Computer Systems Flashcards
What is application software?
Helps a user perform a task
What is system software?
Maintains the computer
What is generic software?
Software that isn’t made for a specific reason. Created for anyone and obtained for anyone
What is integrated software?
A group of similar types of software with similar properties
What is specific software?
Software that is made for a specific purpose and to help people.
What is bespoke software?
Software made for one person only or company. Made to improve a company.
What are logic gates?
Logic gates are the building blocks of digital circuits. Logic gates have one or two inputs that can be turned on or off, the output from the gate will vary depending on the type of logic gate
Define the OS
An operating system (OS) is a suite of programs that controls computer hardware and software resources.
Name some functions of the OS and explain what they do?
interface - provides a user interface so it is easy to interact with the computer
manages the CPU - runs applications and executes and cancels processes
multi-tasks - allows multiple applications to run at the same time
manages memory - transfers programs into and out of memory, allocates free space between programs, and keeps track of memory usage
manages peripherals - opens, closes and writes to peripheral devices such as storage attached to the computer
organises - creates a file system to organise files and directories
security - provides security through user accounts and passwords
utilities - provides tools for managing and organising hardware
What is the NOT gate rule?
The output is the opposite to the input. 1 becomes 0, 0 becomes 1.
What is the AND gate rule?
Both of the inputs have to be 1 in order for the output to be 1.
What is the OR gate rule?
At least one of the inputs has to be 1 for an output to be 1.
What factors effect the performance of the CPU?
Clock speed, cache size, number of processor cores.
What is cloud storage?
Cloud storage is stashing data on hardware in a remote physical location, which can be accessed from any device through the internet.
What are peripherals? Give an example.
Peripherals are external devices that provides inputs and outputs for the computer. Eg, Webcam.
Give some pros and cons to solid state storage and briefly explain how it works.
A solid-state storage device that uses integrated circuits as memory to store data. SSD uses microscopic electronic switches to store data. They have millions of transistors.
Cons
- More vulnerable to abrupt power loss and electromagnetic fields.
- Expensive
Pros
- They are fast as they have no moving parts. It transfers data very quickly.
- Very compact in comparison to other devices so its portable.
- Can store 100mb to 20GB of data.
Name some pros and cons to magnetic storage and briefly explain how it works.
A type of storage that is magnetised and uses platters. While the platters are spinning they will be read by a read/write head.
Pros
- Can store up to 1TB of data.
- It has a fast access and retrieval time compared to other devices.
Cons
- It’s usually inside the computer system and isn’t portable.
- Around £2 per GB / expensive
Name some pros and cons of optical storage and briefly explain how it works.
There are pits and lands which represent binary code. They are read from the disk using a laser.
Advantages
- Relatively cheap.
- It is fairly portable due to its size.
- Can store between 800MB and 50GB
Disadvantages
- This is slower than most other storage devices.
- Optical media is more durable than tape, HDDs and flash drives and less vulnerable to environmental conditions.
Explain the fetch-decode-execute cycle
- The processor checks the program counter to see which instruction will run next.
- Then the program counter gives an address value in the memory of where the next instruction is.
- The processor then fetches the instruction value from this memory location.
- Once fetched the instruction needs to be decoded and executed.
- Once complete the processor goes back to the program counter to find the next instruction.
- The cycle is repeated until the program ends.
Name the registers and their purpose
MAR (Memory Address Register) - holds memory location of data that is accessed
MDR (Memory Data Register) - holds data transferred
CIR (Current Instruction Register) - contains current instruction
What is the ALU?
Arithmetic Logic Unit - allows operations to be carried out
Name the buses and their uses
Address Bus - carries addresses of data
Data Bus - carries data everywhere
Control Bus - carries control signals and commands to CPU
Explain the fetch-decode-execute cycle
- The processor checks the program counter to see which instruction to run next.
- The program counter gives an address value in the memory of where the next instruction is.
- The processor fetches the instruction value from this memory location.
- Once the instruction has been fetched, it needs to be decoded and executed.
- Once this is complete, the processor goes back to the program counter to find the next instruction.
- This cycle is repeated until the program ends.
What is an embedded system?
A computer system that is designed for a specific function.
eg. cars, mobile phones
Pros and cons to cloud storage
Pros
- only pay for storage you use
- automatically backed up
- data available anywhere
Cons
- reliable network connection
- software will need to be its latest version
- dependant on speed of internet
