It's almost exactly the same, except the building blocks are much simpler (=more primitive) so you have to spend more time per useful thing you want to get the machine to do.
If you want to get a taste of what that means that is definitely 100% within your abilities, try to write a Brainfuck interpreter in JS, and a Brainfuck to JavaScript compiler (that yields a string that you can eval() to run the program).
Then try to write some simple Brainfuck programs, then try to write a Brainfuck interpreter in Brainfuck. At this point you won't yet know how to write an operating system, but you'll definitely know how it feels to write one.
Not sure why I'm getting such negative reactions. I've given these exercises to many developers, some of them very junior, and seen them complete them successfully. It's not that hard to do each step after the previous ones, and very rewarding to complete the entire thing.
It sounds doable, just painful! I'm not sure I'm masochistic enough. Like I could do that, or maybe go on a bike ride, or get some ice cream...
I think I have pretty underwhelming dreams relative to OS devs, lol. I feel a ping of reward when a web page loads without crashing, or a npm audit passes without red, or I finish a level in Mini Motorways.
Generally, my secret to a happy life is to aim low, and then be satisfied once I hit half that :)
I promise you it isn't. It's a fun challenge, and not too hard. Smaller and easier, say, than delivering a full eCommerce website end-to-end. I'm not an OS dev myself, I just love playing with technology of all kinds and picking up elegant ideas, and this is one kind :)
Not too much work, either. I once live coded a Brainfuck interpreter in 30 minutes for PyCon IL, and there aren't really any tricks involved, just work, so it should take the average dev that didn't just practice it maybe 2-4 hours: https://www.youtube.com/watch?v=F5P6Q7vs_-Y
If you want to get a taste of what that means that is definitely 100% within your abilities, try to write a Brainfuck interpreter in JS, and a Brainfuck to JavaScript compiler (that yields a string that you can eval() to run the program).
Then try to write some simple Brainfuck programs, then try to write a Brainfuck interpreter in Brainfuck. At this point you won't yet know how to write an operating system, but you'll definitely know how it feels to write one.