WEBVTT 00:00.480 --> 00:04.840 A program is essentially a sequence of machine instructions stored in a memory. 00:04.840 --> 00:10.200 Now, each machine instruction performs a specific operation and is written in the computer's native 00:10.200 --> 00:10.840 language. 00:10.840 --> 00:17.200 Now, understanding this execution flow is essential to grasp how the system works from both the software 00:17.200 --> 00:18.920 and hardware perspectives. 00:18.960 --> 00:23.920 Now, to follow along with this course, you don't need any special hardware, just a computer with 00:23.920 --> 00:24.600 a keyboard. 00:24.600 --> 00:26.080 And the mouse is enough. 00:26.080 --> 00:32.560 And all the exercises in this course can be done on most modern computers running Linux or using a Linux 00:32.560 --> 00:33.760 like environment. 00:33.840 --> 00:39.680 Uh, or it can be a windows, so it doesn't matter at all, to be honest. 00:39.960 --> 00:47.800 Now we typically write programs using high level programming languages like Python, Python, Java or 00:47.880 --> 00:49.200 C, C plus plus. 00:49.240 --> 00:51.000 Yeah, these are the programming languages, right? 00:51.040 --> 00:52.320 That the human can read. 00:53.320 --> 00:55.000 You can read this binary code. 00:55.000 --> 00:55.440 Right. 00:55.960 --> 00:56.720 Nor this. 00:58.040 --> 00:58.520 Right. 00:59.160 --> 00:59.640 Yeah. 01:00.120 --> 01:06.970 Uh, and among this, uh, the fight remains one of the most popular choices and essentially common 01:07.010 --> 01:09.810 on platforms like Raspberry Pi. 01:10.850 --> 01:17.650 And to create and execute simple Hello world program in Python, we will create a new file and we will 01:17.650 --> 01:19.250 name it main dot pi. 01:19.290 --> 01:22.810 Let's for example main dot pi. 01:23.970 --> 01:26.530 Oops, we got the two. 01:29.130 --> 01:38.770 And here what we will do is basically we will print Hello world Occelli. 01:39.690 --> 01:40.570 And that's it. 01:42.370 --> 01:45.170 Or you can also do that with the text editor as well. 01:46.050 --> 01:47.490 It doesn't matter at all. 01:51.490 --> 01:58.330 Or let's use the mouse pad or yeah we don't have the mouse pad. 01:58.490 --> 02:00.570 So we will use the text editor. 02:04.460 --> 02:06.060 Not something. 02:08.660 --> 02:14.300 Yeah, I don't know the name of this text editor, so we could launch one from the terminal, but in 02:14.300 --> 02:16.620 this case, we will just run it from here. 02:16.940 --> 02:17.540 Yes. 02:17.820 --> 02:19.780 Open new. 02:21.620 --> 02:22.980 Go to text editor. 02:23.380 --> 02:24.940 Now it's a GNOME text editor. 02:24.980 --> 02:25.420 Right. 02:26.100 --> 02:30.020 GNOME text editor. 02:30.580 --> 02:31.860 Uh, main dot pi. 02:34.140 --> 02:35.060 And that's it. 02:35.940 --> 02:37.220 Here it will open the main dot. 02:37.220 --> 02:38.900 Pi will write. 02:39.020 --> 02:39.860 Print. 02:40.500 --> 02:41.180 Hello. 02:42.660 --> 02:44.460 Hello, world. 02:46.740 --> 02:49.980 And yeah, you can see we have the syntax highlighting here. 02:49.980 --> 02:50.740 Coloring. 02:51.300 --> 02:53.380 Uh, discard this here. 02:53.380 --> 02:55.500 And as you can see we have the main dot pi. 02:55.540 --> 03:01.500 And basically we will run it from the main dot pi and uh python3 main dot pi. 03:02.340 --> 03:04.140 And you can see hello World here. 03:04.140 --> 03:09.220 And we can do the exactly same thing on the Visual Studio as well. 03:10.700 --> 03:11.540 Terminal. 03:11.860 --> 03:12.980 New terminal. 03:13.540 --> 03:16.340 Main python3 main.py. 03:16.660 --> 03:19.060 And you can see hello world. 03:19.820 --> 03:23.100 Also we will increase the text size a bit. 03:23.900 --> 03:33.220 So you can see font size is going to be 2922. 03:37.700 --> 03:39.380 Text editor font size. 03:43.060 --> 03:44.300 26 maybe. 03:45.380 --> 03:46.380 Yeah that's okay. 03:47.380 --> 03:49.020 24 is better. 03:50.820 --> 04:01.380 And here we can use plus and minus to increase the user interface with Control Plus and Control minus 04:01.380 --> 04:08.510 we can increase and decrease the user interface size in Visual Studio, but this will basically serve 04:08.550 --> 04:10.230 as serve the same purpose. 