Unit 1 - – Memory and storage Flashcards
What is RAM?
This stands for random access memory and is a short term data storage and stores information that is actively being used by the computer.
What is ROM?
This stands for read-only memory and is used to store startup instructions on a computer
What are some properties of RAM?
Ram is volatile
Ram has more storage capacity
Ram is faster
What are some properties of ROM?
Rom is volatile
Rom has less storage capacity
Rom is slower
What is virtual memory?
virtual memory is extra memory that is taken from the storage and used as memory when it is needed.
What is Secondary Storage for ?
We use secondary storage to store data files and information so that we can access it later.
How does Secondary Storage work?
Secondary storage is non-volatile and long term, so if you turn off the computer everything is still saved.
What are the three types of Secondary Storage?
Solid State time
Optical Drive
Magnetic Drive
How does a Solid State Drive work?
Made up of micro transistors and everything is stored in 1s and 0s
What are some properties of Solid state drives?
Large capacity Very fast Very portable Very durable Very reliable Expensive
How does an Optical Drive work?
A laser is used to create marks in a patterns on the disk
What are some properties of Optical Drives?
Limited space Takes a long time to load Can be carried around(needs an optical drive) Can get scratched and damaged Once damaged it is unusable Cheap
How does a Magnetic Drive work?
Everything is stored on the medium and read by the small reader.
What are some properties of Magnetic Drives?
Can store unlimited data Not as fast as SSD They are not really portable The internal disk can be scratched They are reliable They are cheap
What are the Units of Data Storage?
o Bit o Nibble (4 bits) o Byte (8 bits) o Kilobyte (1,000 bytes or 1 KB) o Megabyte (1,000 KB) o Gigabyte (1,000 MB) o Terabyte (1,000 GB) o Petabyte (1,000 TB)
Why do computers use binary?
This is because it is the universal computer language and the computer consists of transistors which consists of 1s and 0s.
How are characters represented?
Characters are represented using character sets.
What is a character set?
A character set are tables of data that link a character to an number
What are some examples of character sets?
ASCII
Unicode
How is ASCII represented?
ASCII is the 8 bit representation of English keyboard characters.
What is Unicode?
The same as ASCII, however it is 32 bits.
What are Images made up of?
Images are made up of lots of different elements called pixels which are represented in binary.
Each pixel is a dot that stores binary data of its colour.
What is color depth?
Colour depth is the number of bits used for each pixel.
The more bits, the more colours available
What is Meta Data?
Digital images are stored as data files. Metadata is the information that is stored about each image.
What details does Meta Data include?
Metadata can include details like Width in pixels Height in pixels Horizontal resolution in dpi Vertical resolution in dpi Colour (bit) depth Dimension
How is Sound stored?
Computers are digital (binary) sound is analogue. It needs to be Encoded to convert it in to binary
What is sampling?
This is measuring the height of sound wave a regular intervals and storing it as binary.
What is Bit depth?
The number of bit used to represent each sample of data
What is Sample rate?
The number of audio samples captured every second.
What is Duration?
Duration is how long the audio file will be played
How do we calculate sound file size?
sound file size = sample rate x duration (s) x bit depth
How do we calculate Image file size?
image file size = colour depth x image height (px) x image width(px)
How do we calculate Text File size?
text file size = bits per character x number of characters
What is Denary?
Denary is standard numbers (eg.10)
How do you convert Binary to Denary?
110 =
4 - 2 - 1
1 - 1 - 0
4 + 2 + 0
= 6
What is the conversion between Binary, Hex and Denary?
Hex Denary Binary 0 0 0000 1 1 0001 2 2 0010 3 3 0011 4 4 0100 5 5 0101 6 6 0110 7 7 0111 8 8 1000 9 9 1001 A 10 1010 B 11 1011 C 12 1100 D 13 1101 E 14 1110 F 15 1111
How do you convert Binary To Hexadecimal
Hex Denary Binary 0 0 0000 1 1 0001 2 2 0010 3 3 0011 4 4 0100 5 5 0101 6 6 0110 7 7 0111 8 8 1000 9 9 1001 A 10 1010 B 11 1011 C 12 1100 D 13 1101 E 14 1110 F 15 1111
01111100
| |
0111 1100
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7 C
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7C
