1 00:00:06,100 --> 00:00:07,240 Everybody what's going on. 2 00:00:07,240 --> 00:00:14,260 This is Caleb with Dev slopes dot com and in this video we're going to be discussing how computers work. 3 00:00:14,290 --> 00:00:18,550 Now if you've ever asked that question of somebody you know how does a computer work. 4 00:00:18,550 --> 00:00:24,310 You may have heard you know one two three different things but I think most of all what you hear is 5 00:00:24,310 --> 00:00:26,770 people will just say binary. 6 00:00:26,770 --> 00:00:28,650 They'll just say it's binary runs on binary. 7 00:00:28,660 --> 00:00:30,610 That's the only thing a computer can understand. 8 00:00:30,790 --> 00:00:34,780 Well great but that doesn't actually tell us how computer works. 9 00:00:34,780 --> 00:00:38,890 How does my input into the computer turn into binary. 10 00:00:38,980 --> 00:00:42,010 And that's exactly what we're going to talk about in this video. 11 00:00:42,010 --> 00:00:48,000 Now from the beginning we're going to just use a simple example of a keyboard pushing a key on a keyboard. 12 00:00:48,070 --> 00:00:49,630 How does that key press. 13 00:00:49,630 --> 00:00:56,170 How does that physical action from me the user translate into binary data that's then displayed on my 14 00:00:56,170 --> 00:01:01,030 computer screen as whatever letter I pushed or whatever keystroke I pressed. 15 00:01:01,210 --> 00:01:07,170 So for example we have our keyboard maybe it's plugged into our computer via US B. 16 00:01:07,330 --> 00:01:12,240 Maybe it is Bluetooth or even in the past if you're on an old school machine you're using what's called 17 00:01:12,280 --> 00:01:12,990 P.S. 2. 18 00:01:13,000 --> 00:01:16,650 That's a type of connector for a keyboard and also a mouse. 19 00:01:16,690 --> 00:01:23,260 But anyway we have our keyboard and what's going to happen is when we push a key on our keyboard that's 20 00:01:23,260 --> 00:01:30,190 going to get sent into the computer through the USP port or over Bluetooth or two and it goes into the 21 00:01:30,190 --> 00:01:34,840 motherboard of our computer and it runs into something called the BIOS. 22 00:01:34,840 --> 00:01:35,310 OK. 23 00:01:35,470 --> 00:01:42,090 Now BIOS that's an acronym and it stands for basic input output system. 24 00:01:42,100 --> 00:01:42,880 All right. 25 00:01:42,880 --> 00:01:49,840 Now just like it sounds it handles the input and output of data and information into the C.P. you which 26 00:01:49,840 --> 00:01:52,410 is the central processing unit. 27 00:01:52,420 --> 00:02:01,570 Now if you are around technology a lot you probably know these words you know BIOS CPQ GPU ram you probably 28 00:02:01,570 --> 00:02:06,160 know all these words so I'm not going to overly explain them and if you want to look up these individual 29 00:02:06,160 --> 00:02:11,100 components you are more than welcome to go google them look them up yourself. 30 00:02:11,290 --> 00:02:17,290 But what you need to know CPQ is the central processing unit that's the brain of our computer that handles 31 00:02:17,950 --> 00:02:21,370 processing and doing all the different calculations that it needs to do. 32 00:02:21,370 --> 00:02:28,150 So what happens is my keystroke goes into my USP port and it meets the BIOS. 33 00:02:28,150 --> 00:02:31,720 Now the BIOS acts like a bouncer outside of a club. 34 00:02:31,810 --> 00:02:36,940 You know they're standing there in front of the door all cool probably with their sunglasses and people 35 00:02:36,940 --> 00:02:41,520 who are on the list people who are good to go they get to go directly into the club. 36 00:02:41,890 --> 00:02:47,290 But people who are not on the list either have to wait or they don't get into the computer. 37 00:02:47,290 --> 00:02:53,910 Now that's what the BIOS does is it handles the input and output of information into the CPQ. 38 00:02:54,190 --> 00:03:01,660 Now what it's going to do is it's going to go ahead and intercept all input like keyboard data mouse 39 00:03:01,660 --> 00:03:08,050 data Wi-Fi even if you have a wife card Internet access anything that goes into the computer is going 40 00:03:08,050 --> 00:03:09,710 to get handled through the BIOS. 41 00:03:09,710 --> 00:03:11,230 It's like a gatekeeper. 