Karteikarten
textbook
Karten in diesem Stapel (31)
- 1what is a CPU?central processing unit
-
electronic circuitry within a computer that carries out the instructions of a computer program - 2what is binary shiftshifting to right or left
-can be used to perform simple multiplication or division by powers of 2
-moving n places is the same as x or / by 2 to the power of n - 3what base is hexadecimal and how many bits are needed to code for 1 hexadecimal thingbase 16
4 bits - 4why is hexadecimal used?converting between hex and binary is easy
and
humans find it easier to remember and understand than binary - 5ASCIIAmerican Standard Code for Information Interchange
-numerical representation of characters
- 7-bit numbers
- so only represent 128 characters
-so hard for other languages - 6extended ascii- 8 bit code rather than 7
- 7Unicode-originally 16 bit
-but now can store up to 32 bits
-can represent over 110,000 characters - 8what are data standards?the rules by which data are described and recorded
- 9data types-images
-sound
-moving image
-alphanumeric
-outline graphics/fonts - 10what is the difference between analogue and digital dataanalogue data is continuous for example a mercury thermometer
whereas digital data break the information up into separate steps. this is done by breaking it to pieces and using binary to represent it - 11why do computers need to convert analogue data into digital data?because computers are finite and so cannot store continuous values. they only have a limited amount of storage
- 12b?bit
1 or 0 - 13B?byte
8 bits = 1 byte - 14kilobyte1000 bytes
- 15megabyte1000 kilobytes
- 16gigabyte1000 megabytes
- 17terabyte1000 gigabytes
- 18define resolutionnumber of pixels
- 19what is a bitmap imagemade of pixels
- 20what are the 2 parameters of bitmap-number of pixels
-colour depth per pixel - 21what is the advantage of using higher resolutions?because the pixels are smaller so they can show greater detail
- 22black and white image using binary
- 23colour depththe number of bits used for each pixel, the more bits, the more colours that can be represented
-affects the amount of memory a picture requires
-doesnt affect the size of image
-affects quality of image - 24how do you work out how many colourscalculate 2 to the power of the number of bits
- 25work out size in pixelsw x h
- 26size in bits size in bytesw x h x d
w x h x d / 8 - 27colour and rbg 1 bit2^1 = 2 colours
black and white
or two other colours - 288 bits2^6 = 256 colours
greyscale - 2924 bit rbg2^24 = 16,777,216 possible colours
- 308 bit indexed coloureach pixel associated with one byte
but value in byte is not a colour value but an index of a table of colours (palette)
same quality as 24 bit but 1/3 of data for storage
colour and animation effects by changing the colour - 3132 bit rgb
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- Beschreibung
- GCSE French, Geog, Computing (Computer Science) Karteikarten am textbook, erstellt von n g am 14/06/2017.
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- n g
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