Showing posts with label von Neumann. Show all posts
Showing posts with label von Neumann. Show all posts

Wednesday, 15 August 2012

The Von Neumann Model


The man you see before you is  John von Neumann, an early computing pioneer. From what I've read so far I can establish that this guy is a pretty big cheese and is credited with the general model that computers are constructed by today. I plan to do a outline history of computing soon with all the major players and their contributions so if you were expecting an interesting article on all of von Neumann's contributions you will have to wait till I write that as this article is actually just an introduction to his 'model'.


John von Neumann

As far as writing about Neumann's life goes my knowledge of him is pretty slim at this moment in time, I will however, in the future plan to do an in-depth piece on him, for now however I am more concerned about his contribution to computer science and what that contribution means to me and you.

 Essentially von Neumann established a model that computers should follow that was logical and effective in its design. This 5 part model describes the form your computer takes underneath all of its hardware and shiny cases.

 Neumann states;

 There are Five major components within the computer system:

 The first is an Input Device
              - This element sends data and information to the system. This information and data is then stored in the next component.

 The Memory Unit
              - The instructions and data are then processed by the next component.

The Aritmetic Logic Unit (ALU)
             - The operation carried out within the ALU are carefully guided by the next component.

The Control Unit
             - To which the results of the ALU and Control Unit's work is sent to the final component.

The Output Unit.
             -Which would be your monitor or your printer.


 This simplified breakdown of what a computer is made up of makes its a bit easier to grasp harder concepts in computer architecture as it allows you to picture in your heads the basic outline of the computers structure. This however is an unfinished model and if we were to add a bit of extra detail to make it a little more complete and a little bit more accurate to today's computing systems we would have to mention the System Bus Model.

  As mentioned previously in another article (here) a bus is basically a method to quickly transport data from one component to another. The system bus model essentially partitions a computer into three sub-units:
 CPU / MEMORY / I/O
These three sub units are the five units established in the von Neumann model only grouped by their purpose.  This refinement of the von Neumann model combines the ALU and Control Unit into one functional unit - CPU. This model also combines the Input and Output units into a single I/O unit.

 The system bus links all these components on a shared pathway made up of:
The Data Bus - Carries the information being transmitted
The Address Bus - Identifies where the information is being sent
The Control Bus - Describes aspects of how information is being send and in what manner

:)


-As I have mentioned previously I will update older articles as my understanding of the concepts within develops so if you find this a rather breif introduction to von Neumann and the basic form of the computer, do not worry I am learning all the time and will update when I have found anything considerable to add. If you have anything else you believe to be worthwhile drop us a comment and I'll add it in. Thanks.

Tuesday, 14 August 2012

The Spirit of Computing


An amazing quote about what computing should be for programmers;

``I think that it's extraordinarily important that we in computer science keep fun in computing. When it started out, it was an awful lot of fun. Of course, the paying customers got shafted every now and then, and after a while we began to take their complaints seriously. We began to feel as if we really were responsible for the successful, error-free perfect use of these machines. I don't think we are. I think we're responsible for stretching them, setting them off in new directions, and keeping fun in the house. I hope the field of computer science never loses its sense of fun. Above all, I hope we don't become missionaries. Don't feel as if you're Bible salesmen. The world has too many of those already. What you know about computing other people will learn. Don't feel as if the key to successful computing is only in your hands. What's in your hands, I think and hope, is intelligence: the ability to see the machine as more than when you were first led up to it, that you can make it more.''




Alan J. Perlis (April 1, 1922-February 7, 1990)



Thursday, 9 August 2012

Gentoomen - Giant book torrent

I did mention I needed to build up some relevant literature to start building up my knowledge base, so I found out about this 36G torrent that holds an impossibly massive libary on just computer science texts that cover every relevant subject imaginable. It truly is epic. I mean I have had it on download all day today, total of about 12 hours and it still has seven left and I have a average download speed of 1.1M, I appreciate that isn't massive but its not bad.






As far as general progress on my quest is going it is still very early days and I am currently finishing the How Computers Work book, so expect a full review shortly plus some extra recap notes and something a little more in-depth and technical.