From: ben <bfranc...@jetnet.ab.ca> To: cctalk@classiccmp.org Subject: [cctalk] Re: terminology [was: First Personal Computer]
> The third thing is a real OS. Nobody has one, as a personal computer. > CP/M and MSDOS does not handle IRQ's. Unix for the PDP-11 is real > operating system but not personal as it requires a admin,and a > swapping media. This an auld refrain among *nix partisans of the ESR type, but I've yet to hear someone offer up a real defense of it. Even putting aside what "handles IRQs" means here (yes, strictly speaking the IRQs on the IBM PC are handled by the BIOS and/or add-on drivers/utilties, but DOS most certainly makes use of the facilities provided,) why does that make it "not a real OS?" What does PDP-11 Unix provide which MS-DOS doesn't to make one "real" and the other not? Certainly, nothing about a single-tasking single-user text-based environment *requires* interrupt-based I/O, even if it may smooth out performance in some aspects. And there's little if any call for a security system that'd require an administrator account in such a model; if one user "owns" the machine, whatever they decide to do to it can be Considered Legitimate. Virtual-memory capability may certainly enable the user to do more than they'd otherwise be able to, but it's hard to make an argument for it as a *requirement;* even *nix can run without swap, and in point of fact DOS can be support virtual memory with a protected-mode extender. Or is it multi-tasking capability itself that makes the difference? Can't see why that should be the case; it's definitely convenient, but as one person can only be doing so much at any given time, it's also hard to see that as a *requirement.* So what, then, consitutes a Real Operating System, and why?
