Input / Output / Storage / Communication Devices

By Muhammad Mustaqim12B1

Input devices

KeyboardUsed to input data into the computer

Advantage• They are very common; all

computers have one and they are easy to use.

Disadvantage• Easy to make mistakes if you

can’t type quickly.Mouse Enables you to control the movement of the on screen curser by moving it around a surfaceAdvantage

Easy to learn to useAccurate for selecting things

DisadvantageNeed a flat space next to the computer.

JoystickSimilar to a tracker ball in operation except you have a stick which is moved rather than a rolling ball.

Advantage• Immediate feel of direction.

Disadvantage• Some people find them more

difficult to use than mice.

MicrophoneUsed to input soundAdvantages

Some systems can understand most peoples voices with voice recognition software

Disadvantages Some systems need to be trained to understand each different voice.

Digital CameraLooks very similar to a traditional camera.  However, unlike photographic cameras, digital cameras do not use film Advantage• No film needed.• Images can be digitally

manipulatedDisadvantage• Need to print out photographsScannerAnother way in which we can capture still images or text to be stored and used on a computer.  Advantage• Can input things from paper

documents• With OCR software, text can

be scanned in Disadvantage• Images can take up a lot of

memory space.

Output devices• Once the computer has processed all the information from

the inputs then it must display or output the information in some way.

• This is when we use Output devices that enable us to see or hear the information stored in the computer.

• Monitors• Cathode Ray Tube: monitors are fairly large

and they are not as common as LCD’s nowadays. CRT’s work by using an electron gun situated at the end of the tube.

• Advantage• They give a better quality display.• Robust and hard to damage• Disadvantage• They produce a lot of heat.• Liquid Crystal Display : monitors are thin

and are more commonly used. They work by using electronically charged crystals.

• Advantage• Produce less heat• Take less space• Disadvantage• Easily damage

SpeakersMost computers are fitted with a

small internal speaker which can produce beeping sounds to alert you if you make an error.

Advantages• They can help blind people to

use the computer because text can be converted into sound

Disadvantages• High quality external speakers

can be expensive

Headphones/EarphonesHeadphones or earphones consist

of a small pair of loudspeakers which are worn over or in the ears.

Advantages• Portability• The sound can be heard by the

user and won’t disturb othersDisadvantages• Often not aware of

surroundings• Risk of permanent hearing

loss

Storage devices• A data storage device is a device

for recording (storing) information(data).• There is internal and external storage devicesInternal R.A.M• Random access memory is a form of computer data storage. • Temporary, short-term working memory• It’s also known as ‘volatile memory’ because the data disappears if the

power is switched off.R.O.M• Read only memory• It is permanent, long term memory which cannot be erased or

changed in any way• It’s also known as ‘non-volatile memory because it doesn’t disappear

after the computer is switched off.

External Hard DiskAn external storage device which

can contain a lot of data.Advantages• Main Backing storage for files

and programs• Can store lots of data compared

to the floppy discDisadvantages• Slow to access• Data can be damaged easily or

reformatted

CD-ROMAdvantages• Data cannot Be erased – you

cannot lose your data• Easy to carry around• Cheap to produceDisadvantages• Fragile • Can scratch easily – this effects

the data when the laser reads it• Slower to access than a hard

drive

Communication devicesThese are devices that can communicate with other people who are out

of range or long distances.Mobile phonesThe work using the transmission of

electromagnetic radio waves. They have a transceiver that is only powerful enough to transmit or receive date from the nearest mobile

Advantages• They can be used while travelling

if a public phone is unavailable.• They can be used to send photos

and videos.Disadvantages• They cost more than a landline• They have a limited battery life

Global Positioning SystemGPS work by making use of

satellites that orbits the earth. They can be used by runners or drives to pinpoint their speed and position

Advantage• Greater accuracy for measuring

distancesDisadvantages• They are expensive• Transmission can be slow

Handheld & PDA’sThey refer to any type of small

computers that can be carried in one hand. They are used by pros whose job requires them to be travelling some or much of the time

Advantage• They are easier to carry than a

laptopDisadvantages• They are expensive as laptops• Its difficult to enter much text

Storage and memory• Across• 3. This can only store 0 and 1• 4. Magnetic tape can also be

known as magnetic .........• 7. WORM stands for 'write once

read ....‘• 8. This contains 1024 kilobytes• 9. RAM stands for Random ......

Memory Down• 1. A byte is made up of how

many bits?• 2. Memory that loses its data

when the power is switched off is known as ........

• 3. When you make a copy of your work onto a storage device, it is known as making a ......

• 5. When your computer first starts up, it is using its ...

• 6. A hard disk is measured in .........

CARBONCOPY DOTMATRIX IMPACT

INKJET LASER LIGHTS MONITOR OUTPUT PRINTER SPEAKER TONER

 

AUTOMATIC MANUAL BARCODE READER

KEYBOARD MOUSE TOUCHSCREEN

MICROPHONE SCANNER JOYSTICK

SENSORS MICR