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''I want to use less than a couple of kilobytes for my OS!''
Sorry, that's probably impossible. An OS using such little memory will be almost unusable. Forget about filesystem drivers, disk drivers, usb drivers, etc. IfFor you want to developdeveloping something small, just make a simple bootloader, not an OS.
YouAnother couldoption would be to try a native Forth; it's like a little OS with the kernel, command interpreter, and assembler all in one tiny binary! Parts of the kernel can even be scripted. YouIt dondoesn't even need a filesystem,; many Forths directly edit and load disk sectors. There's a big catch: Forth is not light on skill. Writing good Forth is a whole other planet which you'llprogrammers would need to understand to get beyond the bare basics. Surprisingly, some Forth fans are good at writing Forth interpreters but are poor Forth programmers. You'llAn OS developer will need to be a good(-ish) Forth programmer to fit OS design concepts to Forth, or to figure out which concepts are not needed. If you can't do thatOtherwise, yourthe OS willwould be ''much larger'' than it needs to be. ;)
It can take a lot of time and thought to figurewrite outcompact how to reduceForth code size. Charles Moore, inventor of Forth, wrote a CAD program which was structured around just 5 lines of code. When asked how long; it took to write those 5 lines, he replied, "Ooh,him about 2 years"!.
=== OS Emulation ===
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