How did CPU (and other parts) making worked in the old days ?

1, These days the machines used to etch chips (flash light onto the chips to carve them out) are mostly made by ASML. The most modern machines are the ASML Twinscan NXE and Twinscan EXE. The raw silicon is coated with different chemicals that react to light, and when the light patterns are flashed onto the silicon, it carves physical arrangements of atoms on the silicon that forms complex electrical circuits.

2. CPUs were literally drawn by hand, and then the drawing was shrunk down with a magnifying glass back in the day. Programs could be written into electrical memory with physical switches (think 100 light switches), punch cards, or electric typewriters. You could pause the computer so that it would wait for you to type in the next program for it to run. By the time we had kernels, we already had large memory banks in the kilobytes that could store the OS between program runs. So you'd type in the OS once when you turned on the computer, and it would keep in in memory until you turned the computer off again.
3. The internet is different computers connected together. This website is just data sitting on a server somewhere, and your computer connects to the server over the internet and asks for the data.
4. Everything is built on the shoulders of giants. There is plenty to learn, but there will always be something you don't know.
5. There's tons of information online if you know where to look. There's also some good courses out there to understand more specific things like cpu design, networking, programming, etc. In university these sorts of questions fall into the field of Computer Engineering, if you're looking for a university program to get into.

With regards to the limits of programming: Making websites is already challenging enough, but the cutting edge can be rewarding too :) Software Engineering is a massive field with infinite opportunities. Start small and work your way towards more complex projects with larger teams.

Here's a good 20 minute video about the history of making microchips: https://youtu.be/Pt9NEnWmyMo

I love your enthusiasm and I love that you are asking questions! Also cool that you feel an urge to learn.

That being said, it is rather many questions you are asking at the same time :)

Watch this brilliant series, it should give you a grasp of what is going on, then take it from there.

Computer Science Crash Course: https://www.youtube.com/watch?v=O5nskjZ_GoI&list=PL8dPuuaLjXtNlUrzyH5r6jN9ulIgZBpdo

1 - I get that light is flashed in binary to code chips but how does it actually fookin work ? What is the machine emmiting [sic] this light made up of ?

This video by Branch Education (on YouTube or Nebula) is a high level explanation of every step in a semiconductor fab. It doesn't go over the details of how semiconductor junctions work, though. That sort of device physics is discussed in this YouTube video by Ben Eater, "how semiconductors work"

2 - How was program's, OSs, Kernal [sic] etc loaded on CPU in early days when there were no additional computers to feed it those like today ?

When the CPU powers up, typically the very first thing it starts to execute is the bootloader. Bootloaders will vary depending on the system, and today's modern Intel or AMD desktop machines boot very differently to their 1980s predecessor. However, since the IBM PC laid the foundation for how most computers booted up for a nearly four decades, it may be instructive to see how it worked in the 80s. This WikiBook on x86 bootloading should be valid for all 32-bit x86 targets, from the original 8086 to the i686. It may even be valid further, but UEFI started to take off, which changed everything into a more modern form.

But even before the 80s, computers could have a program/kernel/whatever loaded using magnetic tape, punch cards, or even by hand with physical switches, each representing one bit.

But how does the computer decode this binary "machine code" into instructions to perform? See this video by Ben Eater, explaining machine instructions for the MOS 6502 CPU (circa 1975). The age of the CPU is not important, but rather that by the 70s, the basics of CPU operations has already been laid down, and that CPU is easy to explain yet non-trivial.

3 - I get internet is light storing information but how ? Fookin HOW ?

The mechanics of light bouncing inside a fibre optic cable is well-explained in this YouTube video by engineerguy. But for an explanation of how ones-and-zeros get converted into light to be transmitted, that's a bit more involved. I might just point you to the Wikipedia page for fibre optic communications.

How the data is encoded is important, as this has significant impact on bandwidth and data integrity, not just for light but for wireless RF transmission and wireline transmission. For wireless, this Branch Education video on Starlink (YouTube or Nebula) is instructive. And for wired, this Computerphile YouTube video on ADSL covers the challenges faced.

Quite frankly, I might just recommend the entirety of the Computerphile channel, particularly their back catalogue when they laid down computer fundamentals.

4 - How did it all come to be like it is today and ist it possible for one human to even learn how it all works or are we just limited one or two things ? Like cab we only know how to program or how to make hardware but not both or all ?

As of 2024, the field is enormous, to the point that a CompSci degree necessarily has to be focused on a specific concentration. But that doesn't necessarily mean the hard stuff like device physics are off-limits, leaving just stuff like software and AI. Sam Zeloof has been making homemade microchips, devising his own semiconductor process and posting it on YouTube..

Specifically to your question about either software or hardware, the specialty of embedded software engineering requires skills with low-level software or firmware, as well as dealing with substantial hardware-specific details. People that write drivers or libraries for new hardware require skills from both regimes, being the bridge between Electrical Engineers that design the hardware, and software developers that utilize the hardware.

Likewise, developers for high performance computers need to know the hardware inside-out, to have any chance of extracting every last bit (pun intended) of speed. However, these developers tend to rely upon documentation such as data sheets, rather than having to be keenly aware of how the hardware was manufactured. Some level of logical abstraction is necessary to tractably understand today's necessarily large and complex systems.

5 - Do we have to join Intel first or something to learn how most of the things work lol ?

Nope! Often, you can look to existing references, such as Linux source code, to provide a peek at what complexities exist in today's machines. I say that, but the Linux kernel is truly a monster, not because it's badly written, but because they willingly take code to support every single bleeding platform that people are willing to author code for. And that means lots and lots of edge cases; there's no such thing as a "standard" computer. X86 might be the closest to a "standard" but Intel has never quite been consistent across that architecture's existence. And ARM and RISC-V are on the rise, in any case.

Perhaps what's most important is to develop strong foundations to build on. Have a cursory understanding of computing, networking, storage, wireless, software licenses, encryption, video encoding/decoding, UI/UX, graphics, services, containers, data and statistical analysis, and data exchange formats. But then pick one and focus on it, seeing how it interacts with other parts of the computing world.

Growing up, I had an interest in IT and computer maintenance. Then it evolved into writing websites. Then into writing C++ software. Right before university, I started playing around with the Arduino's Atmel 328p CPU directly, and so I entered uni as a Computer Engineer, hoping to do both software and hardware.

The space is huge, so start somewhere that interests you. From the examples above, I think online videos are a fantastic resource, but so can blog posts written by engineers at major companies, as can talks at conferences, as can sitting in at university courses.

Good luck and good studies!

1. Flashing code to a chip doesn't really involve light.
2. you used switches on the front panel to load code into the computer by setting individual bits high or low. Typically you toggled in the bootstrap loader, which was a program that read a sequence of number directly into a spot in memory. The first program loaded by the bootstrap loader was usually the absolute loader. This was another program that loaded data from some peripheral, similar to the bootstrap loader, but it could do error checking and also load to non- sequential locations.

3-the Internet isn't light. It's electricity. On fiber the bits may be temporarily encoded as light, but overall it is electric.

4- You can understand it all if you want. It depends on the depth to which you want to understand it. You can understand a mouse has a plastic shell. You need some organic chemistry and chemical engineering to understand how to design plastic.

5- I recommend Ben Eaters YouTube channel to get a good overview of the basics.