[Info-vax] Learning VMS application programming

[Paul Sture]

On 2014-09-06, wendellxe at yahoo.com <wendellxe at yahoo.com> wrote:
> On Friday, September 5, 2014 8:02:22 PM UTC-7, JohnF wrote:
>> > I have been reading through the docs.
>> By which I assume you mean the above? (though your "mostly in dcl"
>> remark suggests maybe you mean something else?)
>
> Sorry all, for that misleading comment. I started out with the DCL 
> manual, then assumed that was what I was seeing elsewhere. It was 
> actually Fortran I was seeing in the OpenVMS Programming Concepts 
> Manual. I never saw Fortran used for systems programming before.

Fortran was the first high level language customers could buy for VMS.
Indeed when we started looking for a replacement for our PDP systems in
1978/9 we dismissed the VAX because Fortran was the only HLL compiler
available at the time (our management wanted COBOL).

By the end of 1980 when I joined a VMS shop, COBOL and an early version
of VAX-BASIC were available, but that was too late for my former employer.

Both the Fortran and BASIC compiler kits contained header files for system
calls, but the COBOL compiler didn't.  In fact the first version of COBOL
for VMS didn't support the full VAX calling standard; it couldn't do a
call by descriptor, which meant that to call many system routines you
wrote a wrapper in Macro (or used Fortran if you had that).

So yes, Fortran was used for system programming in early VMS days, though
in my experience assembler was used more often for that.

> I am finding VMS to be a larger adjustment than when I dabbled in
> BeOS, QNX, etc.

You mentioned using flat files in an earlier post.  This is an area I
found to be quite a large adjustment on encountering *nix like systems. I
was used to having various utilities which converted either input commands
or source files into binary format files, which the runtime apps would
read at initialisation.  That may sound clunky today, but it kept the
runtime component sizes down and made their startup times faster.

-- 
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