Paper 1 Mock - Exam Specification

How does Parallel processing increases the performance of a computer?

• Parallel Processing executes multiple instructions concurrently by dividing each instruction into a single core.

Array

• Static

• Mutable

• Contiguous in Memory

Fixed in memory once declared (Static), stored contiguously in memory (next to eachother) and has fast access times, and it's mutable (can change the elements contents)

Linked list

• Dynamic

• Mutable

• Not stored contiguously in memory

Not stored contiguously (next to eachother in memory), it's Dynamic (can add more elements), you can simply change the pointer to replace an element therefore it's dynamic, and it's mutable (can change the elements contents)

Queue

Follows a first in first out principle, the first item that enters the queue is the first item out.

Stack

Follows a first in last out principle, elements are pushed onto the stack and popped from the stack. The first element to be popped from the stack is the last element placed onto the stack.

Multithreading

Allows a program to run multiple tasks at once.

Compiler

Takes your entire program and translates it into machine code all at once and turns it into an executable file.

Interpretor

Reads your code line by line while it runs with no separate executable.

What is scheduling?

A method used by the operating system that decides which process to run next ensuring the CPU runs at its maximum potential.

First come first serve

The first process to enter the ready queue is the first process to be executed.

Shortest job first

The process in the ready queue that takes the shortest amount of time to be executed is executed first.

Round Robin

Where each process is allocated a fixed amount of time known as a time slice.

The CPU/Processor

Executes instructions which allows programs to run.

Arithmetical Logic Unit

Executes all arithmetical and logical operations.

Shortest Remaining Time

Executes the process in the ready queue which takes the shortest amount of time to be executed. However, since it's pre-emptive it suspends the current process if a higher priority process joins the ready queue.

Multi-level feedback queue

Using multiple ready queues each with a different scheduling algorithm and processes can move between queues as their priorities change.

ROM

Stores the instructions your computer needs to startup such as firmware and bios. Non-volatile (holds contents even when no power) and can not be modified.

RAM

Temporarily stores instructions. Whenever a file or program is opened it is loaded into RAM. Non-volatile, loses its contents when there is no power.

Paging

A memory management where all pages are fixed sizes, sections of memory and are physical divisions.