N5: Computing: Computer Systems (1) Flashcards
State the 5 stages of software development in order.
Analysis, design, implementation, testing and evaluation
How many bits are in one byte
8
How many bytes are in a kilobyte, megabyte and gigabyte?
Kb= 2^10 Mb= 2^20 Gb= 2^30
Put- Megabyte, byte, gigabyte, bit, petabyte, terabyte and kilobyte into order
Bit, byte kilobyte, megabyte, gigabyte, terabyte and petabyte
What is a real number
A real number is any number that includes- positive, negative and decimal numbers
How can you store a real number in a computer system
Using floating point notation
Name the power and decimal components of floating point notation
Decimal- Mantissa
Power- Exponent
How many characters can ASCII store and what does ASCII stand for?
American Standard code for information interchange and 256 characters can be stored.
Name one other text storage system for computing and its advantage over ASCII
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.
Name two control feature/functions
Return and Tab
State a disadvantage of Unicode compared with ASCII
As unicode uses 16 bits to store each character then this takes up more storage space
Define a pixel in computing terms
Individual black dots which form together to create an image
What is bit depth
Bit depth is the number of bits used for the colour code (used to represent each/all the different colours
What is resolution and how can it be in and decreased
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.
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
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)
How does Vector graphics store an image
Stores an image as a list of their objects and attributes as a whole rather than in pixels.
State one advantage and one disadvantage of Bit mapped graphics
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
What is a peripheral device
A peripheral device is any device that can be attached to the cpu for purposes on input, output for backing storage
Give one example of an input, output and backing storage device
Input= Keyboard
Output= Printer, projector
Backing store= USB memory stick, CD disk
What does cpu stand for and name the 3 components of the processor chip
Central processing unit
ALU
Registers
Control unit
Describe the functions of the 3 components of the processor chip within the CPU
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.
Name the three registers from within the processor chip
Instruction register, Program counter and accumulator
What is the function of the main memory within the CPU
The function of main memory within the CPU is to store the programs and data currently being executed by the processor
What two components is Main memory made up of and what do they stand for
RAM= Random Access Memory ROM= Read Only Memory
Name 3 features of RAM and 2 features of ROM
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
How can the processor identify a location in main memory from the thousands of millions of locations and what is this process called
Each locations is given a unique address and this process is called addressability
Name the 3 busses that connect the processor to the main memory
Address bus, Control bus & Data bus
State the function of the 3 busses
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
In computing what is a program
A program is a set of instructions that are executed to solve a problem.
What is machine code
Machine code is the computers own internal language and uses binary codes/digits to represent data
What is a high level computing language
High level language is programming language that uses English command words to write programs
Give 2 examples of a high level language program
Visual basic, python & scratch
What must happen to all high level language programs before they are run?
They must be translated into machine code
Name the names of code that are representative of high and low level languages
HLL = Source code LLL = Object code
There are two different translators that can be used to convert HLL to LLL name them both and one difference between them
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.
