GCSE Computing/Representation of Data in Computer Systems
Section 2.1.4 Representation of data in computer systems
[edit | edit source]Topics
[edit | edit source]Units
[edit | edit source]- (a) Define the terms
- bit,
- nibble,
- byte,
- kilobyte,
- megabyte,
- gigabyte,
- terabyte.
(b) understand that data needs to be converted into a binary format to be processed by a computer.
- (c) Convert positive denary whole numbers (0-255) into 8-bit binary numbers and vice versa
- (d) Add two 8-bit binary integers and explain overflow errors which may occur
- (e) convert positive denary whole numbers (0-255) into 2-digit hexadecimal numbers and vice versa
- (f) convert between binary and hexadecimal equivalents of the same number
- (g) explain the use of hexadecimal numbers to represent binary numbers.
Character
[edit | edit source]Candidates should be able to:
- (h) explain the use of binary codes to represent characters
- (i) explain the term character set
- (j) describe with examples (for example ASCII and Unicode) the relationship between the number of bits per character in a character set and the number of characters which can be represented.
Images
[edit | edit source]Candidates should be able to:
- (k) explain the representation of an image as a series of pixels represented in binary
- (l) explain the need for metadata to be included in the file such as height, width and colour depth
- (m) discuss the effect of colour depth and resolution on the size of an image file.
Sound
[edit | edit source]Candidates should be able to:
- (n) explain how sound can be sampled and stored in digital form
- (o) explain how sampling intervals and other considerations affect the size of a sound file and
the quality of its playback.
Instructions
[edit | edit source](p) explain how instructions are coded as bit patterns (q) explain how the computer distinguishes between instructions and data