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Aucbvax.5935 fa.info-vax utcsrgv!utzoo!decvax!ucbvax!info-vax Sat Jan 23 18:17:30 1982 Interesting patch available, and a comment on UNIX/VMS >From FONER@MIT-AI Sat Jan 23 18:12:07 1982 A couple of comments. For those who don't own EMAC or VMS, read ahead for a continuation of the UNIX vs VMS brouhaha.

For those of you who use Gosling's EMACS and are annoyed by the fact that the VMS TTDRIVER assumes NOBROADCAST when PASSALL is in effect (meaning that EMACS users, who must run in PASSALL, can't get SENDs and other broadcast messages), I have a simple patch to TTDRIVER for VMS 2.3 that eliminates this behavior. Setting your terminal NOBROADCAST explicitly still works, of course, but it won't get implicitly set tht way when PASSALL is in effect.

I can download the patch to this machine and mail it to anyone in a week if anyone is interested. I can mail just the patch (and not how it works, etc) immediately if somebody's in a rush. I don't guarantee, of course, that this patch will work for VMS 2.4, and you should remove it before instaling 2.4. Once we install our own 2.4, I'll make a possibly revised patch available if anyone wants it.

The patch itself, interestingly enough, is a single bit. The problem is that \finding/ that bit took several hours of looking.

As for the merits of UNIX vs VMS, I don't really want to jump into this with blowtorch at the ready. I'll merely make some comments. Note that I am a novice UNIX user and do system programming for VMS.

I tend to like VMS for several reasons. It supports version numbers for files, which makes sense, especially for commercial users. Research users find that disk space is always at a premium, but commercial user, who have more money generally, find that accidentally losing an important file will pay for \many/ disks due to the increased amount of file storage due to multiple versions of files sometimes being around. UNIX users, from my experience, tend to be more cramped for disk space and thus find the lack of version numbers not a particular disadvantage anyway---it helps cut down on space use.

VMS also supports a very good set of diagnostics. As far as I know, UNIX does not even try to log device errors in any convenient or consistent way. VMS keeps a record of any errors that a device encounters and thus allows system managers and programmers to look at the log for a device that is about to fail (memory or a magtape drive, for instance). This has proved invaluable at the sites I use, for instance. And has anyone ever heard of remote diagnostics for UNIX? I certainly haven't, but most commercial sites to my knowledge have remote diagnostics from DEC that can save a LOT of time in tracking down problems... the hardware guy can show up with what he needs most of the time under this system and won't have to go back.

VMS also allows you to layer other software on top of it, if necessary. For instance, on our 11/750, we have EUNICE running on top of VMS. (We're also trying out true Berkeley UNIX for the next week on that machine, also, to see if some of our software will run under UNIX but not EUNICE and try to figure out some problems.) I have never heard, however, of anything like VMS being layered on top of UNIX.

VMS is also very good for unsophisticated users. A colleague of mine, who is also a UNIX novice and is trying to figure out the fairly inscrutable user documentation, has commented that one of the major problems with UNIX is that you really tend to need a UNIX guru for the first two or three days to steer you through the system---it's far too easy to get thoroughly lost by yourself. In this respect UNIX is very much an expert system. (Unfortunately for us, we don't have have a local guru inhouse... so we're learning our Berkeley UNIX on our own unless we break down and call on the distributor.)

VMS, as well as giving very useful and verbose error messages (which \are/ very useful), also gives me many feet of manuals to explain itself. I haven't noticed this from the UNIX folks (though apparently Berkeley UNIX is better than most).

The ability to actually change the operating system is actually not very important, at least at my sites. The patch I mentioned above is absolutely the FIRST time anyone here has needed to change the operating system. Almost everything you might want to can usually be done without actually \changing/ anything... you can just add more code elsewhere. This helps to make the system maintainable, since it resembles almost every other VMS in the world and DEC can (and does) update it for this reason. This is despite the fact that we'reusing some of our VMS systems for some damned strange applications and with some very unusual hardware.

Also, I have heard from people who have taken the VMS Internals course at DEC that the internal organization of VMS is very clean and very well thought out. I have heard just the opposite about UNIX (any version) because it has grown by bits and pieces, mostly of the hack variety. This \must/ have something to do with the maintainability and essential correctness of the system.

Please don't interpret this as unbridled enthusiasm for VMS. There are many things that it could do better. I think many people on this list have touched on the places that could do with improvement. But here are also several areas that can be important to certain classes of users that make it very useful to them, too. Not needing a system programmer on the payroll is one reason. (We have a couple around because we are constantly hanging strange hardware off the machines, for one thing.) Not needing a guided tour throught the first time is another reason. And being \supported/ by a manufacturer can be very nice for reporting bugs and such, unlike many UNIX systems which are essentially reliant on their local gurus (and whatever skills they may or may not have) for fixing. Not every site can afford to pay someone who can deal with ALL possible bugs in the operating system.

Also, as this same colleague of mine has suggested, the fact that UNIX is strongly used by university and research types means that hacks and other useful information is easily propagated by lots and lots of interaction between sites and conversations in the halls. Commercial users don't talk to each other as easily, because they're often doing things that they may not want anyone else to know about. Furthermore, it's more obvious that it took MONEY to come up with whatever useful software they may have, and thus that it's to their own competitive advantage to retain that software and not proliferate it. University users have a very different perspective, almost an opposite one.

If I've stepped on toes, I'm sorry. This is my opinion, biased by systems programming in a VMS environment for a couple of years and being fairly unfamiliar with UNIX (especially at the systems programming level). It's pretty certain that many people may disagree with me---the ARPAnet is composed mostly of university computers, and most university VAXen run UNIX rather than VMS. If the net were composed of mostly commercial users doing number crunching and database handling, the bias of this discussion would be very different.

<LNF>

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