end of year 10 computing exam
- Created by: loupardoe
- Created on: 04-07-16 17:13
Fullscreen
input and output devices
input devices
- keyboard- used for data entry into a computer
- mouse- controls a pointer on screen that can be opened, dragged or controlled by clicking buttons on the mouse
- touch screen- allows the user to interact directly with icons or an on-screen keyboard to control the device
- microphone- uses voice input for communication or to control the device
- camera- captures images or video
- bar code scanner- reads light reflected back from a pattern of thin and thick lines that represent a product code or other identification number
- RFID reader- reads data from an electronic version of a bar code; does not require line of sight; used in shops to identify products, in airports to track luggage, to tag animals, to collect payments automatically in toll booths, to access car parks
- sensor- detects physical conditions and automatically collects data
- eye types- can be used by people with limited physical mobility; camera tracks the movement of the user's eye and can detect which key the user is looking at, a slow blink is used to select the key to type commands into a computer system
- foot mouse- can be used by people with limited hand movement; track ball device that can be operated with the foot
- puff-**** switch- can be used by people with severely limited physical mobility by blowing or ****ing into a small tube
- braille keyboard- can be used by people with visual impairments to type text and commands into a computer system using keys with embossed patterns that match the standard braille characters
output devices
- monitor- displays text, images and video
- printer- produces hard copy on paper
- plotter- reproduces large scale engineering or architectural drawings
- speakers- produce sound output
- actuators- create physical movements in response to a computer command to control aeroplanes, wheelchairs and robots
network topologies
bus
- computers and other devices are attached to a single backbone
- terminator attached at each end to prevent reflection of signals
- signals travel in either direction
- easy to set up
- cheap
- problems with the backbone can bring the whole network down
- limited distance can be covered
- many data collisions slow the network down
star
- client machines are connected to a central switch or hub which is usually connected to one or more servers
- signals travel in either direction
- robust- problems with a connection do not affect the whole network
- fewer data collisions than bus so faster
- needs more expertise to maintain
- can be expensive to set up
- more building work involved
- more network hardware and software needed
ring
- data passes through each node carried in data units called tokens
- traffic is one way which prevents collisions
- very fast- no collisions
- problems with the backbone can bring the whole network down
- data passes through every node- this makes the network vulnerable to malfunctions
client server network
- one or more servers provide services to many client machines where the users work
- servers are computers that are set up to handle network functions
- may be many on a network
- typically high…
Comments
No comments have yet been made