CS3: Fundamentals Of Data Representation Flashcards
What is the difference between Denary, Binary & Hexadecimal?
+ Denary [Base 10]: The standard English number system
+ Binary [Base 2]: The number system used in computers
+ Hexadecimal [Base 16]: A number system used to abbreviate Binary code in a computer system
Why is Hexadecimal often used in programming?
+ It is easier to memorise for programmers
+ It is easier to read
+ Can be used to represent specific colour shades
What are the ways Quantities of Binary code can be represented?
+ As a single binary digit : A BIT
+ As a group of four bits : A NIBBLE
+ As a group of eight bits : A BYTE
+ As a group of 1000 bytes : A KILOBYTE
+ As a group of 1000 kilobytes : A MEGABYTE
+ As a group of 1000 megabytes : A GIGABYTE
+ As a group of 1000 gigabytes : A TERABYTE
How do you add Binary Numbers?
+ 0 + 0 = 0
+ 1 + 0 = 1
+ 1 + 1 = 10
10110110
01011101
————
0001 0001 0011
What is a Binary shift?
+ A binary shift is when you move all the digits in a binary sequence to the left or right
> Shifting the digits to the left multiplies the number (in denary) by two
> Shifting the digits to the left divides the number (in denary) by two
What is a character set?
+ A character set is used to represent all of the possible characters in a system
+ There are two character sets…
> 7-Bit ASCII
> Unicode
What is the difference between Unicode & ASCII?
+ ASCII is a way of representing all the characters of the English language, including numbers & special symbols
> Each character in ASCII is represented by 7 bits of binary code
+ Unicode is a way of representing all characters in all languages. This is for languages with other thousands of characters, such as the Arabian language & Japanese Kanji
> Each character in Unicode is represented by 2 bytes (16 bits) of binary code
+ The first 127 digits of ASCII are the same as the first 127 digits of Unicode
What is a pixel?
A pixel is a single square of colour in a bitmap image
