14 Jul
2010
14 Jul
'10
11:28 a.m.
Ethan Dicks <ethan.dicks at gmail.com> wrote:
On 7/14/10, Jerome H. Fine <jhfinedp3k at
compsys.to> wrote:
RTEM might be something else than RTEM-11, which was a software product
for RSX. Just google for RTEM-11, and you'll find some references for it.
However, I wonder about RTEM for VAX. It's certainly possible, but I
can't find any other reference to it, and DEC's old SPDs, especially
those with software version compatiblity matrixes, are usually pretty
good as a way of finding out what software existed.
As for PDP-11 compatibility in VAXen, yes, the 86x0 machines have that.
Those were the last, however.
For all other VAXen running VMS, if you wanted to run RSX software, you
needed a PDP-11 emulator product for VMS, which was available, in
addition to the RSX additions for VMS, which was also a separate
product. That thing was supported up until fairly recently, though.
But again, that's for RSX stuff...
Johnny
In addition, does anyone know of any systems
currently running
which support RTEM-11 features which allow RT-11 programs
to run in that environment? My assumption is that VMS on a VAX
supported RTEM-11 at some point, but perhaps (if I am correct)
the RTEM-11 support was not continued with
more recent versions of VMS on the VAX and most definitely VMS on the
Alpha. Can anyone comment on these questions?
Based on the vague reference at
http://s-and-b.net/help?key=RTEM~Release_notes&title=VMS Help&referer=
and what I know of VMS and DEC hardware, I'd think that RTEM-11 would
require a VAX processor with "compatibility mode", i.e., a "VAX-11"
processor. The primary models would be the 11/78x, 11/750, 11/730 and
11/725 (I don't recall if the VAX 86xx still had "compatibility mode"
or not, but it should be easy to check). MicroVAXen and such did not
have it, and Alpha processors certainly did not have it.
That being said, I have no experience with RTEM-11, but I would be
surprised to learn it ran on a machine made after about 1986 or so.