Re: Streams in Ada

["Marin David Condic" <marin.condic.auntie.spam@pacemicro.com>]

"Florian Weimer" <Florian.Weimer@RUS.Uni-Stuttgart.DE> wrote in message
news:tgofufwd4x.fsf@mercury.rus.uni-stuttgart.de...
> "Marin David Condic" <marin.condic.auntie.spam@pacemicro.com> writes:
>
> > But wouldn't that posit that there *was* an Ada95 implementation on a
PDP-10
> > and that a Stream_Element was 36 bits?
>
> Well, the poster specifically mentioned portability, and his code does
> not work on such an architecture.  IMHO, portable code hasn't just to
> run on all platforms which exist (this could be called 'practically
> portable code'), but on all Ada implementations.
>
O.K. That's a valid point. But the instant one delves into the theoretically
possible machines, one can spend an enormous amount of energy making code
that is portable to all possible machines, when maybe it is sufficient to
make code that is portable to most machines that are in practical existence.

While there are machines that don't have an 8 bit byte as the logical
storage unit for a Stream_Element (the 1750a comes to mind...:-) and there
are machines that don't even have a storage unit evenly divisible by 8 (the
PDP-10 is a prime example) code that was dependent on an 8 bit storage unit
& Stream_Element is probably going to port to well over 90% of all the
places that are likely to come up or be at all important. Of course, if all
you have to do is a little simple static math in your declarations to keep
things totally portable, its probably worth the effort.

> > Someone mentioned here a few days ago about the existence of PDP-10
> > look-alikes, but I don't think anyone has any evidence of a validated
Ada95
> > compiler for one of them.
>
> GCC is currently being ported to it.

This has *got* to be a labor of love! I find it hard to imagine that there
are thousands (or even hundreds) of PDP-10 sites out there, much less
thousands (or even hundreds) of PDP-10 sites with a burning need for Ada
compilers. (Wouldn't they mostly be in use to maintain legacy systems
written in Fortran, Cobol, or even Bliss?) Either it is a real specialty
need (with the government picking up the tab?) or it is an idle, Quixotic,
excentric programmer with too much time & money on his hands - or a twisted
sense of humor. (Ahhhh.... To be an idle Quixotic excentric programmer with
too much time & money & a twisted sense of humor and a government contract
to pick up the tab! But I digress....) If someone is doing this, I'd be very
curious to find out where & what for.

MDC
--
Marin David Condic
Senior Software Engineer
Pace Micro Technology Americas    www.pacemicro.com
Enabling the digital revolution
e-Mail:    marin.condic@pacemicro.com
Web:      http://www.mcondic.com/