| 00:14 | anybody Remember what we discussed early? . Okay. Sorry. Anything |
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| 00:41 | Yeah, I'm sorry. Okay. . It's where? So this is |
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| 02:00 | a review for what? We More or less. Maybe with a |
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| 02:04 | different angle. This'd problems for but they need very precise instructions. |
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| 02:15 | they can just say, you do this. And they They're do |
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| 02:19 | if you're talking about the real hard of a computer. But if you're |
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| 02:23 | the computer, they can do a of things. So you still need |
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| 02:26 | design a solution on the computer like U. There's not even 1,000,000 |
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| 02:37 | I mean, you could you think a problem that take you, but |
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| 02:59 | . A week? Yeah. Something . Fine. All the numbers |
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| 04:26 | You tell the computer it does it you. So we were just getting |
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| 04:31 | in the frame off. What And then we'll transition to the other |
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| 04:38 | is you need to tell you defend and essentially the way this works. |
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| 05:06 | that right? Solutions a little bit . Um, So once again, |
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| 05:23 | do you need to go to solve problem? Developer, detail solution. |
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| 05:29 | this is something we colored. And you write it up in a programming |
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| 05:33 | and programming languages instead. The dance heart out and we'll talk for a |
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| 05:40 | minutes today. It wants a You thought that reasoning worked out? |
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| 05:55 | only one more pain I think it . What is that? Is this |
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| 06:20 | ? Well, uh, it's a thing is very so the This is |
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| 07:56 | in solving difficult problems. S this is something you touched on last |
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| 08:02 | that. Hurry. So you just on a couple of things working on |
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| 08:45 | That's another way is to divide the , this complex problem into smaller pieces |
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| 08:54 | get the whole difficult thing done in down. Sometimes you refer to is |
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| 08:59 | program. Okay, Does that make ? Any questions so far? |
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| 09:12 | No languages, as we mentioned, speaking and exactly right e so clearly |
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| 09:42 | know exactly what that's zeros and ones any reasonable time. So then way |
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| 10:00 | thing there Is that made any No. So this, of |
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| 10:55 | is probably 50 years, 50 years so, Eso But that's still not |
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| 11:04 | enough. So then other programming languages are called high level language is so |
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| 11:17 | Monory machine is no. So that's we think of level in languages. |
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| 11:45 | , so now you're gonna go the level. These are the high level |
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| 11:49 | . Humans, you know, 99% the time program these days in high |
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| 11:54 | language is there's a fight on Jama mobilised Fortran C Matt Lab. |
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| 12:00 | probably 100 languages that are used. why they're easy to program. That's |
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| 12:07 | the biggest reason they're portable. That , these not only are really definitely |
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| 12:23 | you that would work. Three languages across the board. So they're |
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| 12:43 | you write it for you. And only downside is that in some |
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| 13:00 | why Why the ISS? Eso once write a blank something in a high |
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| 13:07 | language. And so I think and um, the computer hardware and those |
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| 13:40 | interpreters and compilers. So let's say use fight on as an example. |
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| 13:49 | it like? An interpreter. Very . Fight on interpreter will take a |
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| 13:55 | program that you write a few lines readable same mathematical lines and basically create |
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| 14:09 | solution down. The idea is that the interpreter. Maybe a little |
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| 14:24 | but, uh, there's a second is, uh, what's car |
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| 14:33 | So compiler works differently, so you it a bite on program and the |
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| 14:43 | is a program that it's your fight program, which is sort of English |
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| 14:51 | ones you have zeros and ones any computer can directly executed. Yes, |
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| 15:14 | that's a question. Why would you unturned, critter? And why would |
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| 15:20 | a compiler? Um, the reason using an interview her You wear the |
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| 15:47 | thing with compiler compiler will first need process your entire program, converted to |
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| 15:53 | and ones and then executed there might alive. The question isn't Why bother |
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| 16:06 | the compiler? It is X. off your problem quickly. It's a |
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| 16:54 | because you're 1,000,000 light Gord. Then . Any other questions? Okay, |
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| 17:19 | I think that's the most complicated thing going to cover today, so you |
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| 17:22 | relax. Why did we waste off across our toe? Train you for |
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| 17:41 | solving? So five town is relatively to learn and work with washes. |
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| 17:51 | can say in comparison to what it's . Actually, I meant c++, |
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| 18:28 | it's not. The question is, would anybody bother with something like See |
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| 18:41 | four track, which is like, go with other languages which are harder |
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| 18:46 | program? And, uh, the and more subtle, are more |
