Subtitles of the Movie

Let's start with the most basic of topics when we're talking about A Plus and that is how the PC actually works. Now what we're getting at here is the four main aspects of the PC that you're going to be tested on. But first of all, let me kind of draw a very over simplified diagram here of what's going on. First off you have a PC, right? You have a keyboard, a monitor, and then the ah the actual computer itself, or the, some people will call this the CPU although that's not really what it is, but ah, anyway, here's your total computer, right? There's your main components. Now understand this. Your computer only understands two things, that's zeros or ones. Everything that happens inside that PC is reduced to a zero or a one. And so any time that we type on the keyboard, so, so we type on the keyboard here and for example, we type in the letter A. Okay. What happens is, is for the computer to understand what that is we have to convert that to a binary number. So, again, oversimplify but what happens is, is that with this, with this, ah, binary ah, way of, of doing numbers the first thing our computer does, it says, Okay, we're going, I'm going to send you some numbers, okay. I'm going to send you two groups of numbers. The first group that I'm going to send over to the processor tells me what kind of data's coming through and it's telling, it's a letter, ah that somebody's typed a letter on the keyboard, and then this number tells it what letter was typed. For example, I believe it's ah, I believe A is the ah, has that an ASCII ah character set number of 42; I may be wrong on that. But, if it's 42 then this would send a binary number saying, Hey, this is a character and then this number would be the binary number for 42. And the computer would then know to render on the screen the letter A because that's what you typed. Now I hope that makes sense. Again, oversimplified, but pretty much what's happening. Now what's happening is, is as we type these things inside the computer we have a motherboard, and we'll talk a lot more about this later. But the motherboard holds all the components and pieces and connects them together, and notice these little lines on here, and so when we type that information gets sent right here to this central processing unit, or the CPU, and it's seeing a string of these numbers. Now based on what it sees, it passes that off to memory, or somewhere else, to wherever it needs to be, whatever kind of processing needs to happen. Okay. And so, then the computer at that point, the CPU, ah, using the RAM interacts with the applications running on the, ah, the actual computer itself. And so if we've got like Microsoft Word open we type, the CPU converts that into letters and so forth, passes it off to Microsoft Word and we see the letter A appear on our screen. So that's what's happening. But keep in mind everything that's happening are zeros and ones. Now, another aspect of our computer is the fact that we have disks or hard drives inside the computer as well. Now, the hard drive plugs into the motherboard, and so anytime anything on the motherboard or anytime the computer needs to store something, it simply pushes it up to the hard drive. And guess what is stored on the hard drive? It's recorded on the hard drive a series of zeros and ones. So if you could actually see what's on your hard drive you would see nothing but zeros and ones spread all over that thing. And so when say that we have a 60 gig hard drive that means that it can store 60 gigabytes of zeros and ones. That is a tremendous number of zeros and ones, okay. So, that's basically what's happening. Now, when we open a file on our computer, we're simply reading off the hard disk, we're reading all the zeros and ones, the CPU and other components here are translating that back into something that's English-readable, ,and it appears on our screen. But again, keep in mind, all the computer sees is zeros and ones. Now, this is broken down ah, on the ah, exam as the four basic functions of a computer. Number one is input. That is when, when we interface with a computer and through a keyboard, a mouse, a ah stylus, touching the screen, whatever, we're actually giving the computer input. This is being converted into zeros and ones. Processing is what happens once it gets to the motherboard. Most usually the CPU, and processing takes place. And it's either hooked up to another application or the main operating system does something with it. Then output happens. We're going to print it to a piece of paper. We're going to write it onto our hard disk. We're going to do you know something with it, but output happens and then storage happens. And storage is where we put it on any kind of media. We, we put it on a disk. We push it across the network to a disk location. We write it onto a thumb drive. So we've got input, processing, output, and then actual storage. And so those are the four main phases or functions of a computer. And again, keep in mind this is all happening through a number system called binary, which reduces any number out there into a series of zeros and ones and we'll talk about binary in a little bit more detail a little bit later on. So your job then is going to be to troubleshoot what's happening if there's trouble with the computer. Is it the input processing, output or storage phase, and from there we'll learn and more in-depth, how each of these stages works and some of the intricacies of them and some of the common problems that you'll have with them.