VMS was the first multiuser system I used in 1991. I was amazed that a single computer could have 300 users logged in all doing their own thing.
I learned to program in C and tried using Borland Turbo C on a DOS. Go outside of the array index and you could easily crash the entire machine which meant reboot and try it again. I thought the concept of memory protection was incredible! Why didn't every computer have that?
It was the first time I saw email, sending messages, and the phone utility for chatting with other users while waiting for your programs to run in the background.
I moved on to an IBM RT running AIX and got hooked on Unix. That's the system I wanted and have been running Linux since 1994. But VMS still holds a special place.
My roommate with the 386 running DOS tried to explain extended vs. expanded memory and then near and far pointers in C to me. It didn't make any sense to me. I just asked him "Why isn't memory just memory like on the VAX?" He was so used to the limitations of 16-bit x86 and DOS. Neither of us even understood the concept of a "32-bit flat memory model."
I had been spoiled by the VAX and didn't know it was a $200,000 or $1 million system. I found this price list from 1991 but it's hard to figure out how much a system cost.
VAXstations and MicroVAXes weren't that expensive. I knew a guy with a small business that had a VAXStation 3100 or maybe it was a 4000, back in 1991 or 92.
Rebooting on the early PC was so common, they had a hotkey for it—Ctrl+Alt+Delete.
David Bradley, an engineer who worked on the original IBM PC, invented the combination which was originally designed to reboot a PC. "I may have invented it, but Bill made it famous."
VMS had asynchronous programming to its core. Most system calls could be performed synchronously or async. You just had to give the async call a flag that would indicate when the response was ready. So you could read a file or connect to the network, continue execution and when you actually needed the answer, just sys$wait(flag). Or have callback functions.
It worked extremely well as some else mentioned, 64Mb of RAM was enough to handle 200 interactive users with RDB (database IMO far superior to Oracle that was acquired by them and promptly buried)
I can't say I did much w/ NT and parallel ports beyond attaching printers. I'd imagine it could be pretty awful in the "SPP" days, especially with people trying to connect ZIP drives, "Backpack" CD-ROM drives, tape drives, etc. I suspect floppy drives, which I also didn't use under NT very much, could also play hell w/ interactivity.
My first serious (multiuser) system experience was VMS. The concurrency, the power of DCL, the record based nature of files, the mail box concept for process communication, the accounting system, the granular privs, the cluster concept. I came to UNIX second and still miss some of these things.
For me, the distributed lock manager, queues (SYS$ENC / SYS$DEQ), IPC via message passing (mailboxes), SYS$QIO to literally queue IO requests, event flags (SYS$SETEF / SYS$WAITFR)? Amazing clustering, - UNIX just seemed so backwards after learning VMS first! (Apologies though if I got any of those system call names wrong, its been a long time!)
So unfortunate VMS was never open sourced like Solaris was. It was really interesting, and deserved a fate other than obscurity. Would be cool if zOS was open sourced, but on the other hand the various cloud control planes seem like the "real" OS nowadays in many settings.
DEC used to ship source listings to customers. Not in a form you could compile - a CD-ROM full of PDFs. Although not freely redistributable, there are ISO files floating around the Internet
For MVS, the old public domain versions came with some source code, but it doesn’t match up well with the binaries (the supplied source is an older version missing many patches the binaries have). Newer copyrighted versions they made source listings available on microfiche-it would be great if someone who still has those microfiche were to scan them, although I think people are hesitant to do so since they worry IBM might react negatively (they are copyrighted and possibly under NDA too). And then they stopped issuing microfiche, but apparently they replaced it with some system that IBM customers can log in to and look at some of the source code file-by-file but not download it-I imagine they log every file you look at and if you look at too much they might ask you what you are doing. I know other vendors have similar systems-e.g. Oracle has such a system to let their ERP customers look at some of their ERP source code. (Or at least they did when I worked there years ago-I assume they still do.)
MVS and z/OS always had another issue - large chunks of them are written in a proprietary programming language (PL/S or its successor PL/X) for which IBM has never released a compiler. Well, there was a period many years ago when IBM was licensing their PL/X compiler to ISV’s relatively cheaply, but that didn’t last long. Using a proprietary language with no publicly available compiler helped discourage customers from modifying the source code they received, and also helped discourage would-be cloners, especially in the early days when the idea of software copyright was still very new and hadn’t yet been extensively tested in court.
I also have heard they still ship some source for JES2, a bit of an exception to the general rule of “object code only” (OCO).
"Although NT was not an exact clone of Cutler's previous operating systems, DEC engineers almost immediately noticed the internal similarities. Parts of VAX/VMS Internals and Data Structures, published by Digital Press, accurately describe Windows NT internals using VMS terms."
Have you ever been able to get a community license? I've submitted a request for one several times over the last year or two and never received a response, not even a denial.
didn't work with simh 3.12-2 (linked on the page).
Installing simh from "open-simh" and everything works according to instructions, I tried using the version V3.12-5 mentioned on the page https://simh.trailing-edge.com/ and this (and all 3.x?) is the "classic" simh and didn't support the referenced vax780.ini, but the version from github (4.x?) worked. Very cool to see vms boot!
I'm familiar with a site that once had around 30 Vaxen for scientific computing in the late 1980s. This included Vax 11/780s, 11/750s, uVax I's, uVax II's and eventually a Vax 8800 used to feed a Cray Y-MP. All long gone. Linux has moved in and taken over.
Does anyone remember another public VMS system called "Carl" or Carl.best.net or something like that? I had fun playing with VMS on it, but that was years ago.
It looks like even though VMS Software Inc have taken over development of OpenVMS, HP still hosts the v8.4 documentation set, for instance here's the system services reference manual:
> After VSI hosted EISNER for several years, EISNER has now been relocated to Process Software. The Alpha DS20 hardware has been replaced by an emulated ES40 vtAlpha using a license generously donated by AVT and Vere Technologies. VSI continues to provide the complimentary OpenVMS licenses.
I wonder far away QEMU is to supporting OpenVMS on Alpha...
I learned to program in C and tried using Borland Turbo C on a DOS. Go outside of the array index and you could easily crash the entire machine which meant reboot and try it again. I thought the concept of memory protection was incredible! Why didn't every computer have that?
It was the first time I saw email, sending messages, and the phone utility for chatting with other users while waiting for your programs to run in the background.
I moved on to an IBM RT running AIX and got hooked on Unix. That's the system I wanted and have been running Linux since 1994. But VMS still holds a special place.