Tuesday, July 10, 2012

Yesterday, we learned how data is represented in a computer.  Today we will take a look at how it's *stored*.  We obviously have all of our data converted into bits...1s & 0s. Presence or absence.  The book calls this the PandA system.  Presence and absence looks different in different forms of media.

One of the most recognized hardware terms is the "hard drive".  Traditionally, that has referred to a spinning disk which stores data magnetically.

Let's see how a hard drive works!



Currently, data storage is moving toward solid state drives, which are less affected by movement.  Solid state drives are just great big repositories of flash memory.

"What about a CD or DVD?" you might ask.  Well, those are fun to look into also, especially dvd's that we can burn at home...those have dye inside!

Fascinating, isn't it? Let's use this to create a human data transmission/storage medium!


It looks like we get the idea behind data.  So, why do we need to know this stuff to program?  Well, we need to know this, because different types of data take up different amounts of space...but we can talk about that more later.  For now, let's just get back to our JavaScript!


If we start with a basic page, we can hop into the JavaScript world very quickly by adding <script> tags. Let's do it.