I'm not interested in debating the definition of OS. If the textbooks are as wrong as you imply, I guess I'm wrong too.

So which textbooks do you want to start with?

I pick "PC INTERN: system programming", 1992.

https://www.amazon.de/PC-Intern-Programming-Encyclopedia-Dev...

A reference for MSDOS programming on a German amazon page... Am I missing the joke?

Tanenbaum and Silberschatz both have excellent textbooks covering the fundamentals of Operating Systems. Neither book focuses much on "language runtimes".

I live in Germany, do not always bother to check if the URL contains locale information.

Anyone that actually programmed MS-DOS, knows that we used to program directly against the hardware for actual work. MS-DOS was nothing more than what is usually known as monitor in OS literature.

Continuing the texts from people more relavant to the CS world than me,

"An operating system is a collection of things that don't fit into a language. There shouldn't be one." - Dan Ingalls on

https://archive.org/details/byte-magazine-1981-08 https://www.cs.virginia.edu/~evans/cs655/readings/smalltalk....

"Building Parallel, Embedded, and Real-Time Applications with Ada" - John McCormick

https://www.amazon.co.uk/Building-Parallel-Embedded-Real-Tim...

"Project Oberon: The Design Of An Operating System And Compiler" - Niklaus Wirth

https://www.amazon.co.uk/Project-Oberon-Design-Operating-Com...

And not to let this just be theory, here are a few examples of commercial products using the language runtime to interface with the hardware.

http://www.astrobe.com/default.htm

https://www.mikroe.com/products/#compilers-software

https://www.ptc.com/en/products/developer-tools

I programmed MSDOS assembly and on 80s 8-bit machines back in the day too, so you can quit the "back in my day" routine. It was my day too.

Like I said, I'm not interested in debating the definition of OS. Best regards.