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| 19:16 | little more natural and see your fortune in some cases were again sometime. |
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| 19:28 | finally, legacy chords. What's the cord? Yes, essentially one thing |
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| 20:13 | don't have here wear one. Let's . So that's it at this |
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| 20:44 | All right, so see Thio the , so you know, is |
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| 21:24 | Doesn't know. So it's a little like, you know, sort of |
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| 22:29 | it was in a few minutes and kind of issues you might run into |
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| 22:35 | program. Don't stats start. Sometimes things like program runs very slowly. |
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| 22:42 | do so and it can also be issues that are unexpected, which will |
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| 23:14 | . So this is, uh, off course or simplifying things here. |
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| 23:26 | fundamentally, you can think off computer to consists off a central processing |
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| 23:34 | the CPU memory and external devices, processor and devices can be keyboard mouse |
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| 23:49 | card, this display a printer, of those air Diz ices and These |
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| 23:54 | all kind of connected to each other what's called a system. But so |
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| 24:02 | a program, a program. Is just a sequence of instructions that generally |
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| 24:08 | somewhere in the memory? And when run the program, the they're fetched |
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| 24:15 | the memory to the CPU and then and the results have put back in |
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| 24:21 | in the memory. Okay, so just spend a minute on each of |
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| 24:32 | . So first, the central processing . So the first thing about a |
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| 24:37 | that it's blindingly fast, So it's special to have do. Gigahertz running |
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| 24:47 | gigahertz 2,000,000,000. I'm a museum. population of the world by a factor |
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| 25:35 | it's very, very fast. But do you care how fast it? |
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| 25:42 | , one second. Okay. But if you if you're very fast |
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| 26:17 | , you already heard in for the way. Working 3,000,000,000 ability of heat |
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| 26:34 | was busy. And in addition, have a very small memory. One |
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| 26:47 | clock cycle you can do a simple is God on only catch here Is |
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| 27:01 | the size of this cash? This memory is relatively small. It's millions |
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| 27:19 | Okay, remember, So this is or less off bites me questions and |
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| 27:40 | . The next is the memory that the storage. Anything you can put |
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| 27:45 | , you cannot just literally. um, picks a few clock ticks |
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| 27:51 | get data from memory. So if , and this is much lower than |
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| 28:10 | cash, the little special memories, special memory that's attached to the |
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| 28:16 | the good news is a little but it can be much bigger. |
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| 28:27 | is a few G B is not common. It is almost, you |
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| 28:37 | , basically even low and locked up you can get it. G |
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| 28:42 | One thing is that when you turn the computer memories, any questions, |
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| 28:59 | right, so then a little bit devices, they're all kind. Their |
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| 29:06 | , you know, keyboard is a attached. Oh, all of this |
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| 29:10 | the network card you used to get the Internet USB stick. If you're |
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| 29:15 | to get some data in and out displace printers and all that, they |
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| 29:21 | to the computer through a device interface discuss for a second. The disk |
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| 29:29 | also called on the way and I a lot of computers don't have disk |
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| 29:47 | , but they're with me. And why do we need the desk |
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| 29:52 | About it? It's It's massive. huge. Uh huh. And then |
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| 30:00 | is so and and it's not your ? What? Sorry. Secondary |
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| 30:44 | The downside is that its relatively slow access, uh, where you could |
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| 30:51 | do a memory in microseconds or less a microsecond. So, what is |
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| 30:56 | microsecond? What way? We're talking disks that pick millisecond how you access |
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| 31:30 | . So they're humongously slow. So would think interface works. So it's |
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| 32:13 | for bulk access. Um, Any on this way? That's right. |
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| 33:16 | right, so this is, something interesting. If you think about |
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| 33:25 | that way and just it sticks that . You, Marcia, what is |
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| 33:49 | said? It's not that this is Yes. Fine, Yes, |
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| 34:17 | thank you. Think this'll. I that's came out about in eighties. |
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| 34:31 | physical, it's is that the number transistors that was every two years way |
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| 34:45 | speed of computing goes up by So it's just Well, that's the |
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| 35:01 | news. So did Aram Is the . It's another actually name for |
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| 35:07 | the most common memory technology. interestingly, the memory speed doesn't go |
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| 35:15 | that fast. The capacity keeps going . Thing seems to go up by |
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| 35:45 | 60% per year. Capacity go, speed inches up and their desk. |
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| 35:51 | similar capacity keeps going up. But speed not so much and in between |