04:10.230 --> 04:12.950 It's just more nicer basically. 04:13.310 --> 04:20.630 And yeah, we have run the program and you can see we got the printed Hello World and Hello World actually 04:20.670 --> 04:22.630 with two separate Python files. 04:22.910 --> 04:26.950 And we can do the same on the C as well. 04:27.310 --> 04:30.470 Main dot C or let's say test dot c. 04:31.190 --> 04:40.630 And first we will need to include the STD standard input output stdio.h and integer main. 04:40.670 --> 04:43.830 It's going to be return void printf. 04:45.150 --> 04:53.750 Printf hello world from c a new line return zero. 04:53.750 --> 04:56.270 So our application will close after execution. 04:59.030 --> 05:02.270 Yeah basically that's it. 05:04.110 --> 05:07.560 And as I said, we can do the same. 05:07.560 --> 05:09.880 You can see I have test dot c here. 05:10.440 --> 05:13.720 Now we have saved the file in test C. 05:14.160 --> 05:15.880 Now we will need to compile it. 05:16.520 --> 05:19.960 So as you see it's a pretty different with the Python. 05:19.960 --> 05:24.240 And you will see and you will understand why it is right. 05:24.720 --> 05:29.280 Because you need to compile it, compile the C code to run it. 05:30.400 --> 05:33.520 So hello world. 05:34.160 --> 05:36.760 And here we will test dot C. 05:37.480 --> 05:41.800 And here you will see that we have the Hello World here created new program. 05:42.120 --> 05:45.640 And we will just run it with the Hello World. 05:45.640 --> 05:46.720 And here we are. 05:46.720 --> 05:51.560 We have printed the hello from C text. 05:51.600 --> 05:58.480 Now this practical comparison highlights the difference between the interpreted language which is Python, 05:58.720 --> 06:05.320 and compiled language which is C or C plus, plus or many other languages. 06:05.320 --> 06:14.770 There's there's so much compiled languages and yeah, Python translates and runs the code line by line. 06:15.090 --> 06:20.730 Uh, but the C code, on the other hand, must be compiled first into machine instructions before it 06:20.730 --> 06:21.890 can be executed. 06:21.930 --> 06:28.610 Now C allows us to better observe how instructions interact with the underlying hardware, which is 06:28.610 --> 06:31.330 why it is preferred language for this course. 06:31.890 --> 06:37.650 So for the rest of this course we will mainly use C but we will. 06:37.890 --> 06:43.730 We can go through Java Python according to examples to learn best. 06:49.450 --> 06:56.010 And whether a program comes from an interpreter or a compiled file, its instructions and data must 06:56.010 --> 06:59.330 be loaded into the memory before the CPU can run them. 06:59.610 --> 07:01.770 Here's what happens during the execution. 07:02.650 --> 07:09.370 The CPU or let's actually, if you remember from the previous lecture of our course. 07:11.970 --> 07:18.570 And I'm sure you remember it, we had a sum diagram written. 07:18.850 --> 07:22.970 Draw by me and we will open that. 07:22.970 --> 07:24.570 And I will show you something here. 07:25.890 --> 07:27.690 Let's move it into ubuntu. 07:28.170 --> 07:31.010 And here our diagram. 07:31.050 --> 07:31.450 Yes. 07:32.770 --> 07:33.930 Where is our diagram. 07:34.050 --> 07:34.450 Yeah. 07:35.650 --> 07:37.210 It isn't here. 07:52.530 --> 07:53.050 Yeah. 07:53.090 --> 07:57.210 Here we have figure 1.1. jpg file. 07:57.690 --> 08:06.730 Now what you can what you are seeing here is basically the CPU fetches instructions from memory by placing 08:06.730 --> 08:11.180 the address on the address bus and signaling the read operation on the control bus. 08:11.500 --> 08:19.220 You can see the memory system responds by placing the instruction on the data bus for the CPU to receive 08:19.260 --> 08:20.380 right here. 08:20.740 --> 08:21.380 Data bus. 08:21.980 --> 08:28.740 And if data needs to be written back to the memory, the CPU uses data bus to send it. 08:29.300 --> 08:36.860 The address bus here indicate where to store it and the control bus to signal a write operation. 08:36.900 --> 08:41.100 Now this process repeats continuously while the program runs. 08:44.180 --> 08:50.500 Now programs also communicate with the input output devices such as human interface devices or HID. 08:53.380 --> 08:55.060 HID yeah. 08:55.700 --> 08:58.860 Which is keyboard, mouse or touch screen. 