Wednesday, June 6, 2012

Telegraph to Computer


I am taking the best course in computer science out there online for free!  The course is CS101 on coursera.com with the instructor Nick Parlante from Stanford University.  He is truly able to engage and educate about the basics of computer science, which has fabulous realistic comparisons between common objects and computer innards.

My curiosity about the computer is derived from the question, how did we get from the telegraph to the computer?  This seems like a giant leap, as I understand telegraph code with little effort.  The current section that I just finished in my course explains this process for me perfectly, and I filled in the blanks.  You see current in the body or in the computer can fire or not.  This is the only state in which electricity can exist, on and off.  We represent on and off with symbols 1 and 0. 

image from:  http://www.sxc.hu
This is the original computer code, 1 and 0, which is called a bit.  I guess if you are a computer programmer you can say I don’t like this one bit, or you can say I don’t like this zero bit, and in their culture they would completely understand and perhaps even laugh, snort, or snicker.

To get a byte, which is another term you need eight bits.  There are eight bits to a byte and there are 256 different patterns and 255 combinations plus one absence of combination called 0 out of those eight bits.  Each pixel has a red, green, or blue number between the 0 and 255.  At this point if you have an interest in computers, or you have stared at specs as you tried to purchase one, you will know that 256 is former popular number, and bells are sounding in your head with “oh,” and “now that makes sense.”  What I don’t know is why did they choose eight bits to each byte?  Is this a feng shui lucky number?  I am not sure but I would love to know why 8.

We took the telegraph signal and we invented something to process the task, a CPU (central processing unit) and then we keep multiplying the amount of processing that the CPU can process.  We added memory that we store for awhile (short term memory or RAM) and we have things we hope to keep forever (long term memory or hard drive).  This is how we ended up evolving from a telegraph to a white and black jumping jack on the display in the corner of my Commodore 256 computer.

So if you have a kilobyte you have one thousand bytes of information for a computer to decipher, while megabytes get one million and gigabytes get a billion.  (We are going to avoid the kibibyte discrepancy here for simplicity sake.)  I want a Googolplex of bytes and I want them to call it an oogolbyte in memory of my child like sensibilities.  We are currently doubling the amount of bytes according to Moore’s law every 18 months, so perhaps in my lifetime I will get to see this.  

Of course then there is speed, "I have a need, a need, for speed (Movie:  Top Gun, 1986)."  Speed is measured in the same measurement as electricity, hertz, typically GHz gigahertz which is a billion hertz that gets things spinning in our computer machines one spin or cycle or hertz at a time.  This will lead us back to the need for power, not human lust for power, but energy in this Oogleplex new world I have building in my head... but that is for another post on another day.

Thank you Nick Parlante from Stanford!  

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