1.1.3 Input, output and storage Flashcards
what is an input device?
any device that allows you to pass information from the outside world into a computer system
what is an output device?
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
what is a storage device?
any device used for either temporary or permanent storage of data - can be internal or external
How can a device be both an input and output device?
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
Name some examples of input devices (ones that are less common):
sensor
remote control
barcode reader
magnetic strip reader
chip and pin
optical character recognition
joystick
name some output devices (ones that are less common):
digital/data projector
potter
actuators
touchscreens
what are some storage devices?
- 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
What types of questions/things should you remember when answering input/output/storage device questions?
suggest appropriate devices for specific situations
what is a drive (with secondary storage devices)?
the device that reads and writes data from secondary storage
what is the media of a secondary storage device?
what the data is actually stored on
how do optical storage devices work?
shining a laser at the media and processing the reflection from the media
what are the negatives of the optical storage?
slow access times
prone to scratches
what are pits and lands?
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
what are the positives of optical storage?
cheap
lightweight
portable
how do magnetic storage devices work?
they use magnets
the N and S poles represent 1s and 0s
a drive head rotates around the discs
what are the positives of magnetic storage?
cheap
large capacity
what are the negatives of magnetic storage?
slow access times
fragile
how do solid state drives work?
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.
what are the positives of solid state storage?
durable
fast access times
what are the negatives of solid state storage?
cost
limited read/writes (the oxide layers deteriorate making the electron movement unreliable)
what is the ROM?
- read only memory
- small piece of read only memory on the motherboard
- non-volatile
- contains the very first instructions for the computer (bootstrap)
what is firmware?
software stored on the ROM
what is RAM?
- random access memory
- temporary storage of instructions and data
- holds information being executed by the processor
- volatile
- much faster than the hard disk
why is ROM needed?
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
