Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site unisoft.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxj!ihnp4!zehntel!dual!unisoft!pc From: pc@unisoft.UUCP (Paul Campbell) Newsgroups: net.unix-wizards Subject: Re: VMS is UNIX spelled backwards (almost) Message-ID: <365@unisoft.UUCP> Date: Fri, 30-Nov-84 16:26:58 EST Article-I.D.: unisoft.365 Posted: Fri Nov 30 16:26:58 1984 Date-Received: Sun, 2-Dec-84 03:46:17 EST References: <378@hou2g.UUCP>, <126@osu-eddie.UUCP> Organization: UniSoft Corp., Berkeley Lines: 67 [slurp] I too must put my 5c in ... (first a bit about my background ... I port Un*x for a living, I have also spent the last 4 years as a VMS hacker ... so I feel I have a good view of both worlds). I feel the main reason for the 'enemity' between VMS and Un*x people is a lack of knowledge and experience (here I mean YEARS of experience, what you need to really understand an operating system's environment and feel comfortable using it) on both sides. Here are my feelings about them ... 1) EDT vs vi - they are relatively similar in power for normal use vi: good points - better search facilities, can work on almost any terminal bad points - impossible to learn/teach EDT: good points - you can teach a novice computer user to use it in 15 minutes bad points - you have to use a DEC compatible terminal 2a) kernel hacking - VMS provides more 'hooks' than Un*x, but then you don't have the source (or objects) to reconfigure VMS, on the other hand allocation of system resources and the loading of device drivers is done dynamicly either at boot time or while the system is running. If you have the sources you can do 'anything' in Un*x, but in VMS you have the fiche and it is not necessary to change the kernal to do kernal things ... there are ways for a user program to get into kernal mode to do these things. Un*x does a few simple things well, VMS does these things and as well provides you with the hooks do do many operating system things (page mapping signals, interrupts etc). I had to implement virtual Un*x machines on VMS (with the Un*x kernal running in Supervisor mode, each running with its own virtual disk (so we could give students 'virtual disk crashes' for them to recover from)) all the operating system things that you require are there, they are not in Un*x and I don't see how I could possibly do the same without a lot of Un*x kernal modification! 2b) kernel hacking cntd - I feel that the fact that VMS sources are not readily available is a major reason why people don't do more hacking, however DEC do give a good course on VMS internals and once you learn how to read the fiche you can do almost anything. Even though much of the VMS kernel is written in assembler there is no reason why you can't use almost any language for kernel code (I have used Pascal and FORTRAN). Bugs, DEC's support is really very good, it can take time for patches to arrive but if they are really critical they will get them to you express (I come from the furthest reaches of the world, the deep south of New Zealand). 3) portability - Un*x is portable, VMS is not (FULL STOP). I could go on for pages more ... but as a summary ... I feel that they are both good operating systems, each with a different emphasis and that there are good reasons for using either one. Most of the points raised by both sides are probably to some extent valid and at the same time can be shot down in FLAMES by the oposition. Finally just be glad you don't have a 43xx/370 etc, then we could all argue about the merits of many different operating systems rather than just two. Cheers Paul Campbell (ZL4TFW) ..!ucbvax!unisoft!paul