Re: GNAT-VMS and OS version support

[dewar@merv.cs.nyu.edu (Robert Dewar)]

Larry said

"The reason I care about what version others may run is that it is
hard to sell them software which will not run on their machine.
The good thing about the GNAT approach is that in theory I could
make a version which could build programs compatible with earlier
versions of VMS.  The bad thing is that I prefer to avoid being a
toolmaker unless the issue is forced.  Luckily DEC Ada 83 exists
so I have the option of avoiding Ada 95 features in programs for VMS."

GNAT for VMS is very specifically targetted at users who need Ada 95,
both for new development, and for upgrading existing Ada 83 code. DEC
is still supporting their Ada 83 product, so as long as you stick to
Ada 83, you can use the DEC compiler.

We certainly understand that it is very often the case that projects
base line early versions of the operating system, but typically these
same projects have also base lined early versions of the compiler, and
are not typically the sites that are interested in moving into the use
of Ada 95 anyway -- a number of VAX users of Ada have the same profile,
they are considering Alphas and considering Ada 95, but do not see a use
for Ada 95 on their existing VAX systems.

There definitely ARE some users (e.g. Ken Garlington) who have indicated
a possible interest in CLA and elsewhere in GNAT for VMS on VAX, so it
may well be that this makes sense, but first we are concentrating on getting
the Alpha version into good shape. It is coming along nicely. For those of

you who were not at Tri-Ada and missed the VMS Demo (not to mention "The
Maiden and the Mandate" :-), we demo'ed a flight simulator written by
Bevin for DEC Ada on VMS, which used all kinds of DEC specific features.
He ported it in a few hours of work, changing 50 lines of code out of
27,000 -- and indeed almost all of those 50 lines would NOT need changing
now (they were mostly address clauses, and version 4 of GNAT will generalize
the acceptance of address clauses).

P.S. Ken mentions our new pricing policy on single seats. We now have a 
base price for 1-3 seats of support. This change was based on our
experience that single seat support contracts were generating a
proportionately higher level of support requirements, and we need to
tune our prices to the time we need to spend to give people good support!