Path: utzoo!attcan!uunet!sco!seanf From: seanf@sco.COM (Sean Fagan) Newsgroups: comp.os.misc Subject: Re: Cobol Data Corporation Cyber 180 (was Re: 64 bits) Message-ID: <2032@scolex> Date: 8 Jan 89 23:04:46 GMT References: <28200249@mcdurb> <451@babbage.acc.virginia.edu> <1951@scolex> <2618@ficc.uu.net> <1128@raspail.UUCP> <2371@garth.UUCP> Reply-To: seanf@scolex.UUCP (Sean Fagan) Organization: The Santa Cruz Operation, Inc. Lines: 81 In article <2371@garth.UUCP> smryan@garth.UUCP (s m ryan) writes: >The person you're arguing with has a sad case of Unix-on-the-brain: if it >ain't done exactly like in Unix, it ain't worth squat. Having has experience with all three OS's under discussion (NOS, NOS/VE, and Unix), I think I can make a few comments. >Think of all the wonderful things Unix offers that NOS/VE doesn't: >- only two segments, static+heap and stack. Hmm, let me see. In Xenix '286, I can get a segment (it will be a data-only segment until I tell it otherwise), and do with I want with it (except make it a stack, but that's a hardware limitation). Unix also normally has two "segments," but they are code and data (with stack going in code). >- no shared codes except libraries staticly assigned to segments. Text is shared. And, didn't you just say that Unix only has two segments? Please make up your mind. Under Unix SysVr3.x, making a shared library is *very* easy, and anybody can do it. I've been told that it's even easier to do under SunOS 4.0, but I don't have any experience with that. Besides, what did you want to share, if not libraries? Data, I suppose, but shared memory "segments" (there's that word again) provide a method of doing that (and, from what I understand of SunOS's shared libraries, you should be able to share data that way as well). >- no unified command processing. This can be either good or bad. NOS/VE *does* have unified command processing (NOS doesn't), but it's also very cumbersome. Unix, which doesn't have UCP, has also evolved into a fairly standard method. Embos, which runs on Elxsi's only, has the best command-line interface I've ever seen, putting NOS/VE to shame. >- no concept of subsystem which permit a layerring of commands. You could run a different shell. NOS, btw, has a truly horrible idea of a shell: you *can* specify your own shell, but it gets reloaded after every command has been executed (since it doesn't have VM, other than segmentation [i.e., Base + Offset, where Base is set by the OS], and you only have 2**17 usable address bits). The shell is, in my opinion, more flexible, but subsystems are neat (in NOS, a subsystem can schedule it's own processes to run, if it wants to). >- no segment=file concept so all disc io gets an extra transfer through > system buffers between the user space and discs. Memory mapped files have been in Unix for quite a while. BSD 4.3 was, I believe, the first "real" release to support them publicly. >- no ability for file and system security. Ahem. AT&T SysVr3.2 will, supposedly, be B1 secure. This is the same level as NOS. NOS/VE doesn't have that much more over NOS, and, again, Embos beats them both. >By the way, while NOS does not have a `standard error file,' it does have >dayfiles. Lordy, lordy, I wish I had dayfiles on Unix. NOS/VE does, however. It still has dayfiles, though. A problem with dayfiles occurs, however, when you start running out of disk space, and the system wants to report this *in* the dayfile. BTW, with Xenix 2.3-with-C2-security, you will have auditing, which will give you most of the information you would want to get from dayfiles (except that programs under NOS often put little messages into the dayfile, such as what routine they're in [if you wanted to know]). NOS/VE has its advantages, as does NOS. Unix is, for my purposes, much more user-friendly than either (I should, I think, say "programmer-friendly," since NOS/VE was designed for users, while Unix was designed for programmers). NOS and NOS/VE get tremendous I/O throughput (NOS more than NOS/VE), while Unix tends to get trememdous programmer throughput. Embos, of course, beats them all. -- Sean Eric Fagan | "Merry Christmas, drive carefully and have some great sex." seanf@sco.UUCP | -- Art Hoppe (408) 458-1422 | Any opinions expressed are my own, not my employers'.