From: utzoo!decvax!cca!ima!johnl Newsgroups: net.eunice Title: Re: Info on UNITY and IS1? - (nf) Article-I.D.: ima.293 Posted: Mon Feb 21 03:20:40 1983 Received: Mon Feb 21 19:13:44 1983 #R:cca:-434600:ima:14500001:000:2491 ima!johnl Feb 20 14:20:00 1983 Since there seems to be interest yet in Unity, Eunice, IS/1, and the like, here's the party line on IS/1-VMS as best as I understand it. For the record, I work for Interactive Systems, supplier of IS/1, but have no particular connection with the VMS product. The important thing to understand is that IS/1 (which has been renamed IS/WB since we upgraded it to System III) has a significantly different goal from Eunice or Unity. Eunice and especially Unity are designed to emulate Unix as exactly as possible under VMS. Compatibility with native VMS programs is not a major goal in either case. IS/WB is intended to provide as much Unix functionality as we can while admitting that we're in a VMS environment. For example, IS/1 doesn't translate filenames (except to upper case, and change slashes to brackets for directory names) and uses VMS file formats wherever possible, particularly when the files contain text. This means that you can't use all the file names you use under native Unix, so that uucp, which uses strange names, doesn't work right. (We have our own INnet network which works fine and gateways to uucp, by the way.) The other two give you general Unix filenames but have to use complex name translation schemes where the VMS file names bear no simple relation to the Unix file name. Also, IS/WB programs can be run either under the shell which runs them as a separate process, or from DCL which loads them directly into its address space, saving a lot of time. In each case, IS/WB chooses a smoother interface with VMS where the others choose more exact Unix emulation. The point here is that IS/WB is for people who are using VMS in production and want to add Unix tools and programs. The other two seem more for people who want to use Unix but are forced by their system managers to use VMS. It depends on what you want. Please don't flame about how awful VMS is; I'm not too crazy about it but there's a lot of canned software that runs only under VMS. There are other issues too, notably price and support. IS/WB is not cheap, but it has been around longer than the other two and so is probably better shaken down. IS/WB also has a lot of optional mail, networking, and word-processing software that go way beyond what Unix gives you. John Levine, IECC, PO Box 349, Cambridge MA 02238; (617) 491-5450 decvax!yale-co!jrl, harpo!esquire!ima!johnl, ucbvax!cbosgd!ima!johnl uscvax!ism780!johnl, {research|alice|amd70|cca}!ima!johnl