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| 35:58 | , um, and the memory and desk are the so called SS is |
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| 36:06 | yeah, basically in between. And bandwidth has been just being increasing. |
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| 36:19 | tremendously. Have been improving very Yeah, many Grecians Is this |
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| 36:47 | Yeah, yeah, good. So last thing is a little bit on |
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| 36:55 | soft way, with most important is operating system. So I think it's |
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| 37:13 | to understand you'll be writing applications. the job off your application and what's |
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| 37:19 | job off the operating system? So , there's a line here. Below |
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| 37:25 | is the hardware processor memory devices, we talked about about this A |
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| 37:31 | the program and your application runs on as this operating system, although you |
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| 37:38 | argue that in some cases it could directly to the hardware. But by |
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| 37:42 | large. You should think off your on above your operating system. Why |
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| 37:48 | you need this operating system? if, uh, your computer don't |
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| 37:57 | that. So you see, so , yes, some of them are |
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| 38:34 | unnecessary. And I tried to but many of them are essential. |
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| 38:43 | the operating systems job is Now you these 2 50 processes I want. |
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| 38:57 | keep the external devices. When you the security policies, we'll need a |
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| 39:27 | of things. It should be There's, of course, many other |
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| 39:45 | that an operating system burr. All , so we just take us short |
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| 40:03 | . You are any questions? Because insist. I'm not sorry. |
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| 41:03 | Yes. So there is no blackboard all goes well reported, and you |
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| 41:30 | so yes. Okay. All So one more topic on dhe that's |
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| 42:27 | numbers has any if you're being exposed mind and great anyone okay, Anybody |
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| 42:54 | ? Okay. So, again, long as you get a basic |
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| 43:18 | I'm gonna assume nobody has ever heard binary numbers. So 001 is 110 |
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| 43:27 | , too. Is that logical? there's only two days normally you have |
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| 43:43 | , so just one. So this is one and the next. The |
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| 44:01 | combination is, too. There is that makes sense to everybody that the |
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| 44:09 | way. Then 10 is to 11 three and well after 11 you're |
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| 44:31 | And so the next one that is under four would be 100 Okay, |
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| 44:39 | makes sense. So eso basically, find that it's also helpful. No |
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| 44:58 | . So actually, it's sometimes not . One is 1000 which is one |
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| 45:05 | by 10 zeroes. It's also turns that it's also one followed by an |
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| 45:16 | site. 1000 of course, is followed, but lead resort zeros and |
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| 45:20 | Brits can zeroes in binary, and actual number is approximately it is, |
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| 45:28 | 24 years somebody says one gay. case of doubt, you should assume |
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| 45:40 | . And 24. So similarly, bag is, you know, prices |
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| 45:53 | zeros, and one gig is another zeroes. And so so. Any |
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| 46:00 | so far, Any other questions? there, um, finally numbers is |
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| 46:29 | spite reason is that name. These have to be converted. Electronics. |
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| 46:50 | easier design systems. There's just for moment. All right, So Thomas |
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| 47:38 | ready? You need to know, that money for yeah, for this |
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| 47:47 | . So But you should have You be able. So before we figure |
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| 48:03 | how to do that, how do when you have this number 937 in |
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| 48:10 | . So basically the way we're get , this doesn't so Okay, |
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| 50:04 | yes. Four. All right. few minutes. Here's another example. |
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| 50:31 | the same idea. Um, Yes. Good. Wait. |
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| 52:16 | So But, you know, for this class you're not gonna ask |
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| 52:28 | 64 did just a few bits, it's good to know, to be |
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| 52:33 | to convert no one working so little again. We're not going to do |
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| 53:17 | Andrea Arithmetic. But, uh basically, you just need to |
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| 53:24 | because this number 001101 These are um um, one bit. And |
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| 53:45 | you add one and one So this functionality is also the logic off. |
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| 53:58 | called an R through. Basically, off. Um, sort of jumping |
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| 54:05 | here. One can be thought it's true. And zero has falls |
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| 54:17 | zero plus zero is same as phones for others, for us is eso |
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| 54:36 | ? That's all the basic addition You don't need to know. |
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| 54:39 | And in this case, this is called and so both are true. |
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| 54:48 | it's true. 000 for months and forth zero and one. So |
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| 55:05 | you multiply by zero The first tree coincidentally, the mind down. |
|
| 55:20 | so we're gonna wrap up the But s o a terminology a |
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| 55:27 | You hear about it? It hit bite. Is it bits? |
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| 56:10 | what's that? What's the largest? . All right. Any other? |
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| 60:20 | can't just Yeah. No. wait. |
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