Von Neumann Architecture (Edexcel GCSE Computer Science)

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The Von Neumann Architecture is a design of the CPU which was proposed by Mathematician John Von Neumann in the 1940s, which most general-purpose computers are built upon
The Von Neumann Architecture outlines how the computer memory, input / output devices and processor all work together
It is known as the stored program concept, storing both programs (instructions) and data in the same memory (RAM)

A computer needs main memory because access times are considerably faster than secondary storage
This means the time taken to complete operations such as the Fetch-Decode-Execute Cycle is dramatically reduced
Main memory holds the data and instructions that the CPU needs to access whilst the computer is turned on
Due to the fast access times, main memory is used as short term, working memory
Performance of main memory means a much higher cost which limits the amount that is used
For example, RAM is commonly purchased in 16 or 32 gigabytes whereas secondary storage such as a hard drive is in terabytes

RAM (Random Access Memory) is main memory that is directly connected to the CPU and holds the data and instructions that are currently in use
RAM is volatile which means the contents of RAM are lost when the power is turned off
For the CPU to access the data and instructions they must be copied from secondary storage
RAM is very fast working memory, much faster than secondary storage
RAM is read/write which means data can be read from and written to
In comparison to ROM, it has a much larger capacity

ROM (Read Only Memory) is main memory that holds the first instructions a computer needs to start up (Bootstrap)
ROM contains the BIOS (Basic Input Output System)
ROM is a small memory chip located on the computers motherboard
ROM is fast memory, much faster than secondary storage but slower than RAM
ROM is non-volatile which means the contents of ROM are not lost when the power is turned off
ROM is read only which means data can only be read from
In comparison to RAM, it has a much smaller capacity

A smart television allows the user to search the Internet and watch videos online.

The smart television uses RAM

Give two examples of data that the smart television could store in RAM [2]

How to answer this question

Think about the main function of a smart television, watch channels, use apps to stream content and browse the web etc.
For each function, try to think of what data would have to be in the RAM whilst you were actually doing it (in use!)

Possible answers

to absolutely everything:

the (exam) results speak for themselves:

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