Computing

• What is a general purpose machine?


  A device that can perform multiple different tasks
• What are the 3 building blocks of a computer?


  Input - capturing of data

  Processing - Turing data into information

  Output - information displayed or produced
• What is an embedded system?

  A dedicated system designed for a specific purpose.
• What are examples of an embedded system?

  Microwave, washing machine, security system
• What are the characteristics of an embedded system?

  A simpler interface

  A limited operating system

  Uses up less processing power

  Cannot be easily updated/repaired by a user
• What is hardware?


  The physical components of a computer, e.g. mouse, keyboard
• What is software?


  The programs and other operating information run by the computer e.g. websites such as Chrome.
• The CPU processes, all of the data and instructions that make a computer system work.

  True
• What does the control unit do?

  Send signals and manages components by decoding and executing instructions
• What does the arithmetic and logic unit (ALU) do?

  Calculates operations and manages logic
• What does RAM/Main memory do?

  A temporary store of currently running programs
• What do register do?

  Small very fast memory locations
• What does the accumulator do?

  Stores results of calculations in the ALU currently being read/used
• What does the program counter do?

  Holds the memory address of the next instruction to be fetched
• What does the memory data register (MDR) do?

  Temporary store of data fetched from or written to the RAM
• What does the memory address register (MAR) do?


  Holds any memory address about to be used or currently being used by the CPU.
• What is the fetch decode execute cycle?

  It's the basic operation cycle of a computer. It is the process by which a computer retrieves a program instruction from its memory, determines what actions the instruction requires, and carries out those actions.
• What are the factors affecting the performance of the CPU?


  Clock speed, number of cores, cache memory

  ( + Bus width)
• What is system software?


  Software which controls the hardware and software of a computer
• What is application software?


  Software programs which allows the user to perform a task
• What is an operating system (OS)?


  Provides a way for users to interact with computers and run applications
• What does an OS do?

  It determines how much memory the program requires and then allocates enough pages to hold it and it's documents
• What are the functions of an OS?

  Manages all peripheral devices

  Manages the memory

  Manages loading and running programs

  Manages the file system

  Manages security

  Manages error messages

  Manages the interface
• What are device drivers?

  small programs that tell an OS how to use a piece of hardware
• What is memory management?

  Ensures that more than one program can run at the same time
• What is memory broken down into?

  Fixed-size blocks, known as pages
• What is virtual memory?

  When the RAM runs out of space and the Hard Disk has to be used as if it were the RAM, to load and view additional software applications
• What are file backups?

  - full backups (everything backed up)

  - incremental backups (only backs up files recently created or edited
• What is anti-virus software?


  scans through your system looking for infected files and fixes them
• What is anti-spyware software?

  removes pop adverts or malicious recordings of key strokes
• What are firewalls?


  Uses filtering to prevent access to unsuitable sites from a network
• What is encryption?


  if any files get corrupted or stolen, they cannot be read without a key
• What is defragmenting?


  the hard disk reorganises files, so they are stored together contiguously
• What is system maintenance?

  provides detailed feedback on how the computer is running
• What is system clean up?

  utilities will look through your computer for these files and automatically remove them
• What is system formatting?

  ensures all files can be read in the correct format