[Coco] OS-9 Pascal P-code Interpreters

Wayne Campbell asa.rand at gmail.com
Tue Aug 25 20:11:46 EDT 2015


Thanks for the info, John. In that regard, as I recall it from when I was
experimenting with it, the p-code you refer to is machine/implementation
specific. You had to recompile the source on the target machine using the
target implementation to get it's p-code binary. As example, the p-code for
Code Warrior is not the same as the p-code for Turbo Pascal even on the
same machine.

On Tue, Aug 25, 2015 at 1:00 PM, John W. Linville <linville at tuxdriver.com>
wrote:

> I think there is a misunderstanding.  "P-code" refers to the binary
> code for the virtual machine that is the execution engine in the early
> versions of Pascal based on the UCSD p-System.  It is not source code.
>
>         https://en.wikipedia.org/wiki/UCSD_Pascal
>
> Unfortunately, the term "P-code" is often used in a generic way that
> does not specifically refer to the UCSD p-System virtual machine code.
> The OS-9 Pascal compiler claims to use "P-code", but it is not clear
> whether the OS-9 Pascal "P-code" is the same as the UCSD p-System
> "P-code".  I think that is the question Joel was asking, and it is
> definitely the question I would like to see answered definitively.
>
> Thanks anyway!
>
> John
>
> On Tue, Aug 25, 2015 at 08:30:39AM -0700, Wayne Campbell wrote:
> > AFAIK the source from one variant of the language is transportable to
> > another variant, meaning you can take P-code from the CC and compile it
> on,
> > say, an Apple II. However, this does not mean that one implementation has
> > all of the features of another one, so your CC P-code may have something
> in
> > it the Apple II does not understand, or the Apple II may have constructs
> > the CC P-code does not contain. I have never tried to do it, so I am not
> > certain about it. I also know that the later PC variants of the language
> > have huge differences between them, so almost all source compiled in a
> > different implementation had to be rewritten to accommodate the receiving
> > implementation.
> >
> > Hope this helps.
> > Wayne
> >
> >
> > On Mon, Aug 24, 2015 at 2:44 PM, John W. Linville <
> linville at tuxdriver.com>
> > wrote:
> >
> > > On Thu, Aug 20, 2015 at 02:49:40PM -0500, Joel Ewy wrote:
> > > > Hey, does anybody know if the OS-9 Pascal P-code interpreters are
> > > compatible
> > > > with other, UCSD-style P-code interpreters, such as the one for the
> Apple
> > > > II, CP/M, or the original IBM PC?  For a possible future exhibit of
> > > classic
> > > > computers at a local maker space, I would like to try running a
> P-code
> > > > program on a variety of vintage platforms, and I'd very much like the
> > > CoCo
> > > > to be one of them.
> > >
> > > I've had this same question myself -- I think I've even asked it here.
> > > Alas, I don't recall any meaningful answer.
> > >
> > > I reckon that someone needs to do a little ground work, transferring
> > > files from the Apple II (or other) P-system and trying them out on
> > > the CoCo.  I suspect that person will also need to create some sort
> > > of utility to add the "P-code" OS-9 module headers to the programs
> > > as well.
> > >
> > > Hopefully someone is bored enough to try it and let us know! ;-)
> > >
> > > John
> > > --
> > > John W. Linville                Someday the world will need a hero,
> and you
> > > linville at tuxdriver.com                  might be all we have.  Be
> ready.
> > >
> > > --
> > > Coco mailing list
> > > Coco at maltedmedia.com
> > > https://pairlist5.pair.net/mailman/listinfo/coco
> > >
> >
> >
> >
> > --
> > Wayne
> >
> > The Structure of I-Code
> > http://www.cocopedia.com/wiki/index.php/The_Structure_of_I-Code
> >
> > decode
> > http://cococoding.com/wayne/
> >
> > --
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> > https://pairlist5.pair.net/mailman/listinfo/coco
>
> --
> John W. Linville                Someday the world will need a hero, and you
> linville at tuxdriver.com                  might be all we have.  Be ready.
>
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> Coco mailing list
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>


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