Why use U* over VMS

[Scott M. Ballew]

In article <1809.272c3135 at dcs.simpact.com> kquick at dcs.simpact.com (Kevin Quick, Simpact Assoc., Inc.) writes:

>4. Overall, the C RTL is very similar between Unix and VMS, with the effort
>   for VMS C being to adhere to the C "standard" (chuckle, chuckle :-) and
>   make non-destructive language enhancements where needed.  There are some
>   changes, but those are usually documented, and are found by the linker
>   under worst case.

If my memory serves me correctly, the VAX C compiler is identical for
VMS and Ultrix (DEC's Unix).  It was originally written for the Ultrix
world and then retro-fitted to the VMS world.  Similarly, VAX Fortran
was originally written for the VMS world and then retro-fitted to the
Ultrix world.

>5. VMS supports a very large number of third-party terminal devices, so
>   it is not probable that you are going to have problems here.  Although
>   VMS C implements curses, I find the native VMS SMG screen management
>   utilities much more pleasing.

While this is true, the most frustrating "feature" of VMS if ran into
in my VMS days was trying to get the VAX editors (EDT, EVE) to
actually talk to these third-party terminals.  I did the whole bit of
describing to VMS (via there termcap-like method) what our terminals
sent and expected only to find that for reasons of speed and
efficiency, EDT (and perhaps EVE, I don't remember) did NOT use the
SMG routines so would still not talk to our terminals correctly.  In
contrast, I have not yet run into a Unix program that did not use
either the termcap library or curses (which uses the termcap library).

>4. The VMS synchronization is much more specific and explicit, and in
>   some cases much better than Unix synchronization, but that is partially
>   because VMS is specific to Digital machines, whereas Unix is forced
>   to be much more general.

Actually, since Unix was originally designed for DEC machines, this is
not a valid statement.  The difference really lies in the philosophy
underlying the systems' designs.  See Bach's book on the design of
Unix for a discussion.


Having worked under both systems, I agree that each has its relative
strengths and weaknesses.  However, being a bit of a hacker at heart,
I prefer a system where the operating system gets in my way as little
as possible, allowing me to get my work done.  Unix, because of its
research origins, does just that (though at times, it STILL gets in my
way).  VMS, on the other hand, is a much friendlier environment for
the user who is not a programmer.  It has a (fairly) regular set of
options to (rather) intuitive command names.  If the user does not
wish to do anything that requires programming, it is a comfortable,
secure enviroment.  Unix is, however, far more customizable and
extensible, in my opinion, than VMS and so, I have found it a much
more comfortable environment in which to work.

By the way, no one has mentioned Unix's biggest strength:  since most
implementations can be obtained with complete sources on line, it is
realitively easy to repair bugs in or add features to any part of the
system, something that VMS makes nearly impossible.

Scott Ballew
Cypress Network Operations Center
Purdue University Department of Computer Sciences