Topic 13: Low Level Operations (Representing Text and Whole Numbers) Flashcards
Binary means
base 2, only two digits are possible and these are 1 or 0
What are the three reasons computers use binary?
- All computers are 2 state machines.
- Arithmetic rules are simpler
- Circuitry of computers less complex to construct
What does it mean by computers being two state machines?
In their simplest form they represent a 1 by a voltage of 5v passed across a wire(on) and no voltage as a 0 (off)
A bit is
a binary digit i.e. 1 or 0
Byte is
8 bits (bits are stored in groups of 8)
Kilobyte (Kb) is
1024 bytes
Megabyte (Mb) is
1024 Kilobytes
Gigabyte (Gb) is
1024 Megabytes
terabyte (Tb) is
1024 Gigabytes
Petabyte (Pb) is
1024 Terabytes
A character is an
item of text. 1 byte = 1 letter
ASCII stands for and is
American Standard Code for Information Interchange and is coding used to store each character
ASCII can be broken down into 4 groups of character sets, these are;
- Letters: a,b,Z
- Numbers: 0,7,2
- Symbols: £,$,*
- Control Characters: shift, space, enter
Control characters also known as
invisible characters or non-printable characters do not appear on screen but will have an effect
Integers are
numbers with no fractional part. e.g. 4, -2