08:59.580 --> 09:05.540 And the machine interface devices devices which is basically like storage devices. 09:07.380 --> 09:08.550 Network cards. 09:11.270 --> 09:12.390 And so on and so forth. 09:12.790 --> 09:20.950 So input output devices are much slower than the CPU and memory due to varying speeds and data timing. 09:20.990 --> 09:28.390 Now they require explicitly programmed instructions to operate correctly, which is where drivers come 09:28.390 --> 09:29.110 into play. 09:29.830 --> 09:37.550 Although the Advanced Input Output programming for now is beyond this course, we will still use a terminal 09:37.550 --> 09:40.190 screen for the output. 09:48.030 --> 09:55.470 Now, the operating systems provides built in input output functions and the C runtime library. 09:55.510 --> 10:05.310 Here um includes functions to access them easily with this STD input output dot header file and to support 10:05.310 --> 10:06.310 the programming tasks. 10:06.310 --> 10:09.320 In this course, you will need a working Linux based Space environment. 10:10.120 --> 10:13.560 This could be a native Linux machine, a virtual machine, or a windows subsystem. 10:13.560 --> 10:14.040 Linux. 10:16.080 --> 10:19.480 It's a relatively new thing, I can say. 10:20.640 --> 10:27.600 Or you can also use a windows computer, but it is better to use the windows Linux as well. 10:28.400 --> 10:31.080 Specifically Debian based operating system. 10:36.840 --> 10:46.280 Now you can see these are the Debian based operating system, or you can use the Debian itself the most 10:46.320 --> 10:48.200 the best operating system for a beginner. 10:48.400 --> 11:00.560 If I can say it is Linux Linux Mint, I would recommend Linux Mint if you are a beginner because of 11:00.600 --> 11:04.680 the user interface that is pretty similar to windows one as well. 11:07.520 --> 11:11.490 And we have the Linux documentation tools as well. 11:11.610 --> 11:14.850 Like Linux tools provide extensive documentations. 11:17.210 --> 11:20.570 It's the Linux help is not as useless as windows help. 11:21.370 --> 11:23.690 So yeah GCC help. 11:23.930 --> 11:24.250 Uh. 11:28.690 --> 11:29.170 Yeah. 11:29.370 --> 11:38.490 GCC help will give you basic information about the options and parameters you can use with gcc command. 11:39.570 --> 11:41.730 You can use man man man. 11:42.610 --> 11:48.490 Uh, so this is uh basically manual pager utility. 11:49.450 --> 11:55.610 You can find there's almost every there's almost man page for every command in Linux. 11:55.890 --> 12:00.250 For example, we can do lls man or man lls. 12:02.890 --> 12:03.930 Man lls. 12:05.650 --> 12:09.250 And you can see we have the LLS page for man. 12:12.250 --> 12:22.210 That will be pretty handy when you developed or don't know the commands for sure, and you need to install 12:22.210 --> 12:23.610 the info for the deep types. 12:23.970 --> 12:26.090 Sudo apt install info. 12:27.330 --> 12:31.650 Now it's already installed and newest version info info. 12:36.810 --> 12:37.730 Now you can see. 12:42.130 --> 12:42.570 Info. 12:42.570 --> 12:48.170 I can say that better alternative for man, but man is useful as well. 12:48.770 --> 12:49.210 It's. 12:50.050 --> 12:59.610 You can choose how much information you need to read, so if you the info provides more information 12:59.610 --> 13:00.370 than man. 13:02.010 --> 13:09.850 And yeah, basically after doing the steps you also need a word processor. 13:13.780 --> 13:19.500 Now by the word processor, I mean not to use the Libre Office or or Microsoft Word. 13:19.940 --> 13:24.380 Um, they insert hidden formatting into your codes, which can break your code. 13:26.740 --> 13:31.260 But you need to just at the lowest level you can use the VM. 13:32.020 --> 13:35.940 Um, so the apt install vim. 13:35.980 --> 13:38.180 This is more this is for more advanced users. 13:38.180 --> 13:43.020 But once you start using vim you will get addicted to it. 13:47.420 --> 13:50.900 This is a keyboard based women's keyboard based. 