Zusammenfassung der Ressource
Data Representation
- Units
- In computing there are different types of units that we use to represnt data, these are bit:can be
grouped together to make them easier to work with, nibble: four binary digits, byte: a group of bits,
kilobytes: equal to 1024 bytes, megabyte: equal to 1048576 bytes, : gigabyte: equal to one thousand
million bytes, terabyte: equal to one million million bytes.
- Number
- In this section you convert positive denary whole numbers (0-255) into 8 bit binary numbers which can be used by a computer. This
then leads us to how adding 8 bit binary number cause overflow. A overflow error occurs when a computer tries to handle numbers
that are to large for, hence why it cannot handle 8 bit numbers added as its an 8 bit system. Also you can convert positive denary
numbers into 2 digit hexadecimal numbers. You can also convert binary numbers to hexadecimal.
- Character
- Characters use binary codes to represent different characters for example every time a character is
typed on a keyboard a code number is transmitted to the computer, these code numbers are
represented in binary. They do this by using the ASCII character set (American Standard Code for
Information Interchange).
- Images
- A picture that you would take on a phone or a different device would be classed as a Bitmap image, these images include and are made of things called pixels. Pixels are small squares of colour
which are formed in a grid to form the image that you take. You can most of the time zoom into a image and see the pixels. This is the where the resolution of the image come into effect, the
resolution of the image will tell you how many pixels the image consists of and the higher the resolution then the more pixels it includes and better it looks. The quality of the picture can also
depend on its colour depth which is measured in bits and the amount of bits will tell you how many colours the image will have. For example a black and white photo would only include 2 1 for
for each colour and would only have a colour depth of 1. The highest it can be is 8 bit with 256
- Sound
- Sounds that are stored on a computer exist as digital information as audio files. These consist of 3
components sample rates: the number of audio samples captured every second, Bit depth: the
number of bits available for each clip, Bit rate: the number of bits used per second of audio, these
all effect the quality of the audio file.
- Instructions
- When you have an application on a PC it runs instructions and for the cpu to create these
actions in must first translate it into machine code.