div0 wrote:
There's nothing special about a systems language; it's just they have explicit facilities that make certain low level functionality easier to implement. You could implement an OS in BASIC using PEEK/POKE if you mad enough.
I suppose it's like the difference between porn and art. It's impossible to write a bureaucratic rule to distinguish them, but it's easy to tell the difference just by looking at the two. "I know it when I see it!"