13:50.900 --> 13:53.180 You can see uh now. 13:55.300 --> 14:00.780 If you don't know, using the meme like you, you can probably use. 14:10.900 --> 14:15.830 My keyboard Keyboards has some kind of problem here or I don't know. 14:15.830 --> 14:16.150 Yeah. 14:17.990 --> 14:25.590 And basically, uh, what I recommend you to use here, it is either vim if you want more advanced or 14:25.590 --> 14:34.910 professional look vibes, or you can use, uh, Visual Studio Code, uh, which I recommend for flexibility 14:35.030 --> 14:36.830 and graphical user interface features. 14:36.870 --> 14:43.150 Now you can also download the themes for you, like let's say if you want we can also. 14:43.870 --> 14:49.230 Yeah, here it is easily customizable and there's an extension. 14:49.230 --> 14:56.590 So you can almost develop for any languages here even ARM which we will develop in next lectures. 14:57.670 --> 15:02.510 Yeah the Visual Studio Code is good. 15:02.830 --> 15:09.150 But if you like open source, what I can recommend, uh, as you know, Visual Studio Code is not open 15:09.150 --> 15:14.240 source fully, so I think it was V's podium. 15:15.400 --> 15:15.840 Yeah. 15:16.160 --> 15:17.800 Open source binaries for VSCode. 15:17.840 --> 15:19.440 Now, this is basically the same. 15:19.440 --> 15:20.560 Just open source. 15:20.880 --> 15:25.080 Um, and in my windows machine, I use the visual coding Visual Studio Code. 15:25.120 --> 15:26.800 Um, but yeah. 15:29.760 --> 15:30.760 It's also usable. 15:31.320 --> 15:37.440 And how can you you use the Visual Studio Code, install the Visual Studio code is from the apt. 15:37.800 --> 15:42.000 Is sudo apt install code snap. 15:42.040 --> 15:42.520 Oh, yeah. 15:42.720 --> 15:43.400 Sudo snap. 15:43.400 --> 15:44.200 Install code. 15:47.720 --> 15:48.320 Code. 15:49.200 --> 15:50.760 And code is already installed. 15:51.760 --> 15:52.200 Um. 15:52.240 --> 15:56.640 And you can also download from the binary files and compile it yourself. 15:56.960 --> 15:59.320 Or just download the dev file. 16:02.320 --> 16:03.360 To your computer. 16:05.480 --> 16:07.720 Click on release or install. 16:07.760 --> 16:08.920 Yeah here we are. 16:08.960 --> 16:11.400 You can download for windows, Mac OS, Linux. 16:11.800 --> 16:13.840 You can see if you are using the. 16:15.280 --> 16:17.160 Linux machine, you need to install the deb. 16:17.200 --> 16:17.880 Deb file. 16:19.000 --> 16:22.280 Basically, it's almost 100MB. 16:24.240 --> 16:24.840 And yeah. 16:24.880 --> 16:32.240 And in order to run some create some document or open some document, you can you just need to, uh, 16:32.560 --> 16:37.040 add code before your file. 16:37.160 --> 16:44.520 If you want to create a new file, my new file that for example txt you can even edit the txt files. 16:45.040 --> 16:46.120 And here we are. 16:46.240 --> 16:48.840 And you can select the languages see. 16:49.080 --> 16:55.680 And yeah include include stdio dot h and so on and so forth. 16:57.160 --> 17:00.720 And yeah our lecture is been almost 18 minutes. 17:00.880 --> 17:02.640 Uh that's it with our lecture. 17:03.720 --> 17:04.800 Thank you for watching. 17:04.800 --> 17:12.840 Uh, in this lecture, what we have uh, basically learned is CPU execute instructions and contains 17:13.320 --> 17:14.560 fast internal memory. 17:17.690 --> 17:22.970 Memory stores data and instructions. 17:24.890 --> 17:28.210 Input output enables external communication and storage. 17:30.650 --> 17:31.330 Pass. 17:32.410 --> 17:32.770 Uh. 17:32.770 --> 17:38.330 Basically pass transfers the data addresses and control signals. 17:40.090 --> 17:48.010 Program execution is basically how instructions move through the system and programming environment, 17:48.690 --> 17:55.210 which is customizable, and how to prepare your Linux environment for development. 17:56.250 --> 17:58.530 And yeah, that's it with our lecture. 17:59.610 --> 18:04.570 In our next lecture, we will begin learning how data is stored in a memory. 18:04.730 --> 18:10.210 Get introduced to the C language and learn how to use the debugger as an educational tool. 18:10.810 --> 18:13.170 Until then, that's it with our lecture. 18:13.210 --> 18:16.130 Thank you for watching and I'm waiting for you in the next lecture.