Re: [Fwd: F22 completes 11% of its Flight tests]

["jtarver" <jtarver@tminet.com>]

Bill Greene <wrg@Ganymede.com> wrote in message
news:387D011B.2DC@Ganymede.com...
> jtarver wrote:
> >
> > Bill Greene <wrg@Ganymede.com> wrote in message
> > news:387CEE4A.3965@Ganymede.com...
> > > jtarver wrote:
> > >
> > > > Ada was originally envisioned to be platform transparent.  When Data
> > General
> > > > produced the only 100% compliant compliler and the Ada development
> > program
> > > > went for the noncompliant VAX as their standard platform that idea
was
> > out
> > > > the window.
> > >
> > > I don't understand your statement.  IIRC, there was a validated Ada 83
> > > compiler for the Data General (written by Rational?) and there were
> > > several validated Ada 83 compilers for the DEC VAX (written by
SofTech,
> > > DEC, and others).  What do you mean by "noncompliant VAX"?
> >
> > I mean the first rule of the compliance was that there be no extensions
and
> > VAX immediately violated that rule.
>
> The only mechanism I know of for gauging compliance is formal
> validation, which included passing the thousands of tests in the ACVC
> (now ACATS) test suite.  There were and are a number of validated Ada
> compilers for the VAX.

LOL.  Validating that the VAX does what it says it does is not the same as
the compiler meeting the Ada specification.

> But what does it mean to say that "VAX" violated a rule?  Are you
> talking about a particular Ada compiler for the VAX?  If so, which
> compiler is it and what sort of extensions are you referring to?
> Implementation-defined attributes and pragmas?

"extended instruction set" is what I am refering to.

> Also, it's not entirely accurate to say that Ada was intended to be
> platform transparent.

That is exactly the original selling point for the funding of Ada.

> One of the design goals for the language was to allow low-level access
> to the underlying architecture, e.g., in code inserts, which are
> certainly not portable.  But then, no one writing a code insert for a
> VAX would ever expect that code to be portable to a non-VAX platform.

The compiler would necessarily be in the immage of the hardware, but the
code itself was to be independent.

> > > FWIW, my experiences with porting Ada (83 or 95) code have been quite
> > > satisfactory.
> >
> > What did you port as the new platform?
>
> I've ported among VAX, Sun, Apollo, Windows, OS/2, IBM mainframes, and
> Macintosh, to name a few off the top of my head.

VAX to Apollo in Ada sucessfully?  How much effort was the transfer?

John