42 00:03:11,320 --> 00:03:16,900 Now what's going to happen is when I push a key on my keyboard the BIOS says yep you're good. 43 00:03:16,900 --> 00:03:18,070 This is important. 44 00:03:18,070 --> 00:03:25,120 So the BIOS allows that keystroke information to go through into the you and the CPP you is going to 45 00:03:25,120 --> 00:03:31,120 then fetch instructions from memory card that are stored on the computer on how to use these devices 46 00:03:31,120 --> 00:03:32,880 like the keyboard like the mouse. 47 00:03:33,010 --> 00:03:39,280 And then what it's going to do is it's going to execute those instructions billions of times every second. 48 00:03:39,440 --> 00:03:45,880 OK there are billions of calculations and operations that your Sipah is doing every single second now. 49 00:03:45,880 --> 00:03:52,210 Immediate tasks like mouse clicks and keystrokes things like that get sent in right away they get handled 50 00:03:52,210 --> 00:03:53,050 right away. 51 00:03:53,050 --> 00:03:57,640 But other things that are not as urgent can be prioritized and rearrange. 52 00:03:57,640 --> 00:04:02,620 That's the amazing utility of the BIOS in the C.P. working together. 53 00:04:02,720 --> 00:04:11,320 Now each task on your computer has for lack of a better term a program stored in OK so your mouse there 54 00:04:11,320 --> 00:04:19,960 is a set of code files that explain how the Sipa you should handle mouse input if a mouse input comes 55 00:04:19,960 --> 00:04:26,830 in the BIOS sends it to this EPU then finds the mouse program and says OK I got this input from this 56 00:04:26,830 --> 00:04:27,490 device. 57 00:04:27,520 --> 00:04:28,610 What do I do with it. 58 00:04:28,810 --> 00:04:35,800 And that is where we get our input that's how input is handled now of course this is a very simple overview 59 00:04:35,800 --> 00:04:40,840 it's not an extremely scientific overview but we're going to go ahead and dive in a little deeper so 60 00:04:40,990 --> 00:04:46,810 it's not only physical devices in our computer although sometimes it is like our keyboard our mouse 61 00:04:47,230 --> 00:04:55,180 maybe our audio card our Internet or our Wi-Fi chip whatever it is each little device and task has a 62 00:04:55,180 --> 00:04:55,960 program. 63 00:04:56,110 --> 00:05:02,560 Even things like the clock or connecting to the Internet or managing user accounts everything has a 64 00:05:02,560 --> 00:05:06,800 little program and has some code that tells it what it should do and how it should work. 65 00:05:06,800 --> 00:05:11,670 Now these were originally written in human programming languages of course if you're dealing with a 66 00:05:11,670 --> 00:05:17,460 computer like Mac OS Windows or Linux Those were all built by humans in human programming languages 67 00:05:18,120 --> 00:05:20,210 but they tend to be quite large. 68 00:05:20,210 --> 00:05:23,810 They tend to contain things that a computer doesn't always need. 69 00:05:23,820 --> 00:05:29,910 Right but when they are compiled when they're actually built they get converted into what's called assembly 70 00:05:29,910 --> 00:05:36,540 language and assembly language actually has to do with moving bits and pieces of information around 71 00:05:36,600 --> 00:05:41,580 in different registers in your CPQ in a register is basically just a space that's going to hold some 72 00:05:41,580 --> 00:05:46,650 information but a computer can't actually understand assembly language. 73 00:05:46,650 --> 00:05:53,370 That's a kind of an intermediary between a computer language and a human understandable programming 74 00:05:53,370 --> 00:05:54,160 language. 75 00:05:54,450 --> 00:05:59,790 So after it gets converted into assembly language it gets converted into something called machine language 76 00:06:00,300 --> 00:06:05,730 which basically is an intermediary between assembly and binary. 77 00:06:05,730 --> 00:06:12,810 Then after it gets converted into machine language it gets converted down into binary binary is really 78 00:06:12,810 --> 00:06:15,780 the only thing a computer can understand. 79 00:06:15,780 --> 00:06:22,590 Now in our keyboard example when a key on the keyboard is pressed a signal is passed in from the keyboard. 