Re: ProDOS...

[Phoenyx <quazar@dcnet2000.com>]

I have been trying to find a way to explain this in simple and concise
answers, but it doesn't really fit. Long explanations would work, but
this isn't the place for such and much better attempts than mine can be
found in many of the manuals and programming references of the era. Even
better, from the guru's of today like David Empson or David Wilson.

To put it simply, the applications developed for the current ProDos
system are locked into that system and would require modifications that
may not be possible, even if the source were available.

Also, ProDos itself is not an operating system. At least not in the terms
of modern systems. Even when it was developed, it was considered as only
a kernel. Apple defined it this way so others could build their own shells
around it. Essentially these shells defined their own OS. Many developers
didn't follow the shell method and simply created programs which ran in
the P8 environment. These were still basically their own OS in many ways.
True, they followed the P8 disk and file methods and limitations, but they
all relied on their own I/O mechanisms. Very few tried to maintain a
common method of performing these I/O routines which others could use.
Some programmers adopted basic standards which helped and Apple tried to
produce a set of useful standards also, but often developers still failed
to follow them.

In this vein, Basic.system could be considered an OS, similar to the way
it was with Dos 3.x. If it had been written for a 128k environment it
most likely would have been. The 64k version was often considered by it's
users as the primary os/shell system for their II's. Basic.system could
not run by itself. It required the P8 kernel thus the two combined could
be termed an OS much like the MS Windows and MS Dos combination on today's
PC's.

Another, perhaps better example is Appleworks. In it's original version
it was simply a productivity system. However, it was so well designed
that others extended it to become a very powerful OS shell in it's own
right. Several distinguished Apple II persons have suggested that this
system should have become the Apple II's next OS. Possibly even including
parts of it in ROM for better performance. Of course, this was a little
late as Apple Inc had already given up on the II series (again) and had
no interest in such a project.

The current (P8 text) version of Appleworks with many of the early Beagle
Bros Timeout utilities built in has become quite impressive. It can
perform a variety of functions, handle practically any type of memory
expansion and run on almost all II models. Excepting the early II and II+
systems. The II+ might be retrofitted to use it, but I don't have any
specifics here.

Ok, this has turned out to be longer than I had planned so back to the
original subject. A modified or extended ProDos would not be able to use
most of the old applications. If the programmer were careful and
restricted the changes in the lower 64k, it might be possible to run some
of the simpler 64k programs. Those such as Filer which use a limited
number of resources should be ok. To make the changes that would make P8
useful for 128k plus systems would require a larger variety and restrict
the possible applications even further. Still none of the current programs
would take advantage of these enhancements. Assuming source were available
they would probably require some extensive rewrites to do so.

So, it still stands that a new or improved ProDos would still require new
applications, essentially making it a different OS for all intents and
purposes.

Well, that's my 2 bits worth. I hope it makes some sense. I am not trying
to discourage development of this systems. In fact I would love to see
such. I just want to point out that it would require more than the OS for
it to be useful. Most likely, it will even require another, better system
for program development. Either by creating a library for assemblers such
as Merlin or developing a new system to be used in the new OS.

-- 

Thank you for your time and interest. I hope it was helpful
or at least interesting.

Phoenyx,

Apple2 user since March 1984

Links to Phoenyx's pages:
preferred..... http://zip.to/Phoenyx_A2
alternate..... http://www.tinyangeldesigns.com/Apple2