Computer Systems : Data Representation

Question 1

Describe the use of Binary to represent positve and negative integers

Answer 1

Binary is a numeric system which only uses the numbers 0 and 1. Computers operate in binary, meaning they store data and perform calculations using zeros and ones.

Question 2

Advantage of using binary code

Answer 2

Transmitting binary code is much easier and less prone to error than using a denary system where the numbers 0 to 9 would have to be represneted by 10 different voltage levels.

Question 3

Describe Floating point representation

Answer 3

Floating point representation is a very useful way of storing very large or very small numbers, although some accuracy may be lost depending on bits available for storage.

Increasing the number of bits available for the manitssa means the accuracy of the numnbers improves, since more digits can be stored.

Increasing the number of bits available for the exponent means the range of numbers that can be sotred increases.

Question 4

Describe ASCII and its advantges and disadvantges

Answer 4

ASCII can represent 128 characters

Extended ASCII uses the most significant bit and can allow for the representation of 256 characters.

ASCII is less demanding on memory use than Unicode.

ASCII can’t represent characters of several languages because of its 128 and 256 character limits.

Question 5

Descirbe Unicode and its Advantage over Extended ASCII

Answer 5

Unicode uses 8-bit, 16-bit or 32-bit encoding

Unicode represents a wide range of characters including different languages, mathematical symbols and emojis

Unicode can represent a greater range of characters than ASCII

Unicode occupies more space and is more demanding on memory than ASCII

Question 6

Describe Bit mapped graphics and state the adavantges and

Answer 6

Graphics can be stored as bitmaps where a 2D array of pixels is repsented by a number of bits for each pixel.

Bitmap images produce photo-realsitic images which allow pixel-level edinting but can produce large files.

Question 7

Describe Vecotor Graphics and its advantages and disadvatges

Answer 7

Graphics can be stored as vector instructions which stores objects and their attributes to make up the image.

Vector images produce small files and individual objects can be easily edited however they cannot present photo-realistic images

Layering is possible when using vector graphics