We have a VAXStation II running MicroVMS 4.7. We have Pascal code for
our compilers, assemblers, and linkers. We wish to upgrade computers
but I have heard that the OpenVMS does not support the MicroVMS
executables because they are truly different operating systems. Are
there any machines being sold today that can run the old VMS? Are there
any versions of the old VMS that can be run on a PC?
Raytheon Missile Systems Company
Hank Vander Waal
The main difference between MicroVMS 4.7 and VAX/VMS 4.7 was a test in
the startup file to see if you are running on a MicroVAX. If so, it
reported MicroVMS, otherwise it reported VAX/VMS.*
The executables are identical. The executables from MicroVMS 4.7 will
run fine under OpenVMS 7.x. (I have some VMS 3.x executables still
The only problem I have encountered upgrading from 4.x is that some of
the older compiler's installation procedures don't work under the newer
releases of VMS. You may need to update your compilers.
PS: If you want to go to an Alpha, you will need new executables or you
will need to convert your VAX executables using DECmigrate.
* I think the MicroVMS release may have also left out some executables.
Chris Scheers, Applied Synergy, Inc.
> I was wondering if anybody could answer this question:
> We have a VAXStation II running MicroVMS 4.7. We have Pascal code for
> our compilers, assemblers, and linkers. We wish to upgrade computers
> but I have heard that the OpenVMS does not support the MicroVMS
> executables because they are truly different operating systems. Are
> there any machines being sold today that can run the old VMS? Are there
> any versions of the old VMS that can be run on a PC?
A rose is a rose is a rose.
MicroVMS=OpenVMS=VMS (well almost)
Your MicroVMS executables have a good chance of running on any VAX running
any VMS. There may be issues with shared runtime versions but run 'em see
what it it says. you know, like version mismatch.
4.7 is quite old, about eleven or twelve. Be gentle with it.
The main distinguishing feature of MicroVMS was the almost total lack of
manuals shipped with the box. Two little books instead of the orange wall.
One thing is for sure. There ain't no PC that runs any flavour of VMS.
There are people who still run V3.7 because V4.0 changes made their apps
DEC does make changes that cause apps to fail. Most of the time it is
the app writers did some undocumented or unorthodox things. That is not
true, however. Occasionally, DEC breaks something that an app depends on
about how something works like logical names for instance).
I have spent years upgrading software that breaks with changes in VMS. Also,
you just need to relink, but people don't have sources or objects.
Just my opinion,
Chris Scheers wrote:
> Raytheon wrote:
> > I was wondering if anybody could answer this question:
> > We have a VAXStation II running MicroVMS 4.7. We have Pascal code for
> > our compilers, assemblers, and linkers. We wish to upgrade computers
> > but I have heard that the OpenVMS does not support the MicroVMS
> > executables because they are truly different operating systems. Are
> > there any machines being sold today that can run the old VMS? Are there
> > any versions of the old VMS that can be run on a PC?
You seem to be under some of the same misconceptions of some of our vendors.
One claimed that they could not migrate an application written in C on UN*X to
Windoze-NT because they could not find a C compiler for Windoze-NT, only C++.
In the same category, OpenVMS/VAX is just a newer version of the one that you
are running. It will even run on your antique hardware. See the S.P.D. for it
somewhere at the WWW.OPENVMS.DIGITAL.COM site.
Non-privileged VMS code from the earliest version of VMS will usually continue
to run on the later versions. I have code built on VMS 4.7 that runs just fine
on VMS 7.1.
To help you understand the name game further, MicroVMS only existed from 4.0 to
4.3. With the VMS 4.4 release there was a letter explaining that the MicroVMS
distribution had been retired and that the MicroVAXes were now getting the same
kit as the larger VAX systems.
With the release of VMS 5.0, the MicroVMS retirement letter was again sent
around for those that missed it.
So you are not running MicroVMS, you are running VMS.
Sometime about the VMS 5.5-2/6.0 time frame VMS was renamed to OpenVMS. One
day I had VMS systems, then I received the letter and found out I now had
OpenVMS systems. See the FAQ at the OpenVMS web site.
>Are there any machines being sold today that can run the old VMS?
I do not know what the newest hardware that VMS 4.7 will run on.
> Are there any versions of the old VMS that can be run on a PC?
There is a DECpc AXP 150 that will run VMS. It has an ALPHA inside. The low
end line is now being called the personal workstation line.
It depends on your definition of a PC.
The ALPHA executables are incompatible with the VAX executables, but many VAX
executables will run on ALPHA after being run through the DECMigrate product.