80 00:06:22,620 --> 00:06:25,610 The BIOS allows the input through like we said. 81 00:06:26,370 --> 00:06:32,820 And then the request for the keyboard program is accepted and then it requests that that keyboard program 82 00:06:32,820 --> 00:06:33,840 gets run. 83 00:06:33,840 --> 00:06:37,810 Now how does the BIOS know what key was pressed. 84 00:06:38,090 --> 00:06:38,670 OK. 85 00:06:38,790 --> 00:06:43,920 On a traditional keyboard I can think of like in a mechanical clicky keyboard there is something called 86 00:06:44,100 --> 00:06:52,080 the key matrix where basically there are long stretches of a wire essentially and each letter each key 87 00:06:52,080 --> 00:06:54,480 on your keyboard has a contact point. 88 00:06:54,480 --> 00:07:02,100 Now when the key is up it's not making contact but when it pushes the metal contacts then the electricity 89 00:07:02,100 --> 00:07:05,200 of course that's coming in from the USP port. 90 00:07:05,220 --> 00:07:10,710 Essentially what that's doing is it's going in and whenever there's a contact made that contact gets 91 00:07:10,710 --> 00:07:13,420 sent to something called the keyboard's ROM. 92 00:07:13,420 --> 00:07:13,900 OK. 93 00:07:14,220 --> 00:07:18,270 And the ROM is basically a chip on the computer that stores a program. 94 00:07:18,300 --> 00:07:20,780 It can't be written to but it can be read from. 95 00:07:20,970 --> 00:07:29,460 So the ROM holds a program that essentially converts this key press maybe is key number 26 OK and when 96 00:07:29,460 --> 00:07:33,960 the electricity comes through when we make that contact it's going to run all the way over to the RAM 97 00:07:34,260 --> 00:07:38,600 or the RAM sorry and it's going to say OK key 26 that is an F.. 98 00:07:38,730 --> 00:07:39,450 Right. 99 00:07:39,450 --> 00:07:40,400 That's pretty cool. 100 00:07:40,530 --> 00:07:45,150 And then the ROM is going to send that information into the computer through the BIOS. 101 00:07:45,150 --> 00:07:45,880 OK. 102 00:07:46,290 --> 00:07:50,020 In binary it gets written down into binary and it gets sent directly into the CPQ. 103 00:07:50,490 --> 00:07:53,730 Then of course the keyboard program gets brought up. 104 00:07:53,760 --> 00:08:00,450 And it says OK this binary code for the letter F needs to produce an F on the screen so then the keyboard 105 00:08:00,450 --> 00:08:06,810 program can pull up the screen program and display the key on the screen they work together it's very 106 00:08:06,810 --> 00:08:07,930 very cool. 107 00:08:07,940 --> 00:08:14,130 Now this is obviously a really simple example but you can see how various devices would work together 108 00:08:14,130 --> 00:08:19,140 to do this whether it's a printer over USP whether it's a mouse over Bluetooth. 109 00:08:19,290 --> 00:08:21,990 They all sort of work the same way. 110 00:08:21,990 --> 00:08:23,850 Input goes into the BIOS. 111 00:08:23,880 --> 00:08:30,150 The BIOS lets it into the C-p which polls open a particular program that particular program is run because 112 00:08:30,150 --> 00:08:35,550 it knows how to handle the input from a certain device and then those programs can work together to 113 00:08:35,550 --> 00:08:40,180 display information and make changes on your screen which is really cool. 114 00:08:40,180 --> 00:08:42,430 Now back to binary. 115 00:08:42,900 --> 00:08:43,860 Why use binary. 116 00:08:43,860 --> 00:08:48,380 Wouldn't it be easier to just use a human understandable programming language. 117 00:08:48,450 --> 00:08:48,900 No. 118 00:08:48,900 --> 00:08:52,970 Like I said a computer can only understand binary. 119 00:08:53,220 --> 00:08:54,110 But why is that. 120 00:08:54,120 --> 00:08:55,350 That's a great question. 121 00:08:55,380 --> 00:08:59,970 And when people say that our computer can only understand binary that's not helpful it doesn't tell 122 00:08:59,970 --> 00:09:00,830 you why. 123 00:09:00,950 --> 00:09:01,940 But I'm about to. 124 00:09:02,040 --> 00:09:08,200 So what you need to know for now is that binary is simply ones and zeros. 125 00:09:08,310 --> 00:09:15,900 You may have already known that but it's uses a system of numerical notation of base 2 instead of base 126 00:09:15,930 --> 00:09:19,860 10 like our decimal number system based to has two values. 127 00:09:19,860 --> 00:09:22,320 Like I said 1 and 0. 128 00:09:22,650 --> 00:09:28,410 Now in the electronics world this is where it becomes very important for computers in the electronics 129 00:09:28,410 --> 00:09:29,100 world. 