Does anybody have a documentation or a source code of P-Code interpreter, I.5 and IV.2.2 of an UCSD P-system

[Peter Dassow]

I was curious about an automatic P-code translator from the older system
I.4/I.5 of UCSD Pascal (or Fortran or whatever) to a newer one which
runs at DOS, e.g. found at http://pascal.retro8bits.com/ucsd.html .
Any hints for recontructing especially the newer IV.x P-code interpreter
are welcome.

Regards
Peter

[Peter Dassow]

Peter Dassow schrieb:

Correction... in my lack of knowledge I assumed that only P-code has to
be translated. That's only partly the truth, because I looked into
http://www.bitsavers.org/pdf/softech/1-140.41.A_pSysInternArc_83.pdf and
I have to recognize that also a number of subroutines must be
implemented to get a P-Machine running, there is a P-Code command CXG or
SCXG1 will is a CALL to a subroutine. A lot of these CALLs are
"recommended" to be implemented in the PME directly, means coded in
native machine code to get the necessary speed (see page 3-182 in the
mentioned PDF). I am not sure the same number and same functionality is
implemented for I.4/I.5 and IV.2.2 for example.
So not only the P-code differs :-(

Regards
Peter
--
* http://www.z80.eu - a vintage computer info page and blog

[Udo Munk]

8080/Z80 sources for p-code interpreters I.5 and II.0 at:

ftp://ftp.unix4fun.org/z80pack/

You want the ucsd-ix-interp.tgz archives with UCSD filesystem 8" images.
This are the sources I used to build better p-code interpreters for
z80pack, documentation here:

http://www.unix4fun.org/z80pack/doc_ucsd.html

The whole idea of the UCSD p-system is to implement the p-code interpreter
for some target, to be able to run the p-code for that release.
Transforming p-code from one release to another is not practical, too many
changes in the whole system, not just the p-code interpreters.

Udo Munk
--
The real fun is building it and then using it...