The Q should be able to give you a trade in for your VAX compiler licenses for
the newer alpha product, and if you qualify for the CSA program, you will find
it a very good deal.
The ALPHA systems are far more economical than the VAX systems.
Recently a URL from Digital was posted where you could download DECMigrate and
get a license key for it.
Not representing anyone.
VMS, MicroVMS and OpenVMS are the same operating system. (OpenVMS is just
marketing bullshit to confuse the marketplace).
MicroVMS was a SCALED down version of VMS without stuff like DECnet and with
inadequate (and erroneous) documentation. When I migrated from MicroVMS 4.7 to
5.0, the layered products seemed to continue to work as did the C programs I
had running. I beleive that there may have been cases of some programs needing
to be re-compiled, and some deep down drivers changing. Most of the problems
were in the upgrade itself (having to change command procedures etc etc).
No, if you are to buy a new machine today, it is all likely to be based on the
Alpha chip which is different from VAX. You will need to recompile your
programs, but the operating system is essentially the same. (There was a
program called "VEST" which allowed one to run VAX-executables on the ALPHA
machines, but I have heard that Digital/Compaq pulled the pulg on that
Sorry, when I bought a microvax II in 1987, it came with microVMS 4.6, and
shortly thereafter went to microVAX4.7. The next step was VMS 5.0 (came with
decnet and was able to do a SET HOST/DTE instead of using programs I had
written myself to emulate SET HOST/DTE).
Elliott Roper wrote:
> The main distinguishing feature of MicroVMS was the almost total lack of
> manuals shipped with the box. Two little books instead of the orange wall.
Ohh, no substitue for the orange wall but they were good little books I
VMS system management and systems programming in a nutshell type of thing.
Tim Llewellyn, OpenVMS System Manager, Remarcs Project
MedAS at the BBC, Whiteladies Road, Bristol, UK.
Email tim.ll...@bbc.co.uk. Home tim.ll...@cableinet.co.uk
My work email is not working reliably at present.
I speak for myself only and my views in no way represent those of
MedAS or the BBC.
Chris Scheers wrote:
> * I think the MicroVMS release may have also left out some executables.
If I remember correctly, it only had drivers for MicroVAX hardware, not
thelarger Unibus and BIbus (were there BIBus VAXEn then?) boxes. This did
help somewhat in fitting MicroVMS onto smaller disk drives.
Attached is what the OpenVMS Wizard had to say...
-------------------------- pure personal opinion ---------------------------
Hoff (Stephen) Hoffman OpenVMS Engineering hoffman#xdelta.zko.dec.com
"OpenVMS" is not different, it is simply another name for "VMS".
See the OpenVMS Frequently Asked Questions (FAQ) for details.
Assuming that the code is user mode code with no "clever" hacks or
assumptions about the underlying hardware architecture, there is no
reason to expect that your code will not just compile and work on any
later version of OpenVMS, on VAX or likely even on Alpha. In most
cases, the code will work without recompilation.
Upward-compatibility of user-mode code is a core of OpenVMS VAX releases,
and portability of user-mode code from OpenVMS VAX to OpenVMS Alpha is
If you want to stay with MicroVMS V4.7, your choices of hardware are
quite limited -- no current VAX systems are supported on that release.
The MicroVAX II is extremely old and slow.
The Wizard would recommend finding a used VAXstation 4000 series -- the
VAXstation 3100 is another option, but the system disk size is limited
to 1.073 GB or less on that system -- and simply try moving your programs
to (say) OpenVMS VAX V7.1. Depending on your code, you may be surprised
at how smoothly it works. Start by copying over the executable images
and just RUN them.
If you choose to move to OpenVMS Alpha, install the necessary layered
product kits, copy over the sources and the build procedures, then
perform a recompilation and relink. Then try the application. Further
information on the (few) differences between OpenVMS VAX and OpenVMS
Alpha are available in the documentation set, in the migration manual.
Which gives one a very warm feeling when you read a trade report that
says that 50% of the applications that run on Windows NT 4 are crashing
spectacularly on the present internal cut of Windows 2000.
HEY ! Don't insult my teenager !
MicroVMS V1.0 was the first release, with the next (really popular)
release being V4.1M, the first release for the MicroVAX II series.
MicroVMS and VMS coexisted for systems up through V4.7 (or V4.7a?),
with the VMS distribution prefered for use in specific (cluster)
The MicroVMS and VMS kits were always quite similar, differing in
areas such as the product name, the packaging, the documentation, the
distribution media, and in one or two image files (LOGINOUT was one