1.1.3.Input, Output and storage (Chp2)

Question 1

Input devices

Answer 1

An input device is one which can be used to put data and information into a computer. e.g. keyboards, webcams, barcode reader, magnetic stripe reader

Question 2

Output devices

Answer 2

An output device is one which can be used to send information from the computer. e.g. a touchscreen outputs info in a visual way, monitor, speakers, printers, projectors

Question 3

What is Optical storage

Answer 3

Optical devices are4 read from and written to using lasers.
Binary info is represented by portions of the disk surface. The portions which are recessed, called pits scatter light when the laser is pointed at it - this represents 0. The flat portions surrounding the pits are called lands, which reflect light back at the laser to represent 1.

Question 4

DVDs

Answer 4

Digital video disc.
higher storage capacity than CDs making them suited to store digital videos as they require more storage than audio files or photos.

Question 5

CDs

Answer 5

Compact disc. They store small quantities of information. Most commonly used for audio files.

Question 6

Blu-ray

Answer 6

advancement over DVDs has they have more than 5x as much storage than DVDs making them useful for storing high-resolution films.

Question 7

Optical storage pros and cons

Answer 7

PROS =  small, thin and light which makes them very portable.
CONS = 
-easily damaged by scratches
-limited storage capacity
-relatively slow transfer speeds

Question 8

what is Magnetic Storage

Answer 8

They are devices which store info magnetically and represent binary information using two magnetic states: polarised and unpolarised. They are read by a read/write head.

Question 9

Magnetic storage PROS and CONS

Answer 9

PROS =
-large storage capacities
-any part of the platter can be accessed by read/write head on actuating arm.
CONS =
-slow data transfer speeds
-tendency to become damages by movement due to their moving parts (delicate)

Question 10

Flash

Answer 10

The technology makes use of silicon semi-conductors forming logic gates NAND and NOR to store electrical charge in 1 of 2 states. Used to represent binary True ir False.

Question 11

flash pros

Answer 11

• fast and compact
• portable and light
• no moving parts so more robust
• non-volatile so don’t lose contents when power is lost.

Question 12

flash cons

Answer 12

• limited lifespan

- high costs

Question 13

RAM - Random Access Memory

Answer 13

• type of fast main memory used to store data and programs that the computer is currently using. This speeds up the computer’s execution as Ram has higher access speeds than flash.
• volatile
• can be accessed in any order at any time
• read/write

Question 14

ROM Read Only Memory

Answer 14

non-volatile

-read-only so cannot be modifies, therefore it stores instructions of BIOS

Question 15

Virtual Storage

Answer 15

the name given to storing info remotely so that it can be accessed by any computer with access to the same system. e.g. over the internet.

• it is convenient to access and share
• its disadvantages include limitations of a user’s network speed and high costs.