Data Rep Revision

Data Rep

Computers are used to store different types of information including:

Numbers

1, 45, 7.3

hello, total, 4R

These are stored using on and off pulses of electricity.

These on and off pulses are the computers own language called Machine Code.

The on and off pulses are easily represented by 1 and 0 which are called binary digits or bits.

Binary Conversions

Numbers are stored using 8 binary digits.

We use the following headings to do the binary number conversions:

128 64 32 16 8 4 2 1

these are just:

2^5 2^4 2^3 2^4 2^3 2^2 2^1 2^0

How to convert Binary to Denary- Watch the video if needed

Using the headings above : 128 64 32 16 8 4 2 1

How to convert Denary to Binary- Watch the video if needed

Using the headings: 128 64 32 16 8 4 2 1

Revision Game for Binary conversions Click here for Link to game

Text

text is a symbol or letter on the keyboard.
a list of all the characters available to the user is called the character set.
text can be represented using ASCII, American Standard Code for Information Interchange. Extended ASCII uses 8 bits per character, ranging from 00000000 to 11111111. This gives a possible 256 different characters

Graphics

Vectors

A vector image is made up of a number of objects and is saved using the attributes of each object.

(startX, startY, 2ndX, 2ndY, 3rdX, 3rdY, 4thX, 4thY, 5thX, 5thY, line colour, fill colour)

(startX, startY, end X, endY, line colour, line thickness)

(startX, startY, length, height, line colour, fill colour)

(centreX, centreY, radiusX, radiusY, line colour, fill colour)

Graphics

Bitmaps

made up of tiny dots called pixels.
the resolution determines the quality of the picture. The smaller the pixels the finer the detail that can be displayed on the screen. Resolution is the number of pixels in a given area and is measured in dots per inch (dpi).
the higher the resolution, the larger the file size (storage size).

Why use each Graphic?

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