The Rise of the Microprocessor.........

The microprocessor got into main stream computing some time in the 70s. Before that microprocessor and its smaller cousins -microcontrollers were used to control electro-mechanical systems, like perhaps the door of a space craft.

Von Neumann/harvard architecture and the Stored Program Concept.

In simple words,what all the processors do is Fetch,Decode,Execute. Fetches an Instruction and data from memory , decodes this instruction - decoding is the step where the processor figures out what it has to do with the data , perhaps the instrution is a simple addition or may be a complex multiplication like in a game.

This sequence of operation looks fairly simple and this is what exactly happens if you are doing a single task - like may be playing an Mp3 on the Computer.

But it is not this simple in todays computer - it has to do a million tasks at the same time.
so what the processor does is sends a chunk of data to your sound card to play that music and goes back an Idle state or perhaps goes back to fetch data from ethernet to display on your browser. When the sound card is done playing the chunk of music..it sends a signal to the processor asking for more sound data, the processor then SUSPENDS all the task that it was doing for you ..goes to throw another chunk of sound data ino the buffer of the sound card.
Ofcourse there is an elaborate mechanism that governs this switching between the tasks.

A Little Test :- If you run Windows Try the following thing. Open the Task Manager and click the performance Tab. Here you will see the Usage of the Processor. The usage when you are doing nothing will be between 0-10%. Now open a simple 'Notepad' window. Put the mouse on the Title bar and drag the Notepad window across the screeen back and forth repeatedly. You will see that the processor usage suddenly shoots to 100% and stays there..till you stop dragging the Notepad Window... Surprised ????....I would call this poor software (MS!!) design..!!

THE General Puspose CPU that runs Windows:-
So far what we have discussed is a processor that has eventually become a Jack of all Trades and Master of none. Most software writers are have no idea of the hardware beneath..that is kept hidden by the 'visual software tools'..These development tools add lines and lines of useless code that decreases the overall perfromance. The more close language to the hardware , the faster will be the performance. C language is more closer to the hardware than Visual C. Assembly Language directly talks to the hardware and is even more closer to the hardware than say C

Coming Next - Is the personal computing Industry Maturing ?????

posted by netrama @ 5:01 PM