What he's getting at is there isn't any hardware protection available for DOS- at least on the pre...
It would be wonderful if it did do a clean crash. MS-DOS does not; again, I will repeat myself. MS-DOS is...
One of my favorite old-time war stories is one I call "how I learned the difference between MS-DOS and a real operating system." It fits into this thread, and maybe this is a good opportunity to confirm that I understand the issues involved.
To make it as brief as possible .... I, a person with some years of mainframe experience but little exposure to PCs, was using my new (as of 1980-something) PC, running MS-DOS, to learn Pascal. One of my homework programs had a bug whose symptoms were that the entire computer ceased totally to respond to keyboard input, including control-alt-delete. I'm sure most of you can guess what the problem was (especially if I mention that the homework program was intended to teach about using pointers), but it was news to me that there were "operating systems" that don't protect their own memory from users.
I was appalled, asBAH seems to be, but the co-worker who explained to me what the problem was claimed that the underlying hardware (this would have been an early something-86) had no support for memory protection, so it was not surprising that the o-s didn't provide this feature. Anyone care to comment on whether this is an accurate sensible explanation?
-- B. L. Mbuttingill ObDisclaimer: I don't speak for my employers; they return the favor.