[Coco] OS-9 Pascal P-code Interpreters

[John W. Linville]

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.
> >
> > --
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> >
> 
> 
> 
> -- 
> 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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-- 
John W. Linville		Someday the world will need a hero, and you
linville at tuxdriver.com			might be all we have.  Be ready.