130 00:09:29,100 --> 00:09:33,640 There is a device a tiny tiny device called a transistor. 131 00:09:33,660 --> 00:09:38,510 It changed the world as we knew it in 1947 at Bell Laboratories. 132 00:09:38,510 --> 00:09:41,830 K that's the research arm for AT&T. 133 00:09:41,910 --> 00:09:42,990 If you didn't know that. 134 00:09:42,990 --> 00:09:48,190 Now basically a transistor has three pins sticking out of a little device. 135 00:09:48,510 --> 00:09:55,980 And one pin is called the emitter one pin is called the base and one pin is called the collector K.. 136 00:09:56,070 --> 00:10:02,280 Now electricity can flow from the collector to the emitter but that's controlled by the base pin as 137 00:10:02,280 --> 00:10:04,220 sort of like an electric switch. 138 00:10:04,540 --> 00:10:10,510 If a small amount of current is placed on the base pen it allows a larger amount of current to flow 139 00:10:10,510 --> 00:10:14,080 from collector to emitter which is very very cool. 140 00:10:14,080 --> 00:10:18,640 Now of course in a computer if you think about that there's all these signals coming in and electricity 141 00:10:18,640 --> 00:10:26,940 flowing in when it gets converted down to binary zero can represent off and one can represent on. 142 00:10:26,950 --> 00:10:33,580 So if we want electricity to flow through a certain number of transistors we can apply a zero to the 143 00:10:33,580 --> 00:10:35,840 base pin of one transistor so it's off. 144 00:10:35,950 --> 00:10:41,430 We can apply one to the base pin of another transistor so it's on and then another one on and it will. 145 00:10:41,470 --> 00:10:46,720 It allows for the current and electricity to flow from transistor to transistor. 146 00:10:47,020 --> 00:10:53,350 And of course there are tons of different examples of ways to combine transistors in very complex ways. 147 00:10:53,350 --> 00:10:57,400 But basically these transistors make up our CPQ. 148 00:10:57,490 --> 00:11:03,730 So when the binary gets sent in we're turning off and turning on millions and millions of transistors 149 00:11:04,210 --> 00:11:08,940 the average CPQ has more than one hundred million transistors inside of it. 150 00:11:08,950 --> 00:11:14,560 Tiny little microscopic transistors which is fascinating because the original transistor was about this 151 00:11:14,560 --> 00:11:17,940 big about two inches by two inches it was huge. 152 00:11:17,950 --> 00:11:24,880 So the fact that we have microscopic transistors is incredible now because of the transistors simple 153 00:11:24,910 --> 00:11:26,120 ON-OFF design. 154 00:11:26,200 --> 00:11:31,660 It makes it perfect for working with binary because a one is on and a zero is off. 155 00:11:31,660 --> 00:11:33,600 But why should we really care. 156 00:11:33,910 --> 00:11:37,780 Well programming languages are human readable languages. 157 00:11:37,900 --> 00:11:43,900 OK that eventually make their way down to binary in order to control certain behaviors and elements 158 00:11:44,170 --> 00:11:50,560 of the devices that we use programming languages facilitate the turning on and turning off of hundreds 159 00:11:50,560 --> 00:11:55,460 of millions of transistors billions of times every second. 160 00:11:55,480 --> 00:11:56,270 It's amazing. 161 00:11:56,270 --> 00:12:02,970 So this is kind of a brief overview here of how computers work information gets sent into the BIOS. 162 00:12:02,980 --> 00:12:09,070 The BIOS allows information into the Sipa you which then request programs from memory to understand 163 00:12:09,280 --> 00:12:15,490 how that binary data should be interacted with those programs of course turn on and off the transistors 164 00:12:15,490 --> 00:12:21,650 in the you in just the right sequence to allow the information in to display information on the screen. 165 00:12:21,670 --> 00:12:27,640 It's mind blowing mind numbing if you think about it too much so this is an overview of how computers 166 00:12:27,640 --> 00:12:28,010 work. 167 00:12:28,000 --> 00:12:29,430 It's absolutely fascinating. 168 00:12:29,430 --> 00:12:32,550 So let's head over to the next video now where we're going to continue learning. 169 00:12:32,560 --> 00:12:34,570 This is Caleb with Deb's slopes dot.com.