1.1.3 Input, output and storage

Question 1

what is an input device?

Answer 1

any device that allows you to pass information from the outside world into a computer system

Question 2

what is an output device?

Answer 2

any device that can take data stored in digital form and convert it into another format such that humans can process such as sound, images or vibrations

Question 3

what is a storage device?

Answer 3

any device used for either temporary or permanent storage of data - can be internal or external

Question 4

How can a device be both an input and output device?

Answer 4

there may be components that are used as input devices as well as components considered output devices.

you can say it is either as long as you justify the answer

Question 5

Name some examples of input devices (ones that are less common):

Answer 5

sensor
remote control
barcode reader
magnetic strip reader
chip and pin
optical character recognition
joystick

Question 6

name some output devices (ones that are less common):

Answer 6

digital/data projector
potter
actuators
touchscreens

Question 7

what are some storage devices?

Answer 7

• optical (CD, blu-ray, DVD)
• solid state (USB/flash drive, SD card, portable or internal SSD)
• magnetic (hard drive, mass storage tape, external hard drive)
• cloud storage

Question 8

What types of questions/things should you remember when answering input/output/storage device questions?

Answer 8

suggest appropriate devices for specific situations

Question 9

what is a drive (with secondary storage devices)?

Answer 9

the device that reads and writes data from secondary storage

Question 10

what is the media of a secondary storage device?

Answer 10

what the data is actually stored on

Question 11

how do optical storage devices work?

Answer 11

shining a laser at the media and processing the reflection from the media

Question 12

what are the negatives of the optical storage?

Answer 12

slow access times
prone to scratches

Question 12

what are pits and lands?

Answer 12

areas where an optical disc is burned (in CD-R) by a laser that is suitable for representing ones and zeros
where the pit starts, the laser light scatters and is not reflected as well. it is the change of reflective and non-reflective that’s read as 1s and 0s

Question 12

what are the positives of optical storage?

Answer 12

cheap
lightweight
portable

Question 13

how do magnetic storage devices work?

Answer 13

they use magnets
the N and S poles represent 1s and 0s
a drive head rotates around the discs

Question 14

what are the positives of magnetic storage?

Answer 14

cheap
large capacity

Question 15

what are the negatives of magnetic storage?

Answer 15

slow access times
fragile

Question 16

how do solid state drives work?

Answer 16

flow of electricity forcing electrons between floating gates. this causes a change in the charge of the floating gate that can be registered as a 0 or a 1.

Question 17

what are the positives of solid state storage?

Answer 17

durable
fast access times

Question 18

what are the negatives of solid state storage?

Answer 18

cost
limited read/writes (the oxide layers deteriorate making the electron movement unreliable)

Question 19

what is the ROM?

Answer 19

• read only memory
• small piece of read only memory on the motherboard
• non-volatile
• contains the very first instructions for the computer (bootstrap)

Question 20

what is firmware?

Answer 20

software stored on the ROM

Question 21

what is RAM?

Answer 21

• random access memory
• temporary storage of instructions and data
• holds information being executed by the processor
• volatile
• much faster than the hard disk

Question 22

why is ROM needed?

Answer 22

when the computer system first receives power, there are no instructions in the CPU.
the system needs to load the OS so it can function. However, the OS is stored in secondary storage and the computer does not know that the hard drive exists.

the ROM contains the bootstrap which is a set of initial start up instructions

Question 23

What is the POST?

Answer 23

power-on self-test
- first initial instructions
- sends signals to all connected components, wakes them up and checks they are working and makes the CPU aware of their existence

Question 24

what is virtual storage?

Answer 24

• cloud storage
• the concept of storing and retrieving data over the internet in the cloud instead of a local storage device

Question 25

what are the advantages of virtual storage?

Answer 25

• data can be accessed any time
• … from any device …
• … as long as there is internet access
• Data can easily be shared without the need for removable media transfer
• Easy to collaborate
• Storage considered to be “limitless” from the user’s POV

Question 26

what are some disadvantages of virtual storage?

Answer 26

• can become quite expensive
• if connectivity is poor, access times can slow
• No internet connection means no access to your files

Question 27

how is virtual storage actually stored?

Answer 27

data actually resides on physical permanent storage media in some remote location

Question 28

what can virtual storage also refer to?

Answer 28

the abstraction or separation of logical storage from physical storage

Question 29

how does the way data is presented to a user differ from the way it is actually stored?

Answer 29

folders, files and associated data could be stored across lots of different media while it is presented as being in one logical filing system or location