Computer Systems Flashcards
What are the components of the processor?
- Arithmetic Logic Unit (ALU)
- Control Unit
- Registers
What does the arithmetic logic unit do?
Carries out mathematical operations and logic operations
What does the control unit do?
Controls all the hardware that is part of the computer. Clock line, which is part of the control unit, dictates when the hardware should execute the next instruction
What are registers?
Temporary storage locations that the CPU uses to store small pieces of data to be accessed quickly
What are the three types of memory?
- Random Access Memory (RAM)
- Read Only Memory (ROM)
- Backing Storage
What is random access memory?
Storage component that stores currently used programs/data in unique memory locations
What is read only memory?
Storage component that stores important instructions in unique memory locations (e.g: how to turn on, how to display media on the monitor etc.)
What is backing storage?
Used to save data when the computer is turned off (e.g: CD, DVD, USB, Hard drive etc.)
What are the two bus types?
- Data Bus
- Address Busa
What does the data bus do?
Is bidirectional and carries data to and from the processor and main memory.
What does the address bus do?
Is unidirectional and carries the address in which the data on the data bus is to be read from or save to from the processor to the main memory
What are high level languages?
Human readable instructions that are easy to code and understand
What are low level languages?
Machine code - the only instructions that a computer can understand - that is nearly impossible to code or understand
What is translation software?
Software to translate high level languages into low level languages so that the computer can understand the program
What are the two types of translation software?
- Interpreter
- Compiler
What are the advantages of the interpreter?
2
- Quicker to start execution
- Can highlight lines with errors
What are the disadvantages of the interpreter?
3
- Takes up more space in memory
- Overall execution time is slow as lines are often translated multiple times if there are loops etc
What are the advantages of the compiler?
2
- Execution time is quick because after the translation the code is ready to run
- Original program soure code is not available to view, edit or plagiarise
What are the disadvantages of the compiler?
2
- Unable to identify lines where errors occur
- Program should be completed and error-free before it is compiled
What is floating point representation?
Used to store decimal numbers in a computer’s memory
What is the mantissa?
The numbers that come after the decimal point
What is the exponent?
The power of the number that is being multiplied by the decimal
How many bits represent characters in ASCII?
7
How many bits represent characters in extended ASCII?
8
What are characters stored and represented as?
Stored as a binary number and represented as a unique number
What are control characters?
Characters that do not print out anything on the screen, but carry out an action (e.g: delete)
What are printable characters?
Characters that print onto the screen (e.g: ?)
What are bitmapped graphics?
Graphics that are stored as a grid of pixels - each pixel is stored as a binary number that represents its colour
What are the advantages of bitmapped graphics?
1
The file size of a bitmapped graphic doesn’t change when you add more graphics to the file
What are the disadvantages of bitmapped graphics?
2
- Bitmapped graphics don’t allow layering, meaning if you place a graphic on top of another the bottom graphic is overwritten
- They are resolution dependant, so when scaled up they lose their quality and become blurry
What are vector graphics?
Graphics that are stored as a set of objects - objects are stored as a set of attributes
Vector graphics:
What are the four types of objects?
- Rectangle
- Ellipse (circle)
- Line
- Polygon (shape with multiple sides)
Vector graphics:
What are the three common attributes?
- Co-ordinates
- Fill Colour
- Line Colour
What are the advantages of vector graphics?
2
- Not resolution dependnat, so when scaled up they do not lose their quality
- They support layering, so when an object is placed on top of another the bottom one isn’t overwritten
What are the disadvantages of vector graphics?
1
The more objects you add to a vector graphic, it will increase the file size and transmission time
What is a firewall?
A netwrok security system designed to prevent unauthorised access to or from a private network or computer system
How does a firewall work?
2
- All messages entering or leaving the network / computer pass through the firewall
- The firewall examines each messagw and either allows or blocks specific IP addresses or traffic from specific ports
What is encryption?
When data is coded or made unreadable to prevent unauthorised usage if accessed by third parties
What monitor settings can be adjusted to help the environment?
3
- Reduce brightness setting
- Activate efficiency mode
- Use energy efficient monitors
What power down settings can be adjusted to help the environment?
3
- Power down monitor after set period of time
- Power down computer system after set period of time
- Control settings for individual components
What standby settings can be adjusted to help the environment?
1
Set computer system to be in standy mode, which uses a lot less power
