On 17/05/2019, Roderick <hru...@gmail.com> wrote: > As far as I know, DOS was not multitasking.
You're mostly correct, except there were task-switchers and there were some multitasking-capable versions of DOS, notably Novell (ex-DR-) DOS 7. This was not very successful in the marketplace, in part because it was late in DOS's life cycle*, but also because Microsoft engaged in anticompetitive practices in that they deliberately engineered the DOS-based Windows of the day to be incompatible with Novell's arguably technically superior DOS flavour. This led to the "AARD" lawsuit -- which Microsoft settled for a cool 280 million dollars, as has since been disclosed. And that was the end of that. *though we may also ask if DOS's life cycle might have been extended had DOS 7 succeeded ------------------------------------------------------------------------ > On Fri, 17 May 2019, gwes wrote: >> "single user" = a system running with no resource restrictions >> and all but the absolutely essential services and processes stopped >> A prime example of a "single user" system according to your definition >> is MSDOS. No restrictions on anything. How reliable is/was it? I think the OP inaccurately equated "single user" with single-task. Correct me if I'm mistaken, but to my understanding, a Unix-like system (to wit: OpenBSD) in "single user" mode is still multitasking, albeit just between essential services. ------------------------------------------------------------------------ > On Fri, 17 May 2019, gwes wrote: >> You can delete files. Do you want to be able to accidentally delete ANY >> file? Or do you want to be able to write-protect some of them? >> A prime example of a "single user" system according to your definition >> is MSDOS. No restrictions on anything. How reliable is/was it? In the history of the (Berkeley) Fast File System, has there ever been an attempt to implement DOS-like undelete for FFS/UFS? (I understand that for technical reasons, this could require running a daemon that remembers just enough metadata to keep data recoverable so long as it's not overwritten. I also understand that running a daemon that remembers things nominally deleted would have security implications, which may not keep me from running a daemond that w/o being perfect could protect me from myself at least some of the time.) I did find this: https://lists.freebsd.org/pipermail/freebsd-questions/2016-May/271785.html -- which didn't seem to suggest that the answer was any yessier now than thirty years ago. So, that's a no, then? Anyone? Bueller? On 17/05/2019, Roderick <hru...@gmail.com> wrote: > > On Fri, 17 May 2019, gwes wrote: > >> You are correct on the surface and very misled as to the underlying >> concept. > > You gave him an excellent answer. I hope many people read it. > > He should just read the Unix paper I mentioned in other post. Not > the multiusersystem is a burden, bloat in modern unixoiudes. > It is a very simple and usefull concept. > >> A prime example of a "single user" system according to your definition >> is MSDOS. No restrictions on anything. How reliable is/was it? > > Well, that was not a good example. As far as I know, DOS was not > multitasking. If there may be many processes, then the idea of > classifying and restricting them follows immediately. > > But what is the cause of this confussion? Most desktop systems, > the ones that perhaps the OP has in mind, are a big confuse bloat, > so that the simple unix idea is difficult to recognize in them. > > Rodrigo > >
