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2. Von Neumann layout

A diagram of the Von Neumann architecture is shown below.

von neumann architecture

Note that a 'computer architecture' is not an actual computer - it is an idea of how a computer should be built. So the features listed below are what a computer needs to have, based on the Von Neumann architecture idea.

Features of the Von Neumann architecture

The Von Neumann architecture
There is enough memory available to hold both programs and data. This makes it easy to change task by loading a different program. In modern computers this memory is RAM.
There is a Control Unit responsible for handling the movement of instructions and data around the computer.
Data and instructions are carried on buses (which are the arrows in the diagram above).
There is an Arithmetic Logic Unit responsible for carrying out calculations and logic comparisons.
There is a special type of memory called registers which do specific jobs. The Accumulator is one such register. There are many other types of registers.
There is a way of inputting data into the computer and a way to output information.

This architecture is so powerful, most computers today are built with this idea in mind.

However, the Von Neumann architecture does have some limitations which are discussed on the next page.

Challenge see if you can find out one extra fact on this topic that we haven't already told you
Click on this link: Computer architecture