N5: Computing: Computer Systems (1)

Question 1

State the 5 stages of software development in order.

Answer 1

Analysis, design, implementation, testing and evaluation

Question 2

How many bits are in one byte

Answer 2

8

Question 3

How many bytes are in a kilobyte, megabyte and gigabyte?

Answer 3

Kb= 2^10
Mb= 2^20
Gb= 2^30

Question 4

Put- Megabyte, byte, gigabyte, bit, petabyte, terabyte and kilobyte into order

Answer 4

Bit, byte kilobyte, megabyte, gigabyte, terabyte and petabyte

Question 5

What is a real number

Answer 5

A real number is any number that includes- positive, negative and decimal numbers

Question 6

How can you store a real number in a computer system

Answer 6

Using floating point notation

Question 7

Name the power and decimal components of floating point notation

Answer 7

Decimal- Mantissa

Power- Exponent

Question 8

How many characters can ASCII store and what does ASCII stand for?

Answer 8

American Standard code for information interchange and 256 characters can be stored.

Question 9

Name one other text storage system for computing and its advantage over ASCII

Answer 9

Unicode and it is advantageous as it can store a much larger range of characters as it stores each character in a 2byte (16 bit) code meaning it can store accents and symbols from foreign languages.

Question 10

Name two control feature/functions

Answer 10

Return and Tab

Question 11

State a disadvantage of Unicode compared with ASCII

Answer 11

As unicode uses 16 bits to store each character then this takes up more storage space

Question 12

Define a pixel in computing terms

Answer 12

Individual black dots which form together to create an image

Question 13

What is bit depth

Answer 13

Bit depth is the number of bits used for the colour code (used to represent each/all the different colours

Question 14

What is resolution and how can it be in and decreased

Answer 14

Resolution is the number of pixels in a fixed area. Resolution can be increased by having a large amount of pictures in a small area whereas it can be decreased by having a small amount of pixels in a large area.

Question 15

How do you work out the storage requirement of a black and white bit mapped image in kilobytes e.g- If the dimensions were 640 x 960

Answer 15

Number of bits= 960 x 640= 614,000
Number of bytes= 614,000 / 8= 76,800 bytes
In kilobytes= 76,800 / 1024= 75 Kilobytes (Kb)

Question 16

How does Vector graphics store an image

Answer 16

Stores an image as a list of their objects and attributes as a whole rather than in pixels.

Question 17

State one advantage and one disadvantage of Bit mapped graphics

Answer 17

Advantage- As each pixel is stored individually they can be edited at pixel level so that fine detail and irregular shares can be seen in the image
Disadvantage- File sizes can be very large as each pixel is stored individually

Question 18

What is a peripheral device

Answer 18

A peripheral device is any device that can be attached to the cpu for purposes on input, output for backing storage

Question 19

Give one example of an input, output and backing storage device

Answer 19

Input= Keyboard
Output= Printer, projector
Backing store= USB memory stick, CD disk

Question 20

What does cpu stand for and name the 3 components of the processor chip

Answer 20

Central processing unit
ALU
Registers
Control unit

Question 21

Describe the functions of the 3 components of the processor chip within the CPU

Answer 21

Arithmetic logical unit (ALU)- Performs arithmetic/mathematical operations such as addition and subtraction as well as logical decisions such and AND, OR and NOT
Registers- Used to store items of data that the processor is currently working on
Control Unit- Fetches and executes program instructions one at a time.

Question 22

Name the three registers from within the processor chip

Answer 22

Instruction register, Program counter and accumulator

Question 23

What is the function of the main memory within the CPU

Answer 23

The function of main memory within the CPU is to store the programs and data currently being executed by the processor

Question 24

What two components is Main memory made up of and what do they stand for

Answer 24

RAM= Random Access Memory
ROM= Read Only Memory

Question 25

Name 3 features of RAM and 2 features of ROM

Answer 25

``` RAM= Programs and data can be written to RAM, Its contents can be changed & All content is lost when the computer is turned off ROM= Cannot be written to but can be read, its contents cannot be changed & It does not lose its contents when the computer is switched off ```

Question 26

How can the processor identify a location in main memory from the thousands of millions of locations and what is this process called

Answer 26

Each locations is given a unique address and this process is called addressability

Question 27

Name the 3 busses that connect the processor to the main memory

Answer 27

Address bus, Control bus & Data bus

Question 28

State the function of the 3 busses

Answer 28

Address bus= Used to specify the location is to be used to read or write data Data bus= Used to carry/transfer the data from a memory location to the processor Control bus= Used to send out signals which initiate the task that the other 2 busses will perform

Question 29

In computing what is a program

Answer 29

A program is a set of instructions that are executed to solve a problem.

Question 30

What is machine code

Answer 30

Machine code is the computers own internal language and uses binary codes/digits to represent data

Question 31

What is a high level computing language

Answer 31

High level language is programming language that uses English command words to write programs

Question 32

Give 2 examples of a high level language program

Answer 32

Visual basic, python & scratch

Question 33

What must happen to all high level language programs before they are run?

Answer 33

They must be translated into machine code

Question 34

Name the names of code that are representative of high and low level languages

Answer 34

``` HLL = Source code LLL = Object code ```

Question 35

There are two different translators that can be used to convert HLL to LLL name them both and one difference between them

Answer 35

Compiler & Interpreter Difference= Compiler translates the entire program into LLL before it is run then runs it whereas an interpreter translates each statement one at a time while the program is running.