connect segments of a LAN, they contain multiple ports. All segments of the LAN can see the packets as they are copied to other ports.

Switch-A devce that electronically and logically connects other devices together.

+Cheaper cost to get switches with more ports

+Reduces the number of broadcast domains

-Security attacks

-Spoofing

-Not as good as a router in limiting Broadcasts

Uses a table of MAC addresses to detrmine the port in which data is to be sent to

-Connects LAN segments

COMPUTER COMPONENTS 

CPU- Manages all the hardware activities. It is responsible for interpreting and executing most of the commands "Brain" of the computer.

-Consitsts of multicore processors- allows multiple packages to run

-Control unit- Ensures all instructions which are required to operate the computer are retrieved and interpreted in the correct sequence.

-ALU- Undertakes mathematical equatuions

MOTHER BOARD

-Allows all computer components to receive power and communicate with one another.

COMPUTER STORAGE

-Storage devices can be internal or external these include:

• Hard drive disk- permanent storage device, connected to motherboard or external through using a USB. Uses a magnetic disk where binary is stored + & -
• Solid state- Permanent storage device, uses flash memory connects to motherboard using USB
• Flash Drive- USB which uses flash memory. Removable and rewriteable.
• SAS- Serial attatched SCSI. moves data to and from computer storage devices…